Open Pit Mining Methods Research Articles

The Role of LEM in Mine Slope Safety: A Pre- and Post-Blast Perspective

Slopes are formed as a result of mining operations. These slopes are classified as artificial slopes. Improper planning of slopes can lead to instability and potentially trigger landslides. PT. Allied Indo Coal Jaya employs the open-pit mining method in its coal mining operations. Slopes are naturally formed in open-pit mines. Additionally, PT. Allied Indo Coal Jaya utilizes blasting for rock demolition. Therefore, it is crucial to assess the impact of blasting activities on slope stability. This study investigates the influence of blasting on slope stability in coal mines using the limit equilibrium method (LEM). The study evaluates the effects of factors such as ground vibration, blast distance, and blast hole count on the factor of safety (FoS) of slopes. The limit equilibrium method (Fellenius, Bishop, Janbu, Spencer, and Morgenstern-Price) is employed to determine the factor of safety. The factor of safety is modeled using RocScience SLIDE version 6.0 in this study. The factor of safety (FoS) is defined as the ratio of the stabilizing force to the destabilizing force acting on the slope. This study also models the influence of ground vibration, distance, and total number of blast holes on the factor-of-safety (FoS) value. The results indicate that the slope remains stable both pre- and post-blasting, with an overall FoS value greater than 1 for the five slopes examined using various limit equilibrium method (LEM) techniques. However, the FoS value decreased prior to blasting due to the impact of ground vibration and blast distance. It is evident that the ground vibration (PPA) increases with the number of blast holes. The amount of ground vibration decreases as the number of blast holes increases. An increased number of blast holes leads to a decrease in the FoS value. The observed decline in slope FoS values and the increase in PPAs is attributable to the growing number of blast holes. The type of explosive, along with its power and rate of detonation, influences the amount of energy produced, which in turn affects the degree of ground vibration. The findings indicate that the slopes remain stable (FoS > 1) both before and after blasting, although blasting slightly reduces the FoS. The study reveals that as the number of blast holes increases, both ground vibration (PPA) and the reduction in FoS increase, underscoring the effects of explosive power and detonation rate on slope stability.

Dynamic correlation between surface carbon response and underlying emissions from spontaneous combustion goaf: field study of an abandoned coal mine

Abandoned coal mine goaf is affected by air leakages and prone to spontaneous combustion, resulting in environmental pollution and geological disasters. Haizhou Open-pit Mine adopts both underground and open-pit mining methods. During the long-term mining process, the original stable stratum structure is constantly destroyed, and the slope slides, increasing cracks and severe air leakage around the goaf and roadway. The spontaneous combustion of coal is particularly prominent after the mine shut down. At present, there is no suitable indirect monitoring method to effectively explore the spontaneous combustion area in goaf. The study developed an all-weather monitoring plan and conducted multi-point continuous long-term measurements of the spontaneous combustion state in one abandoned coal mine goaf located in the eastern part of the Haizhou Open-pit Mine. We evaluated the dynamic correlation between surface CO2 flux (SCF) and changes in the underground fire areas, determined the scope and evolution trend of the fire areas, and identified the distribution and change laws of SCF. The results show a significant positive correlation between SCF and soil temperature; moreover, the SCF value was found to reflect the CO2 emission intensity of the goaf. The high SCF in the test area showed month-wise expansion and increase, while the CO2 emission gradually increased monthly, and the calculated annual total emission was approximately 7017 t. Hence, the study can further provide guidance for the monitoring of spontaneous combustion in shallow coal seams, goaf and the assessment of CO2 emissions from underground coal fires through the on-site monitoring and analysis results.

Use of Technogenic Mineral Formations: Current State, Identified Trends

It has been established that there is a constant increase in the accumulation of waste within the borders of the RF, in which the main share consists of waste from mining. The correlation between the annual mass of waste generated from technogenic mineral formations (TMF) and the volume of mineral extraction and the specific share of the open-pit mining method has been determined. The distribution of accumulated waste across the Federal Districts has been identified and the situation with their use has been characterized. It was noted that in the Federal Districts with the largest volume of accumulated waste, the percent of their involvement in secondary circulation for the period 2019–2022 decreases (relative decrease percent 41.2–7.2%). A conclusion is made about the unsatisfactory state of affairs in the field of application of SWM, which requires the number of measures to solve problems that complicate the introduction of man-made deposits into economic circulation.

Perancangan Sistem Penyaliran Tambang Pada PIT XYZ PT Karya Bhumi Lestari Jobsite PT Kartika Selabumi Mining Desa Kedang Ipil Kota Bangun II Kabupaten Kutai Kartanegara Provinsi Kalimantan Timur

Water is one of the things that is very influential in the mining process, mining water is water that is at the location and/or comes from the process of mining activities, both mining and processing, including runoff water in the mining area. Surface runoff water is rainwater that overflows into mining areas and is not a result of mining activities. The open pit mining method will cause the formation of a large basin so that it has the potential to become a water storage area, both from surface runoff and groundwater. During extreme weather conditions with high rainfall, water from surface runoff can inundate the ground floor and cause the mining front to become muddy, which can hamper mining activities. Handling waterlogging in mining forts requires good pumping performance, as well as re-planning the mine drainage system for the mine progress area. So that mining activities run smoothly and the mining front is free from puddles of water after rain, the drainage system must be well designed. Based on research that has been carried out, the total area of ​​the Catchment Area is 52.14 Ha with a runoff discharge of 82,567.79 m³/month. The planned discharge using the MF-290 Pump with RPM 1600 is, 290.00 m³/hour or 123,540.00 m³/month. After comparing the MF-290, MF-385 and DND-200 pumps, the MF-290 pump was selected for use. This is because the fuel consumption of the MF-290 is smaller so it saves costs and it is also deemed sufficient to use the MF-290 pump. Pump Ratio on the MF-290 pump April 6.71. May 3.93, June 6.44, July 6.36 and August 8.83, which means the pump is safe to use because the ratio is >1.

Pelaksanaan Reklamasi Lahan Pasca Tambang PT Rekasindo Guriang Tandang di Bengkulu

Coal mining in Indonesia is generally carried out using open pit mining methods, thereby disrupting and destroying the ecosystem and natural balance, causing negative impacts that result in environmental damage. Therefore, sustainable development with an environmental perspective is important for every nation and country that wants to protect its natural resources. The main cause of damage to the ecosystem or environment is humans. This research was conducted using a qualitative approach method. According to Williams (1988), the qualitative method is an approach that in the research proposal, process, hypothesis, going into the field, data analysis and data conclusions up to writing uses aspects of trends, non-numerical calculations, situational descriptive, interviews, in-depth analysis, deep. contents, snowballs and stories. The research findings regarding the study of the implementation of ex-mining land reclamation at PT Rekasindo Guriang Tandang's Coal Mining Business License in North Bengkulu Regency, Bengkulu Province are regarding community knowledge and participation in reclamation activities, land preparation, implementation of activities, equipment, costs, and commitment of directors or managers. The implementation of reclamation activities at PT Rekasindo Guriang Tandang did not go well because the plant growth success rate was low and plant growth was less than optimal. So the government and Mining Business License (IUP) managers need to take policies to involve the community more to play a more active role in reclamation activities carried out in areas around their environment.

ANALISIS BALIK LERENG LOWWALL PADA “BLOK X” KABUPATEN TANAH BUMBU, PROVINSI KALIMANTAN SELATAN

Coal mining companies usually apply the open pit mining method in carrying out coal mining. Mining activities always have risks that cannot be avoided and unpredictable, one of which is a landslide in the mining area. Therefore, it is very necessary to control the risks of mining activities. One of them is like designing a slope design in the mine which is included in geotechnical aspects. And in the geotechnical aspect, it has a reverse analysis method that is very useful to determine the cause of avalanches in the area.

Stable Slope Design Based On Limit Equlibrium Method (Lem) And Finite Element Method (Fem) At Pit X, Lahat, South Sumatra

Coal mining process using open pit mining method is closely related to slope stability. A slope whose stability is disturbed will have a higher potential for landslides. The slope stability analysis in this research is conducted by Limit Equilibrium Method (LEM) with the calculation of Morgenstern-pice slice method and Finite Element Method (FEM) with the calculation of Shear Strength Reduction. The highwall simulation was modeled with a Bench height of 10 meters, Bench width of 6.5 meters and bench tilt angle varying between 30°, 45°, 60° and groundwater condition using steady state FEA. From the results of the LEM analysis on the highwall with a bench tilt angle of 30 °, 45 °, 60 ° has a safety factor value of 1.005; 0.76; 0.584. While the results of the FEM analysis on the highwall with a bench tilt angle of 30 °, 45 °, 60 ° have a Strength Reduction Factor value of 0.98; 0.72; 0.57. Comparison of the safety factor values of the two methods has an average difference of 1-2%. This is because the FEM takes into account the stress-strain in the material which describes how the material behaves. The stable slope design based on LEM is a highwall slope with a Bench slope angle of 22° which has a safety factor value of 1.478 and based on FEM is a highwall slope with a Bench slope angle of 22° which has a Strength Reduction Factor value of 1.42.

Application of Active and Passive Treatment of Acid Mine Drainage to Comply with the Threshold Parameter of Coal Mining Wastewater

Most of the coal mining in Indonesia that uses the open pit mining method faces serious problems, namely the treatment of acid mine drainage. This constitutes a relatively large volume of wastewater, especially in areas that have rainfall in the range of 2000–4000 mm yearly. Acid mine drainage as acidic wastewater formed during excavation cannot be avoided due to the oxidation process during overburden removal. The acidic wastewater that has formed must be managed strictly and appropriately prior to being released into public waters. There are two methods of treating acid mine wastewater, namely active and passive treatments. Active treatment is generally used more frequently during operations, considering the time, effort, and costs; however, when entering the mine closure period, natural processes must be used at lower costs. Undertaking passive treatment in this area has shown a reduction in the chemical materials used and has enabled a greater amount of wastewater to be managed. The purpose of this research is to describe the active and passive treatment processes in the management of acid mine drainage and to analyze the results of passive treatment in preparation for the mine closure stage. Development of passive treatment by swampy forest system can reduce cost of treatment, naturally process and more environment friendlier by reducing the quicklime materials.

Improvement of the transitional technology from open pit to underground mining of magnetite quartzite

The paper analyzes the disadvantages of the technology of iron ore open pit mining and current environmental problems of open pit mining. The paper also addresses problems of possible displacement and strains of rocks in the classical open pit mining method with extraction of minerals exclusively by open pit mining, studies current transitional technologies from open pit to integrated open pit-underground and subsequent underground mining, and presents an improved methodology for studying the stress-strain state of the massif during transition from open pit mining to integrated open pit-underground and subsequent underground mining. There are studied, developed and proposed options of environmentally friendly technologies of integrated open pit-underground mining with mining waste disposal in the worked-out space of underground mines and open pits, highly efficient calculation schemes for studying the stress-strain state of a rock massif during transition from open pit to underground mining with formation of protective barrier pillars, an option with the development of the lower room of stage II under protection of an ore pillar left within the contours of the upper room of stage I, and an option with the development of the lower room of stage II under protection of an artificial pillar made of the consolidating backfill in the upper room of stage I. The stress-strain state of the massif and possibilities of forming internal waste rock dumps when applying integrated open pit-underground mining technologies are studied and substantiated. Transition technologies from open pit to underground mining of iron ore raw materials under the bottom of an operating open pit are developed and proposed on the example of Kryvyi Rih iron ore basin.

EVALUASI PELAKSANAAN REVEGETASI PADA LAHAN PASCATAMBANG BATUBARA (STUDI KASUS DI PT. X DI KABUPATEN TANAH BUMBU PROVINSI KALIMANTAN SELATAN)

Coal mining company in PT. X, in Tanah Bumbu District, South Kalimantan Province, uses the open-pit mining method, causing the initial vegetation loss of an area. PT. X has rehabilitated areas affected by mining by reclamation and revegetation to comply with government regulations. The types of vegetation that grew in the post-mining land revegetation area in the planting years 2012, 2014 and 2016 were acacia (Acacia mangium WILLD), trambesi (Samanea saman), sea sengon (Paraserianthes falcataria), and woody and fruit plants such as mahogany (Swietenia macrophylla), agarwood (Aquilaria moluccensis), meranti (Shorea Spp.), sungkai (Peronema canescens), rubber (Hevea brasiliensis), durian (Durio zibethinus), jackfruit (Artocarpus heterophylla), cashew (Anacardium occidentale), mango (Mengifera indica) and galam (Melaleuca cajuputi). Land characteristics have a steep slope of 35° in 2012 and range from 5°-20° in 2014 and 2016 The drainage system for planting years 2012, 2014 and 2016 looks good no erosion strains, planting years 2014 sites are flooded. The results of soil analysis are pH 4.48 - 4.97; the value of C-organic compounds 0.20% (very low) - 1.33% (medium); P2O5 1.89 mg/100g-1 (very low) - 40.10 mg/100g-1 (high); K2O with values of 8.57 mg/100g-1 (low) - 15.50 mg/100g-1 (medium), 0.20 me/100g-1 (very low) – 19.59 me/100g-1 (low); Mg-exchange at a value of 0.10 me/100g-1 (very low) - 0.20 me/100g-1 (low); Na-exchange of 0.05 me/100g-1 - 0.10 me/100g-1 is low; K-exchange with a value of 0.03 me/100g-1 - 0.05 me/100g-1 is very low, CEC 27.85 me/100g-1 - 52.48 me/100g-1 is low, saturation 0.95% (very low) - 41.56 (high). Based on the success rate of reclamation with revegetation parameters according to the Regulation of the Minister of Forestry No.P.60/Menhut-II/2009, it can be concluded that the success of revegetation obtained for the overall value with an overall value of 24 out of the target value of 50 with a percentage of plant growth of 27%, then the success value of revegetation is categorized as low.

Study Of Total Suspended Solid (TSS) Reduction In Coal Mine Water Management In Block III Of PT. Antang Gunung Meratus, South Tapin District, Tapin Regency, South Kalimantan Province

PT. Antang Gunung Meratus is a coal mining company with an area of 22,433 Ha with open pit mining method. PT. Antang Gunung Meratus has been equipped with a wastewater treatment system using active control methods, where the pH, Fe, Mn and Cd content of mine water is normal while the total suspended solid (TSS) value is more than 200 ppm in a state exceeding the water quality standard limit set by South Kalimantan Governor Regulation No.36 of 2008. The purpose of this study is to determine the results of water quality before and after it is managed and what methods are used in its management and how much costs are spent in managing the mine water. The research methods used are literature study methods, research in the field, primary and secondary data collection, data processing, data analysis and conclusions. The results showed that mining water in the WWTP area had the highest total suspended solid (TSS) content in July 2022 reaching 4.788 mg/l, while at the outlet the total suspended solid (TSS) value was 23 mg/l, the pH value was 7.22. Iron content (Fe) of 0.04 mg / l manganese content (Mn) of 0.006 and Cadmium (Cd) content of 0.004 mg / l, the content in the outlet comes from laboratory tests and costs incurred in mine water management worth Rp. 840,854,400 as of July 2022.

EVALUASI TANAH PENUTUP PERTAMBANGAN BATUBARA CV. INTAN KARYA MANDIRI, DI KABUPATEN BANJAR, PROVINSI KALIMANTAN SELATAN

Coal mining activities using the open pit mining method can affect depreciation of the quality of the surrounding environment, one of which has an impact on reducing the classification criteria for soil chemical properties. The soil organic matter shrinks after being mined due to the lifting of the top layer due to the dismantling of the coal covering material. The research objective is to analyze the effect of mining activities on soil classification in the disposal area. The research method is descriptive analysis. Sampling and observation in Cintapuri Village, Cintapuri Darussalam District, Banjar Regency. Soil classification in Disposal 1, soil pH is classified as "Very Acid" to "Sour", C-organic is classified as "Very Low", N-Total is classified as "Very Low" to "Low", phosphorus is classified as "Very Low", Cation-exchange capacity (CEC) is classified as "moderate". Disposal 2, Soil pH is classified as "acid", C-organic is classified as "Very Low", N-Total is classified as "Very Low" to "Very Low", phosphorus is classified as "Very Low", CEC is classified as "Medium" and "High". Based on the research, the existence of coal mining activities causes the chemical properties of the soil in the disposal area as low criteria.

Strategies of water flow treatment of Paringin Pit Lake to meet wastewater discharge compliance

Coal mining by the open-pit mining method creates the formation of a pit lake. The ex-mining site, over time, was gradually filled with contaminated water and must be returned to the water quality standard of compliance level. With proper treatment, the pit lakes have the potential for several benefits and subsequent uses. This study aimed to analyze the existing condition of the Paringin Pit Lake at South Kalimantan by identifying the quality of the water flow, and it is compliance with the parameter threshold values. The results showed that the pit lake water management had been carried out supported by good management of the catchment area and was indicated the stable category by geology technical study. The success of its revegetation processed in the area was shown by an erosion study in which the result was a very low-level category. No less important is the management of runoff water both in the quantity of water balance control and consistent water quality treatment to meet the quality standard values that have been set. The Paringin Pit Lake water management strategy is a form of activity that demonstrates compliance with good and responsible mining principles to support sustainable development that can serve as a good reference and example for other mining activities in terms of mine closure preparation.

Влияние статической нагрузки от горнотранспортного оборудования на устойчивость уступов, расположенных в скальных породах

Most of the enterprises applying open-pit mining method at deposits face challenges of pit wall steepening when approaching the pit wall to the final position or reducing productivity. The main task when increasing the angle of pit slope is to determine its stability. One of the ways to steepen the open-pit wall is to increase the slope angle of benches composing the open-pit wall. The bench stability is primarily determined by its physical properties and structural uncertainty. The higher the strength properties of rocks, the steeper the slope angle formed in these rocks can be. The "Rules of stability..." provide for the possible accounting the loads from mining equipment when assessing the stability, but this possibility is provided for the calculation of bench stability of open-pits and cuts, formed by semi-hard and dispersed rocks, dumps formed from clay or semi-hard rocks and (or) from a mixture of clay and hard rocks. At the same time, it is of interest to assess the impact of static loading from the located mining transport equipment in a stationary state on the stability of the benches located in hard rocks. It is shown that the load from the track dozer scraping the berms has an impact of no more than 6-7% for a distance of about 15 m from the top crest of a 30-meter long bench with a slope angle of 80° to the edge of the track, which is generally insignificant for maintaining bench stability. The minimum value of the safety factor of the bench with the load from the BELAZ-75306 mining dump truck is at a distance of 8 to 10 m from the top crest to the edge of the wheel. That is, at this distance the mining dump truck has the maximum impact. At 30 m distance from the bench’s top crest, mining dump truck has no impact on the bench stability. The maximum impact of the dump truck on the stability is 22 to 25%.

TRANSITION FROM OPEN PIT COAL MINE TO THE UNDERGROUND MINE IN SOFT ROCKS

To achieve a successful and effective operation, the transition from open pit to underground mining requires accurate planning and analysis. Numerical modeling utilizing programs like FLAC3D has been an important tool for simulating and analyzing the complicated geomechanical behavior connected with this shift in recent years. The use of FLAC3D to develop a model for the switch from open pit coal mining to underground coal mining in soft rocks with using room and pillar mining method is explored in this abstract. It presents the development of model to analyze and simulate the complex dynamics of this transition. The significant considerations that went into developing the model, such as geotechnical characteristics, rock mass behavior, and mine design parameters, are highlighted in the abstract. It highlights how essential proper input data are to producing reliable simulations and forecasts in soft rocks. The usage of FLAC3D for tracking pit wall stability during the transition period, evaluating the influence on nearby infrastructure, and optimizing underground mine design are covered in the abstract. The models flexibility allows the investigation of various conditions and offers valuable insight about the transition process. The research emphasizes the potential of the FLAC3D model to lead decision-making during the transition from open pit to underground mining through detailed analysis like choosing appropriate width for main entrance and cross section stopes and their interpretation. It emphasizes how important it is to understand the geomechanical behavior of the coal deposit, optimize the mines design parameters, and ensure safety for employees. The room and pillar method is utilized to recover coal resources from deep underground mines, and the results from the model can help improve efficiency, sustainability, and risk prevention. KEYWORDS: Underground mining, Open pit mining, Room and Pillar mining method, FLAC3D, Coal mining, Soft rocks.

Erosion Rate in Post-Coal Mining Reclamation Area in Kutai Kartanegara District, Indonesia

Erosion is the transport of parts of the soil from one place to another by natural agent, namely water, and wind. Mining in Indonesia generally uses open-pit mining methods. Generally, open pit mining has a very high erosion rate due to damage to soil aggregation and high interaction with rainwater. This study aims to determine the erosion rate and hazard class in the post-coal mining reclamation area. The research location was in the Jembayan Muarabara Group, Kutai Kartanegara Regency, East Kalimantan Province, from February 2021 to May 2021. The erosion rate measurement in this study used the stick method by measuring the erosion rate based on the change in soil surface loss in centimetres (cm) units. Erosion rate data collection is carried out periodically every month. The results showed that the highest erosion was in the Disposal area, namely 558.55 - 1341.94 tons/ha/year, including class V (very high), in the Stock Soil area with an erosion rate of 471.79 - 693.51 tons/ha/year including class IV (high) to class V (very high) and the lowest erosion rate in the reclamation area in 2019, namely 189.51 - 673.88 tons/ha/year including class IV (high) to class V (very high). Factors that affect the magnitude of the erosion rate are land cover vegetation, soil slope, and the soil's physical properties.

Perencanaan Kebutuhan Pompa Untuk Sistem Dewatering Tambang Emas Desa Bakan Kabupaten Bolaang Mongondow

One of the most frequent problems in open pit mining methods is the presence of water puddles in the lowest elevation of the pit. This often causesthe delay of production activities.Therefore, it is a need to design a good drainage system planning to deal with it. In this regard, pumps were needed. The aim of this research was to determine the of needed pumps and the best type of pumps to remove water in the pit effectively. This research used maps of mining sequence planningwhich would be then analysed with software Surpac 6.5.1.This was to identifythe width of catchment area. Furthermore, the rainfall data wasanalysed using polygon Thiessen method. The next process is to determine the rainfall plan with Gumbel method. Next was to determine the rainfall intensity plan by using Mononobe equations. Following this was determine the total discharge using rational method. Finally, the process was ended with the determining of the pumps type and pumps spesification to dry the water puddles in the pit. the result indicated that in the sump of the 3rd quarter 2020 with 100 l / sec pumping flow, pumping time 14 hours, total head 76.26 m, recommended pump type is a Multiflo MFC 385 with a rotation speed of recommendation per minute of 1400-1500, and an efficiency of 60% -65%. For 4th quarter sump 2020 with 105l / sec pumping discharge, 20 hour pumping time, total head 105,91 m, recommended type of pump is Multiflo MFC 385 with rotation speed recommendation permenit 1600-1700, with efficiency 60%. For the 1st quarter sump 2021 with a pumping rate of 102 l/sec, the pumping time is 20 hours, total head is 122.26 m, the recommended type of pump is Multiflo MFC 385 with a rotation speed of recommendation per minute 1700-1800, with 50% -60% efficiency. It can be suggested that it is necessary to add one more pump, Multiflo MFC 385, for the dewatering pit process.

Near-face stockpile open pit mining: a method to enhance NPV and quality of the plant throughput

ABSTRACT Stockpiles are of great importance in open pit mine production scheduling and are widely used for different reasons while being placed in different locations. Near face stockpile (NFS) is a new mining concept which combines the IPCC (in-pit crushing and conveying) method with an in-pit near-face (and near crusher) stockpile. The stockpile decouples the whole mining flow into two weakly related subsystems, which are the mining subsystem and processing subsystem. There are many theoretical advantages in comparison to the traditional open-pit mining method, such as higher tolerance on uncertainties without compromising production, higher equipment utilisation, less operating cost, better blending results, etc. The introduction of NFS, however, requires reconsideration of production planning in open pit mines. In this paper, we developed a mixed integer linear programming model to solve long-term production scheduling problem in open pit mines. To quantitatively measure the performance of the NFS mining method, we implemented the model in a real mining case study and compared the results with the traditional open pit mining method with an out-of-pit crusher. The results reveal that implementing the NFS method can improve the net present value by 9.3% and decrease the plant MWT head grade deviation by 20%.

Application of Good Mining Practice at PT. Gunung Bale, Malang, East Java

This study aims to determine the application of Good Mining Practice at PT. Bale Mountain. Mining activities at Gunung Bale consist of processes: Stripping and Top Soil Management, Mining Production Operations, Stock Pile Activities, Quality Control and Transportation to Consumers. The methodology used is a study of the application of Good Mining Practice. Data and information are processed and tabulated for later analysis descriptively and quantitatively. The results showed that the Mining Technical PT. Gunung Bale uses the open pit mining method with a Quarry mining system with a site hill type and a pit type. Mineral conservation is carried out using the method of calculating the volume of resources and reserves with the Triangular method using the Block model concept (software used is SURPAC 6.6.1). To prevent work accidents at the mine site, warning signs are installed and Personal Protective Equipment (PPE) and first aid kits are provided. Every time starting mining activities, a safety talk is held with the workers. Environmental management includes waste management, restoration and monitoring of water quality, handling of acid mine drainage, revegetation, and making a reclamation plan. The main mining infrastructure for road construction cuts around ±2 Ha. The total length of the road is 2,731 m. Processing and refining facilities are not located in the mining area.

Maximum height estimation for mine waste dumps

Waste dumps are widely used to discharge stripped mine wastes in open pit mining methods. As mining progresses, the height of the waste dumps will increase gradually, which may induce sliding failure once the height exceeds a critical value. Therefore, estimation of the maximum dumping height is crucial to the life-cycle use of a waste dump. However, published information about the maximum height of mine waste dumps are extremely rare. In this study, the maximum dumping height is estimated based on the strength-reduction technique by numerical simulations. The influences of dump geometry and properties on the maximum height are investigated. The results show that the maximum dump height decreases as the dump slope inclination angle a or the unit weight of dump materials y increases, but decreases when the shear parameters of dump materials (cohesion c and internal friction angle 9) increase. The maximum height starts to increase with the ground inclination p when shear failure occurs at the interface between the dump and the base. Furthermore the effects of the dump width B, Young's modulus E, and Poisson's ratio u of dump materials on the maximum height are almost insignificant. Good agreement was found between numerical results available in the literature and those obtained in this study.