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By DeVerle P. Harris

The structure of an exploration model reflects a number of design considerations, one of which is the question or issue-to be investigated by the model. Thus, a model designed to evaluate the magnitude of risk and its economic implication to optimal decision making at each decision juncture of a multistage exploration architecture differs considerably from one designed to evaluate, say, the long run average cost of discovery, in which the architecture of exploration is suppressed and risk is simply an element of average cost. The perspective of the model examined in this paper is that exploration is investment in (purchase of) information and that the next stage of an exploration program is undertaken only when the expected value of information to be acquired in that stage exceeds its cost. The degree to which this perspective is honored influences considerably model design. Consider two design objectives:

Jan 1, 1989

By Kadri Dagdelen

Production scheduling of an open pit mine is one of the most important steps in open pit mine planning. The production schedule of a mine defines the distribution of cash flows and as a result directly influences the net present value and overall economic feasibility of a project. It is becoming more and more critical to obtain an exploitation schedule of a deposit such that highest possible returns are achieved from a project. As the mining industry mines lower and lower grade ores, production scheduling is becoming a key item which can make or break a project. Although the need to plan and operate a mine with an optimum production schedule has been obvious for some time, the methods used to obtain such a schedule have not been. There is not a single, mathematically proven, optimum mine production scheduling algorithm which is widely accepted and used today. In an attempt to determine a production schedule which is optimum, a new algorithm was developed. This algorithm, in theory, is based on the lagrangian concepts of mathematics and in practice is based on the parameterization concept of mining. This paper describes the fundamentals of this newly developed algorithm.

Jan 1, 1986

By John N. Murphy

In fiscal 1996, the US Congress directed that the US Bureau of Mines (USBM) be closed. Certain functions were reassigned to other agencies. The remaining employees were separated and the unoccupied sites were decommissioned. As a result, 12 locations were closed and about 1,200 employees were terminated in March 1996. About 600 employees at five locations were reassigned to other federal agencies. This article provides a summary of the continuing functions, the agencies involved and the points of contact for each continuing function. The functions that were discontinued are also identified. The functions that have been maintained and transferred to other agencies are: ? Portions of USBM's Mineral Information and Analysis program formerly conducted in Washington, DC and Denver, CO were assigned to the US Geological Survey (USGS). ? The Mineral Land Assessment program in Alaska (Anchorage and Juneau) was transferred to the US Bureau of Land Management (BLM). ? The Health and Safety Research program in Pittsburgh, PA and Spokane, WA was reassigned on an interim basis to the US Department of Energy (DOE). In fiscal year 1997, it was permanently assigned to the National Institute for Occupational Safety and Health (NIOSH). NIOSH is part of the Centers for Disease Control and Prevention within the US Department of Health and Human Services. ? Environmental Research at Pittsburgh, PA was assigned to DOE. ? Materials Research at Albany, OR was assigned to DOE. ? The helium program was assigned to BLM, where it will be managed pending privatization. ? Coal and noncoal mine maps were transferred to the Office of Surface Mining Reclamation and Enforcement (OSMRE). The following locations were closed: ? Research centers in Denver, CO; Minneapolis, MN; Reno, NV; Rolla, MO; Salt Lake City, UT and Tuscaloosa, AL. ? Field operations centers in Denver, CO and Spokane, WA. ? Washington, DC headquarters office. To provide a concise picture of all of the affected functions, the following is a synopsis of the USBM program functions and facilities immediately before the closure. There were two principal programs: information and analysis, and research.

Jan 1, 1997

By Qiong Wu, Qinghua Gu, Yichuan Lv, Jin Yuan, Caiwu Lu

"The cut-off grade is one of the important parameters of mining production. Different material cut-off grade is directed to different destinations. Based on reasonable and optimal cut-off grade, long term mining plan and investment decision analysis can be made for mining managers. In view of multiple-metals open-pit, the paper has proposed that multiple-metals cut-off grade optimization model is set using the objective function to maximize net present value (NPV). The method of equivalent coefficient calculation is proposed to convert multi-metals cut-off grade optimization to a single metal cut-off grade optimization. Then the optimization model is applied in a molybdenum and tungsten large open-pit mine in china. The parameters of concentrate price are calculated by PRT in the model and the curve of grade-recovery rate is analyzed and studied according to actual production data. Based on 3D metal deposit model, the distribution of grade-tonnage is analyzed. At final step, an optimal cut-off grade is proposed to guarantee to maximize NPV. The example shows that the model of multiple-metals cut-off grade optimization can provide reasonable analysis for optimal multi-metals cut-off grade and develop optimal production strategies. Introduction Cut-off grade is one of the most important parameters in metal ore mining because of its influence on the overall economic profit of mining production. Along with the development of the mining production, dynamic optimization of cut-off grade is necessary through the analysis of technical economy. It is better to manage the mining production according to the variation of market. The cut-off grade plays an important role in mining production."

Jan 1, 2017

The first of this two part series takes a look at some of the history and types of flotation as well as agents and mechanisms involved in it. Part two, next month, will examine flotation processes as applied to various sulfide and nonsulfide mineral ores. Flotation-"froth" flotation-is a physicochemical method of concentrating finely ground ores. The process involves chemical treatment of an ore pulp to create conditions favorable for the attachment of predetermined mineral particles to air bubbles. The air bubbles carry the selected minerals to the surface of the pulp, there forming a stabilized froth that is skimmed off and from which the predetermined mineral particles are recovered. Other minerals remain submerged in the pulp.

Jan 3, 1982

By Michael Karmis, Emily A. Sarver, Ellen S. Gilliland, Leigh-Anne H. Krometis

"Public engagement is increasingly important in ensuring the success of projects related to energy development, particularly with regard to issues of environmental protection, public health, and socio-economic impacts. This is due to concurrent trends in public behavior, including a rise in public interest in these projects that is not matched by a rise in science literacy, and increasing organization and participation of the public through social media, citizen science, and grassroots initiatives. In recent years, several high-profile incidents have demonstrated that when public concern is ignored or met with a passive response from industry, it can rapidly grow into organized opposition that negatively impacts or wholly derails a project. Engaging, listening to, and educating stakeholders during early planning and development phases are therefore essential to earning credibility and trust. Moreover, maintaining two-way lines of communication throughout the lifespan of a project demonstrates social responsibility and facilitates cooperation, acceptance, and even support from communities and others. Positive experiences with specific projects at a local, community level can influence the larger public opinion of an entire industry sector. This paper presents cases studies of public engagement related to shale gas development (including hydraulic fracturing and pipeline construction), mountaintop removal mining, and management of mixed-use watersheds near surface mining operations. The experiences highlighted in these case studies are used to draw best practices of public engagement for sustainable energy development.Introduction Within the scientific research community, the importance of public engagement has gained increasing recognition. In a 2007 article in Nature, medical researcher, Patrick Taylor, stated that public engagement has both “gone viral” and “gone global” and has the ability to make real impacts to research (Taylor 2007). Nancy Baron, the science outreach director for COMPASS, an organization providing communications training for scientists, provides further evidence for the increasing focus on engagement, including shifting attitudes observed during her own experience as a communications coach and documented in surveys, the recent inclusion of communication and engagement activities in academic tenure review, and the surge of workshops, materials, and other resources available on the subject (Baron 2016). In addition to COMPASS, a number of organizations and institutes have been developed to train scientists for communication and engagement with the public, perhaps most notably the Alan Alda Center for Communicating Science at Stony Brook University, and academic fellowship programs, such as the Leopold Leadership Program at Stanford University and the Wilburforce Fellowship Program, have been established for the same purpose."

Jan 1, 2017

By Daryl L. Gusey, John T. Neubert, Matthew A. Sares

The Colorado Geological Survey completed an inventory of environmental degradation associated with abandoned and inactive mines on National Forest System lands in Colorado. In the course of the inventory, areas with naturally occurring acid rock drainage were also noted. Approximately 18,000 abandoned mine- related features were inventoried, including about 900 features that are considered significant enough environmental problems to warrant further investigation. Water quality data, such as pH and conductivity were gathered at all features where water was present, such as draining adits, seepage at the toe of dumps and tailings, and standing water in shafts. Samples were taken where field tests indicated low pH andlor high conductivity, including several areas with naturally occurring acid rock drainage. Samples were analyzed for dissolved and total metals, and for selected anions. All mine locations and data collected by the field geologists were entered on field forms and, subsequently, into a computer database and GIS format. With the information provided by the inventory, the Forest Service, in cooperation with other agencies, has been able to prioritize abandoned mines for reclamation. In most cases, cleanup is approached on a watershed basis. Mines in priority watersheds have been selected for reclamation first. Watersheds where studies prerequisite to cleanup are occurring include the upper Anirnas River, Willow Creek (tributary to the upper Rio Grande), Chalk Creek (tributary to the upper Arkansas River), the Uncompahgre River, and the Alamosa River. During the inventory, evidence of naturally occurring water quality degradation was found in areas where little or no evidence of mining activity exists. These areas include the upper Alamosa River, the Middle Fork of Mineral Creek, Peekaboo Gulch, and Handcart Gulch. Water from these natural sources has been found to significantly exceed Colorado water quality standards for several metals.

Jan 1, 2000

By Reinhard Gnilsen

Ground pillar control in soil and weak rock often represents a critical and sometimes a determining factor for mined underground civil structures. A concept is desirable that minimizes the restrictions possibly imposed by pillar control requirements on geometrical tunnel characteristics and on the mining operation itself. Conventional concepts are discussed and an alternative concept is introduced. This concept reduces pillar control requirements to ground control measures required with "regular" tunnels. The conventional model of pillar mechanics with potential yielding of a ground body in more than one direction, is then avoided. Due to the complexity of pillar mechanics, the level of engineered design furnished to the contractor is crucial to optimizing ground pillar control. Conventional versus alternative contractual arrangements for pillar control are described and their important role is illustrated. The concept introduced relates to principles inherent to the New Austrian Tunneling Method (NATM). However, tunnel projects using other mining concepts can employ alternative ground pillar control principles as well, if certain criteria are observed. Case histories in the United States and abroad are presented and the impacts from different concepts of ground pillar control are illustrated. The paper concludes by analyzing concept characteristics that can infer monetary impacts on both the owner and the contractor.

Jan 1, 1987

By Jean-Claude Bianchini, Paul Bauernfeind, Erwin Gartung

Introduction The city of Nuremberg, located in Bavaria in the Federal Republic of Germany, started building a subway in 1967. The construction operations began in a southern suburb, where no complications were encountered in the design and execution of the job. As the first subway line approached the downtown area of the city, the civil engineering challenges increased rapidly. Tunnels had to be excavated next to, or below precious historical buildings, and the work of the responsible engineers was closely watched by the public, who were very anxious about any damage to the existing beautiful old houses and churches. The job has been handled successfully to date in cooperation with the owner-designer, the geotechnical consultant and the contractors, who jointly went through a process of systematic learning and gathering of experience, and who developed a modern tunneling technique specifically tailored to the natural properties of the encountered ground conditions and the requirements of the city of Nuremberg. The application of scientific methods has been an important part of this development. Research into the geotechnical properties of the predominantly encountered soft Keuper sandstone, studies of the geomechanical performance of grout reinforced sand sections and finite element analyses of various tunnel problems for the prediction of displacements, for the assessment of stability, or

Jan 1, 1979

By Gerrit V. R. Goodman, Charles D. Taylor

A technique was developed to determine the fraction of air recirculated from the scrubber exhaust toward the face and the fraction of gas captured by the scrubber. To determine these two values, a series of tests was required. In the first test, gas was released at the face area and concentrations measured at the scrubber exhaust. In the second test, gas was released directly into the scrubber with concentrations again measured in the scrubber exhaust. The simultaneous solution of two independent flow expressions gave values of recirculation and scrubber capture. A series of tests was conducted with various combinations of scrubber flow, curtain flow, setback distance, and machine location. Statistical analyses then were conducted to determine those factors which influenced the levels of scrubber recirculation and scrubber capture in a deep cut. INTRODUCTION As cutting depths increase, the trend is toward the use of blowing face ventilation systems. With these ventilation systems, the potential exists for recirculation between the scrubber exhaust and the intake air stream. One concern is that methane gas, having been removed from the face area, is subsequently recirculated back into the intake airflow. Under these conditions, methane-laden air could be substituted for fresh intake air, leading to increased methane concentrations at the face. There is currently no standard for recirculation between the scrubber and intake airflows. The implied understanding of the Mine Safety and Health Administration (MSHA) is, and has always been, that any recirculation of ventilation air is unacceptable. To minimize recirculation potential, MSHA suggests that operators maintain scrubber and curtain flows within 0.47 m3/sec (1000 cfm) of each other. Given that recirculation may occur in some circumstances, the question arises as to how much recirculation constitutes a hazard for the face workers. Unfortunately, there is currently insufficient information to answer this. Emphasis must instead be placed on means to quantify the amount of recirculation between the scrubber and face area. Methods must also be examined to control this phenomenon. This paper presents a technique for quantifying recirculation and scrubber capture levels in a blowing face ventilation system. Several ventilation parameters are investigated to determine their effects on these levels. DEVELOPMENT OF RECIRCULATION EXPRESSIONS One way to measure airflow quantities at a point near the face would be to measure the gas flow rate Qgas, and gas concentration c at that location. The airflow Qair, would be simply the ratio of these two values, Qair, = Qgas/c. Although gas concentration values, c, can be obtained easily with existing gas monitoring equipment, it is more difficult to obtain gas flow readings, Qgas, at specific locations. To obtain these values of Qgas, another method was needed. Previous work in this area was conducted by Kissell and Bielicki (1975). However, the calculations in their model assumed a constant gas concentration in the region around the continuous miner. In a deep cut, it is questionable that gas concentrations would remain constant or uniform around the mining machine. The technique presented here does not rely on this assumption. It instead assumes that the gas concentration in the scrubber exhaust remains constant. A quantity of gas released at the cutting face either flows into the scrubber inlets or bypasses the inlets and flows around the off-curtain side (in this example, the right side) of the continuous miner (Figure 1). The fraction of the face gas that flows

Jan 1, 1993

By T. McCallum, B. Wellbrook, T. Ratnaweera

"Pressure oxidation (POX) leaching of copper (Cu) concentrates continues to be explored as the next generation of leaching processes to sustain existing Cu Solvent Extraction/Electrowinning (SX/EW) operations as easily leachable ores become scarcer. The leach liquors produced, particularly from total pressure oxidation, contain elevated concentrations of Cu and acid, making solvent extraction processing more challenging. Addressing this challenge will require innovative processing techniques and continuous improvement to be successful in achieving satisfactory physical and metallurgical performance in the SX plant. The ability to efficiently process these feeds via SX plays an important role in the continued success of POX technology. Characteristics of a concentrate leach pregnant leach solution (PLS) are discussed, along with best practices that should be considered for processing by SX. Findings discussed in this paper will shed light on ways to reduce process risk and bring additional improvement to the industry with minimal change to the SX plant. INTRODUCTION Hydrometallurgical processing of copper concentrates continues to gain interest from the industry. Treatment by smelting and electro refining continues to dominate, accounting for ~80% of global copper production, but is faced with its own challenges. The case for increased hydrometallurgical processing has been discussed as high grade ore deposits are diminishing, capital costs for smelting are high, and the environmental aspects present challenges for sustainable practice. The hydromet copper industry is also turning a corner as easily leachable copper oxide deposits are depleting, and excess SX-EW capacity exists in certain regions. The transition to hydrometallurgical processing of copper concentrates will take a bit of effort as leaching of copper sulfides is difficult and byproduct credits must be considered. Various POX leaching processes have been studied and proposed to the industry as viable practices. Of the many processes, commercial use has been practiced with the Mount Gordon Copper Process, total and partial pressure oxidation by Freeport-McMoRan at their Bagdad and Morenci, Arizona complexes, the Sepon Copper Process in Laos, and the bioleach BIOCOP™ process in Chile. The experience related to the current paper centers around Cu concentrate leaching performed by Freeport McMoRan (known as CLP). The patented process was developed as an alternative to smelting and refining in 1998. The technology applies to both molybdenum and copper concentrates. Commercial CLP research and development began with Phelps Dodge in 1999 to 2001. The first commercial plant was commissioned in 2003 at the Bagdad operation. Initial operating conditions of the Bagdad CLP were under high temperature conditions before converting in 2005 to medium temperature conditions. In 2007-2009, the CLP technology was commissioned in Morenci, operating medium temperature and high temperature lite conditions until shutting down due to the economic downturn. The Morenci CLP restarted operation in April 2015 due to acid production benefits for the Morenci leach operations. Renewed solvent extraction test work initiated well before restart and has been an ongoing focus for further SX plant optimization."

Jan 1, 2018

By W. A. Crosby, A. Bauer

The recent increase in size of open-pit mining operations has resulted in major improvements in efficiency that are beneficial to the mining industry. Higher bench heights, larger diameter blast-holes, and more powerful explosives have played an important part in reducing mining costs. These measures have, however, resulted in increased energy concentrations in the blast area, which can result in severe backbreak problems for final pit walls. If backbreak is not controlled, a decrease in the overall pit slope angle will ultimately be necessary, and consequences, such as decreased recoverable ore reserves and increased waste-to-ore ratios, will result. Greater amounts of loose face rock will be produced, and planned safety berms will be less effective or nonexistent. Hazardous working conditions can also result. Remedial measures, such as scaling large areas and using wire mesh or other artificial support, are very expensive and difficult to implement. There must be a trade-off between the money saved by using larger blasts, and the time spent to maintain pit wall quality. The best approach is to control blasting effects so the inherent strength of pit walls is not destroyed. Presplit and trim blasting are two control blasting techniques used to accomplish this. Both techniques are designed to create a low explosive energy concentration per unit of wall area at the perimeter of the pit. Energy concentration of the main production blast must also be controlled to avoid damaging the final pit wall. A low-energy concentration at the final wall can be obtained by decoupling charges, decking charges, using less powerful explosives, decreasing blasthole diameters, and changing the burden and spacing. Rock properties-fragmentation and the final state of the pit wall-influence the success of a blast. The most important properties to consider are: in situ rock strength, and the nature, frequency, and orientation of structural features. Since these variables cannot be controlled, they must be evaluated by suitable field tests, and then a control blast can be designed using controllable variables, such as spacing, burden, and hole diameter, so the blast will be successful for appropriate rock conditions. One main thrust of this article is to show how control blasts can be successfully designed for larger hole sizes, up to 381-mm-diam. While efforts to produce a good control blast in shovel/truck pits have been ongoing for some time, recent use of a modified presplit technique in dragline operations has helped reduce water problems, improve safety, and increase dragline productivity in a number of surface coal mines. This article presents examples on designing and using presplit and trim blasting for large hole operations in both shovel/truck and dragline mines. Presplit Blasting As introduction to presplit blasting, Fig. 1 illustrates a typical presplit blast layout using 102 mm-diam presplit holes for 381¬mm-diam production holes. For this type of blast, presplit holes would normally be drilled first, ahead of main production holes. The choice can then be made between loading and firing the presplit line or infilling the main blast. In the latter case, the presplit line would be fired instantaneously 100-150 milliseconds before the main blast. As shown in the figure, the presplit line is formed ahead of the main

Jan 2, 1982

By Edward S. Plotkin, Joseph D. Guertin

In a continuing effort to upgrade tunnel design and construction practice, the New York City Transit Authority sponsored a geotechnical monitoring program on a recently completed section of the E. 63rd Street line in mid-town Manhattan. The purpose of the program was to document rock behavior as well as temporary and final rock support systems to provide a possible basis for either confirmation or modificification to design methods and construction specifications. This paper describes those portions of the study associated with rock behavior and temporary support systems. The entire study included monitoring of rock movements above the tunnel as well as adjacent to a 36.6m (120 ft) shaft, monitoring of stresses in steel ribs, monitoring of loads in rock bolts in two test sections and monitoring of stresses in the final concrete lining. PROJECT DESCRIPTION Route 131-A, Section 4 is located in mid-town Manhattan extending from under the Central-Park Zoo on Fifth Avenue eastward under 63rd Street to the end of contract between Madison and Park Avenue. Figure 1 is a Project Locus Map. The contract included approximately 355m (1165 l.f.) of 4 track tunnel(13.4m (44 ft) wide by 13.7m (45 ft) high excavated dimensions) plus a 22.9m (75 ft) by 19.8m (65 ft) by 36.6m (120 ft) deep ventilation shaft. The entire tunnel and most of the excavation shaft was excavated in metamorphic rock, known locally as the Manhattan Schist. The depth to tunnel invert varied from approximately 27.4m (90 ft) at the west end of the contract to 35.Om (115 ft) at the east end. Rock cover above the excavated crown varied from approximately 6.7m (22 ft) at the approximate mid-point of the contract to 18.9m (62 ft) at the western end. A plan view and interpreted geologic profile are illus-

Jan 1, 1979

By Robert S. Hendricks

The paper describes the design and operation of a Shaft Boring Machine (SBM). The machine has been developed by The Robbins Company. It is anticipated that the prototype, which will bore shafts in the 6.1 to 7.3 m (20 to 24 ft) size range, will be placed in operation during 1985. This pioneering application of rapid excavation technology is expected to lead to significant improvements in the cost and speed of shaft construction. The technical and economic factors which have limited the employment of Shaft Drilling and which caused unsatisfactory results with earlier attempts at Shaft Boring are reviewed. The design criteria adapted to overcome these problems are discussed. Cost and performance estimates are presented and are compared to conventional sinking methods. Factors that influence the application of the SBM to specific projects are reviewed.

Jan 1, 1985

Design models for belt conveyors used in mines predict both the belt power requirements and belt tensions. Conveyors with slightly downhill profiles are more complex to predict due to the way that models such as CEMA interpret friction. Performance of a particular conveyor in relation to other conveyors in the same system requires an analysis of natural stopping times, braked times and take-up location. A review of CEMA-based PC models is presented for design of underground multi-flight belt systems.

Jan 1, 1995

By D. J. Dunn

Grinding balls, simple in shape, are actually sophisticated machine components, and essential elements of mineral grinding mills. Their physical properties and quality must be adequate to achieve design life and grinding mission with few failures. Consistant properties and freedom from breakage are essential. Size, mass, hardness profile, chemistry, and microstructure are important variables which should be designed, specified, controlled, and verified to achieve optimal mill performance. Failure to specify ball properties in detail or failure to obtain required ball properties and quality can cause milling productivity losses and excessive costs that could endanger a milling operations survival in the competive mineral industry.

Jan 1, 1989

By E. D. Goddard, D. S. Murphy

Acid resistance, zeta potential and ESCA (electron spectroscopy. for chemical analysis) experiments were performed on emperador marble and four calcium carbonate samples (onyx calcite, travertine calcite, Iceland spar calcite and aragonite). Six fluorine-containing reagents were used to treat the surfaces of these materials: magnesium hexafluorosilicate, zinc hexafluorosilicate, sodium fluoride, zinc fluoride, strontium fluoride and stannous fluoride. The acid resistance of treated samples proved to be much higher than that of their untreated equivalents. The isoelectric point of treated samples approaches the isoelectric point of fluorite. Also, the fluorine content, as measured by ESCA, of a marble surface treated with magnesium hexafluorosilicate is much higher than that of an untreated sample. The binding energy off of fluorine and calcium the treated marble is consistent with the formation of calcium fluoride.

Jan 1, 1994

By Fred A. Breu, Jerome C. Neyer, James F. Peters, John W. Critchfield

This paper describes experiences with methane and hydrogen sulfide gas encountered during design and construction of a sewer tunnel in rock, in Rochester, N.Y. Design explorations are summarized, including geologic setting, measurements of gasses in test borings, laboratory analyses of gas samples, and measurements of gas pressure and flow rates from a sealed borehole. Contract specifications regarding gas are outlined. Results of the Contractor's additional explorations and testing are presented, along with a description of selected equipment and provisions for ventilation and degassification.

Jan 1, 1985

By Rimas Pakalnis, Lyndon Clark, Tom Brady

A major focus of ground control research presently being conducted by the Spokane Research Laboratory of the National Institute for Occupational Safety and Health (NIOSH) is to incorporate data on weak rock masses into existing design relationships, with an emphasis on updating the span design curve for manned entries and the overbreak curve for longhole entries. Both curves were originally developed at the University of British Columbia, Vancouver, BC. The original database has been augmented by information from mines throughout the United States, Canada, Australia, and Europe. The common factor in all these mines is the presence of a weak back and/or walls. In most cases, the ore zone is the weakest rock unit and must be stabilized so that the mineral-bearing rock can be extracted safety. The current NIOSH research attempts to provide rock mechanics tools to assist a mine operator in making economic decisions that will also ensure a safe working environment. This paper documents the Nevada database with a special emphasis on Nevada underground gold mines.

Jan 1, 2005

By Jiachen Wang, Nan Wang, Yang Li

The energy structure and consumption ratio in China determine the practical demand for the collaborative mining of coal and co-associated resources. The multi-layer mining of coal, uranium, coalbed methane, and oil and gas co-associated resources, represented by the Ordos Basin, Junggar Basin, and Tarim Basin, faces numerous challenges. Additionally, coal has been found to coexist with various mineral resources in 33 coal-bearing basins worldwide. The scientific issues related to the multi-layer development of coal related co-associated resources urgently need to be addressed. This paper discusses the unique challenges and potential solutions in the multi-layer development of coal-related co-associated resources. The challenges include large extraction space, high mining intensity, intense overburden movement, rapid surface subsidence, and severe overburden damage due to repeated mining disturbances. Proposed solutions include the establishment of a correlation mechanism between multi-layer mining and the carrying capacity of the overburden environment, analysis of the impact characteristics of multiple field couplings, and exploration of their superposition evolution laws. The paper also proposes the development of a comprehensive evaluation and prediction system for overburden environmental capacity loss, a global sensitivity analysis model for overburden environmental capacity, and an intelligent identification and early warning system based on multi-source information fusion. These solutions aim to achieve scientific and precise mining with minimal overburden environmental capacity loss. And the multi-layer development of coal-related co-associated resources is a complex task that requires a multidisciplinary approach and innovative solutions, and further research is needed to validate these strategies and explore new methods and technologies for efficient and sustainable extraction.

Jun 25, 2024