scholarly journals Safety Analysis of Synergetic Operation of Backfilling the Open Pit Using Tailings and Excavating the Ore Deposit Underground

Minerals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 818
Author(s):  
Qinli Zhang ◽  
Bingyi Zhang ◽  
Qiusong Chen ◽  
Daolin Wang ◽  
Xiang Gao

The transition from open pit mining to underground mining is essential for mineral resources to achieve deep excavation. Recently, cemented paste backfill (CPB) has been proposed as a novel technology to achieve open pit backfill (OPB). The proposed method not only eliminates the danger of the open-pit slope but also reduces the disposal of waste tailings. In order to ensure safe mining during the synergetic operation of OPB and underground mining, it is of great significance to improve this technology. In the present study, an open-pit metal mine in Anhui Province was taken as the research object. Then, the safety of underground stope roofs, underground backfill pillars, and open-pit slopes was evaluated during OPB. To this end, numerical simulations were performed and experiments were conducted on a similar physical model. Accordingly, the backfill mechanical parameters were optimized. The obtained results show that backfill height exerts the most significant effect on the safety of roofs and underground backfill pillars, accompanied by small displacements along the vertical direction during the backfill process. Moreover, concentration was observed at the foot of the slope, while the overall structure remained stable with no considerable displacement. The overall safety factors met the safety requirements. Based on the obtained results, the optimal foundation strength, foundation height, backfill strength and backfill height were 4 MPa, 10 m, 1.5 MPa, and 120 m, respectively. Moreover, it was concluded that displacements in the abovementioned three regions tend to be stable when the backfill height exceeds 150 m without damage. The present article provides a certain theoretical and application guideline for OPB practices in similar metal mines and suggests possibilities for cleaner production.

2021 ◽  
Vol 6 (2) ◽  
pp. 114-120
Author(s):  
J. J. Z. Caixao

At present time,Mozambiqueis called the “Rising Star of South Africa” mainly due to the rapid development of its mining industry. Mineral resources sector ofMozambiqueis one of the most dynamically developing sectors of the country’s economy.China,BrazilandIndiahave recently become the main partners forMozambique. Recently, a number of projects is being implemented in the country, for example, Auroch Minerals Manica Gold in gold production. Increasing coal production is connected with commissioning of the Moatize open pit, which is being developed by Brazilian Vale Company, as well as Benga mining company owned by Indian ICVL consortium. The analysis of the extraction of certain mineral types inMozambiquepresented in the paper demonstrates general picture of mining industry development in the country. The analysis findings allow identifying the causes of negative phenomena in the industry, manifesting themselves in decreasing production of certain types of minerals. For instance, the main reasons for the decline in coal production were dropping labor productivity, deterioration of mining conditions, and depletion of the most accessible coal reserves, extractable by open pit mining. In this regard, development of underground mining methods providing for opening of deep deposits by vertical shaft sets is highly relevant. The experience of the neighboringRepublicofSouth Africashows that, in the mining and geological conditions of the south of the African continent, highspeed shaft sinking methods accelerating deposit development can be successfully applied.


2019 ◽  
Vol 105 ◽  
pp. 02006
Author(s):  
Tatiana Gvozdkova ◽  
Pawel Stefanek ◽  
Michaela Koščová

Ecological problems in the open pit mining of coal deposits are extremely hard, since mining operations are accompanied by disturbed land to a large depth with significant changes in the landscape, hydrometeorological conditions, mixing of rocks and removal of infertile or even harmful rocks with radioactive isotopes to the surface. Disturbed lands are unusable if they are not repaired. All man-made disturbances of the environment caused by open pit mining are divided into landscape (changes in terrain, vegetation and soil cover) and environmental (violation of living conditions within the allotment and adjacent lands: changes in water regime, pollution of the soil, air and water basins) onesOne of the most important areas in the field of environmental protection is the reclamation (restoration) of the earth’s surface. In accordance with the requirements of the protection of the subsoil, enterprises engaged in the development of mineral deposits are obliged at their own expense to bring disturbed lands into a state suitable form for their further use. Reclamation of ought to be carried out during open pit mining operations and must be completed after mining of mineral resources in the terms established by the authorities that provide land for use.


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

Significance On the agenda is the issue of legislation on open-pit mining and the stopping of the export of unprocessed ores. This follows Cimatu’s confirmation in post by the Commission on Appointments on October 4. Previously acting secretary, Cimatu replaced the controversial Regina Lopez, who was not confirmed as environment secretary earlier this year. The Philippine mining industry was wary of Lopez’s pro-environment, anti-mining policies, and now wants to see what Cimatu’s plans are. Impacts Under Cimatu, mining firms could gain more opportunities to engage with policymakers. Environmental and anti-mining groups will see Cimatu’s appointment as a betrayal; protests are possible at mining projects. Peace in Mindanao would unlock an estimated 1 trillion dollars in untapped mineral resources.


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.


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