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By R. Jedrzejczak

Endako Mine is an open pit molybdenum mine located in the north central region of British Columbia, Canada, approximately 160 km. west of Prince George. Production for the latter part of 1992 is expected to average at 63,500 tonnes per day of which 27,000 tpd constitute the mill feed. This production is achieved with five 15 to 19 cu. yd. electric shovels, six Euclid R190 and two Unit Rig M120 diesel-electric haul trucks, and three 121;.1 inch electric rotary drills. There are three ore zones delineated into pit areas called the Endako, Denak East and Denak West. Present mill feed source is the South East stage of the Endako Pit while the stripping is carried out in the South Wall stage also of the Endako Pit. The mine high grade aggregate is reduced in the primary and secondary crushing circuits before processing in conventional RM/BM/flotation circuits. The majority of the Molybdenum Sulphide (MoS2) is roasted on site to produce technical grade Molybdenum Oxide (MoO3) while a portion is further refined and treated to yield a 99.9% pure Molybdenum Sulphide (MoS2) "Ultrapure" product.

Jan 1, 1993

By R. H. W. Chadwick

We in Kennecott are well aware that Alaskans are interested in the progress of our project at Ruby Creek. We would very much like to be able to present you with a final report at this time and tell you about a new mine. I'm afraid, however, that it will be several years at best before such a report can be made. This, then, is an interim report to describe briefly some of our findings to date, and to acquaint you with some of the problems, both geologic and economic, which must 5e resolved favorably before we can talk about a mine. There are several things about this project which make it unusual and interesting to those of us who have been connected with it. Firstly, there is the fundamental importance to Alaska, in the present stage of its economic history, of any undertaking which offers promise of turning a natural resource into a competitive export product. I am sure all of us would get a lot more satisfaction out of having a part in bringing in a new mine in Alaska than we would out of adding another one to the long list in, say, Arizona.

Jan 1, 1960

By J. A. Marts, R. C. Gilmore, Jr. Bogin, S. Saki, J. F. Brune, J. W. Grubb

"Researchers at the Colorado School of Mines have studied the influence of headgate side ventilation controls near the longwall start-up room on the formation of explosive gas zones (EGZs) in underground coal longwall bleeder ventilated gobs. In a project funded by the National Institute for Occupational Safety and Health (NIOSH) researchers developed a Computational Fluid Dynamics (CFD) model to study the formation of methane-air mixtures in the gob, start-up room, and bleeder entries. The relative change in size and location of EGZs are examined in response to ventilation controls in the headgate side bleeder entries near the start-up room. Modeling suggests that adjustments to the ventilation controls can be made to minimize the size of the EGZ. However the EGZ may form in or around active working areas regardless of the ventilation control settings. Research found regulators on the crosscuts into start-up room and first entry inby can force air into to crosscuts outby the start-up room causing more air to flow through the gob. INTRODUCTION Underground longwall mine ventilation systems may operate with either a bleeder ventilated gob or a progressively sealed gob. Bleeder ventilated gobs must meet the standards for safe operation of the bleeder system by examining bleeder system effectiveness. As defined in the United States Mine Safety and Health Administration (MSHA) Program Policy Letter (PPL) No. P13-V-12 (MSHA 2013), the pillared area or gob is “any area where a reduction in pillar size has occurred during retreat mining” and includes the “caved and broken material, the interstices within the caved material, and the open spaces surrounding the caved material.” The PPL further states that the intended purpose of ventilating the gob is “to protect active workings from the hazards of methane accumulations …” The requirements for operating a bleeder system as stated in The United States Code of Federal Regulations (CFR 2013) Title 30 §75.334(b) is to pass ventilation air though the gob “and to continuously dilute and move methane-air mixtures [from the gob] away from active workings and into a return air course …” where the concentration cannot exceed 2 percent methane (CFR 30 § 75.323). Further clarification of the bleeder system as described in the PPL states the following: “A bleeder system includes the area from which pillars are wholly or partially recovered, bleeder entries, bleeder connectors, and all associated ventilation control devices that control the air movement through the area. Bleeder entries are air courses designed and maintained as part of the bleeder system.”"

Jan 1, 2015

By V. Badaker, R. J. Sweigard, C. D. Barton, J. W. Stringer, J. M. Ringe, A. D. True, D. H. Graves

Field studies have demonstrated the relationship between the growth of high-value trees on surface mined land and the physical conditions of the root growth medium. Specifically, the survival and height of hardwoods grown on less compacted material are far superior to those grown on compacted material. Furthermore, studies have demonstrated that the physical condition of the root growth medium can be characterized by dry bulk density and penetrometer resistance and that these parameters are also related to tree growth measurements. Site indices are useful for evaluating and predicting the productivity and timber yield for a specific location. A method has been proposed to estimate the site indices for various tree species on reclaimed surface mined land as a function of the physical properties of the root growth medium.

Jan 1, 2005

By T. M. Barton

Coal mine bumps the violent failures of over-stressed coal', present a safety hazard to miners when mining is conducted in deep, bump prone coal mines. Two different longwall gate entry systems were evaluated in a Southern Appalachian coal mine located in the Pocahontas No. 3 Coalbed under approximately 610 m of overburden which included a massive sandstone member. Both gate entry systems employed a center abutment pillar flanked by yield pillars. The original design employed a 24.4 m square abutment pillar' while the new design employed a 36.6 by 54.9 m' abutment pillar. Rock mechanics instrumentation data analysis and in-mine observations indicated that this increase in abutment pillar size significantly decreased bump potential. The new design in worse case conditions increased effective bearing area 62 pct with only a 9 pct increase in gate entry system width and eliminated face bumps that wer7 experienced with the original gate entry design.

Jan 1, 1991

By R. W. Lankston

Uranium mill tailings disposal facilities present unique problems with respect to siting, design, and long-term stability because their contents remain potentially hazardous for 100,000 years. Dawn Mining Company, operator of a uranium mill in Washington, undertook geological and geophysical studies relative to planned expansion of existing disposal facilities. Seismic refraction and reflection, resistivity, and ground magnetics data were integrated with limited drill data to determine the configuration of Quaternary sediments and the underlying basaltic and granitic bedrock. Analysis of multiple reflections and magnet modelling on a micro-computer with CRT graphics added detail to the interpretation.

Jan 1, 1980

By M. Kuchta

A linear integer programming (MIP) model to solve the long-and short-term production-scheduling problem for sublevel caving operations is presented. The MIP model is designed as a multi-time-period problem to provide monthly schedules that meet production, blending and sequencing requirements. One of the most important issues during the development of the MIP model was the requirement of sequencing between blocks. In this mathematical model, unique constraints that ensure sequencing of the production from sublevels are developed. A suggested method of handling a large number of variables is also given. The MIP scheduling model was implemented on a data set obtained from the Kiruna Iron Ore Mine located in northern Sweden. The initial MIP model implementation was successful and provided a solution that optimized resource recovery while meeting monthly and yearly production constraints. The scheduling results obtained based on the Kiruna Mine are further presented and discussed.

Jan 1, 2003

By J. Philip Bromberg

Any effectuation of a viable program of air pollution control will' require a basic understanding of the chemistry of atmospheric processes, the fate and migration of SO2, and the ultimate health effects of the sulfur oxides themselves. The migration and ultimate fate of Sop discharged into the atmosphere will be discussed with particular emphasis on the various conflicting views and how these relate to our present emission control regulations. Our present lack of knowledge is a severe detriment, and consideration will be given to those particular areas where future research may best be directed to provide the answers to a number of perplexing questions.

Jan 1, 1976

By C. J. Savage

Rio Tinto Minera, S.A. operates in Southern Spain, at one of the most ancient mining sites in the world, using advanced computerised mine planning. This paper describes the development and application of the mine planning systems to the copper and gold/silver operations. It briefly covers the hardware configuration, and the advantages and improvements in mine planning achieved. The system's application started with the long term mine planning of Cerro Colorado (open pit) copper mine and was gradually extended to cater for the medium and short term planning requirements of the other operations of the Company. The base of the system is a mineral inventory established by the combined use of the geology and geostatistical methods, and compatible with the mine planning requirements. The planning system has three major components: one used for open pit design and long term mine planning, another used for blast evaluation and finally one used for short term mine planning. Recently, a fourth component has been added to the system for reconciliation between predicted and actual tonnages and grades. There is common data file transfer throughout the system.

Jan 1, 1986

By Lianhui Jia, Yali Han

"The key technologies of a large rectangular pipe jacking machine with dimensions of 10.12m × 7.27m (width x height) include selection of rectangular cross-section cutting modes, analysis on the strength and stiffness of the rectangular shield, integrated control of electro-hydraulic proportional thrust systems and ground conditioning for excavation are presented in detail in this paper. These key technologies have been successfully applied and verified on site during tunneling, providing a new concept for the building of large rectangular traffic and pedestrian tunnels in urban areas for the future.1 INTRODUCTIONIn the past, underground tunnels were mainly used for drainage, sewage, utilities, metro tunnel, etc. and most of them had circular cross-sections. Recently, as a result of economic development, gradually accelerating urbanization process and diminishing ground space, underground tunnels have already become a new trend for urban underground space utilization. Due to the heavy traffic flow, the demands for rectangular cross-section underground tunnels, such as pedestrian underpass and road tunnel, are increasing gradually.The Rectangular pipe jacking machine (hereinafter referred to as RPJM) was firstly developed in Japan for the construction of metro station, pedestrian underpass, underwater tunnel by-passes, etc. Kazunaki Kawai et al. introduced a RPJM developed and manufactured by KOMATSU in 2002 [1]. Tosikazu Kubota et al. confirmed the rectangular tunnels’ superiority to circular tunnels with regard to larger inner cross-section and lower construction cost in their RPJM construction reports [2]. Compared to circular pipe jacking machines, a RPJM also has the merits of a higher inner tunnel space utilization ratio and is able to excavate in shallow overburden areas. As shown in Figure 1, the effective area of a rectangular tunnel is more than 20% higher than that of an equivalent circular tunnel."

Jan 1, 2016

By J. LaForest, R. Riggle

In today’s challenging mining environment, everyone is focused on minimizing cost per ton. With haulage costs approaching up to 45% of the overall mining costs, and loader performance driving production, optimizing payload on the truck is a big opportunity. This paper will focus on technology’s role in loaders achieving the truck target payload. There are constantly new innovations in technology, but not everyone uses them correctly. Technology is intended to help achieve the next level of performance, but still requires the right people and processes to effectively utilize the benefits. In today’s mining business, miners, engineers, trainers, supervisors, and managers have ever increasing roles and responsibilities as never seen before in past decades. Technology can make these roles more efficient, but fully relying on the technology can detract from optimization. Sometimes the old-fashioned method of loading to a consistent pass match will provide a lower cost per ton. Before blindly trusting your technology feedback, know these three areas discussed in this paper: (1) Prerequisites to utilize technology in payload management; (2) Types of payload management technology; (3) How to use the data to manage operator behavior. The objective of this paper is to provide low-cost recommendations to efficiently increase production. INTRODUCTION Whether miners claim to have been around and experienced it all, or they are the data-driven new generation on the mine site, miners are expected to execute the mine plan at the lowest cost possible. So why is it so difficult to execute this task? Shouldn’t supervisors just have to staff the equipment, tell operators to have a safe day and tally up the numbers at the end of the shift? Let the technology system do the rest; what could go wrong? Lots. Having examined numerous mining operations that use the latest loading technologies over the past several years, one common denominator is the opportunity to improve loader operator performance. Mining companies seek help from consultants, training departments, performance reporting systems and an arsenal of resources. Armed with all this information, but the improvements don’t happen, what could have gone wrong? It comes down to people, not managing the resources to drive the right behavior and as a result, the mine’s performance is not where it should be. Understanding how to make “Great Miners” out of these people is critical to this constant struggle to move more with less and get the costs down. Extraction CPT (Cost-Per-Ton) is most sensitive to optimizing loader production which can be generalized into 3 categories of influence: machine specifications, cycle timing, and continuous management using technology. After establishing a basic production machine configuration, utilizing technology to manage cycle times, operator efficiency and payload can be advantageous. Prerequisites to Utilize Payload Management Technology It is important to begin with the primary considerations that enable the use of technology to continuously manage loading productivity. All systems are interdependent in mining, but these are divided into the simplest terms to remember. First, fix your timing and geometry.

Jan 1, 2019

By Wen Lan Chen

In the plant where the 800m diameter cyclone was tested, 500 STPH of 50m x 0 raw coal was pulped in a heavy medium tank and pumped originally to four 700mm heavy medium cyclones. For the test one of these units was replaced by an 800mm diameter cyclone with the subsequent feed pressure for both units sets at approximately 15.0 psi. Since this was a feed to zero plant, an appropriate bleed of heavy medium to the dilute medium circuit was established to en- sure that the cleaning of the 500m x 0.5mm raw coal would not be adversely affected by high levels of 0.5mm x 0 fine coal present in the heavy medium. The medium gravity measured varied between 1.41 and 1.43. During a three-hour test on June 10, 1983, the raw coal sample was collected from the feed belt while the clean coal and refuse samples were collected separately at proper locations along the product streams of the two different diameter cyclones. All of these samples were shipped to the laboratory for screen and sink- float analyses. The raw coal screen and ash analyses are shown in Table 1.

Jan 1, 1984

By Z. Hajnal

Three years ago a research program was initiated at the University of Saskatchewan to develop seismic surveying techniques for use in the Precambrian geological environment. The success of the reflection method in many younger geological settings suggested that this is the technique which would be the most suitable for experimentation. A successful adaptation of this technique to the Shield environment would make mapping of rock formations possible to much greater depth than is possible at the present time with any other applied geophysical technique. This presentation attempts to illustrate the advances which have been made in this program and will provide some insight into future plans. The field investigations were limited to the Flin Flon basin near to the town of Flin Flon, Manitoba (Fig. 1). This area was chosen because the surface geology has been mapped in great detail and it is a very important base metal producing region. It is an ancient sedimentary basin with some characteristics similar to areas where the reflection method has been successful.

Jan 1, 1976

By Zohreh Kazemi Motlagh, Virginia T. McLemore

There are more than 15,000 abandoned mine features in New Mexico. A considerable number of these mines have not been cataloged or assessed for prioritized reclamation efforts. These mine wastes can be examined as a resource of critical minerals. Many of legacy mine waste deposits have undiscovered commodities and critical minerals, due to low recovery processes during past production. In this project, Black Hawk mine wastes in Grant County, New Mexico are examined by thorough mineralogical and geochemical characterization. This project seeks to characterize and estimate the critical minerals in mine wastes of Black Hawk mine, and determine the acid generating potential of mine waste. Identifying and producing critical minerals in New Mexico may directly benefit the U.S economy and national security.

Feb 1, 2024

By A. M. Whiting

Competition for coal producers and their primary customers has constantly increased during recent years. The effects of the Clean Air Act Amendments of 1990 on the electric utility industry, coupled with the normal complexities of coal production, quality control, transportation and contracting techniques have spurred both buyers and sellers to increase their level of sophistication. This paper will review the basic aspects of the U.S. coal business and explore the commercial approaches which have proven to be most successful.

Jan 1, 1994

By T. Hayes

Track-type tractors remain one of the most cost-efficient stripping tools available to coal miners. Whether they are "sweetening up" a dragline operation with pre-benching or serving as the primary stripping tool, dozers can play an important role in driving down mining costs. This paper reviews the application zone of track-type tractors. In addition, it provides tips on site set-up, equipping of tractors, and machine operation which the audience can take home and apply.

Jan 1, 1996

By R. A. Metz, Willard C. Lacy

Survival of the mining industry as a viable economic entity in the United States is being seriously threatened by declining grades of ore reserves, rising operational and capital costs, and increased governmental taxes, restrictions, and subsidizing of third world competition. Discovery of major high-grade deposits is becoming increasingly unlikely. International competitiveness of the U.S. deposits will depend upon 'Yankee Ingenuity,' innovations in mining methods, metallurgical treatment, and financial arrangements, and a viable national strategy. This will require not only effective management for control of operations, but management that encourages breakthroughs in technology, financing, labor relations, and in public and governmental understanding. The mine geologist and the exploration geologist both have important roles to play in all aspects of this fight for survival of the industry.

Jan 1, 1992

By J. Bartrum

Kidston Gold Mines is a 14 000 tonnes per day rated operation located 280 kilometers west of Townsville in Queensland. The principle shareholder is Placer Development Limited. Kidston's orebody consists of 44.2 million tonnes graded at 1.79 g/t gold and 2.22 g/t silver. Production commenced in January, 1985, and despite a number of control, mechanical and electrical problems, each month has seen a steady improvement in plant performance to a current level of over ninety percent rated capacity.

Jan 1, 1985

By R. O. Harma

Wet autogenous grinding is utilized in three iron ore concentrating plants operated by The Cleveland-Cliffs Iron Company (CCI). This paper will trace some of the development in converting from the use of metal grinding mill liners to the use of rubber and will update the current performance of rubber liners in these applications. The Cleveland-Cliffs Iron Company is a natural resources firm with major interests in iron ore mining and processing and oil and gas contract drilling. The company also has interests in oil shale, uranium, forest products, and Great Lakes shipping.

Jan 1, 1982

By III Feeley

Coal is the nation's most abundant fossil energy resource and serves as the primary fuel for the U.S. electric-power industry. However, its continued and expanded use is often challenged by the nature and amount of its associated impurities, such as mineral matter, sulfur, and trace elements. The moderate- to high-sulfur content of many U.S. coals is of particular concern today as potentially more stringent regulations requiring further reductions in sulfur dioxide emissions are being considered. The most prevalent method currently employed to control SO2 emissions from coal-burning facilities is post-combustion flue-gas desulfurization. However, physical coal cleaning (a.k.a. beneficiation, preparation) methods can also be effective in removing sulfur and ash impurities from coal prior to combustion. In a typical physical cleaning operation, raw coal is crushed to about 50-mm (2-inch) topsize, and then screened into coarse, intermediate, and fine size fractions. Crushing liberates some of the ash-forming minerals, including the portion of inorganic sulfur (pyritic) not chemically bound to the coal matrix. The percentage of impurities liberated generally increases as the coal particle size is reduced. Coarse- and intermediate-sized coal particles are typically subjected to specific gravity-based cleaning methods, while fine-sized (less than 0.5-mm) coal particles are beneficiated using froth flotation, a technique based on surface property differences. Greater cleaning potential exists at finer sizes because of increased liberation of impurities, but this potential is not fully realized because of inefficiencies associated with fine particle separation using state-of-the-art coal cleaning technologies.

Jan 1, 1990