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By M. C. Roberts

In assessing the future markets for a mineral from a producing district, three key aspects must be considered: 1) the future growth in markets, 2) the competitiveness of the district in terms of production costs and reserve adequacy, and 3) the competition from alternative sources of supply. This paper will focus on the first issue by developing a method of predicting the demand for phosphate from the trends in the major markets for phosphate products, primarily the fertilizer and agricultural markets. The paper will show how broad changes in the final end use markets for phosphate products have evolved over time and how this has affected the needs for phosphate rock. These trends are then projected into the future to make an assessment of future phosphate requirements.

Jan 1, 1998

By Jacob Carr, Chenming Zhou, Nicholas Damiano, James Noll, Jingcheng Li

Machine-related injuries are one of the major safety concerns in underground coal mines. Severe injuries and fatalities occur when a miner is struck, crushed, or pinned by mining equipment such as a continuous mining machine (CMM), shuttle car, or a scoop. Proximity detection systems (PDSs) have been applied in mining to reduce these types of injuries and fatalities. All of the PDSs that are currently approved by the Mine Safety and Health Administration (MSHA) for use in underground coal mines are magnetic-field based and could be affected by metallic objects such as trailing cables. Researchers from the National Institute for Occupational Safety and Health (NIOSH) investigated the influence of trailing cables on the performance of PDSs. In particular, the magnetic field coupled from proximity system generators to a de-energized trailing cable was characterized. The results show that significant energy can be coupled from the proximity system generators to a trailing cable when there is a closed loop in the cable. The effect on PDS performance from the magnetic field radiated around an energized trailing cable was also quantified for different current amplitudes in the cable. It is shown that the magnetic field caused by the electric current in the trailing cable mainly consists of a 60-Hz signal and its harmonics which causes little interference to the PDS. The results presented in this paper can help PDS manufacturers to design better systems that are more immune to these effects.

By D. E. Ranta, M. G. Schulz

Mining of Molybdenum at Questa, New Mexico has been accomplished by block cave methods since August, 1983. As caving progresses, a periodic geologic evaluation is made of the rock types present in finger raises on the Grizzly Level of the mine. The production maturity of the cave can be monitored by relating this data to geologic cross-sections through the orebody. The draw point mapping program is a simple and effective tool that is used in making draw control decisions at Questa.

Jan 1, 1992

By Patrick Linzer

The majority of existing models describing (methane) gas transport within, and liberation from, coal structures treat these as continua wherein two main gas flow modes (diffusive and Darcy permeable) prevail, and use finite difference techniques to generate solutions to the resulting multivariate parabolic partial differential equation(s). Isotropy and homogeneity in the physical and geometric coal structure properties are often assumed, and the existence of fundamental random fluctuations in these proper- ties is not catered for. The model proposed herein does not suffer these inadequacies, and its efficiency is enhanced by the replacement of the diffusion equation by an accurate approximation. Dynamic mining activity, gas contributions made by the geology surrounding the mining seam, goafing of overlying strata and the effects of induced strain are all taken into account.

Jan 1, 1995

By Donald W. Peters

The 191 million acres of public lands that are managed as National Forest System Lands contain extensive geologic habitat for over 40 industrial minerals. The Forest Service actively encourages exploration for and development of industrial mineral deposits within the National Forests. However, due to competing interests, the Forest Service may not always be able to accommodate industry needs. In order to successfully compete with ever-increasing demands for all resources in the 1990's, industry needs to become more active in public involvement and education and in communicating its contributions and needs to public land managers.

Jan 1, 1991

By Cliff G. Paton, Sheldon B. Bland, Roger E. Melley

This paper looks at four critical lubricants used in the conveyor systems of the northern Albertan oil sand facility. The requirements for the lubricants used in the electric motors and gear boxes of the drive systems, the pulley bearing and the idler bearings are discussed in terms of the applications and the environment. A number of developments that have occurred in recent years are presented. Data from the field and from custom designed testing in the laboratory are used to support the role of simulation testing in problem solving in this area of technology.

Jan 1, 1996

By Gordon R. Wicker, Peter V. Avotins, Steven S. Ahlschlager

Laterite ore slurries exhibit Bingham plastic behavior and can be characterized by the magnitude of their yield point and Bingham viscosity. These two parameters are affected by ore composition, solids concentration, and temperature and are used to predict the pressure drop in pipelines and heat transfer coefficients in shell-and-tube heat exchangers. In cycloning of laterite slurries, the calculated cut size is corrected by factors obtained from the rheological parameters.

Jan 1, 1979

By L. A. Puchkov

The paper presents the outline of the results in the algorithms and software of the microprocessor-based system for the powerful drugline bucket automatic motion, as well as the technological process control and functional diagnostics of the electrical equipment. The system is, aimed at the increasing both the draglines' working efficiency and the professional, competence of the operators. The excavator-dragline, equipped by the automatized operation, diagnostic and information processing system, possesses considerable technological: flexibility, which can widen therefore its field of application. The tasks of the dragline bucket motion optimal operation, programming of the excavation and overburden dumping processes, as well as the tasks of the control and the analysis of the technological parameters and the diagnostics of electrical equipment conditions, are defined in the paper. In our paper we present the results of these tasks being solved, providing the algorithms of the main mechanisms for the automatic operation for the swinging bucket controlled motion, the algorithms of the statistical analysis of the working efficiency parameters the algorithms of the diagnostics for electrical driving systems. The algorithms of the motion operation are constructed using the predicting dynamic models. The diagnostic algorithms at the normal working conditions form a number of algebraic invariants always equal to Ø with the accuracy up to when the electrical equipment is parametrically adequate. The algorithms of evaluating and analysis of the excavation efficiency make use of the direct measurement and analytical identification. The working condition and quality of the operation and control algorithms are investigated by simulation and natural testing. The results of the mathematical simulation of the bucket motion (with the 20 m3 capacity) of the excavator-dragline with the boom of 90 m in length are given in the paper.

Jan 1, 1992

By L. M. Nuelle

Rare earth element (REE)-and gold-bearing breccia pipes are a potentially significant economic target in the Pea Ridge iron ore mine, Washington County, Missouri. The Pea Ridge deposit is one of eight known volcanic-hosted iron ore deposits in the Middle Proterozoic St. Francois terrane, which are similar to the Olympic Dam-type deposits of Australia. The iron orebody is steeply dipping, tabular-shaped, and cuts across the host rhyolite. The footwall of the deposit is zoned from the massive apatite-bearing magnetite core outward to heterolithic breccia, pseudobreccia, specular hematite zone, to an extensive silicified zone. The hanging wall is zoned from the massive magnetite core outward to a heterolithic breccia, pseudobreccia, and an amphibole skarn zone. The REE-rich breccia pipes cut through the various lithologies along the footwall at or near contacts. They are typically 60 m long, 15 m wide, and extend at least 120 m vertically. The pipes are comprised of fragments of rhyolite host rock, massive magnetite zone, specular hematite zone, and silicified zone rocks supported in a matrix of rock flour, barite, feldspar, monazite, apatite, chlorite, xenotime, and, locally, gold. Total REE oxide content of samples of the ground mass material, which are not diluted with lithic fragments, average about 20 weight percent. Grades from working faces in the mine are lower and average about 12 weight percent. Gold distribution is erratic, but concentrations are as high as 371 parts per million.

Jan 1, 1991

By D. H. Davidson

The basic principal in the ISL process involves the recovery of metal values by moving fluids through rock instead of moving rock. The process combines surface and sub-surface operations, with the economic performance controlled by four major factors; rates of fluid injection and production from wells; the rate of mineral solubilization; the volume of rock swept by the fluid; and the volume of solution processed through the system. This paper discusses various technical and economic parameters affecting these four factors and how they impact project costs.

Jan 1, 1985

By Emmet K. Oslen

Kaiser Steel Corporation, the pioneer steelmaker on the Pacific Coast, was founded by the late Henry J. Kaiser. In 1944 the Company purchased from the Southern Pacific Railroad an iron ore property 200 miles east of Los Angeles known as Eagle Mountain. Today the domestic operation of Kaiser Steel Corporation consists of the iron mine at Eagle Mountain; two coal mines, one each in Utah and New Mexico; an integrated steelmaking complex at Fontana, California; and several steel fabrication and erection facilities along the west coast. Kaiser Steel also has interest in Hamersley Iron, Ltd., Australia, and Kaiser Resources, Ltd., British Columbia. Eagle Mountain Mine is located about 80 miles east of Palm Springs and adjacent to the southeast corner of Joshua Tree National Monument. The area is one of the most arid in the world averaging only two inches of rain annually. Geologically, the mine is at the western edge of the Basin and Range Province which covers about one-half million square miles of the western United States. The Province is typified by north to northwesterly trending fault block mountain ranges separated by sediment filled valleys, Production has totaled over 82 million tons of finished products since the first shipment in June, 1947. Over 500 million tons of material have been mined from the deposit to date. Eagle Mountain Mine is noted for the pioneering use of the largest and most up to date equipment to mine and process its ore. In 1961 Eagle Mountain received the first fleet of 100-ton haulage trucks in the mining industry. There were thirteen semi-trailer units in the fleet. The first 12 to 17-yard size shovel in the mining industry was placed in operation at Eagle Mountain during 1962. Rotary drilling was introduced at Eagle Mountain in 1954 to replace churn drilling. Eagle Mountain was the first major mine to use metallized slurry when three aluminum slurries were introduced for primary blasting in 1962.

Jan 1, 1972

By Robinson Leon-Diaz, Alberto Jaen-Toribio, Raymond Blanchard, Mike Deevy, Miguel Fuentes-Llanos

"Tunnels designed to NFPA 502 are required to withstand the RWS time-temperature curve, more specifically prevent progressive spalling and loss of strength of steel reinforcement. Fire boards or spray-on layers can be effective, however, these solutions have capital and whole-life cost implications. The use of “fire resistant” concrete based on a suitable aggregate with polypropylene fibers has also increased in recent years. This article presents a new methodology for thermal and structural analysis of segmentally lined tunnels, which permits the analysis of project specific fire curves and an assessment of different fire protection strategies. The effectiveness of fire boards is assessed along with whether “fire resistant” concrete alone is a viable means of achieving the required protection. Finally, since NFPA 502 recommends water-based fixed fire-fighting systems for Category C and D tunnels, we discuss the question of how a fixed fire-fighting system should be addressed within the structural design. INTRODUCTION Protecting road tunnels from structural damage and collapse is a key requirement for both life safety and business continuity. Where road tunnels are part of key highway corridors, protecting business continuity is a high priority for owners, operators and the Authority Having Jurisdiction. For existing tunnels, compliance with NFPA 502 may require upgrades with either passive fire protection and/or water-based fixed firefighting systems. For new tunnels, compliance with NFPA 502 requires a combination of good practice in design and fire testing. A water-based fixed firefighting system is a Conditionally Mandatory Requirement1 for Class C and D tunnels, i.e. all tunnels greater than 300m and 1000m long respectively. The basis for fire safety design of new tunnels and assessment of existing tunnels is the worst-case fire scenario. A number of factors, including but not limited to the following, influence this design fire scenario:"

Jan 1, 2016

By Tracy T. Morris

The current state of the mining community has made it imperative for operations to reduce costs and increase productivity in order to remain competitive. This has been done in Colorado with the installation of an Outokumpu flash flotation machine for the production of a gold/silver/lead concentrate.

Jan 1, 1987

By M. Ramachandran, R. G. Reddy

"A direct route for the reduction of magnesium oxide to magnesium using thermal plasma processing, with methane as the reducing gas, has been systematically evaluated. A feasibility study of the reduction reaction has been performed on the MgO-CH4 system at different methane concentrations and temperatures. The effects of changes in the key process parameters, such as the oxide-to-methane ratio and plasma power, on the yield of magnesium have been systematically evaluated. A maximum yield of about 61 mol% Mg was obtained using power of 20.0 kW and a molar ratio of MgO:CH4=1:1. Phase, morphological, elemental and binding energy analyses were performed on the product powders to understand the reduction reaction. Surface oxidation was observed in smaller magnesium particles in all the experiments, while the in-situ sintering of magnesium rods was observed at a molar ratio of MgO:CH4=1:1.5. Magnesium carbide (Mg2C3) was observed in the product, and its mechanism of formation is proposed using phase equilibrium data and a predominance diagram.IntroductionMagnesium has an excellent combination of low density and high strength. These properties have increased worldwide demand for and use of magnesium. Two major processes are used in the commercial synthesis of magnesium metal. The first method is electrolytic reduction and the second is thermal reduction using Pidgeon process. These processes can be classified as traditional techniques, but there are numerous emerging technologies that aim at reducing the production cost of Mg, its environmental impact and energy consumption. Thermal plasma processing is one emerging technique that has great potential in all the abovementioned key areas of magnesium production.Traditional reduction techniques. Two major reduction techniques, namely electrolytic and thermal reduction, have been used in the commercial production of magnesium. Electrolytic reduction is typically carried out in electrolytic cells from magnesium chloride (obtained from seawater or well and lake brines) (Tripp, 2009). The following simplified reaction shows the reduction of magnesium chloride to liquid magnesium and chlorine gas:"

Jan 1, 2015

By D. Hodouin

The optimisation of mineral processing plants requires the evaluation of performance indices such as production rate, product quality, valuable mineral recovery and process efficiency. Decision to change operating conditions or equipment to improve plant performances rely on the significancy of the estimated performance indices. The better is the quality of the estimation, the better is the discrimination capability of the index and as a consequence the larger is the operation improvement. The reliability of performance calculation depends on the sensors nature, accuracy and location, on the data redundancy, on the correction method applied to raw data and finally on the propagation of measurement errors along the calculation of performance indices. To maximize the quality of the data collected for performance evaluation, the following techniques are presented, discussed and illustrated: redundancy and observability analysis, data filtering for mass conservation, variance analysis of performance calculation, and data acquisition strategy design.

Jan 1, 1991

By L. Berwick, A. Karunanayake, D. Skutt, H. Heath, J. Wang

Thallium (Tl) is a highly toxic heavy metal, soluble over a wide pH range. Tl levels may exceed discharge limits in mining-influenced water associated with processing gold, lead, cadmium, zinc, and copper ores. In this work, the effect of sodium permanganate (CARUSOL® C liquid permanganate) on Tl removal from mining wastewater was studied. Factors influencing Tl removal, namely permanganate dosage/demand, coagulant and flocculant use, order of chemical addition, and co-existing metal ions were examined. The results show that permanganate addition is very effective at removing Tl to below target limits and can provide a unique solution for improving wastewater quality and optimizing overall treatment costs. In addition, several on-line monitoring techniques were evaluated for process optimization. The Hach DPD Free Chlorine method was optimal, allowing plant operators to rapidly and easily spot check effluent samples for excess permanganate dose.

Mar 2, 2022

By J. S. Jaspal

Mining of thin coal seams is both difficult and uneconomical. As a result, most of thin-seam coal reserves in the U. S. are not being mined. It is estimated that nearly 910 Gt (K. Unrug, 1985) of coal reserves exist in 355 to 710 mm thick seams. The Bureau is attempting to develop new techniques for mining 150 to 1065 mm thick coal seams. This paper summarizes the research work on existing thin-seam mining techniques, testing on small and full scale physical models of the Bureau slot mining concept, and computer modeling of the full-scale process.

Jan 1, 1992

By R. L. Frederking

Geological remote sensing is, "....the study of the Earth utilizing electro-magnetic radiation (EMR) which is either reflected or emitted from the land surface in wavelengths ranging from ultra-violet (0.3 micrometre) to microwave (3 metre)."1 Selected examples which illustrate a variety of successful geologic applications include lithologic mapping, 2 engineering soils mapping,3 tectonic interpretation,4 and mineral and petroleum exploration.5 This report examines the applicability of remote sensing for bauxite exploration in northeastern Mississippi. Specific objectives were to map lithologies of northeastern Mississippi from LANDSAT imagery, to determine the utility of LANDSAT imagery for delineating and mapping known deposits of bauxite, and to discover and map new bauxite deposits.

Jan 1, 1977

By A. E. Aldrich

The Pittsburg & Midway Coal Mining Co. (P&M) is expanding a combination of surface and underground coal mining operation in Northeastern New Mexico. The York Canyon Complex, located 35 miles west of Raton, New Mexico, is aggressively pre-paring for increased production while meeting present requirements. Surface mining activities in four separate mining areas are preparing the complex for additional markets. Drag-line, truck/shovel, highwall miner and contour stripping are surface mining methods currently planned. In addition, P&M will move a Marion 8200 dragline from Kansas to the York Canyon site, finish constructing a $20 million coal preparation plant, and complete conveyor upgrades to the existing underground mine. This paper will describe the diverse York Canyon Complex.

Jan 1, 1993

By Robert M. Rowe

Among the increasing operating costs affecting today' s processing facilities are those necessary in meeting the continually growing requirement for safe and environmentally sound materials- control and handling procedures. Of particular interest are materials listed as hazardous, the need to maintain accurate records of their acquisition, consumption and disposal, and the obligation to employees and the community to have information available regarding such materials. Some requirements affecting modern operating facilities are reviewed in this paper, and potential methods for dealing with complex handling and documentation requirements, including computer automation, are discussed.

Jan 1, 1991