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By G. T. Lineberry

A systematic, comprehensive, balanced approach is presented for underground coal mine design, capable of being standardized and generalized. This approach epitomizes professionalism and must preceed the physical product. Design involves a varied senior staff and requires extensive selective input data. Engineering follows a total systems approach, operating in and for a constricting geologic setting, heavily constrained for safety, health, and environmental protection. It must also anticipate execution and operation. Engineering prominence and momentum are maintained, with sub-optimizations balanced by judgments--the "art and science" of engineering. The flow-chart starts with organized input data: Company Capabilities, Property Description, Geologic Analysis and Reserve Analysis. Engineering combines Ground Control with Excavating and Bulk Handling to map feasible Mining Methods, the crucial Milestone Diagram. Layout and Sequencing follow, with numerous alternatives examined. Scheduling is performed on the best designs, using predicted advance (performance) rates. Active and mined-out areas are isolated into time-related parcels, or increments, for the mine life. Bulk Handling, Life Support (especially ventilation and drainage), and Normal Support systems occupy each parcel. Regulations are then checked. Management concerns are covered, and an Economic Analysis is performed for profitability. This and the design represent an Initial Tentative Solution. Continued iterations produce multiple and improved choices.

Jan 1, 1987

By A. W. Khair

This paper deals with the causes and mechanisms of pillar failure in a southern West Virginia coal mine. The conclusions are based on in-mine observations and analysis of mining methods, eyewitness account of the sequence of events, topographic and geologic conditions, and mechanical properties of mine roof, coal, and floor. The study indicated that massive pillar failure was caused by the collapse of the mine roof. The collapse of the mine roof was due to the combined effects of high lateral compressive stress and high extraction ratio causing excessive bending of the roof beyond its limit. It was assumed that the higher lateral compressive stress under such a shallow cover was probably due to the drastic change in the structural geology of the area and possible residual stresses. Eased on the analytical study it was concluded that the sudden release of elastic energy (shock) due to the rupture of the roof caused the squeezing of approximately eighty mine pillars.

Jan 1, 1983

By F. A. Edwards

The Macassa Division of Lac Minerals Ltd. is a high grade gold mine that has been operating in Kirkland Lake, Ontario for the past 51 years. It produces approximately 120,000 tonnes of ore per year, averaging approximately 18.7 grams per tonne (0.45 ounces per ton) of gold. Over the years, the ore body has been developed to a point where mining takes place below the 1,220 m (4,000 feet) elevation and 1,830 m elevation (6,000 feet) west of the original shaft. The mine is currently serviced by two surface and two winze shafts. (Figure 1). The ore body extends below the 1,930 m (6,400 feet) Level which is the bottom of the existing mining operation. An ambitious underground exploration program has substantially increased these reserves. Concurrent with the discovery of greater reserves, has been rapidly escalating mining costs, particularly labour which constituted 66% of the total cost in 1981. These costs continued to escalate as the major proportion of mining was carried out to the west, far away from the existing hoisting systems. This required a three lift hoisting system for men, materials and ore. In addition to the increased travel time and ore handling expense, increased humidity, temperature, ventilation and compressed air losses have added to the inefficiency of the operation. As a result, studies were initiated in 1980 to assess the future of the Macassa operation. The results of the studies indicated that a new deep shaft with a potential to hoist from 2,135 m (7,000 feet) or below was the most attractive option. Detailed design of the shaft and associated surface plant commenced in January, 1982 and the following milestone dates were achieved: 1980 - initial study of hoisting and haulage facilities; January, 1981 - ore reserves in excess of 1 million tonnes of ore at 18.7 g/tonne (0.45 oz/ton) confirmed; March, 1982 - preliminary study of Macassa No. 3 Shaft completed; April, 1982 - permanent hoisting plant purchased; June, 1982 - site clearing commenced; September, 1982 - shaft collared; May 1, 1983 - shaft sinking commenced; February 11, 1985 - shaft reached 1,600 m (1mile); December 1, 1985 - shaft scheduled for completion.

Jan 1, 1985

By Ivor Hawkes, Malcolm Mellor

INTRODUCTION There are currently around fifteen companies in the United States and Europe manufacturing hard rock tunneling machines. In recent years upwards of 200 hard rock tunnels of lengths up to 12 miles and diameters to the order of 30 ft have and are being successfully driven by over 100 different machines. It has been predicted that within the next decade over 2,000 miles of tunnels will be driven for transportation purposes in the United States alone (OECD Advisory Conference on Tunneling, Washington, 1970) and it is expected that eventually most tunnels including mine drivages will be excavated by machines. All tunneling machines have certain common basic functions; thrust is applied to drive or hold the rock cutting tools into the face, and torque is applied to rotate the cutting tools over the face so that they can continuously break out rock. The speed of head rotation, together with the torque requirement, determines the cutter head power. (The power required to push the head forward is usually negligible.) There are many factors which determine how successfully a given tunneling machine will perform in a given rock but one of the most important is effective utilization of cutter head power. This paper is a review of the specifications and performance of hard rock tunneling machines, obtained from manufacturers' catalogs, published literature, talks with manufacturers and visits to operating machines throughout the United States and Europe.

Jan 1, 1997

By J. A. Harrison

Most coal being used in the United States has been subjected to one or' more processes of coal preparation. The physical and chemical characteristics of a coal have a marked influence on the ultimate uses that coal may have. The selection of the proper preparation processes may similarly be important in producing the best practical coal product for any particular use. The physical composition and distribution of physical constituents in the coal will partially determine the efficiency of the preparation process chosen and conversely distribution and concentration of coal macerals will, to a degree, be controlled by the preparation process. A number of preparation processes have been evaluated to determine this interrelation. If a coal having' certain specifications is desired, these evaluations trill assist in providing information needed for the production of this coal.

Jan 1, 1962

By Pat DeWilliam

The Yakobi nickel-copper deposit is located essentially at tidewater in the east-central part of Yakobi Island, about 16 1 airline km (100 airline miles) west of Juneau, and can be reached by float plane and boat from Juneau and Sitka. The fishing village of Pelican, population 400, is situated 14.5 km (9 miles) to the east. An unimproved road, approximately 4 km (2.5 miles) long, connects a dock site at Lisianski Strait with the main part of the deposit known as the Basin Area (Fig. I). Other mineral occurrences are known as the Takanis, Flapjack, and Beach Areas. Another smaller nickel-copper deposit is located about 32 km (20 miles) to the south on Western Chichagof Island and is known as the Mirror Harbor nickel-copper deposit. The original discovery of the Yakobi deposit was made by S.H.P. Vevelstad about 1920 and a 47.5-m (156-ft) long adit was driven on the southwest side of the deposit in the Basin Area. The deposit was examined by J.R. Van Fleet of Union Carbide in 1930 and by J.G. Fairchild in September 1931. Stanley and Yates of the International Nickel Co. of Canada (Inco) visited the property in August or September 1937. In 1942, the controlling interest in the deposit, covered by 124 unpatented claims, was said to be held by Vevelstad and associates

Jan 1, 1991

By Robert D. Coale

This paper will describe the copper concentrate slurry pipeline and pumping system between the concentrator and the port at Bougainville Copper Ltd. The operations of Bougainville Copper Ltd. are located on the island of Bougainville in the South Pacific. Geographically, it is the northernmost island of the Solomon Group but, politically, it is part of Papua New Guinea. Papua New Guinea is a United Nations Trust territory administered by Australia, having recently been given self-government, with independence scheduled for December 1974. (Fig. 1). The island is approximately 130 miles long by 30 miles wide, with the Crown Prince mountain range forming a spine along its length. The mountains in place are over 8,000 feet high with the mine located on the western flank at an elevation of 2,200 feet. Exploration on Bougainville for copper by Conzinc Riotinto of Australia (CRA) began in 1963 and by 1968, through geophysical, geochemical and diamond drilling methods, an orebody containing nearly one billion tons of ore grading approximately 0.48% Cu. and sane gold had been outlined. Bougainville Copper Ltd., the company operating the mine, is 53.6% wined by CRA, 20% mined by the government of Papua New Guinea with the public Folding the remainder of the shares. The first copper concentrate was produced in early 1972, with production for the first full year, 1973 being:

Jan 1, 1974

By Michael F. Gleason

In 1986, Gold Fields began negotiations with a large Nevada electrical power utility to supply power for its Chimney Creek Mine In northern Nevada. After the long negotiations reached an impass over various costs associated with the power line, a decision was made by Gold Fields to generate its own power. Self-generation is not uncommon overseas, but it is rare for any but very large or very small operations in the United States. Surprisingly, under certain conditions a mine can generate its own power profitably and Gold Fields has found that the associated operating and maintenance problems are minimal. The following report details what factors went into this decision and how it works. Hopefully, it can serve as a guideline for those who may find themselves in a similar position.

Jan 1, 1990

By Basilio Giurgola, Jeremiah M. Jezerski, Filippo Azzara, Federico Bonaiuti, Russell H. Lutch

The Northeast Boundary Tunnel Project consists of a 23 ft diameter, 27,000 ft long, CSO tunnel, multiple underground connections, and significant surface works within an urban corridor. The NEBT alignment depths range from 60 to 140 ft and includes seven shafts ranging in depth from 77 to 155 ft with diameters varying from about 19.5 to 56 ft, some as in-line connections and others required adits for connection to the main tunnel. This paper focuses on the design and construction of two major underground connections which are the First Street Connector Tunnel and the Mount Olivet Road Diversion Sewer.

Jun 13, 2023

By John M. Marek

INTRODUCTION This paper is for the mining manager, generally meaning mine superintendent, chief engineer, and others who have control over the mine operation responsible for feeding the insatiable beast called the mill or processing plant. The author is not from mine management but from the field of technical mine engineering consulting. This fact illustrates the authors gross inadequacy to comment on this subject. On the other hand, the consulting profession allows visits to many mine operations, worldwide, supplying many different commodities. The common complaints and misunderstandings that have been heard worldwide will be shared within the following few paragraphs. In order to discuss optimization, one must first define it. There certainly will be many papers in the following sessions that claim to optimize something, or other, based on a technical definition of cost, efficiency, throughput or some other quantifiable basis. DEFINE OPTIMIZATION Actual optimization of an operation is not as easily achieved as most of us in the technical world would like. Borrowing terminology from the technical world, the boundary conditions and the optimization function are usually not well defined. The problems in many cases do not lend themselves to quantification. Typical management procedures are to establish goals or strategies that set the approach or general boundary conditions to the overall plant. Three simple cases are listed below as possible corporate strategies to optimization of a mine-process plant complex. 1) Maximized discounted cash flow 2) Minimized long term cost of product 3) Maximized resource utilization This list seems simple when presented in the above context, uncluttered by constraints such as market position, capital availability, or environmental limitations. Sometimes the best approach is a prioritized combination of the above items. Typically, the Board or CEO has established these strategic priorities. They may

Jan 1, 1991

By D. W. Park

Longwall Strata Control and Maintenance System (LoSCoMS) is a software and data communication system developed at the University of Alabama. This system integrates real-time shield monitoring, data presentation, analysis and forecasting of forthcoming events. The main objective of this system is to provide stability information on longwall panels including excessive shield load, low setting pressure, leg leakage and poor shield performance, eminent maintenance problems, etc. Analyses of various mining and geological parameters were also performed to determine past and present roof characteristics and to forecast roof loading patterns for the following mining cycles, next periodic weighting, etc. A local coal mine in the Warrior Coal Basin has adopted this system to provide daily evaluation of ground stability and maintenance problems of their longwall panels. Two years of experience with this system is covered in this paper.

Jan 1, 1998

By Robert T. DeGavre

I have been asked by the Society of Mining Engineers to present a paper on Inco Limited's Indonesian nickel project as a case study in the financing of large overseas mining projects. I welcome this opportunity It is a story worth telling not only because the project itself represents a significant human achievement but also because there are certain important lessons that can be derived from our experience in financing the project. The paper will be divided into four sections: (i) a brief history of the project, (ii) a critical appraisal of the project's financing plan in terms of the goals that we sought to achieve, (iii) some comments on certain factors underlying the relative success of the financing plan, and (iv) the contributions that the engineering staffs must make to a successful financing plan. The paper will not present a technical assessment of the project since Inco Limited has been asked to submit a series of papers on this subject at the International Laterite Symposium as part of the 108th Annual Meeting of the AIME in February 1979.

Jan 1, 1978

By Brenton Cook, Nate Long, Larry Applegate, Aaron K. McCain

"The Northgate Link Extension project is the third phase of the Sound Transit master plan to extend light rail throughout the greater Seattle metropolitan area. When completed, the Northgate Link Extension will extend the existing light rail system north by about 7 km (4.3 miles) from the University of Washington to the Northgate neighborhood. A general overview of the project alignment is provided as Fig. 1. The project was funded by a combination of federal grants and allocations from local taxes. The general contractor on the project was JCM Northlink LLC (JCM), a joint venture between Jay Dee Contractors, Frank Coluccio Construction Company and Michels Corp. SoilFreeze, Inc. was retained as a subcontractor to provide ground freezing design and construction services.The project involved the construction of two parallel 5.5-m, 25-cm (18-ft, 10-in.) (inside) diameter tunnels using earth pressure balance (EPB) tunnel boring machines (TBM) and precast segmental concrete tunnel liners. The two tunnels maintained roughly the same elevation along the alignment and were spaced roughly 12 m (40 ft) apart (centerline to centerline). A total of 23 cross-passages connecting the two tunnels were included at approximate 244-m (800-ft) intervals. Cross passage excavations were elliptical in shape with dimensions of approximately 5.6 m (18.5 ft) in height and 5.3 m (17 ft) in width. The cross-passages were 5.8 to 6.1 m (19 to 20 ft) long as measured between the exterior of the tunnels at springline elevation. Cross passages were intentionally located directly beneath public right-of-ways thus avoiding buildings. Many of the cross passages were located beneath narrow roads in residential neighborhoods with mature vegetation, existing utility structures and piping and limited parking areas. Excavation and support for each cross passage was completed using the sequential excavation method (SEM).The subsurface soil and ground water conditions at the cross-passage locations were described in the Northgate Link Geotechnical Baseline Report (GBR) prepared by Jacobs Associates and the Northgate Link Geotechnical Data Report (GDR) prepared by Shannon and Wilson, Inc. Soils along the project alignment were glacially overridden and characterized as very dense or hard. Subsurface soils consisted of cohesionless sand and gravel (CSG), cohesionless silt and fine sand (CSF), cohesive clay and silt (CCS) and till and till-like deposits (TLD)."

Dec 1, 2018

By Antonio Nieto, Jesus Castillo

Research and Development (R&D) departments in the mining sector are essential for creating new solutions on productivity, safety, and sustainability. Nevertheless, the selection of R&D projects is complex, often influenced by subjective judgments and uncertainties. This paper explores the application of the Multicriteria Decision Analysis (MCDA) as a structured approach to evaluate and prioritize innovation projects based on various criteria such as safety, cost, environmental impact, and social acceptability. By assigning weights and quantifying criteria, MCDA enhances decision-making transparency and objectivity. This study aims to show a method that facilitates strategic thinking, resource optimization, and stakeholder engagement, ensuring that selected innovations align with the company’s long-term objectives and commitment to responsible mining practices.

Feb 1, 2025

By Chuang Sun, Feng Luo, Guo‑dong Li, Xue‑qing Li, Tuan He

The mining-induced failure of the coal seam floor is essential for water inrush. The mining disturbance to the floor, especially in the thick coal seam, is severe, and the water inrush risk is also higher than that in regular thick coal seam excavation. The superposition of many stresses, including in situ stress, mining-induced stress, and confined water pressure, must be considered in the prediction of the floor failure depth. This study adopted the elasticity analysis, FLAC3D numerical simulation, and on-site acoustic wave test comprehensively. The thick coal seam working face of the Zhong-Yu coal mine affected by confined water was selected as the engineering background to study the characteristics of the floor failure. Based on elastic foundation theory and the superposition principle, the mechanical model and the failure depth criterion of the floor were established, respectively. The distribution and evolution of mining-induced stress and the plastic zone in surrounding rock during the mining process are obtained by FLAC3D. In addition, the changes in the P-wave wave velocity in the floor before and after mining were compared and studied by the acoustic wave test method. The range of floor damage depth is determined on the basis of the above research.

Jun 8, 2022

By Hojong Kim, Isehaq Al-Nafai, Kwadwo Osseo-Asare

The standard Gibbs free energy of formation (ΔGo f, 298) of bastnasite, (Ce, La, Nd, Pr)FCO3, was estimated using four different methods. The obtained average values were − 1589.5 kJ/mol for CeFCO3, − 1599.5 kJ/mol for LaFCO3, − 1589.1 kJ/mol for NdFCO3, and − 1595.4 kJ/mol for PrFCO3. The value for cerium bastnasite, CeFCO3, was used to construct a potential vs. pH (Eh-pH) diagram to investigate the stability relations of cerium bastnasite. The diagram shows that CeFCO3 is stable in neutral to basic conditions (pH ~ 6.5–11).

By B. Qiu, Y. Luo

The design of the predriven recovery room is not an easy task, because the stress distribution in the barrier pillar, standing supports, fender pillar and the immediate roof is changing as the longwall face approaches the predriven recovery room. An analytical approach is proposed to determine the stress distribution in the barrier pillars, fender pillars, standing supports and immediate roof of the recovery room based on the fracture mechanics approach. Based on the developed mathematical model, a stand-alone computer program has been developed to facilitate the required computations. The parameters such as overburden depth, recovery room width, mining height, shield and standing support capacities are incorporated into this program to access the feasibilities of predriven recovery room designs. Compared to the finite element method previously employed, this analytical approach offers the same, if not better, accuracy without requiring expensive computer hardware and software or specialized expertise.

Jan 1, 2012

By D. Chakravarty, G. Samanta, B. Samanta

The present study highlights the planning and design aspects of a well-known openpit copper deposit in India. The mine has been operational since 1982 and presently reaches a depth of 168 m below the surface. The present planning effort has been given due consideration in view of the recent upsurge of copper prices in the global market. The prime focus of the study has been directed towards examining the possible extent of final pit beyond the current pit outline and generating an extraction sequence of future mining operations. To this end, an orebody model of the deposit has been developed and the optimized pit has been derived using L-G 3D algorithm. A sensitivity analysis has also been performed to scrutinize the possible effects of the changing economic scenarios on the ultimate pit configuration. It has been observed that with the current production rate, mine life can be extended another 40 years. With a five-year production plan, these materials can be extracted in eight push-back schemes. The extraction sequence of these push-backs has been outlined in this paper.

Jan 1, 2011

By Marko Oosthuizen, Charl P. Botha, Lidia Auret, Annelette Malan, Marthie de Leeuw

Flotation performance is affected by upstream disturbances (e.g., mineralogy, water quality, flow rate) and controlled variables (e.g., pulp level and air addition). Process disruptions can lead to undesired conditions, such as pulp overflowing flotation cells (with insignificant/absent froth, and thus no valuable mineral concentration). Early detection and appropriate intervention of pulping events improves concentrator performance. An approach to real time flotation pulping event detection by means of convolutional neural networks is presented, including a case study of the industrial application of this technology on three flotation banks.

Feb 22, 2026

By Shanming He, Jinliang Wang, Xiaoming Wang, Chunfa Liao

Large amounts of manganese-rich slag were generated from smelting low-grade manganese ore containing high iron and high phosphorus in electric furnace or blast furnace, which contain 25–40 mass% Mn. This paper describes an efficient hydrometallurgical process for the utilization of high manganese slag instead of conventional usage of pyrometallurgical route for manganese recovery. Pressure acid leaching of manganese-rich slag using air as pressurized gas is studied systematically. The effects of mass ratio of manganese-rich slag to pyrite, concentration of sulfuric acid, leaching temperature, partial air pressure, leaching time, and liquid-solid (L/S) ratio on the separation of manganese with other main impurity components were investigated comprehensively. Under the following optimal process conditions, weight of manganese-rich slag powder,100 g; mass ratio of manganese-rich slag to pyrite, 20:1; sulfuric acid concentration of 140 g/L; air pressure of 0.6 MPa; leaching temperature of 140 °C; leaching time of 1 h; L/S of 7:1; ore size of 75–80 μm; and stirring rate of 600 rpm, the extraction rate of Mn reached 94%, and the dissolution percentage of Si, Al, and Fe are as low as 2%, 6%, and 10%, respectively. The leaching slurry presented a good solid-liquid separation characteristic. The silicic acid formed during sulfuric acid leaching manganese silicates was converted to filterable dehydrated SiO2 particles which precipitated in the residue under the condition of higher temperature with higher pressure. The effect of adding pyrite may be to reduced iron ions and decreased the output of iron hydroxide colloid and also reduced MnO2 to manganese sulfate in sulfuric acid leaching. Thus the formation possibility of colloid such as silica gel and iron hydroxide was decreased, and higher yield of manganese sulfate could be achieved.