scholarly journals Productivity Analysis of Raisebore RB-50X for Raise Slot Drilling at Extraction level GBC PT. Freeport Indonesia

Author(s):  
R J Kakisina ◽  
Yudho Dwi Galih Cahyono

PT Freeport Indonesia is the largest gold and copper mine in Indonesia, located in Mimika Regency, Papua Province. In its operation, PT. Freeport Indonesia applies two mining systems, namely open pit mining and underground mining. Underground Mine at PT. Freeport Indonesia consists of DOZ, Big Gosan, DMLZ, Kucing Liar, and GBC, with one of the methods applied by PT. Freeport Indonesia is a block caving method. The Grasberg Block Cave mine has entered the production stage since September 2018, but in its operation the GBC Mine is still developing its operational area to meet production targets (development). The development cycle (cycle development), which is the main operation carried out, namely drilling and blasting, loading & transporting (mucking & hauling), primary support, and secondary support. To support the main operations, it is necessary to have main support consisting of access and area, ventilation, water and water, electricity, pull of tests, surveys, and dewatering. In the blasting process at the drawbell, one free face is needed which functions as the direction of rock collapsing in the blasting process on the drawbell. Making free face or commonly known as slot raise using a rasiebore machine from PT. Redpath for slot raise drilling. Meanwhile, in the drilling stage, the slot raise has a problem that has resulted in delays in the drilling process for the RB-50X raisebore tool. The impact of the delay in making the slot raise resulted in not achieving the production target due to a delay in the blasting process, where the blasting process in the drawbell area functions to break the rock so that it falls and can be transported to the crusher to enter the rock sizing process.

2016 ◽  
Vol 38 (3) ◽  
pp. 35-48 ◽  
Author(s):  
Phu Minh Vuong Nguyen ◽  
Zbigniew Niedbalski

Abstract The primary objective of the present paper is an attempt at evaluating the influence of sub-level caving operations on the slope stability of a still-functioning open pit coal mine in Vietnam. Initially, various methods of predicting the impact of underground mining on surface stability are discussed. Those theoretical considerations were later utilized in the process of constructing a Flac-2D-software-based numerical model for calculating the influence of underground operation on the deformation and possible loss of stability of an open pit slope. The numerical analysis proved that the values of open pit slope displacements were affected mainly by underground exploitation depth, direction of operation (i.e., from one slope to the other) and the distance from the slope plane. Real geomechanical strata parameters from the Vietnamese coal basin of Cam Pha were used in the modeling process. The paper is, therefore, a critical review of the hitherto proposed methods of predicting the impact of underground operation (UG) on open pit mining (OP), illustrated with selected examples of case studies on OP-UG interaction, followed by an original experiment based on numerical modeling method. This is first such study for the genuine conditions of the coal mining in Vietnam. The obtained results, however, should not be generalized due to a highly specific character of the analyzed phenomenon of mining-induced surface deformation. The practical implications of the study may occur extremely useful in the case of an UG-OP transition. Such a transition is often necessary for both technical and economical reasons, as in some coal basins open pit operations at greater depths occur unfeasible, which calls for a proper selection of parameters for a planned underground operation.


2016 ◽  
Vol 26 (6) ◽  
pp. 1065-1071 ◽  
Author(s):  
Eugene Ben-Awuah ◽  
Otto Richter ◽  
Tarrant Elkington ◽  
Yashar Pourrahimian

2014 ◽  
Vol 926-930 ◽  
pp. 593-596
Author(s):  
Fang Wang ◽  
Chong Shi ◽  
Kai Hua Chen ◽  
De Jie Li ◽  
Ke Han

The process of open-pit mining can lead to high slopes in iron mines, and natural slopes should be rebuilt by the method of roof fall as the exploitation style turns from open-pit mining to the underground mining. So the slope can be steep, deep and may has the characteristics of collapse. It is difficult to describe the stabilization of the mining slope by a conventional safety factor method. Through the numerical simulation of underground mining process, this paper analyzes the result of distortion stress and rock movement rupture range. Studies have shown that the failure mode is dominated by tensile failure as a pattern of collapse and few is dominated by shear failure. The failure zone is controlled by rock mass parameters and structures. The results can be helpful for the proposition of exploitation program and safety management design.


Kakosa South copper deposit is located about 450km northwest of Lusaka between Chingola and Chililabombwe. A comprehensive study of Kakosa South deposit was carried out. In Kakosa area the footwall aquifer rocks comprising sandstone and conglomerates which are thin and as such are not expected to represent major aquifers. Copper mineralisation is found in the upper quartzite and ore-shale. The inclination of the deposit ranges from 250 up to 350 . The hangingwall formations above the upper quartzite are represented by a sequence of dolomite and shale formations. Based on Kakosa geotechnical analysis and rock mass classification, fuzzy TOPSIS approach was employed for the selection of optimal extraction techniques. FTOPSIS approach has precise and specific quantities which are used in order to establish criteria and option weights. Triangular fuzzy numbers were determined to represent semantic variables. The fuzzy numbers for Kakosa South parameters were used as input data in the decision making model and matched against the criteria required for the mining method. Applying FDM model, extraction techniques were ranked. The results indicated that open pit extraction technique was ranked first with 78.90 scores followed by sublevel stoping with 66.88 scores. It is concluded that the Kakosa South copper ore deposit can optimally be extracted by open pit mining up to transition depth and transit from open pit mining to underground mining employing sublevel stoping.


2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Rongxing He ◽  
Jing Zhang ◽  
Yang Liu ◽  
Delin Song ◽  
Fengyu Ren

Continuous mining of metal deposits leads the overlying strata to move, deform, and collapse, which is particularly obvious when open-pit mining and underground mining are adjacent. Once the mining depth of the adjacent open-pit lags severely behind the underground, the ultimate underground mining depth needs to be studied before the surface deformation extends to the open-pit mining area. The numerical simulation and the mechanical model are applied to research the ultimate underground mining depth of the southeast mining area in the Gongchangling Iron mine. In the numerical simulation, the effect of granular rock is considered and the granular rock in the collapse pit is simplified as the degraded rock mass. The ultimate underground mining depth can be obtained by the values of the indicators of surface movement and deformation. In the mechanical model, the modified mechanical model for the progressive hanging wall caving is established based on Hoke’s conclusion, which considers the lateral pressure of the granular rock. Using the limiting equilibrium analysis, the relationship of the ultimate underground mining depth and the range of surface caving can be derived. The results show that the ultimate underground mining depth obtained by the numerical simulation is greater than the theoretical calculation of the modified mechanical model. The reason for this difference may be related to the assumption of the granular rock in the numerical simulation, which increases the resistance of granular rock to the deformation of rock mass. Therefore, the ultimate underground mining depth obtained by the theoretical calculation is suggested. Meanwhile, the surface displacement monitoring is implemented to verify the reasonability of the ultimate underground mining depth. Monitoring results show that the indicators of surface deformation are below the critical value of dangerous movement when the underground is mined to the ultimate mining depth. The practice proves that the determination of the ultimate underground mining depth in this work can ensure the safety of the open-pit and underground synergetic mining.


2021 ◽  
Vol 315 ◽  
pp. 01006
Author(s):  
Tatiana Tyuleneva ◽  
Roman Shishkov ◽  
Elena Kucherova ◽  
Marat Moldazhanov

In recent years, there has been a decline in the efficiency of coal mining by traditional methods. On the one hand, the volume of coal outside the contour of the cut, which is economically impractical for open-pit mining, is increasing. On the other hand, when using underground geotechnology, the cost of production exceeds the cost of performing mining operations using open geotechnology, this is due to differences in the factors of operation of the open pit and the mine. This circumstance determines the use of open-underground technology for mining coal reserves outside the contour of the open pit as an actual and promising direction. This article describes a methodological approach based on the use of technological schemes for the preparation and treatment of reserves of powerful shallow coal seams, the justification of the parameters of combined geotechnology with a coordinated and balanced development of open and open-underground mining operations with the distribution of reserves for open and open-underground mining of coal reserves beyond the limit contour of the open pit, the preparation of excavation sites directly from its workings and the coordination of production capacity and the speed of their development. Its application will increase the production capacity of the coal mining complex without additional environmental burden and will provide an increased return on investment.


2021 ◽  
pp. 43-47
Author(s):  
K. Sanakulov ◽  
N. P. Snitka

The international geological community has acknowledged Muruntau gold deposit as the greatest discovery in the mid-to-late 20th century. Muruntau mine field holds the total appraised resource potential of more than 4.5 thousand tons of gold. Hydrometallurgical plant GMZ-3 implements gold-ore processing by gravitational sedimentation and adsorption. The technological and instrumental modernization of the gold processing circuit toward its higher capacity, gold recovery and thoroughness are the important aspects of production improvement and cost reduction. The developed and introduced ore milling flowchart provides replacement of the second milling stage pumps by higher-capacity pumps backed up with additional cyclones. Aiming to ensure stable gold production at plants GMZ-2 and GMZ-3, Navoi MMC’s experts accomplished the feasibility study of mining operations in Chukurkuduk and Turbai deposits in 2020. The growth prospects for open pit mining in Murunatu–Myutenbai fields after 2060 are estimated using the model of optimized ultimate pit limit design at the gold price of USD 1500/t. The model ultimate pit limit embraces all probable reserves as per the detailed 2D seismic data as of early 2020, including proven reserves intended for open pit and underground mining. The gold ore appraisal and the expansion program elaborated for Muruntau gold mining and refining integrated works in joint Muruntau–Myutenbai field, through implementation of operation phases V and further make it possible to forecast stable performance up to 2030–2050.


Mining Revue ◽  
2021 ◽  
Vol 27 (2) ◽  
pp. 59-75
Author(s):  
Crina-Adriana Gurică ◽  
Mircea Georgescu

Abstract In this article an impact assessment is carried out, generated by activities in the energy sector related to Rovinari mining area. Energy-related activities in this area are carried out by open pit mining activities in the context of Tismana, Roșia, Pinoasa, Peşteana and Rovinari locations and Rovinari thermal power plant. Some information that has formed the input for the author’s approach has been provided by SC. Complexul Energetic Oltenia SA (CEO) and S.C. Institute of Scientific Research, Technological Engineering and Mine Designs on Lignite S.A. Craiova (ICSITPML) which has been processed, analysed and used for the presented environmental impact assessment. Two methods from specialized studies have been used for the impact assessment, namely: the Matrix Method for Rapid Impact Assessment (MERI) and the Method for Integrated Quantitative Impact and Risk Assessment of Environmental Pollution (EIRM). Based on the analysis carried out, it can be concluded that the activity in this sector does not lead to significant negative effects strictly associated with it.


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