Indonesia Conference Directory

Corresponding Author
Wahyu Asmoro Nursandi

Institutions
PT Kaltim Prima Coal - Hatari Pits Department

Abstract
ABSTRAK KONFERENSI INTERNASIONAL ILMU KEBUMIAN, MINERAL DAN ENERGI II Analisis Sensitivitas Produksi Liebherr R9800B dan Penerapan Metode Loading 2-1 Menunjang Produksi R9800B All Crew-Operation Section, HATARI Department, PT Kaltim Prima Coal Wahyu Asmoro Nursandi, ST.1 Harry Asjuhar, SE.2 1Superintendent Production Shift, Operation Section, Hatari Dept, PT. Kaltim Prima Coal 2Mining Statistician, Technical Section, Hatari Dept, PT. Kaltim Prima Coal Perkembangan dan persaingan industri pertambangan dunia semakin ketat, sehingga perusahaan pertambangan dituntut lebih kompetitif dan menerapkan praktek operasional tambang yang efektif, efisien, dan produktif tanpa mengesampingkan aspek safety. Unit Liebherr R9800B adalah salah satu alat gali muat terbesar di dunia dioperasikan oleh PT. Kaltim Prima Coal. PT. Kaltim Prima Coal mengoperasikan 3 unit Liebherr R9800B, 2 unit di Bintang Department (S601 dan S602) dan 1 unit (S603) di Hatari Department. Pengoperasian Liebherr R9800B mempunyai tuntutan dan ekspektasi produksi yang tinggi, sehingga peningkatan overburden yang dipindahkan selaras dengan batubara yang terbuka. Beberapa improvement dilakukan untuk meningkatkan produksi R9800B, mulai dari metode sistem pemuatan, kombinasi truck yang digunakan, metode penggalian, memaksimalkan waktu operasi digger (pembuatan access refueling, access pergantian operator), dll. Area operasional Hatari Department berada di sisi utara area PKP2B PT. Kaltim Prima Coal. Karakteristik area utara memiliki nilai UCS batuan rendah 1.71-2.37 Mpa dan kerapatan interburden batubara lebih rapat dibanding area selatan. Hal ini menjadi tantangan tersendiri jika mengoperasikan Liebherr R9800B dengan berat 800 ton dikombinasikan dengan truck Euclid EH5000 500 ton. Berdasarkan plan 2019, usage R9800B ditargetkan sebesar 60.02%, dengan productivity 3,069 bcm/hour, dan produksi 37,932.49 bcm/day. S603 berpindah dari area operasional Bintang Department ke area operasional Hatari Department pada pertengahan tahun 2017. Saat beroperasi di area Bintang department, S603 mencatatkan rata-rata produksi 54,012.49 bcm/day dengan pencapaian produksi maksimal sebesar 29,120.83 bcm/shift dalam periode 2 (dua) tahun. Kemudian saat berpindah area kerja Hatari Department, tercatat rata-rata produksi sebesar 62,229.15 bcm/day dengan produksi maksimal 33,108.32 bcm/shift dalam kurun waktu yang sama. Dengan karakteristik area operasional yang berbeda jauh dibandingkan area Bintang, S603 mampu berproduksi lebih baik saat beroperasi di area Hatari. Tetapi hasil produksi antar crew section operation Hatari Department di tahun 2018 menunjukkan variance yang terlalu tinggi, produksi didominasi oleh satu crew. Crew Alpha memimpin perolehan produksi R9800B, crew Bravo mampu bersaing, sedangkan crew Charlie tertinggal jauh. Berdasarkan review performance tahun 2018, maka operation dan technical section berkerja sama melakukan analisis terhadap performance R9800B mulai awal tahun 2019.

Keywords
Analisis Sensitivitas Produksi

Topic
Mining and Metallurgy Engineering

Link: https://ifory.id/abstract/Fcrw2vAeKYCy

Corresponding Author
muhammad bagaskoro

Institutions
a) ITNY Yogyakarta
b) Faculity Of Mining Enginering

Abstract
Activities can make the impact to a land, so that needs to be done reclamation in an effort to increase the quality of land and improvement of the condition the former land of the mine. Kulon progo has a lot of andesite reserves. The aim of this study are 1) assess the factor causing physical damage caused by mining of Andesite in Pengasih district of Kulon Progo, 2) analyse the extent of the damage. This research uses direct field observation method and survey. Data taken in CV. Elita Karya Pratama in districts Pengasih, in CV. Elita Karya Pratama taken eight sample of the mine site that is in the moor. Quantitive analysis is done by means of weighting and scoring and qualitative. Each parameter is weighted in accordance with standards set by the environmental damage in the DIY Govener Decree No 63 of 2003. The factor known to cause damage through interviews and questionnaires administration. As a result, the damage caused by mining in the area were severely damaged moor categorized as medium damaged. Factor that influence the damage is lack of socialization.

Keywords
Andesite, Enviroment, Mining

Topic
Mining and Metallurgy Engineering

Link: https://ifory.id/abstract/7BCN8QmpMzRq

Corresponding Author
Heri Prabowo

Institutions
Universitas Negeri Padang

Abstract
Based on observations in the field In the IUP 412 Ha area overburden (soil) found on the Tajarang hill, mining must be carried out first so that the next limestone mining process can be carried out, because the limestone is blocked by overburden (soil). On soil slopes in IUP 412 Ha area it has a height of 27 meters and a slope of 79˚. On this overburden (soil) slope, several laboratory tests were conducted to obtain the safety factor (FK) value from the soil slope with several tests. The analysis of the tests carried out was testing the original soil content, soil moisture content, direct shear angle and proctor testing. The results of the analysis of the calculations performed are obtained from: The average fill weight of the 10 soil samples tested was 1.9233 grams / cm3. The average soil water content of the 8 soil samples was 46.75%.

Keywords
soil, shear

Topic
Mining and Metallurgy Engineering

Link: https://ifory.id/abstract/H6xGZJbamdRK

Corresponding Author
Reza Adhi Fajar

Institutions
a) Post Graduate Program in Mining Engineering, ITB, Ganesa 10 Bandung, Indonesia.
*reza[at]poliban.ac.id
b) Department of Mining Engineering, Poliban, Kayutangi Banjarmasin, Indonesia.
c) Graduate Program in Biotechnology, School of Life Sciences and Tech., ITB, Ganesa 10 Bandung, Indonesia.
d) Department of Microbiology, School of Life Sciences and Technology, ITB, Ganesa 10 Bandung, Indonesia.
e) Research Group for Earth Resources Exploration, ITB, Ganesa 10 Bandung, Indonesia.
f) Senior Hydrogeology, PT.BC, Pemuda 40 Tanjung Redeb Berau, Indonesia.

Abstract
Liquid waste with high amount of total suspended solid (TSS), is one of the significant environment issues from coal mining activities in Kalimantan island under high precipitation in of a very wide zone of coverage. The TSS concentration with Nano-sized particle in mine drainage caused by clay minerals which is dominated by montmorillonite type. Therefore, a huge chemical agent is usually used to treat TSS concentrations of the liquid waste less than 300 mg/L based on government regulation. However, in this case, the chemical flocculant triggers the onset of secondary pollutant because its carcinogenic and non-biodegradable. This study aims to observe specific fungi, Marasmius sp, as bio-flocculant for the treatment of mine drainage with extra high TSS. The fungi can produce biodegradable polymer that have ability to precipitate the montmorillonite with two mode action, they are bio-flocculant polymeration and mycelial trapping. A role model was running in laboratory scale less than 1 L in several graduated/measuring cylinders under 22-30 oC. The results of clarity test by using spectrophotometer shown a number of 86% clarity value averagely in one-hour treatment, while flocculation rate test indicated the amount of TSS concentrations became 110.1 mg/L. In this term, the minerals in the mine drainage samples from PT.BC mining excavation area, had been precipitated rapidly from previous measured TSS concentration at 11,000 mg/L.

Keywords
Total suspended solid; Mine drainage; Bio flocculant; Concentration

Topic
Mining and Metallurgy Engineering

Link: https://ifory.id/abstract/DGT29WhYaem8

Corresponding Author
Oktarian Wisnu Lusantono

Institutions
a) Universitas Pembangunan Nasional “Veteran” Yogyakarta, Yogyakarta 55283, Indonesia
b) Yayasan Emas Artisanal Indonesia

Abstract
Artisanal and Small-scale gold mining (ASGM) is an interesting issue in the development world related to the sustainable development goals in environmental topics. Mercury is a one of the several focuses related with ASGM and its usage has been limited by the implementation of Minamata Convention on Mercury. Indonesia as development country with quite significant number of ASGM miners has been ratified and forced the implementation of Minamata Convention since 2016. In this study, a typical ASGM operation located in Tobongon, East Bolaang Mongondow, North Sulawesi Province was selected as a site of study. Tobongon is one of the few people-s mining area (Wilayah Pertambangan Rakyat – WPR) that has been verified by Ministry of Energy and Mineral Resources (Kementerian Energi dan Sumber Daya Mineral – ESDM). This study is cover several topics such as current state of operation in relation with mercury usage, legal status, and couples of activity that has been done for capacity building in the area. The result of this study will provide an illustration about ASGM conditions in Indonesia with its complexity and challenges for improvement and development.

Keywords
Artisanal and small-scale mining, responsible mining, mercury reduction

Topic
Mining and Metallurgy Engineering

Link: https://ifory.id/abstract/gvumzYMxbTtw

Corresponding Author
Tri Wahyuningsih

Institutions
1 Metallurgical Engineering, Mining Engineering Department, Mineral Technology Faculty, UPN "Veteran" Yogyakarta, Jl. SWK 104 (Lingkar Utara) Condongcatur Yogyakarta 55283 Indonesia
2 Metallurgy Engineering, FTTM, Bandung Institute of Technology (ITB), Bandung 40132, Indonesia
3 Laboratory of Geomicrobiology, Biomining & Biocorrosion, Research Center for Bioscience and Biotechnology, Bandung Institute of Technology (ITB), Jln. Ganesha 10, Bandung 40132, Indonesia
a)Corresponding author: tri.wahyuningsih[at]upnyk.ac.id
b)skchaerun[at]metallurgy.itb.ac.id
c)esanwani[at]mining.itb.ac.id;

Abstract
Abstract: Several studies have been conducted on the benefits of bacteria to replace chemical reagents in the bioflotation process of copper sulfide minerals. Most of the processing of copper sulfide minerals is carried out by flotation by adding reagents. Flotation is one of the mineral processing processes to separate valuable minerals and their impurities, by utilizing different mineral surface properties. In copper sulfide minerals there is a high sulfur content of pyrite impurities (FeS2) which must be separated or depressed (become more hydrophilic) to be separated with valuable minerals, while valuable minerals will remain hydrophobic (prefer air). However, not all bacteria can survive at high sulfur concentrations. In this research characterization of the interaction of biosurfactant-producing bacteria that can survive in environments with high sulfur content (Citrobacter youngae strain SKC-4) with pyrite minerals. The effect of bacterial and pyrite interactions is observed by analyzing the composition of mineral surface elements and the morphological changes of the sample with SEM-EDS (Scanning Electron Microscope - Energy Dispersive Spectrometer) showing the interaction of bacteria that is able to stick and make mineral particles into complex aggregates and from the EDS results show that in the presence of bacteria are able to change the components of the initial mineral elements, this is dominated by the element components Fe, S, and a little content of element C which is the main element of microbial activity. Sampling for functional group testing (FT-IR Spectroscopy) was carried out on days 0,7,14, and 30 when bacteria interacted with minerals, showing a peak of C = O carbonyl bonds and carboxylic acid formation on the 7th day. The contact angle value of interaction culture with pyrite minerals results in a decrease on the 7th day, this causes the pyrite minerals to become more hydrophilic. From the results of the interaction characterization, the Citrobacter youngae strain SKC-4 has the potential as an alternative to a depressant reagent in a more environmentally friendly copper sulfide mineral bioflotation process.

Keywords
interaction, biosurfactant, pyrite, depressant

Topic
Mining and Metallurgy Engineering

Link: https://ifory.id/abstract/V6rQbU9kj283

Corresponding Author
Fanteri Aji Dharma Suparno

Institutions
(a) Department of Mining Engineering, University of Jember, Indonesia
Jalan Kalimantan No 37, Jember, Jawa Timur, 68121
fanteri.teknik[at]unej.ac.id
(b) Geological and Mining Engineering and Sciences, Michigan Technological University, United States of America

Abstract
One of the critical jobs in the mine planning and design is to optimize an open pit mine under many uncertain factors. This paper explains the incorporation process of the volatility of commodity price or market uncertainty into production phase design and ultimate pit limit using a maximum flow minimum cut algorithm. The Ornstein-Uhlenbeck (OU) mean-reversion process was used to generate 50-coal price simulations for 10-years ahead. For implementation, data from an Indonesian coal mining site was integrated into the method and resulted in 42% differences compared to a conventional way.

Keywords
Mine planning, Commodity price, Maximum flow minimum cut algorithm, Mean-reversion, NPV

Topic
Mining and Metallurgy Engineering

Link: https://ifory.id/abstract/D4mE3gvdKVuL

Corresponding Author
Surya Dewa

Institutions
a)Mining Engineering of Universitas Pembangunan Nasional “Veteran” Yogyakarta, Indonesia
*suryamaulana1995[at]gmail.com
b)Mining Engineering of PT. Bukit Makmur Mandiri Utama, Indonesia
c)Fresh Graduate from Mining Engineering of Universitas Pembangunan Nasional “Veteran” Yogyakarta, Indonesia

Abstract
One of the main problems in open pit mining is the presence of water. Water in the mining area can disrupt mining operations and, in consequences, the production target will not be achieved. The mine drainage system is one part of the system used to overcome the presence of water. The rational method is the method most widely used by hydraulic engineers to estimate the discharge. The open channel dimension is designed based on the discharge estimation. Runoff coefficients are critical parameters for rational methods. There are several sources of literature determining the value of runoff coefficients, such as the approach of the American Society of Civil Engineering (ASCE), Schwab, Perry, and Gautama. In this paper, we examine the method selection effect of open channel dimension for determining the runoff coefficient value in the same conditions both of the rain catchment area and the rainfall intensity

Keywords
Runoff Coefficients; Open Channels; Rational Methods; Mine Water Distribution; Open Mine; Mine Drainage

Topic
Mining and Metallurgy Engineering

Link: https://ifory.id/abstract/AuPvaKC7MZcJ

Corresponding Author
Liqiang Ma

Institutions
School of Mines, China University of Mining and Technology

Abstract
During mode-I crack development of sandstone flattened Brazilian disk (FBD) specimen, the thermocouple multi-channel temperature measuring instrument is used to measure the temperature variation. The thermal infrared imager is also used to measure the infrared radiation temperature variation. In the thermocouple multi-channel temperature test, about 95% of the specimens have experienced stress change at crack initiation. Meanwhile, there is a sudden increase in physical temperature. The maximum temperature increases by 0.74°C and the average temperature increases by 0.16°C. In the test by thermal infrared imager, about 20% of the infrared radiation temperature rises at crack initiation (the average temperature increases by 0.03°C). The experimental results show that the physical temperature measurement technology and infrared temperature measurement technology can capture the temperature variation in crack development before coal and rocks fail. The results can be applied in mining engineering, such as crack development in water-preserved mining, rock strata control and so on.

Keywords
Flattened Brazilian disk; Mode-I specimen; Temperature field; Infrared radiation; Crack development; Water-preserved mining

Topic
Mining and Metallurgy Engineering

Link: https://ifory.id/abstract/yJK3WYE8ahGc

Corresponding Author
Tedy Agung Cahyadi

Institutions
Lecturer of Mining Engineering of Universitas Pembangunan Nasional Veteran Yogyakarta, Indonesia Jalan SWK 104, Sleman, 55283, Indonesia

Student of Bachelor Mining Engineering of Universitas Pembangunan Nasional Veteran Yogyakarta, Indonesia Jalan SWK 104, Sleman, 55283, Indonesia

Mine Plan Engineer, PT Bumi Suksesindo, Banyuwangi, Indonesia

Abstract
Indonesia is a country rich in natural resources, especially gold resources. Gold mining in Indonesia is commonly using open pit and underground mining system. Although underground mining is not directly connected with weather and rainfall, that does not make an underground mining free of mine dewatering system-s problem. The problems that may be occurred in the working front area of an underground mine are the high of the total head that has to be lifted by a pump, dimension of the mine channel and sump that small due to limited space of the tunnel, and flood. Flooding in a tunnel commonly caused by groundwater on the tunnel-s surroundings. An accurate calculation of groundwater inflow into the tunnel is important to design the underground mine dewatering system. Measurement of actual groundwater inflow had been done to prove the accuracy of groundwater inflow-s calculation using an analytical solution by El Tani method. This paper presents the alternative of the groundwaters seepage calculation those flows into the tunnel. The result of this research is the groundwater inflow can be predicted using an analytical solution accurately so that the design of the underground mine dewatering system can be held precisely

Keywords
Mine Dewatering, Pump Network, Seepage, Total Head, Working Front Area

Topic
Mining and Metallurgy Engineering

Link: https://ifory.id/abstract/Mx9zj43KYfhU

Corresponding Author
Waterman Sulistyana Bargawa

Institutions
1Master of Mining Engineering, UPN Veteran Yogyakarta, Jl. SWK 104 Yogyakarta Indonesia
2Department of Mining Engineering, UPN Veteran Yogyakarta, Jl. SWK 104 Yogyakarta Indonesia

Abstract
Modeling and estimation of ore grade are very essential in geostatistical ore resources estimation. Resource modeling is generally carried out on gold, copper, nickel and bauxite ores. This study applies the geostatistical method for modeling and estimation of iron ore grade. The objective of the study is to apply estimation techniques (OK, ordinary kriging; IDW, inverse distance weighting, and NNP, nearest neighbor polygon) and evaluate the accuracy of these techniques in iron ore resources. This study uses detailed exploration, which are 68 drill holes with 170 iron ore grade composite data. In the iron ore resources estimation, block modeling method is applied. The results showed RMSE (root mean square error) values of various estimation techniques. Based on statistical analysis, visualization of comparisons between borehole data and models, and probability plots, the accuracy of each iron ore resource estimation technique in the study area can be determined. All estimation techniques have the same accuracy on low CV (coefficient of variance) values. The relative kriging standard deviation values determine the classification of measured iron ore resources.

Keywords
iron ore, resource, modeling, geostatistics, kriging

Topic
Mining and Metallurgy Engineering

Link: https://ifory.id/abstract/J6tU4GRxzmgC

Corresponding Author
Tedy Agung Cahyadi

Institutions
1Universitas Pembangunan Nasional “Veteran” Yogyakarta, Indonesia
2Dewatering Engineer, PT Bukit Asam Tbk

Abstract
This research was conducted in the North Sump area of the Air Laya Mining Unit at the Tanjung Enim, PT Bukit Asam Tbk. The sump is a former open pit mining area in the form of a very large basin. Previously this sump functioned to gathers water from the pit. Since there is no mining operation in that pit, then that sump-s functionality is changed into a disposal area, so the sump is needed to be dried. The draining plan is carried out with mine drainage and mine dewatering. Mine drainage is an effort to prevent runoff water to enters the sump. Mine dewatering is the effort to remove water from the sump by pumping. The initial draining plan is not able to dry the sump. It can be seen from the water surface-s elevation on the sump that has not decreased, so it is necessary to study the plan to drain the sump. The study conducted considers the calculation of the water balance. Water balance is influenced by inflow in the form of runoff water and outflow in the form of evaporation and pumping. Based on the calculation of the water balance, three alternatives are proposed in sump drying, which from each alternative can be seen changes in the volume and depth of the sump in a certain period. Alternative I is done by adding the number of pumps, the alternative II is done by increasing the pump impeller rotation, and the alternative III is done with alternative I and alternative II combination. The alternative chosen is alternative III with a drying time of 72 days.

Keywords
Dewatering, Pump Network, Alternative Aproach

Topic
Mining and Metallurgy Engineering

Link: https://ifory.id/abstract/ercpYqmdJfAV

Corresponding Author
Taruna Fadillah

Institutions
Mine Operation Department, Antam Pongkor Underground Gold Mine, Indonesia

Abstract
The stability of tunneling in the underground mine is an important factor in the production of mines that must ensure productivity and safety. In Antam Underground Gold Mine, the production cycle starts by drilling the tunnel then charge the explosive material. After that, the tunnel is blasted before the ore mucking activity. The activity continues to reinforcing the tunnel and back again to the beginning of the cycle, drilling activity. The drilling is using Jumbo Drill which has 3-meter drilling rod. With span progress is about 2.7 from 3 meters or 90% of the drilling rod length, in a tunnel with dimension 5-meter-high and 5-meter-wide, the mining is producing 170 tons in 8 hours which can be considered the productivity 21.25 ton per hour each Jumbo Drill. Among many rock conditions affecting stability, the width and height of tunnel are an important design factor. In this paper, the aim is to optimizing blasting activity by considering the maximum unsupported span (MUS) using the Q system. The mining factor like the equipment size, geological condition and productivity cycle are combined and considered to get the optimum span value in a variety of rock mass at Antam Underground Gold Mine. The output of the research is the maximum unsupported span value has a variety figure from 1.8 to 8 meters depending on the rock mass characteristic. By observing the mining operation factor, the maximum span can be proposed in 4.2-meter length. Although the drilling time getting longer 20%, the production tonnage increase 40% which mean productivity also climb 20%. As a result, by utilize MUS and considering the mining factor, the productivity can be enhanced and safety guaranteed.

Keywords
Maximum Unsupported Span, Q-System, Underground Gold Mining

Topic
Mining and Metallurgy Engineering

Link: https://ifory.id/abstract/xFD7n4a8RgGw

Corresponding Author
Sylvianopa Magdalena

Institutions
1 Lecturer of Mining Engineering of Universitas Pembangunan Nasional Veteran Yogyakarta, Indonesia Jalan SWK 104, Sleman, 55283, Indonesia
2 Student of Magister Mining Engineering of Universitas Pembangunan Nasional Veteran Yogyakarta, Indonesia Jalan SWK 104, Sleman, 55283, Indonesia
3 Dewatering Engineer, PT Darma Henwa, Bengalon, Indonesia

Abstract
Althought it has often been done, the mine drainage system can be complicated process, depends on the condition of the location and the excavation requirements with the purpose that the water entering the mine does not interfere with mining activities. In this paper discussed the costs that are of concern in mine water management case study at Pit B, PT Darma Henwa Bengalon site in 2019, using the variable costing method. From the research results, the cost of contruction an open channel with geometry top width (B): 5,17 m, under width (b): 2,6 m, hydraulic mean depth (h): 2,24 m, sloping width (a): 2,57 m, which is Rp 36.808.096,-, making sump Panel 1, sump Panel 2 and 4, sump Panel 3 using PC1250 and HD465 are Rp 3.920.833.504,-, then the costs for investment, installation pipes and pumps, as well as operating costs at the beginning of dewatering are Rp 63.426.709.502,-. The costs of a mine drainage system in the form of the costs of making open channels, contruction of sumps and pumping costs consist of components in the form of employee salaries, assets equipment costs like pumps, material costs in this case the materials used in the istallation of pumping circuits such as pipes, bolts and flanges. Operating costs in the form of fuel and lubricants which are used, lastly the indirect cost company incurred by the direct cost. Indirect costs are available when purchasing pumps unit or assets. It usually form in percentage and consist of material costs, salaries, equipment cost and operating cost.

Keywords
open channel, sump, pumping, dewatering cost, variable cost

Topic
Mining and Metallurgy Engineering

Link: https://ifory.id/abstract/RzxEJ9PKwvHX

Corresponding Author
Dr. Donatus Setyawan PH, S.Si., M.Si Purwo Handoko

Institutions
FMIPA
Jurusan Kimia
Universitas Jember
Jl. Kalimantan 37 Jember

Abstract
PREPARATION, MODIFICATION AND CHARACTERIZATION CATALYST Ni/ZSiA ABSTRACT Modification and characterization of the catalyst Ni / ZSiA are prepared from natural zeolite have been carried out. ZSiA catalyst was prepared by washing zeolite with aquadest, followed by dipping in HCl 2M solution, adding Na2SiO3 5% b/b, dipping in NH4Cl 2M, calcination at 500 oC under nitrogen with flow rate of 20 mL/min for 2 hours, oxydation under oxygen flow rate of 20 mL/min and impregnation of Ni metal into catalyst surface using Ni(NO3)2&

Keywords
zeolite, Si / Al ratio, acidity, pore

Topic
Mining and Metallurgy Engineering

Link: https://ifory.id/abstract/FUjapXNJV84Y

Corresponding Author
Aldin Ardian

Institutions
a) McGill University, department of mining and materials engineering, 3450 rue University, Montreal, Quebec H3A 0E8, Canada.
*aldin.ardian[at]mail.mcgill.ca
b) Universitas Pembangunan Nasional "Veteran" Yogyakarta, department of mining engineering, jalan Ring Road Utara, Yogyakarta 55283, Indonesia.

Abstract
Mining industries face uncertainties over time, including in the gold mining. The uncertainty in the gold mining project is most likely due to the financial risk (i.e., prices). The gold price fluctuation in the industry may shape the industry characteristic, either risky or not. Moreover, the gold prices are hard to predict, decision makers are suggested to quantify the project risk in advance. In this paper, the risk is quantified by correlation analysis, Copula method. Copula is a powerful tool to describe not only linear, but also non-linear correlation between random variables. In addition, the Monte-Carlo simulation – a popular and standard approach to assess the risk – is incorporated in the Copula. This approach is straightforward, fast, and applicable for different project or country. A case study is performed to make the approach more clear.

Keywords
Risk assessment, risk quantification, uncertainty, copula, mining industry

Topic
Mining and Metallurgy Engineering

Link: https://ifory.id/abstract/2qQKw6JyA9LW

Corresponding Author
Muhammad Rahman Yulianto

Institutions
UPN "Veteran" Yogyakarta

Abstract
The stability of rock slopes is important for the safety of personnel and equipment in the open pit mine. Slope instability and failure occur due to many factors such as adverse slope geometry, geological discontinuities, weak or weathered slope material due to weather influences. External loads such as high rainfall and seismicity could play an important role in slope failure. For this reason, a precise classification of rock mass is needed for the basis of determining technical policy. Rock slopes in open pit coal mining areas, especially in Indonesia, are characterized by applying various rock mass classification systems, such as Rock Mass Rating (RMR) and Geological Strength Index (GSI), because the study area comprises well exposed rock formations. In the RMR system, there are five main parameters viz. Uniaxial Compressive Strength (UCS) of rocks, Rock Quality Designation (RQD), spacing of discontinuity, discontinuity conditions, and groundwater conditions were considered. In this paper, several rock mass classification systems developed for the assessment of rock slope stability were evaluated with the condition of rock slopes in the tropics, especially Indonesian region, particularly in sedimentary rocks in the open pit coal mining area in order to get the corrected GSI equation used to characterize rock slopes based on quantitative analysis of rock mass structure and surface conditions of discontinuities

Keywords
Sedimentary Rock ,Rock Mass Rating, Geological Strength Index

Topic
Mining and Metallurgy Engineering

Link: https://ifory.id/abstract/2Aj9ayqTt4ge

Corresponding Author
Lilik Eko Widodo

Institutions
Research Group on Earth Resources Exploration,
Faculty of Mining and Petroleum Engineering,
Bandung Institute of Technolgy, Bandung, Indonesia

Abstract
Wet muck forms due to the accumulation of fine material and water in drawbells in a block cave mine system. It results in the potential for mud rushes or wet muck spills, which have a significant influence on safety and production. Butcher, et al (2005, 2007) stated that the wet muck contributing factors are fine materials and water; according to Widodo, et al (2018), wet muck is formed because of the contribution of five factors, namely, fine material, water, height of draw, no mucking days and rainfall. Widodo, et al (2018) focussed on the expert opinions about five wet contributing factors facilitated by fuzzy logic and resulting in the wet muck class, thereby indicating the status of the corresponding drawpoints in terms of the qualitative wet muck spill potential. With the increasing number of wet muck spill occurrences, there is an opportunity for evaluating the expert opinions on data or facts about wet muck spill evidence. In this paper, the process of wet muck class prediction is based on the views of experts, such as those illustrated by Widodo, et al (2018), and strengthened by the system-s learning / training process for wet muck spill occurrence data, which his facilitated by using an adaptive neuro–fuzzy inference system (ANFIS). What is conveyed in this paper is the development of the system presented in Widodo, et al (2018), which is based solely on the opinions of experts; moreover, it involves additional system development that can intelligently recognise the wet muck class from the data of wet muck spill events or wet muck spill history and then used to predict further wet muck spill potential.

Keywords
Block cave mine, wet muck, mud rush, wet muck spill potential, prediction, fuzzy logic, ANFIS.

Topic
Mining and Metallurgy Engineering

Link: https://ifory.id/abstract/68zJFyuqW3p7

Corresponding Author
Mingshi Gao

Institutions
School of Mines,
China University of Mining and Technology

Abstract
Rock-bursts, which are usually collapsed, caved-in, or sealed off instantaneously, cause risks to mine safety and production. Approximately 85% of rock-bursts happen in roadways when the elastic complementary energy accumulated in the rock exceeds the minimum kinetic energy associated with damage to the surrounding rock. The greater the difference between the elastic complementary energy and the minimum kinetic energy, the more likely the rock-burst is. According to the mechanism of roadway destruction by rock-bursting, a strong-soft-strong (3S) structural model to prevent rock-bursts from occurring was established and analysed. The result showed that the 3S structural model encompassed: the strength characteristics of the structure itself, stress adjustment, wave absorption, deformation and anti-deformation, energy consumption, etc. Stress criterion and energy rule for the small inner support structure destroyed by rock-bursting were deduced. Finally, based on the 3S model, the engineering application was theoretically discussed; several techniques such as decreasing shock energy, deploying adequate soft structures, and improving support strength were proposed to prevent roadway destruction by rock-bursts.

Keywords
mining engineering; rock-bursts; roadways; strong-soft-strong (3S) mechanical model; engineering applications

Topic
Mining and Metallurgy Engineering

Link: https://ifory.id/abstract/HdWcFwvbAg3M

Corresponding Author
Pantjanita Novi Hartami

Institutions
Trisakti University,

Abstract
The selection of appropriate rock support system in accordance with rock properties and rock mass classification should be applied to get the underground mine stability. Underground gold mine of Pongkor Indonesia use friction bolt (split set) and H-beam. For efficiency of rock support system, it is planned to replace the previous rock support system with Mechanical Anchor Bolt as an alternative rock support system. The trial of Mechanical Anchor Bolt was conducted on Cross Cut 519 to Southern on Kubang Kicau vein. The lithology of location dominantly consists of andesite tuff, tuff breccias and quartz veins. The mapping of geological structure was applied to obtained the structural condition. In line with the scanline, the laboratory testing is also carried on in order to get the physical and mechanical properties of rock. By using Rock Mass Classification and the viability index wedge analysis, the technical performance of both supporting was compared and evaluated. The duration of installation of Mechanical Anchor Bolt is observed during the trial and its was compared to previous supporting system. Numerical modeling using Dips, Un-wedge and Examine are applied to model the underground stability. Based on the trial results, the use of Mechanical Anchor Bolt was evaluated to be applied in production stope (Ciguha Flat Back 475 and Gudang Handak Sill Drift Vein C Ramp Down Connect 450) and development access (Pasir Jawa Access Ramp Up to South)

Keywords
friction bolt, H-beam, mechanical anchor bolt, rock mass classification, numerical modelling

Topic
Mining and Metallurgy Engineering

Link: https://ifory.id/abstract/fKtwBhjcz2kC

Corresponding Author
Lilik Eko Widodo

Institutions
Research Group on Earth Resources Exploration,
Faculty of Mining and Petroleum Engineering, Bandung Institute of Technolgy, Bandung, Indonesia

Abstract
The cycle time in mining activities is the time needed by a mining equipment or a combination of several mining equipments to complete one or one series of several particular jobs or tasks. The cycle time in some cases will never be constant but follows a certain distribution with an average and certain standard deviation of time. This is due to the fact that each mining equipment and / or each component of the work varies in time to complet the task. The cycle time of some mining equipments and / or some components of work is basically an arithmetic operation of the variation of cycle time of each individual mining equipment with its individual distribution. Arithmetic operation of several data distributions can be done stochastically by using Monte Carlo method or method with fuzzy number operation. This paper will briefly describe the uncertainty analysis of cycle time using both methods and finally comparing the results of both.

Keywords
Cycle Time, Monte Carlo Method, Random Number, Fuzzy Number Operation

Topic
Mining and Metallurgy Engineering

Link: https://ifory.id/abstract/zxvVj73WJpPb

Corresponding Author
Syafrizal Syafrizal

Institutions
Earth Resources Exploration Research Group, Faculty of Mining and Petroleum Engineering, Institut Teknologi Bandung, Bandung, Indonesia

Abstract
Three vein zones hosting gold mineralization have been outlined at the Poboya prospect, named as the River Reef Zone, the Hill Reef 1 Zone, and the Hill Reef 2 Zone. The vein zones were observed within metamorphic rocks leading to an issue regarding classification of the deposit type and exploration of the gold deposit. Macroscopic observation on considerable number of veins collected from the Hill Reef 1 and Hill Reef 2 Zones show that the vein textures consist of massive chalcedony, massive quartz, massive carbonate, banded chalcedony, colloform, crustiform, cockade, and lattice textures. These textures represent primary growth and replacement textural groups, which are similar to the vein textures observed at the River Reef Zone. Accordingly, the gold mineralization at the Hill Reef 1 and Hill Reef 2 Zones can be classified as a low-sulfidation epithermal deposit. In addition, the predominance of massive and lattice textures in the surface indicate that the veins analyzed in this study are from Chalcedonic Superzone and gold mineralization at the Hill Reef 1 and Hill Reef 2 Zones are well preserved.

Keywords
Epithermal, low-sulfidation, gold mineralization, vein textures

Topic
Mining and Metallurgy Engineering

Link: https://ifory.id/abstract/vmXqZ9TBHnPy