INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN SOCIAL SCIENCE (IJRISS)

ISSN No. 2454-6186 | DOI: 10.47772/IJRISS | Volume IX Issue X October 2025

Page 7358

www.rsisinternational.org

Roadmap for the Management of Mineral Gangue - Pyrite and the

Environmental Cost Impact

Rudi Toba., Dr. Ir. Eymal B Demmallino, M.Si., Dr. Abd. Wahib Wahab, Msc., Dr. Ir. M. Farid Samawi

M.Si

Hasanuddin University Makassar, Indonesia

DOI: https://dx.doi.org/10.47772/IJRISS.2025.910000600

Received: 28 October 2025; Accepted: 03 November 2025; Published: 19 November 2025

ABSTRACT

Green and smart mining in today’s industry has become one of objectives target to be fulfilled by the mining

operator, it respectively in looking into current and future challenges of climate changes along the strategy

implementation of decarbonization and energy conservation. The orebody containing negative characteristic

of geochemical lead into the needs of effort to handle them in later stage of mining process. It’s created an

extra cost due to the needs to perform activities meeting standard compliance and or paying the consequences

following fail in fulfil the contractual obligations. Composition of metal concentrate containing un-expected

residual mineral or gangue could create an extra effort for the facility of metal refinery or smelter for handle it.

Especially at containing gangues who can negatively impacted and suffering the environmental. The better

understanding of value impact since this presenting of negative chemical ores can further provide a sufficient

program and preparation of resources upfront for risk mitigation. On the other side of risk positive, there is

benefit generated by use this pyrite on another application. It then calls for a need of resources to handling and

converting them to become valuable product for selling. Planning for resource allocation under the establish

program to better of managing the risk and lead into success of organization to execute the target. It therefore

there are two essential things shall organization be considered in address this, they are: establish roadmap or

program for properly managing the pyrites and make the determination at the needs of resources to be

allocated into each activity under it’s setup roadmap. This written paragraph aiming exercise the key criteria in

establishing the roadmap of handling pyrites by firstly understand the cost consequences into the living

environmental at the do-nothing action. The determination of roadmap itself is achieved by conducting the

risk assessment to early engineering design process activities and the effectiveness of exist control with

residual risk to be continue review and monitor under the setup of roadmap program.

Preliminary Study of the Geoenvironmental of the Grasberg Ore Body

Pyrite, also known as "Fool's Gold," has long been recognized for its economic value when managed well.

Although it may not have the same value as gold or other precious metals, pyrite remains an important mineral

in today's economy. Pyrite has a number of uses across various industries, ranging from construction to

electronics. Pyrite is also a source of sulfur, a basic material in the production of sulfuric acid, which is used in

a variety of applications including fertilizers, detergents, and dyes. In mining with metal commodities from the

sulfide ore body group, there are occasionally pyrite gangue minerals present. This creates a need for special

handling in order to maximize the recovery value of processing facilities and also poses a risk to the

environment due to its negative impact in generating acid mine drainage. Pyrite as an impurity mineral can be

considered beneficial when managed properly. In several applications, its use can be as:

1. Civil infrastructure and construction work: One of the most common uses of pyrite is in the

construction industry. It is often used as aggregate in concrete and as a building material. The strength

and durability of pyrite make it an ideal material for these applications; however, its acidic, corrosive

nature and its impact on the durability of buildings warrant separate studies. Additionally, because of its

unique and eye-catching elements, pyrite can be used as decorative stone in buildings.

INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN SOCIAL SCIENCE (IJRISS)

ISSN No. 2454-6186 | DOI: 10.47772/IJRISS | Volume IX Issue X October 2025

Page 7359

www.rsisinternational.org

2. Electronics industry: Pyrite is also used in the electronics industry, particularly for the production of

computer chips due to its good semiconductor properties and its ability to manage the flow of

electricity within the chip. This makes pyrite an important component in electronic devices.

3. Sources of sulphur: Pyrite is one of the sources of sulphur and a raw material for the production of

sulfuric acid. Sulfuric acid is used in various applications such as fertilizers, detergents, and dyes.

Pyrite is also used as a raw material in the production of sulphur dioxide, which is widely used for

bleaching paper and as a preservative for wine. Pyrite is also an important raw material in the energy

sector, being used in the production of natural gas and crude oil. Without sulphur, the production of

these resources would be limited, and their prices would soar.

4. Jewellery: Pyrite is used to make jewellery and decorative objects. It is often used as a substitute for

gold due to its similar appearance.

While pyrite can provide economic benefits, it cannot be denied to also have negative environmental impacts.

This occurs when pyrite is exposed air, oxidated and flow or entering water bodies then producing acid mine

drainage. This then results in serious consequences in the form of degradation of water quality and aquatic life.

Additionally, pyrite can release harmful metals such as arsenic and lead into the environment. The economic

value of pyrite can be enhanced by its usage beyond what is currently considered as merely 'fool's gold',

especially if it can be managed well. Its use in the construction, electronics, and as a source of sulphur in the

energy industry can make it an important mineral today and in the future. Nevertheless, the negative impacts of

pyrite on the environment also need to be addressed to provide guidelines for planning mitigation measures.

Pyrite, long known as 'fool's gold', has been an important mineral for centuries due to its economic value.

However, the potential negative impacts on the environment also highlight the importance of engineered

design for its management. The oxidation of pyrite can generate acid mine drainage (AMD) due to the acidic

solution containing high levels of heavy metals, which can significantly affect the water quality in the

surrounding environment. This can have a devastating effect on aquatic ecosystems, including the death of fish

and other aquatic life. In addition, the release of AAT can also lead to soil contamination and can affect the

health of plants and animals. To address environmental issues related to pyrite, various measures have been

taken. Here are some perspectives on dealing with pyrite:

1. AAT Processing: is a primary method to address the environmental impact of pyrite through AAT

processing. This can be done through various techniques, including the addition of materials with

alkaline properties to neutralize the acidity of the solution and the use of other chemical treatments to

remove heavy metals from water.

2. Removal of negative effects of pyrite: In some cases, mitigating the negative effects of pyrite can be

achieved by tracing the geological formation of the rocks and planning mixing operations as part of the

mining activities conducted. This can help prevent the release of Acid Rock Drainage (ARD) and other

environmental impacts associated with mining on ore bodies containing pyrite.

3. Land reclamation: Another approach to addressing the environmental impacts of pyrite is through land

reclamation. This involves restoring mined land to conditions similar to those before mining, liming,

isolating deposition areas including replanting vegetation and restoring water pathways.

4. Recycling: Although pyrite has economic value, this mineral can be recycled for other purposes while

still considering due diligence to handle its negative impacts. For example, pyrite can be used as a

source of sulfur supply in the production of sulfuric acid, a basic component in fertilizer production and

applications in other industries.

Although pyrite has economic value as mentioned above, it is important to consider the potential

environmental impacts of its exploitation and use. Considering control measures aims to ensure that the

economic benefits of pyrite can be achieved without causing undue harm to the environment.

The management of pyrite today is more focused on addressing the impacts when it comes into effect for the

environmental following the presence of acid mine drainage. Effort programs in eliminate of potential negative

impacts while simultaneously enhancing the positive benefits in existence of pyrite in orebodies present a

study that outlines challenges align into treatment while opportunities align into potential of utilization that

needs to be developed. Considering the opportunities and the risk of environmental issue, it can be

accommodated throughout the Geometallurgy and Geoenvironmental modelling study program. The modelling

INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN SOCIAL SCIENCE (IJRISS)

ISSN No. 2454-6186 | DOI: 10.47772/IJRISS | Volume IX Issue X October 2025

Page 7360

www.rsisinternational.org

includes objective program to make all information are available for the stakeholders, as such availability for

utilization in industries, guidelines for policymakers, operational references for mining operators, and the

public knowledge. Modelling not only presents the potential environmental issues that may arise related to

certain types of mineral deposits with negative chemical characteristics of the rocks, but it also provides

information on how the environmental impacts associated with mineral deposits can be avoided, minimized,

and or mitigated.

The research study for the Grasberg porphyry to indicate orebody has hosting by carbonates material, which

could provide potential natural mitigation of acid mine drainage generation due to the presence of sulphide

rock minerals- pyrite. Large amount of pyrites in the orebody create a need of assessment for environmental

risk mitigation while see into future possibilities of commercialize the pyrites.

INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN SOCIAL SCIENCE (IJRISS)

ISSN No. 2454-6186 | DOI: 10.47772/IJRISS | Volume IX Issue X October 2025

Page 7361

www.rsisinternational.org

The general lithology observed in the Grasberg Intrusion Complex (GIC) consists of:

 Early volcanic pile (banded clay, bonded tuff, unbonded tuff, volcanic breccia, andesite flows)

 Fragmental In (andesitic composition)

 Intrusive In (dioritic composition)

 Main Grasberg Intrusion

 Late intrusion phase: plagioclase dike, South River Intrusion, gravel dike breccia

 Heavy Sulphide Zone

The main copper minerals in the Grasberg orebody are chalcopyrite, bornite (less than 20%), and digenite,

covellite and chalcocite in small amounts. Bornite has a composition on the upper body of the Grasberg ore but

becomes more abundant at the depth elevation. Covellite occurs on the perimeter side of the ore body with a

content of one percent copper equivalent. Pyrite is only an accessory component of sulphide mineralization in

the ore zone and increases in terms of composition volume at depth. The mining complex has two large

intrusion complexes, namely the Grasberg intrusion (GIC) and the potassium-rich Ertsberg intrusion,

commonly referred to as the "alkaline" intrusion. The Ertsberg rocks are classified as Monzo diorite, quartz

Monzo diorite, monzonite, trachyandesite, and trakhidacete. The location, size, and shape of intrusions in this

area vary over time. Older intrusions (4-5 million years ago) occurred in the southern part of the ore body up to

younger intrusions (2.6-3.5 million years old) on the northern side of the ore body. The mass of the ore body

consists of primary, original K-feldspar, plagioclase, and quartz, which has been partially replaced by altered

quartz and K-feldspar. Magnetite (0.2-0.6 mm) makes up ~1 to 2% in the unaltered rock and is locally

associated with ferromagnesian minerals. In this mass composition, the composition of magnetite rock is very

fine. Compared to the type of deep Diorite rock, the plagioclase phenocrysts from the Main Grasberg Intrusion

generally have a more solid composition. The Heavy Sulphide Zone (HSZ) is an irregular and non-continuous

narrow boundary/zone at the contact between the Grasberg Intrusion Complex (GIC) and sedimentary rocks,

especially limestone, as its parent rock. HSZ consists of sulphide minerals (pyrite, pyrrhotite, chalcopyrite),

but also contains magnetite-hematite and epidote-chlorite minerals. The definition of high pyrite zone (HSZ)

INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN SOCIAL SCIENCE (IJRISS)

ISSN No. 2454-6186 | DOI: 10.47772/IJRISS | Volume IX Issue X October 2025

Page 7362

www.rsisinternational.org

itself is considered to have at least a volume of pyrite greater than 20%. Magnetite rocks generally have a

composition that is more closely related to limestone than pyrite. Epidote rocks seem to appear at the top of the

high sulphur zone (HSZ) system. The origin of the formation of minerals in the high sulphur zone (HSZ) area

is still under research, but it is highly likely that it is related to the formation of the Wild Cat ore body reserves

that occurred post-mineralization of the Grasberg ore body.

Anhydrite and actinolite become more common with depth at the margins of the Grasberg deposit. Actinolite

occurs in localized zones and as patches of coarse aggregates on the centimetres scale in veins, or as a very

fine-grained replacement of igneous rock. Anhydrite is virtually absent in the core of the deposit. Anhydrite

occurs in banded zones located about 500m from the centre. Anhydrite replacement occurs as white to purple

veins that are wide up to several centimetres and as fine-grained material (≤ 0.5mm, poker chip type and hard

zones). MacDonald and Arnold (1994) estimated anhydrite content ≥ 5% in the interior of the Grasberg

porphyry system. At an altitude of 3500m, anhydrite and gypsum have been washed away by groundwater.

Near the edge of the Grasberg volcanic structure, anhydrite is either crushed or transformed into gypsum by

groundwater and through a process of alteration involving illite-pyrite.

Through a case study on the Grasberg ore body with steps to identify the potential generation of acid mine

drainage by the presence of the gangue pyrite, it provides considerations for managing environmental impacts.

Engineering considerations for mining operation design to meet compliance in properly managing the risk on

potential acid generation covers:

 Challenges in the provision of pyrite concentrate processing facilities

 Processing ores with high content of pyrite

 A significant tendency towards oxidation processes and acid formation

 Potential impact on the geochemical stability of waste rock dumps in deposition areas.

The management solutions taken to manage pyrite:

 Modifying the flotation circuit to separate pyrite concentrate

 Channelling the pyrite concentrate to the deposition area via piping

 Handling pyrite in the deposition area through encapsulation.

It is a common practice in mining operations address potential impact since of acid mine drainage due to the

presence of pyrite in orebody. Nevertheless, there are potentials areas which can be optimized through

improvements of engineering design of mining operations in eliminate environmental impact. It respectively

by look into program of managing the pyrites from the upstream process of mine design and incorporate into

plan strategy achieving green mining concept. This differ than what is commonly done today, which focus on

handling the pyrites at the mill-plant facilities and paying the cost consequences. The early mitigation program

can provide more benefit for planning for resource and will certainly be more effective in perspective of

financial cost. Opportunities gaining by investigate option commercialize the pyrites may limit in this

assessment due to its linked with other requirement of assessment for the industry who buy the final product.

It however, this study will only include a brief commercial benefits and roadmaps when it comes into apply.

LITERATURE REVIEW

Julie Hunt et al. (December 2023) through their research and study entitled A Special Issue Dedicated to

Geometallurgy: Preface arguing the prevention and proper management of the negative impacts of chemical

elements in rocks can be achieved through a study of geometallurgy aspects. In modern mining today, at

advances of exploration technologies, prediction of rock characteristics along requirement of more detail data

targeting an outcome for efficient and minimum environmental impact is find more attainable. The facing

challenge is more about the differences way on way of deploying the methods in optimizing the values. As

INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN SOCIAL SCIENCE (IJRISS)

ISSN No. 2454-6186 | DOI: 10.47772/IJRISS | Volume IX Issue X October 2025

Page 7363

www.rsisinternational.org

such obtain the full benefit from the final product by evaluate mill-plant recovery performance while reduce

the environmental consequence following the presence of rock chemical composition in the orebody. This

research and technical paper writing do not specifically discuss the presence of pyrite and outline the

mitigation roadmap from a geometallurgical standpoint. Faramarz Doulati Ardejani et al. (March 2022) in their

research and journal writing entitled Developing a Conceptual Framework of Green Mining Strategy in Coal

Mines: Integrating Socio-economic, Health, and Environmental Factors describe seven main achievement

targets from the implementation of green mining. The seven achievement targets include; becoming an

important means in creating innovative technology in sustainable improvement programs, a medium for

developing conservative business practices in the use of materials, water, and energy to reduce environmental

impact, maximizing the use of minerals by reducing waste material left for future generations, minimizing

environmental impact at every stage of mining, helping organizations establish safe working procedures and

eliminating the risk of occupational diseases, and modeling reclamation efforts and land use conversion in the

post-mining stage. The research and this technical paper writing do not take case studies on metal-mineral

mining/only for coal mining. While cover the green mine concept, its not fully depicting the plan for handling

the negative impact since the presence of chemical element of rocks. Mayra Jefferson et al. (July 2023), in

their research and technical paper writing entitled 'Effect of pyrite textures and composition on flotation

performance: A review,' stressed the influence of the size and shape of pyrite grain into the recovery process in

the processing plant. Pyrite flotation performance can be varied due to the ore size and other features which

can further affect the flotation ability where is crucial for an efficient depression process and better handling of

the negative impacts of pyrite. This study provides a reference at the needs of proper comminution programs

which recommend for an effective grading of pyrites and its particle size that suit for processing facilities. It

however, research does not specifically outline a roadmap for managing size reduction efforts and its

consequences in terms of impact to environmental aspects for not doing it. Anita Parbhakar-Fox and Bernd G.

Lottermoser (December 2015), through their research and journal writing entitled 'A critical review of acid

rock drainage prediction methods and practices,' arguing the failure to predict the formation of acid mine

drainage (AMD) will have a long-term impact into ecosystems, human health, and will also adding extra cost

and reputational consequences for mining operators. Thus, modelling of ore reserves from a geoenvironmental

perspectives becomes the critical things to be managed. As such to have an early prediction on the natural

mineral’s concentration along with their future potential negative impacts. The integration process enables

predicting of upcoming potential occurrence of acid mine drainage from earlier stage of mine will provide

recommendations for effectively handling the issues and reduce the financial impact in the final stages of

mining. Nonetheless, this writing paper has not elaborated in more detail on the steps to get process in fully

integrated. Tomás Martín-Crespo, David Gómez-Ortiz, and Silvia Martín-Velázquez (2019) in their research

and technical paper writing entitled 'Geoenvironmental characterization of Sulphide Mine Tailing' believed

controlling environmental quality degradation could happens through doing the process of early identification

of potential acid generation by understanding the geoenvironmental characterization, indicate evolutionary

process duration, and observation material composition presence in the mining sediment area. This study was

conducted in several locations of ex used mining lands that are no longer in operational with not fully

investigate an early mitigation program from the mining operator which prepare since the initial stages of

design engineering. Nevertheless, it can serve as a good reference in conceptualizing a roadmap for managing

the environmental risk aspects. Gerard F. Laniak et al. (2013) in their research and written paper entitled

Integrated Environmental Modelling: A Vision and Roadmap for the Future emphasizes the modelling in

properly managing the environmental issues in today's modern world can be done through the computerized

systems. Decision-making can be conducted effectively and in a timely manner due to well-integrated data and

information. This research and paper writing provide a reference on conceptual roadmap for addressing

environmental aspects in the future, although it does not specifically discuss handling the issues happens in the

mining industry. Suhejla Hotia, Laurent L. Pauwelsb, and Michael McAleer (2004) through their research and

writing paper entitled Measuring Environmental Risk, describing an essence of the use Environmental

Sustainability Index (ESI) in quantifying the consequences of risks related to environmental aspects. This

study writing provides a good reference in identifying the impacts but does not in deep address environmental

risks in associated to the mining operations. Wiktoria Sobczyk, Koji Cristobal Ishimi Perny, Eugeniusz J.

Sobczyk (2021) through research and written journal entitled Assessing the Real Risk of Mining Industry

Environmental Impact: Case Study emphasizes the analysis of key risks in mining operations related to the

environmental impact. This especially concerning the assessment of impacts on major water resources affected

INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN SOCIAL SCIENCE (IJRISS)

ISSN No. 2454-6186 | DOI: 10.47772/IJRISS | Volume IX Issue X October 2025

Page 7364

www.rsisinternational.org

by mining activities. The research highlights the impact on water availability and aquatic environments which

can be served as a reference, although it differs from study to discuss environmental impacts since presence of

pyrite in the orebody. Rafael Fernandez Rubio (2015) in research and technical paper writing entitled

Sustainable mining: Environmental Assets, persuade the investment through the procurement of items and

environmental infrastructure support in the mining operations has an essential value in managing and address

environmental issues for future. This study does not specifically discuss facilities and infrastructure for

handling sulphide rock and the potential impact of acid mine drainage. Mark Sharfman and Chitru S Fernando

(2008) through their research and technical paper writing entitled 'Environmental risk management and the

cost of capital,' arguing study conducted on 267 companies in the United States who has done the

improvements in environmental risk management proven as the organization with the lower investment cost.

This value of investment is compared to the costs incurred as result for consequence payment to meet

environmental standards, which generally seen greater. This study helps for building the theory regarding the

benefits obtained by improve environmental risk management from the early stages of operation for an

enterprise. Although it is not specifically related to the mining operations but can be used as another reference

in forming the roadmap for environmental control of mining activities. The overall literature review that has

been conducted provides beneficial references for this research and writing; however, it does not fully depict

the relationship with the handling of the gangue pyrite in the orebody and its negative impact for the quality

degradation of environmental. It respectively on way of build a robust roadmap in efficient and effectively

handling the pyrite.

Study of Environmental Aspects in the Control of Pyrite

In refer to separate simulation happens through the system dynamic, its indicate there is potential future

financial risk due to the environmental impact by do nothing on pyrite handling actions. The estimate of value

impact using dynamic system modelling with the vensim software. Based on that simulation under 7 mining

operation scenarios without handling efforts in the mining operations and only relying on processing at the

plant, there will still be residual risks of tailings dam leakage and seepage. It presents in the graph as below

LTD 3 who shows the greater impact compared to rest other plan operational scenarios. The magnitude of this

residual risk can be described as:

Leakage of tailing dam (leakage of tailings dam, direct evaporation, or seepage);

Pyrite Cost ($386,449,000 x Coefficient) + Closure Cost ($1,021,949,000).

INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN SOCIAL SCIENCE (IJRISS)

ISSN No. 2454-6186 | DOI: 10.47772/IJRISS | Volume IX Issue X October 2025

Page 7365

www.rsisinternational.org

Through this analysis of potential residual risks, actions of properly handling the pyrite from the early stages of

mining operations become more important. There will be a needs of roadmap program ensuring handling steps

for pyrite are carried out through a standard process as part of strategic mine planning, visible in execute, along

with program for monitoring which agree by mining operators and the control of authority agent. The

mitigation steps following the potential negative impact due to the presence of pyrite in the orebody commence

by conducting a study into activity area that is in direct influence. There are three major areas who has direct

influence with the pyrites, they are mining area, mill-plants and the sedimentation pond area. These three

major areas will be the focus for study at the things which requires any efforts to control their negative

impacts. The series of processes can be illustrated in the following diagram:

The study in these three locations to describe activities that will directly influence into aspect of properly

managing the pyrite. As such.

a. Mining operation study

The engineering study for mining operations is conducted to see if anything can be putted in place allows for

better of managing pyrite and reduce the workload of processing facilities.

b. Ore processing facility study Engineering of processing facilities that can effectively managing and control

the pyrite on its possibility of generation acid mine drainage.

c. Study of mining waste management facilities (tailings pond)

To look into effort for minimizing until eliminate any residual risk of tailing permeabilities and the failures of

storage ponds wall.

Mining Operation Study

A case study on the handling of pyrite in the Grasberg ore body using a simulation model of the ore handling

system with a production target of 160,000 tons per day. This production capacity considers the composition

INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN SOCIAL SCIENCE (IJRISS)

ISSN No. 2454-6186 | DOI: 10.47772/IJRISS | Volume IX Issue X October 2025

Page 7366

www.rsisinternational.org

and volume of pyrite with the solution to handling them as part of mining operation scenario. Study to includes

the impact on fragmentation programs and the efficiency of ore processing at the mill-plant due to the scenario

of blending pyrite-ANC along its impact into demand of electrical power feeding. Simulation models will

evaluate engineering design of the mine along the needs of infrastructure to support mine productivity through

a best fit of ore handling system. There are possibility adjustments needs who caused by requirement of ore

handling system. The study impact to includes equipment and its ore characterization, the needs of process,

number of availabilities drawpoints, ore fragmentation, and mining operation procedures. Ore handling

simulation along with engineering design of mining operation in consider above aspect as of follows.

 Understanding the operation-production scenarios with an effective program of fragmentation,

secondary breakage, and special handling needs for ores with a specific geological characterization.

 Conceptualizing and developing accurate graphic and mathematical models of ore handling systems.

 Defining the input and output requirements of the model. Simulating the program using Arena software

to illustrate graphics and mathematically model ore extraction.

 Verifying that the Arena simulation accurately represents the production operation model.

 Validating that the model accurately represents the proposed operations.

Mapping of ore and readiness of the drawpoint for production mucking are key factors in effectively modelling

the underground block caving operations. Mapping the ore based on the level of economic value and the

determination of readiness to extract ore from the cave, meeting the criteria for rock fragmentation programs

are vital and essential for successful for mine production. The size of the rock blocks that are not optimally

reduced through production blasting can create an effort for additional size reduction activities. In general, the

evaluation happens under three conditions as defined to high/medium-hang-up, low-hang up, and block sizes

that do not allow for ore extraction from drawpoints. High hang up was not much considered in this

simulation because mining engineering handling has accommodated this and the frequency of its occurrence

will be low by look into geological structure. Medium and low hanging rock conditions in prediction will

occur more frequently and are modelled in this simulation. Medium and low hanging occurs at or above the

threshold of the pull space with a height of about 3 to 5 meters. Data on the possible conditions can be mapped

from geological data into the following matrix table.

This additional handling includes scenarios through six blasts per day to support the effectiveness of the rock

fragmentation program. Secondary size reduction of the rocks is also carried out using a stationary mechanical

rock breaker above the production pit. Analysis of the size/distribution of secondary blasting and breaking

provides details about the sequential drilling and secondary blasting for low and medium-hanging rocks, which

will serve as a reference for adjusting the activities of extraction from the collapse space. These possibilities

need to be simulated into production operation scenarios, including their impact on the planning of pyrite-ANC

mixing.

INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN SOCIAL SCIENCE (IJRISS)

ISSN No. 2454-6186 | DOI: 10.47772/IJRISS | Volume IX Issue X October 2025

Page 7367

www.rsisinternational.org

Several other considerations need to be made as steps to optimize the size reduction activities through the

improvement of the rock fragmentation program. This is done through the study of blasting activities and the

development of rock slopes to produce ore size gradation and lighten the burden on processing facilities. In the

effort of mixing pyrite-ANC, it adds extra load to the processing facilities to grind the acid-neutralizing

material (ANC). Thus, considerations in the rock fragmentation program mined need to include the

characteristics of the ANC material.

The content of pyrite that is transported to the ore processing plant will reaching 9.5% per year from the total

of volume ore at 93Mt for total duration of mine life. The grade and amount of pyrite from this underground

mine are significantly higher than the previous Grasberg open-pit mine where additional handling efforts were

INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN SOCIAL SCIENCE (IJRISS)

ISSN No. 2454-6186 | DOI: 10.47772/IJRISS | Volume IX Issue X October 2025

Page 7368

www.rsisinternational.org

not included in the previous planning. Since the pre-feasibility study phase in 2003, 309 composite ore samples

have undergone for rock characterization testing. Handling ore samples from exploration drilling requires

separate management to prevent damage during their delivery to the laboratory. This is particularly due to

additional cracks or fractures that may occur during the transportation, it can affect the recommendations in the

fragmentation program. In addition to that, collecting ore samples from the drill respectively to correct

locations is important. This contributes into the accuracy of geological data and provides better results in

testing and characterizing the ores. The need for data and information regarding the potential environmental

impacts since of the development Grasberg deposit reserves requires an integration process from early stage of

exploration program. The Grasberg deposit reserves have the potential to generate high acid water and high

metal content, thus making it necessary to address geometallurgical aspects from the early stages of mining.

Engineering of Processing Facilities

To process ore from the Grasberg mine with a high level of pyrite to call for modifications and additional new

facilities at the mill-plant. It includes the addition of a grinding facility (SAG Mill) fulfil requirement of finer

particle size, and for the waste material can be effectively managed in the sedimentation pond area.

Furthermore, the addition of a copper cleaner facility was also implemented to separate pyrite from other

materials before being released into the sedimentation area. The separated pyrite is then pumped through pipes

to the storage pond after undergoing for thickening processes. The concentration flow of GBC pyrite has been

designed to recover 85% of the pyrite at a high grade (85%). Therefore, the concept of reducing the volume of

pyrite along with the needs for transportation and storage will make the cost of this facility become more

effective. The design parameters for the handling and storage of pyrite will require the addition of limestone to

minimize the possibility of acid formation. The total cost investment for the processing of Grasberg ore

reaches $797 million, with $132 million for the installation of the ore regrinding circuit along with

improvement on effectiveness of the flotation process, $480 million for pyrite concentrate along with handling

and storage, $29 million for the distribution of the electrical network, and $156 million for providing an

additional power supply of 45MW during the operation of the new facility.

The processing of the Grasberg Block Cave ore requires the following circuit installation:

 The Cu regrind circuit with:

 Six (6) new mills with a capacity of 1500hp are required, in addition to two existing grinding facilities

(ball-mills) with a capacity of 2500hp, namely BM14 and BM20, aimed at regrinding coarse

concentrates from the C3 and C4 reduction facilities before the modified copper cleaning circuit. The

demand increase is almost threefold from the previous capacity of 5000hp to 14000hp. This arises due

to the characteristics of GBC ore and the additional load of carbonatite reduction due to mixing

activities (pyrite-ANC). Coarse Cu grinding will produce approximately twice as much as the Grasberg

ore from the previous open pit mine.

 Six (6) additional Knelson gravity separation facilities have been introduced to ensure that gold is

processed more easily and effectively. This is due to the need for grinding the main copper mineral

which requires a certain level of fineness, so modifications also need to be made to the process

recovery of gold prevent them from being wasted.

 Copper cleaning circuit with:

 Five (5) column cells 18’øx50’ to clean and separate coarse concentrate for re-grinding into the final

copper production.

 Six (6) cells of 18'Øx50' to clean the tailings in the cleaner column and produce the final copper

concentrate product.

 Three (3) banks consisting of nine (9) mechanical scavenger cells 3000ft2 that process scavenger

cleaner tailings to produce tailings rich in pyrite and supply them to the pyrite cleaner circuit.

INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN SOCIAL SCIENCE (IJRISS)

ISSN No. 2454-6186 | DOI: 10.47772/IJRISS | Volume IX Issue X October 2025

Page 7369

www.rsisinternational.org

 Pyrite cleaning circuit with:

 Three (3) 1500hp mill towers to polish the pyrite-rich tailings from the Cu cleaning circuit. In this way,

the surface of the pyrite mineral will be clean and ready to be reactivated by flotation reagents and

purified at the pyrite cleaning facility (pyrite cleaner).

 Eight (8) column cells with a diameter of 18’ and a length of 50’ to produce pyrite concentrate.

 Thickeners circuit for pyrite concentrate with:

 One (1) thickener sized 200’ø to produce pyrite concentrate with reduced water content value.

 Storage and pumping of pyrite concentrate with:

 Four (4) storage tanks for pyrite concentrate with a capacity of 850,000 gallons.

 Three (3) Geho slurry pumps to pump the pyrite concentrate to lower areas through a special pipe.

 Pyrite Concentrate Pipeline

 Two (2) 10” pipes capable of handling 12ktpd at 65% solid composition

 Pyrite Concentrate Storage in the settling area, consisting of:

 Two (2) storage ponds 1.35km x 1.35km 56.8Mt

 One (1) emergency storage pond 0.75 x 0.75km 8.4Mt

The schedule for the installation of new circuit equipment is shown below, with the following notes:

 The existing SAG cleaning circuit is sufficient to process GBC ore until 2022 when mining operations

reach full capacity of 160ktpd.

 A second pyrite concentrate line is needed in 2021 because new pyrite production will exceed 11ktpd,

which exceeds the nominal capacity of the first pipe.

 A second holding pond is not required until 2028.

INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN SOCIAL SCIENCE (IJRISS)

ISSN No. 2454-6186 | DOI: 10.47772/IJRISS | Volume IX Issue X October 2025

Page 7370

www.rsisinternational.org

Tailings Management Engineering

The Grasberg ore body during mining at depth has a high mineralogical content of pyrite sulphide. The pyrite

content during full mining operations of the underground mine (GBC and KL) can reach 24%, while the pyrite

content from the tailings currently stored in the deposition area is less than 3%. To prevent the formation of

acid mine drainage due to the oxidation of pyrite content in the deposition area, additional efforts are needed. A

series of separation processes to reduce the content of pyrite before being transferred to the deposition area has

been carried out. The waste of mineral contaminants from pyrite must be separated before being transported to

lowlands through special pipelines to be managed in designated deposition ponds. According to a

geoenvironmental study, 240 million tons of pyrite tailings will be produced by the end of the mining period

and will be contained and managed in a special pond. The design engineering of the containment and

deposition pond based on the results of the preliminary study has included site investigation, liquefaction

assessment, deformation and stability analysis, laboratory experiments on pyrite waste, as well as water quality

modelling, with plans to construct three pyrite deposition ponds.

Pyrite Tailings Storage (Million Ton)

129

Average Thickness of Sediment in Pyrite Tailings (m)

Pond Fill Elevation (asl)

103.2

99.2

91.0

Pond Height (m)

Maximum Pond Height (m)

Technical Age (year)

The waste mineral byproduct of pyrite will be transported through pipes to a tailings storage location made

with a waterproof layer on the walls of a pond built above ground. The bottom of the pond will be excavated

gradually to a depth of 3 meters below the groundwater surface to produce construction material. This

management approach was chosen to maintain the saturation level of pyrite, minimize leakage from the storage

facility, and comply with government regulations regarding wastewater management from pyrite storage

facilities.

INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN SOCIAL SCIENCE (IJRISS)

ISSN No. 2454-6186 | DOI: 10.47772/IJRISS | Volume IX Issue X October 2025

Page 7371

www.rsisinternational.org

The layout of the pyrite storage facility has been optimized based on the results of investigations and

evaluations of supporting data. The design of the tailing storage facility consists of three rectangular ponds

bordered by embankment walls. These ponds will be built from north to south and operated sequentially, where

each pond will operate for 7 to 8 years.

Pond

Length

(m)

Width

(m)

Ground

Elevation

(ml)

Average

Slope of

Pond

Base (%)

Crest

Elevation

(m)

Embankmen

t Height (m)

Pyrite

Tailing

Thickness

(m)

Stored

PyriteTailing

Tonnage+ 20%

Surplus (Mt)

Years of

Storage

1,080

1,800

78 -88 (83

average)

1.7

103.2

13 – 28 (21

average)

8 – 18 (13

average)

1,490

1,800

68 – 82 (75

average)

1.7

99.2

18 – 34 (26

average)

15 – 24 (20

average)

1,890

1,800

57 – 68 (63

average)

1.3

91.0

23 – 36 (30

average)

20 – 24 (22

average)

129

INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN SOCIAL SCIENCE (IJRISS)

ISSN No. 2454-6186 | DOI: 10.47772/IJRISS | Volume IX Issue X October 2025

Page 7372

www.rsisinternational.org

During the operation of this facility, rainwater and pyrite tailings process water will be mixed and discharged

from each pond separately. After the pond is full, discharge is expected to occur throughout the day due to the

inflow of slurry water with an estimated average monthly volume between 0.3 m3/second and 1.4 m3/second.

During operation, water discharge will be conducted through two HDPE pipes designed for the highest flood

conditions. Tolerance limits for the highest flood peaks and wave heights have been considered when

determining the highest peak height of the embankment. The collected discharge water in the northern part of

the pyrite tailings storage facility will be redirected to the settling area to reduce water pressure on the tailings

foot embankment pond. Diversion can be done by aligning access roads, installing ditches and culverts, or

damming the lowest parts to redirect the flow to the settling area.

The leakage from the pyrite tailing storage facility, which is partially lined with a waterproof layer, to the

groundwater will be minimized by the presence of a waterproof layer on the embankment that has been

designed and the low hydraulic conductivity of the pyrite tailings as well as the base of the deposited pyrite

tailings. The predicted leakage rate for each storage facility until the end of operation (when the embankment

and pyrite tailings are at maximum height) ranges from 42 l/s (storage facility 1) to 94 l/s (storage facility 3).

Immediately after completion, the storage facility will be filled with rainwater and the low hydraulic

conductivity pyrite tailing layer has not yet formed at the base of the storage facility, so leakage at that time

will be higher, estimated to range from 76 l/s (storage facility 1) to 15 l/s (storage facility 3); this condition will

be temporary, lasting only for a few weeks or several months.

Numerical modelling shows that the percolation water flow from the pyrite tailings storage facility entering

through the bottom of the storage facility will flow together with groundwater to the south. Unpredictable

percolation water from the pyrite tailings storage facility flows towards Kwamki Lake or towards drinking

water wells in Timika. The estimated flow rate is very low (around 0.4 m/day) and percolation will mix with

the regional groundwater flow that flows beneath the pyrite tailings storage facility.

INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN SOCIAL SCIENCE (IJRISS)

ISSN No. 2454-6186 | DOI: 10.47772/IJRISS | Volume IX Issue X October 2025

Page 7373

www.rsisinternational.org

To achieve the results of pyrite management planning, a study of Geoenvironmental characteristics needs to be

conducted. This involves tracing the activities that must be carried out at each stage of mining and modelling

efforts to minimize the impacts arising from environmental aspects. The initial stages of exploration activities

and sample testing provide an estimate of the geoenvironmental characteristics of a mineral deposit.

Understanding the characteristics of the rock provides a reference for recommendations on waste rock

management, including the management of other mineral impurities more effectively along with planning for

rehabilitation. The chemical characteristics of the rock can be determined through studies and analyses of

many rock samples.

Nevertheless, due to the extensive coverage of the mining area, there is a possibility that some locations are

inaccessible, so statistical analysis can be used to supplement the missing data. Alternatively, this may serve as

a guide to conduct exploration activities alongside development and production operation phases. Another

action that can be taken is to investigate the sulphur content levels in the ore body to assess the potential

impact on the environment. Sampling through exploration drilling activities and laboratory testing can

demonstrate PAF (Potentially acid forming) characteristics as shown in the following table.

Lithology

Paste PH

ARDI

Total Suplhur (%)

NAG pH

ANC (kg 𝐻

𝑆𝑂

/𝑙)

NAPP (kg 𝐻

𝑆𝑂

/𝑙)

Clastic Sediment

8.6

17.9

1.2

2.4

18.7

39.9

Dacite

8.4

19.5

0.7

Volcaniclastite

7.9

21.7

0.6

2.8

11.1

19.2

Basalt

8.2

21.5

0.4

2.9

13.7

9.9

This table data shows that the mineralogy per lithotype (the formation of sedimentary rocks through

precipitation activity or magma solution) is not displayed due to the varying impacts of hydrothermal pressure

changes. From this sample investigation, both volcaniclastics and clastic sediments show potential

geoenvironmental risk with a high ARDI (Acid Rock Drainage Index) and total sulphur; low values of ANC

(Acid Neutralizing Capacity) and NAG pH (Net Acid Generation) (i.e., <pH 2.8). The type of mineral group in

the rocks that potentially offers neutralization of acid is basalt rock (which has the lowest NAPP - Net Acid

Producing Potential), however, its distribution is sometimes sporadic. The exploration of rock characteristics

from the chlorite–sericite alteration zone, phyllites, propylitic, and potassium requires further observation

through advanced drilling programs and sampling. Phyllites alteration is estimated to increase acid generation

capacity (this group of rock types includes: quartz, sericite, and pyrite); potassium (which consists of

potassium feldspar, biotite, and anhydrite) is considered to reduce acid generation because coarse feldspar

reduces rock reactivity, and propylitic alteration tends to enhance acid buffering capacity because calcite

(along with epidote, chlorite, and pyrite) is a group of rocks that are generally present in ore bodies. Large

porphyry copper reserves are likely to contain a significant volume of pyrite dispersed at the outer boundary of

the mineralization zone. However, some observations indicate that pyrite is not always the dominant type of

INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN SOCIAL SCIENCE (IJRISS)

ISSN No. 2454-6186 | DOI: 10.47772/IJRISS | Volume IX Issue X October 2025

Page 7374

www.rsisinternational.org

sulphide rock outside the mineralization zone. This occurs because sulphides have different acid-forming

potential, and understanding this proportion can refine the total potential for acid production. Evaluating how

these observations relate to the geoenvironmental model of porphyry deposits (USGS) requires full-scale

mapping of the alteration zone in both the cover rock domain and the contaminating minerals. The use of the

latest technology such as hyperspectral core drill scanners (e.g., Corescan or Terracore) will aid in identifying

which part of the ore body formation it originates from and allow refinement through the reconstruction of the

mineralization process in the past. Despite the, observations show that the volume of sulphide rock does not

have a predictable distribution within each alteration zone, which also indicates that the introduction of

sulphide mineralizing fluids into this system is a late-stage multi-episode event (as indicated to have occurred

in the Wild Cat ore body that happened after the Grasberg porphyry). With the challenges faced in the study of

geoenvironmental characteristics, several other methods can be used to effectively predict the potential for acid

generation from sulphide rocks. An alternative is through mapping based on the criteria for classifying cover

rocks, accessory minerals, and contaminant minerals, which are typically developed using a combination of

total sulphur, NAGpH, NAPP, or net neutralization potential (NPR) ratio values. Referring to classification

practices in mining operations at Diavik, Canada, cover rocks are categorized into three different types based

on sulphur content (i.e., Type I—< 0.04% S; Type II—0.04 to 0.08% S; Type III—> 0.08%). Such an approach

could be adapted for this site, with ARDI values, Hy-GI (HyLogger geoenvironmental index), and total sulphur

being used instead.

Type I:

total S: <0.1%; ARDI: <0/50; Hy-GI: >10,000 Lowest risk/ANC offered

Type II:

total S: 0.1 to 0.3%; ARDI: 1 to 20/50; Hy-GI: 1000 to 10,000 Low risk/NAF

Type III:

total S: 0.3 to 1%; ARDI score: 20 to 30/50; Hy-GI: <1000 High risk/AMD probable

Type IV:

total S: >1%; ARDI score: >30/50; Hy-GI: <500 Highest risk/rapid AMD

Type IV materials have the highest risk of generating acid on-site, and require greater attention in planning

their handling through separation. Conversely, if encapsulation is seen as a solution, then the method of placing

it in the middle of the pile requires primary consideration. Closure can be done using type III cover rock, but it

should be noted that although acid formation will be less than before, it is still possible to occur in this type.

An outer type II shell can then be used to finalize the waste rock pile before it is capped with type 1 and other

ANC materials, and finally covered with clay. In some mining locations with an imbalanced composition of

NAF and ANC, additional external supplies will be required, which will increase project costs.

Initial Handling and Control Plan

The management of environmental impact risks starts from the early stages of mining operations and

determining control planning, providing opportunities for better resource preparation. This includes allowing

for the evaluation of appropriate actions based on effective control hierarchy levels. By identifying this early in

the project phase, this funding can be accounted for in the budget. Acid mine drainage has implications for acid

formation from sulphide rocks, metal mobility, and the release of these products into the environment.

Evaporation caused by high tropical temperatures can affect evaporation and precipitation rates, making it also

a consideration in the initial handling review. Similarly, the permeability value of the cover waste rock pile in

the deposition area can vary due to the influence of grain size and the density level of the material. These

factors require consideration when designing retention ponds and sedimentation areas. Copper porphyry ore

bodies (Cu) are known to potentially generate waste materials that produce acid. The discovery of new

porphyry deposits will necessitate engineering studies to predict geo-environmental characteristics efficiently

INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN SOCIAL SCIENCE (IJRISS)

ISSN No. 2454-6186 | DOI: 10.47772/IJRISS | Volume IX Issue X October 2025

Page 7375

www.rsisinternational.org

during the exploration phase. In this study, two new methodologies (modified ARDI and Hy-GI) can be

developed as complementary prediction tools to drilling data, which helps in understanding the chemical

characteristics of the rocks present in the ore body. Sample data from the exploration drilling results of the

Grasberg ore body can provide a mineralogical assessment of this porphyry deposit and reveal the complex

mineral distribution related to alteration processes, such as epidote, biotite, and calcite with variable

proportions of pyrite, pyrrhotite, and chalcopyrite. Using a combination of mineralogical and chemical data,

four waste classes are proposed and should be used to assist with the early engineering of waste stockpiling.

From the identified waste units, volcaniclastic and feldspar porphyry are considered as Type III/IV while basalt

and diorite intrusive units are more akin to Type II. This study shows that by using modified ARDI and Hy-GI,

waste properties can be effectively predicted before the official static testing program begins. Doing so will

allow mine operators to start developing a plan for handling mineral contaminants with negative chemical

elements more effectively.

INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN SOCIAL SCIENCE (IJRISS)

ISSN No. 2454-6186 | DOI: 10.47772/IJRISS | Volume IX Issue X October 2025

Page 7376

www.rsisinternational.org

Initial investigations into the rock formation of ore bodies can provide a reference for the potential formation

of acid mine drainage. Looking at the data tables and the mineral composition of the rocks in the Grasberg ore

body, they can be grouped into classifications J, K, and L which are combinations of Extremely Acid Forming

(EAF) and effective neutralizer ANC. This classification then provides a reference for control plans by adding

anticipation programs for the potential occurrence of acid mine drainage into design engineering activities:

 Mining operations, consideration of pyrite-ANC mixing

 Ore processing facilities, optimization of grinding, treatment of leftover material (tailings), and

potential utilization of pyrite contaminant minerals

 Management of overburden waste (tailings)

Establishment of Steps or Roadmap for Impact Risk Management of Pyrite

The main goal of the Geoenvironmental modelling described in this compilation is to provide information that

can be used to understand, anticipate, minimize, and remedy the environmental effects of mineral deposits and

mineral resource development. Mine operators can use these models to develop perspectives on historical

environmental impacts and potential future impacts related to mineral reserves. Additionally, these models

should help in developing mitigation strategies and ecosystem-based land management plans. Many models

include data, such as the natural environmental baseline before mining, which can be effectively applied during

post-mining remediation efforts. These models include objective information available to all stakeholders; they

have the potential to benefit industries, regulators, land managers, and the public. Some models not only

present potential environmental issues that may be related to certain types of mineral deposits, but also provide

information on how to avoid, minimize, or mitigate the environmental impacts associated with mineral

deposits. A roadmap is a strategic planning technique that sets targets and achievements within measurable

time frames. Mining operations are closely related to the potential disruption to the environment, thus

requiring proper management planning throughout all stages. Taking the case study of the Grasberg sulphide

mineral ore body, the environmental impact and influence can be described through the implementation of the

following activities:

Survey of baseline environmental conditions before mining

Considerations for more effective, technology-feasible, and realistic handling must be conducted to remediate

mining locations to their original conditions caused by acid mine drainage. This begins with tracking the initial

conditions before mining takes place along with the potential impacts that may arise and affect the

environmental quality standards. This is primarily due to the potential formation of acid mine drainage by the

INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN SOCIAL SCIENCE (IJRISS)

ISSN No. 2454-6186 | DOI: 10.47772/IJRISS | Volume IX Issue X October 2025

Page 7377

www.rsisinternational.org

contaminating mineral content of pyrite. At the initial condition before mining operations commence, there

may already be surface outcrops of pyrite-contaminating minerals that have oxidized due to natural conditions,

thus generating acid from the start. Measurement and identification of this aspect need to be conducted to

understand the exposure that has occurred since the beginning. Mapping the potential impacts, management

forms, and involved parties can be performed through the following tabulation:

A. Study of Environmental Impact Potential

 The formation of acid mine drainage with the consequence of declining surface water quality.

 Oxidized pyrite sulfide rocks that are not neutralized can form acid rock drainage.

 The formation of Acid Mine Drainage (AMD) can be controlled so that the impact on surface water

quality can be minimized with indicators:

 Monthly pH value recording on the Wanagon River in Banti Village (#57) ≥ 6

 No increase in the concentration of dissolved metals (Cu, Cd, Zn, Pb, As, Ni, Cr, Hg) in surface water

was found in the long term.

 The drainage water from the mine and the overburden can be utilized and used directly.

B. Study of Environmental Management Forms

 Ensuring that all stockpiles of overburden rock with pyrite content are mixed with lime.

 Channeling the drained water from the overburden waste pile to the ore processing plant through the

established network (lime canal)

 Draining surface runoff and seepage water through limestone rock drains.

 Ensure that all sediment flows into the designated sedimentation area.

 Reclamation of areas covered with overburden adjusted to the mining reclamation plan.

 Determination of the capacity for Net Acid Production (PAN) of waste rock from the excavation and

drilling of blast holes to classify the category of waste rock based on its geochemical characteristics.

 Performing engineering operations for the mixing of mining ore between acid-forming rock and acid-

neutralizing rock.

 Modify the collection pond and sedimentation area to accommodate the pyrite content in the ore body.

 Sample collection from blast holes and excavation areas

 Location of stockpiling waste overburden

 Sample of underground drainage water

 Sample of ore processing plant

Carried out during the life of the mine

C. Liability - Environmental Management Institution

Environment Department - PTFI

 Environmental Agency of Mimika Regency

 Environmental Agency of Papua Province

 Ministry of Environment and Forestry

 Environment Agency of Mimika Regency

 Environment Agency of Papua Province

 Mining and Energy Agency of Mimika Regency

 Mining and Energy Agency of Papua Province

 Ministry of Environment and Forestry

 Ministry of Energy and Mineral Resources

The initial measurement of pH value as a reference for the environmental index regarding the potential risk of

acid mine drainage before the underground mining operations are carried out shows a value of ≥ 6. This value

is taken from the Wanagon River in Banti, which is the final discharge point of wastewater from the mine.

Assessment of potential impacts through data exploration studies

Knowledge about the potential environmental effects related to mineral exploitation with specific rock

chemical element content can be integrated into exploration programs to complement mining planning data.

Mining an ore body with a high potential to generate acid mine drainage may provide lower environmental

mitigation financing if abundant carbonate rocks or other types of rocks that can neutralize acid are also found

INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN SOCIAL SCIENCE (IJRISS)

ISSN No. 2454-6186 | DOI: 10.47772/IJRISS | Volume IX Issue X October 2025

Page 7378

www.rsisinternational.org

at the same location. Potential risk assessments can be conducted in various ways, such as through ARDI (Acid

Rock Drainage Index) assessment based on exploration data and field sampling. Sampling through exploration

drilling activities and laboratory testing will describe the characteristics of the rocks and their influence on PAF

(Potentially Acid Forming) and requires an integrated program. The study not only considers the need for

process optimization based on metallurgical aspects but also includes the chemical elements of the rocks that

will affect the overall mining operation towards the ultimate goal of achieving green mining. Conducting an

effective environmental ore characterization study at the pre-feasibility/feasibility stage is very important for

efficient mining operations, as well as reducing post-production environmental impacts. Environmental

parameters that need to be characterized include the tendency of rock in the ore body to form acid, chemical

reactions of hazardous elements, and the toxic potential of heavy metals. A common practice in predicting the

formation of acid rock drainage (ARD) that is widely developed today is carried out through geochemical

assessments based on laboratory tests and is examined in conjunction with mineralogical evaluation of the ore

body. Assessment of rock texture in the context of ARD requires a clear explanation and includes

measurements of sulfide content and main neutralizing minerals. This assessment also includes the evaluation

of mineral groups in the rock at each stage in the process of forming acid. More consideration is given to the

reactivity of rocks during the acid formation stage, particularly concerning the specific surface area. Textural

characterization studies are an example of a method that is considered effective to this day in assessing the

potential for rock acid formation, focusing on micro-scale evaluation.

Planning and development of mines that accommodate environmental aspects

Predictive capabilities that can be enhanced through geoenvironmental modelling will enable mine planners to

better estimate, plan, and mitigate potential environmental issues, rather than dealing with them later. This is

especially relevant to the view of technical challenges with issues that will increasingly evolve and become

more complex. Additionally, there will be the possibility of financing that will be much greater if the

environmental impact issues have created exposure and require urgent handling. The inherent geological

characteristics of a particular deposit can be utilized to help mitigate potential environmental disturbances that

may occur in the future, for instance by using natural resources in the form of carbonate rock content from the

ore body itself. Similarly, other types of chemical elements in the rocks can function as acid neutralizing media

and mitigate the potential occurrence of acid mine drainage based on prior predictions. Planning mining

operations, ore processing, and managing rocks with the potential to generate acid mine drainage should be

considered from the early stages of mining with studies on the use of natural media present in the ore body

itself. The study of geoenvironmental aspects that has not been effectively involved in current mining

operation engineering has become its own discussion literature and requires a roadmap to ensure that it

becomes an important part of strategic mining operation planning. The focus of geoenvironmental study is on

geospatial modelling in fields related to the earth's environment concerning industrial activities, ecology,

hydrology, management of sedimentation ponds or reservoirs, potential geological risks, estuary ecology,

groundwater, agriculture, climate change, land-water resource, and forests. Geoenvironmental modelling

techniques have developed over the last few decades within the earth and social environmental science

research community due to their ability to understand various complex issues and to develop new approaches

to addressing environmental disturbances caused by industrial activities. Geoenvironmental modelling in the

mining industry can clearly and effectively help align operational planning that meets the context of green

mining.

Remedial Program

The model presented in this compilation summarizes crucial geological, geochemical, and hydrological

information (such as geological control over groundwater flow, ore mineralogy, and material geology) needed

by mining professionals to develop effective remediation plans at mine sites. Some of the remediation plans

currently being implemented overlook or greatly simplify geological information that is important to determine

the improvement program in case failures occur at early stages. Identifying pockets of water or potential

seepage flows that will inundate locations with large volumes of pyrite will then determine the remediation

program through water diversion. The engineering of water diversion can take the form of creating drainage

holes or sealing rock fractures through high-pressure injections of cement or flocculating liquids.

Geoenvironmental modelling can be used to identify the type of deposits with the geological structure of rocks,

INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN SOCIAL SCIENCE (IJRISS)

ISSN No. 2454-6186 | DOI: 10.47772/IJRISS | Volume IX Issue X October 2025

Page 7379

www.rsisinternational.org

faults, or other natural hydrological pathways that may occur. Reducing the flow rate of water and redirecting

it to designated paths can reduce the exposure of key elements that form acid mine drainage, making it a part

of the remediation solution study.

Post-Mining Guarantee Considerations / Addressing the issues of former mining land

Although mineral resource extraction has been carried out for several millennia, minimizing environmental

effects has received minimal attention in recent decades. This has resulted in many abandoned mining and

mineral processing sites that are now potential sources of environmental pollution. In some countries, such as

the United States, land management agencies are currently facing the daunting task of identifying and

prioritizing the remediation of all abandoned mining lands that have become public land. Some remaining

mining land, although not requiring serious repairs, still poses an additional burden for the government

regarding the land use conversion. The geo-environmental modelling presented in this compilation provides an

initial study on the potential of land use conversion and future planning once a mine is no longer operational.

The roadmap developed offers opportunities for strategic studies of mining operations while also considering

the post-mining period. Mitigation programs through the early identification of environmentally friendly

mining achievements also consider long-term programs at each stage of mining, from exploration,

development-construction, production and processing, mine closure to post-mining. This includes prioritizing

environmental studies and developing remediation plans for former mining lands containing chemical elements

of rocks that may pose environmental risks.

A series of laboratory-scale research/tests consisting of static geochemical studies (Acid Base Accounting Test)

aimed at characterizing the geochemistry of the Grasberg rock. The results of this characterization test indicate

that the geochemical study of the rocks can be classified into four types, namely:

 Green Type, Acid Consumer, NAG = 0

 Blue Type, Acid Producer, with NAG = 1 – 35 kg H2SO4/ton, Pyrite: 1-3%

 Red Type, High Acid Producing Capacity, with NAG > 35 kg H2SO4/ton, Pyrite: 3-20%

 HSZ Type, High Acid Producing Capacity, Pyrite > 20%

Research has been conducted to test the success of covering the cap rock using limestone with a thickness of 2

meters. The study was carried out by piling limestone on one of the cap rock panels that contained sulfide

minerals. The results of these tests can also be used as a reference for the planning of mixing operations.

The data from this research is as follows:

 The mixing of blue and red cover rocks with limestone in a ratio of 75%: 25% and 50%: 50% is

effective in controlling the formation of AAT.

 Covering with limestone can neutralize the formation of AAT in BP stockpiles at a rate of 0.2 - 0.5

m/year. Covering also slows down the oxidation process, which is presumed to be due to high rainfall

factors that increase the amount of dissolved alkalinity intake from the limestone covering into the

body of the stockpile rock.

 The placement of limestone and cover rocks in layers is not effective in controlling the formation of

AAT because the limestone layer will create a coarse layer that facilitates the flow of oxygen to the

interior of the pile.

 The release of acid from blue and red type cover rocks occurs over a short period, while acid release

from cover rocks rich in pyrite minerals (HSZ) will take a very long time. This is believed to be due to

the fact that pyrite minerals that form HSZ are more stable and not very reactive to water and air. In

the mixing process, the layering of pyrite minerals by jarosite and aluminosilicate will slow down the

oxidation process.

INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN SOCIAL SCIENCE (IJRISS)

ISSN No. 2454-6186 | DOI: 10.47772/IJRISS | Volume IX Issue X October 2025

Page 7380

www.rsisinternational.org

The characteristics of rocks can be determined based on the geochemical characteristics of the rocks through a

series of tests, namely static tests with measurements of Total sulphur, pH paste, NAG pH, ABA method,

which will be verified by kinetic tests through the Free Draining Column Leach Test (FDCLT) by measuring

physical and chemical parameters, as well as mineralogical tests with X-RD to determine the mineral

composition contained in the rocks. The prediction of potential acidity levels can be obtained through a

collaborative program between exploration activities and the initial engineering design phase of mining

operations. This program requires a flow of implementation that can be used as a guideline in executing the

work.

The determination of steps or a roadmap for managing the potential impact of pyrite contaminating minerals

from the upstream production operations can then be illustrated in the following chart.

The analysis strategy regarding the handling of pyrite contaminating minerals requires achieving results in the

early stages of mining operations, which is to obtain the acid potential value and the neutralizing acid potential

value. From these two assessments, the mining operation pattern is then determined with the aim of balancing

ore extraction from the drawpoints. For the block caving mining method, the design engineering of production

operations not only focuses on mapping for economic benefits in terms of mineral content grade but also

considers the composition of pyrite. This is done by establishing patterns and directions of caving based on the

pyrite block model and the simulation of acid-neutralizing rock (NP) mixing.

INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN SOCIAL SCIENCE (IJRISS)

ISSN No. 2454-6186 | DOI: 10.47772/IJRISS | Volume IX Issue X October 2025

Page 7381

www.rsisinternational.org

The initial prediction of rock composition with acid-generating potential and acid neutralization potential is

obtained through exploration data and mixing tests that are conducted. In the Grasberg porphyry ore body, it

shows a balanced composition between sulfide rock groups and carbonate rock groups. The mining operation

scenario can consider a balanced extraction by first creating acid rock drainage (ARD) modeling and creating a

pyrite block model.

Mapping of pyrite through this column block model allows for the simulation of ore extraction from the cavity

along the X, Y, Z axes for achieving balanced composition of Pyrite - ANC.

INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN SOCIAL SCIENCE (IJRISS)

ISSN No. 2454-6186 | DOI: 10.47772/IJRISS | Volume IX Issue X October 2025

Page 7382

www.rsisinternational.org

Planning for draw order with the objective of balancing the percentage composition of pyrite – ANC during

the mining lifetime can be simulated in several achievable operational scenarios. The strategy scenario in plan

for implementation in this situation of complexity geometallurgy of orebody covers; adjustment of cave

sequence in properly managing the pyrite, optimizing the performance of processing facilities and the

consistency of energy supply, reduce potential residual risks in the period end of mining and/or stage of post-

mining.

The handling of pyrite and its potential negative impacts who can generate acid mine drainage requires a

specific and integrated management roadmap. This especially in supporting scenario of achieving an efficient

operation scenario considering the cost effectiveness without suffering the quality of environment. The

proposed handling roadmap will serve as a reference for preparation AMDAL (Environmental Impact

Analysis) and the development of the scope for monitoring activities.

Risk mitigation is carried out through the engineering design targeting efficiency and environmentally friendly

on mining operations who require a robust guideline to ensure that all aspects have been taking into

consideration. This includes for any requirements coming from various stakeholders in propose to meet and

shall align with the plan operational scenario. The authority agent as such Government agency who are

responsible for managing, supervising, and making decisions can perform their duties effectively in accordance

with the availability and sufficient information is provide on data. In regard to the Environmental

Management Plan (RKL) and the Environmental Monitoring Plan (RPL), the establishing roadmap also

provides a reference for:

a. Environmental Management Plan (RKL), which includes studies and evaluations concerning:

 Managing environmental impacts

INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN SOCIAL SCIENCE (IJRISS)

ISSN No. 2454-6186 | DOI: 10.47772/IJRISS | Volume IX Issue X October 2025

Page 7383

www.rsisinternational.org

 Impacts that arise

 Sources of impacts

 Indicators of success in environmental management

 Forms of environmental management

 Environmental management efforts

 Management locations o Management period

 Environmental management institutions

 Implementers

 Supervisors

 Report recipients

b. Environmental Monitoring Plan (RPL), which contains studies and evaluations regarding:

 Monitored Environmental Impacts

 Arising Impacts

 Sources of Impacts

 Impact Parameters

 Forms of Environmental Monitoring

 Data Collection Methods

 Data Analysis Methods

 Monitoring Locations

 Monitoring Time & Frequency

 Environmental Monitoring Institutions

 Implementers

 Supervisors o Report Recipients

The risk mitigation program through integrated mining design engineering can function well and provide

assurance for the management of potential impacts if a standard implementation roadmap is created and make

to available.

CONCLUSION

The handling of pyrite requires a roadmap that allows for the execution of work to be carried out completely,

comprehensively, and independently. The management of negative impacts from the chemical components of

rocks requires special treatment considering it involves different knowledge backgrounds and has significant

impacts if not done correctly. The financial impact of improper handling is not only on the internal funding of

production operations but also on the potential extra cost due to the consequences of degraded standard quality

INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN SOCIAL SCIENCE (IJRISS)

ISSN No. 2454-6186 | DOI: 10.47772/IJRISS | Volume IX Issue X October 2025

Page 7384

www.rsisinternational.org

of environmental. In addition, there are positive benefits from the presence of pyrite-contaminating minerals in

other industrial uses that can be discussed in a separate study. All of this can be studied in an integrated manner

between the efforts to handle the negative impacts of pyrite and the positive benefits of using pyrite in separate

industries through the creation of a roadmap (Pyrite Roadmap). The created roadmap will provide guidelines

for the implementation on each stage of the mining operation starting from the stage of exploration, sampling

and testing, and finally the stages of engineering design for mining operations. The roadmap for handling

pyrite is to setup based on the steadiness value that will be achieved in the concept of eliminating the potential

environmental risk that caused by pyrite oxidation, which enters waterways and generates acid mine drainage,

while also considering the potential benefits of using pyrite in the other applications.

Propose Roadmap of Handling and Managing the Pyrite through exercise treatment of negative impact while

enhancing the opportunity to commercialize Pyrite.

ACKNOWLEDGEMENT

The authors would like to thank the Doctorate Program, Environmental Science –Hasanuddin University for

sponsoring this research. Extended authors acknowledge on the support of Freeport Indonesia where the data

is obtained and place for research is conducted.

REFERENCES

1. Julie Hunt et all (December 2023) A Special Issue Dedicated to Geometallurgy: Preface

2. Faramarz Doulati Ardejani et all (March 2022) Developing a Conceptual Framework of Green Mining

Strategy in Coal Mines: Integrating Socio-economic, Health, and Environmental Factors

INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN SOCIAL SCIENCE (IJRISS)

ISSN No. 2454-6186 | DOI: 10.47772/IJRISS | Volume IX Issue X October 2025

Page 7385

www.rsisinternational.org

3. Mayra Jefferson et all (July 2023) Effect of pyrite textures and composition on flotation performance:

A review

4. Anita Parbhakar-Fox, Bernd G.Lottermoserand (December 2015) A critical review of acid rock

drainage prediction methods and practices

5. Tomás Martín-Crespo, David Gómez-Ortiz and Silvia Martín-Velázquez (2019) Geoenvironmental

characterization fo Sulfide Mine Tailing

6. Gerard F. Laniak et all (2013) Integrated environmental modelling: A vision and roadmap for future

7. Suhejla Hotia, Laurent L. Pauwelsb and Michael McAleer (2004) Measuring Environmental Risk,

mempersuasikan penggunaan metode Environmental Sustainability Index (ESI)

8. Wiktoria Sobczyk, Koji Cristobal Ishimi Perny, Eugeniusz J. Sobczyk (2021) Assessing the Real Risk

of Mining Industry Environmental Impact: Case Study

9. Rafael Fernandez Rubio (2015) Sustainable mining: Environmental assets

10. Markp Sharfman and Chitru S Fernando (2008) Environmental risk management and the cost of capital