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By Rolando Gonzalez

Mexico’s role in the world economic community continues to grow. And it is important that the country makes use of its natural wealth, including its large underground deposits of minerals and metals. With that in mind, Industrias Peñoles S.A. de C.V.(Peñoles), a mining, smelting and refining company, began mining lead, zinc and other metals from the Francisco I. Madero Project (FIM). The mine is located about 600 km (370 miles) northwest of Mexico City in the state of Zacatecas. Peñoles plans to remove about 3 Mt/a (3.3 million stpy) of ore from FIM. To achieve this goal, the company needs to optimize its processing, to maximize the amount of metal it extracts through FIM’s large flotation lead-zinc concentrator. To ensure high productivity, Peñoles and its contract engineering firm, M3 Engineering and Technology, of Tucson, AZ, have implemented anore processing system.

Jan 1, 2003

By Frank L. Gaddy

Falls of roof account for over 50% of the fatalities that occur in coal mines in the US. Thus, roof control is one of the more important phases of underground mining. In reality, the control of roof influences the system of mining and is a major determinant of the width and spacing of working places, operations at the mining face, ventilation control, and surface subsidence. Frequently, the control of roof is the largest single cost item. Roof control is a never-ending task, not only at the working face and throughout sections where men are working, but along haulways and air- ways that must be maintained for the life of the mine. This is because roof, even the best of roof, slowly deteriorates, so it must be frequently examined, with corrective support applied when needed. As coal is excavated, stresses are set up in the roof because the previous equilibrium is upset, resulting in pressures that cause fractures and slight movements that are frequently hard to detect. Unless the immediate roof, in the excavated area, is given support by artificial means, it might fall or there might be a succession of falls, varying from a thin scale to several feet, depending on the nature of the top. Exceptions to this are those rare mines, or sections of mines, with hard, strong, nonweathering roof that requires no support.

Jan 1, 1981

By C. M. Jones

The training program developed at Sierrita over the last twelve months has led to several significant improvements in both safety performance and productivity. Our most easily quantified results have been in truck productivity, where we have also experienced a 6% decrease in truck cycle times. We feel this is due to increased skill levels and awareness on the part of our operators due to our new training effort. The cycle time improvement has resulted in an increase in Truck productivity of 6%. Costs associated with productivity training have been $160,300. This includes program development and execution costs, as well as lost productivity during the training itself. These costs are offset by $1,400,000 in savings directly attributable to the increased skill levels of our technicians due to our training effort. As such, this represents a solid, high return investment at Sierrita.

Jan 1, 1998

By John McDonald, Peter C. Raleigh, Christopher Dishlip

This paper will discuss how the construction management team and the contractor working together on the City of Los Angeles, North East Interceptor Sewer project, managed information on a daily basis. Data was synthesized from various sources including: inspection, survey, instrumentation, laboratory and the tunnel boring machine data logger systems to produce state-of-the-art reports and graphics which will become industry standard. Special emphasis is placed on how the data is managed and interpreted in a clear and objective manner, permitting the tunneling processes to be carefully monitored and suggesting appropriate action to be taken by the construction management team and contractor.

Jan 1, 2005

By R. F. Davis

The evaluation and selection of coals for producing metallurgical coke is indeed a com- plex process simply because coal is a complex and variable substance which is sensitive to how it is treated from the time it is mined until it is transformed into coke. A review of the the more common evaluation tests made on coal and how the test results are applied in commercial practice. Parameters used to select coal blends for wet and preheated charges should also be of interest.

Jan 1, 1980

By P. R. Dugan

Sulfur removal from high sulfur coal has several objectives including: a) reduction of the atmospheric load that contributes to the problem of acid precipitation; b) reduction of ash, which contributes to decreased energy transfer in boilers, as well as ash disposal; and c) alleviation of the social and economic dislocations related to uneven geographical distribution of sulfur in coal reserves. Cost in relation to the value of refined coal will govern the development of an emerging coal refining industry. Estimation of the premium paid by power companies for coal with a low sulfur content is a good estimate of the value that will be added as the result of refining. Estimates of premiums paid in 1984 are $28.65/t ($26 per st) for reduction of total sulfur from 370 to 1% S and greater than $28.65/t ($26 per st) for removal below 170 sulfur.

Jan 1, 1988

By I. M. Ahmed, R. S. Hassan, M. I. Aly

Extraction and separation of La, Sm and Dy ions from acidic sulfate-phosphate solutions was investigated using a cation exchange extractant, bis(2,4,4-trimethylpentyl) phosphinic acid, CYANEX 272, in kerosene. The influence of shaking time, equilibrium pH, extractant, sulfate and phosphate ion concentrations, diluent type and temperature was studied. The extraction was found to be pH-dependent, and increasing the phosphate ion concentration inhibited the extraction which was found to be endothermic. The stoichiometry of the extracted metal species was found to be MOH.H2OHSO4H2A.A2. Aliphatic diluents were found to enhance the extraction compared to aromatic diluents. The results showed that there was a separation mode between the metal ions when varying the hydrogen ion and sulfate ion concentrations, under the used experimental conditions. The investigated process was used for the recovery of La, Sm and Dy from the acid solution resulting from the leaching of low-grade monazite.

By R. Maurice King

In the operation of today's large scale ore-processing mills, it is extremely important to have some way of making an objective evalu¬ation of the performance of the available flotation reagents. Attempts to do this may often result in inconclusive findings since the magnitude of the difference in the mill results for any two reagents is apt to be quite small compared to the variability introduced by the process and 'the analytical procedures used to measure them. In cases where two reagents give vastly; different mill results, evaluation becomes a simple matter and as such deserves no further attention here. A question of primary concern, however, is how a mill can go about evaluating the performance of two reagents which may, for example, give a difference of only 0.001% copper in the-tailings or of 0.2% in copper recovery. The casual observer may feel that such small differences may be of little importance, but in a mill-whose daily tonnage is between 30 and 40 thousand, these differences could mean a substantial savings. Before the presentation of an actual example of a reagent testing scheme designed for just this-purpose, perhaps a few minutes should be devoted to a review of some statistical methodology to be used later in the discussion.

Jan 1, 1964

By P. L. Sibrell

Previous research by the U.S. Bureau of Mines showed that autoclave cyanide leaching of used automobile exhaust catalysts for recovery of platinum group metals (PGM) was technically feasible. This work involves a more detailed investigation of the chemistry of the dissolution of PGM in cyanide solutions. The PGM species in solution identified by ultraviolet spectroscopy. Pt and Pd cyanide complexes were square were The planar in geometry, while the Rh complex was octahedral. The rate of dissolution of the PGM was also investigated using a rotating disk technique. Dissolution rates increased in the order of Rh, pt, and Pd, respectively.

Jan 1, 1994

By Henry A. Russell

During the last ten years Parsons Brinckerhoff has become a leader in the area of tunnel rehabilitation. A significant part of any tunnel rehabilitation program is the control of groundwater infiltration into the structure. This leakage over time, causes deterioration of the structures, and creates numerous operational problems for the tunnel operator. This paper will address current procedures for identification, documentation, and recommendations of repair methods for the control of groundwater infiltration in rail and highway tunnels.

Jan 1, 1993

By S. S. Peng

In this paper, the precise definitions for a number of commonly used subsidence parameters are given. The subsidence parameters have been determined using an integrated approach for 110 subsidence cases collected in the major US coal fields. Attempts have been made to establish empirical formulae for the parameters. The results of this study indicate that some traditionally-held concepts should be changed.

Jan 1, 1995

By D. S. Kimbal

The McCoy/Cove mine is located 48 km (30 miles) south of Battle Mountain, Nevada, USA, in the Fish Creek Mountains at an elevation of 1548 m (5080 ft), see Figure 1. Joseph H. McCoy first discovered gold at this location in 1914. This discovery led to the Gold Dome Mine which produced the first gold from this area in 1928. After the Gold Dome era, the land remained relatively dormant until Houston oil and Minerals Corporation purchased the claims from the Summa corporation and defined an ore body at the present day McCoy pit. In 1986 Tenneco Minerals (formerly Houston oil and Minerals corporation), sold the McCoy mine and adjoining claims to Echo Bay Minerals corporation. The Cove ore body was discovered soon after the sale to Echo Bay. Echo Bay expanded the heap leach operation and built the present mill which began processing ore in the fall of 1989.

Jan 1, 1993

By V. Anthony Cammarota

MINERALS INFORMATION PROGRAM Mineral data collection by the Federal Government actually began in 1882 with an appropriation by Congress to the U.S. Geological Survey (USGS). Although the Bureau of Mines was instituted in 1910, it was not until 1924 that the collection, interpretation, and dissemination of worldwide information on production, consumption, and availability of minerals became the responsibility of the Bureau. The objective of the Bureau's minerals information program is to maintain and provide reliable, timely, and comprehensive data for analysis of national minerals problems. This program is implemented by a staff of specialists who cover about 100 mineral commodities and the mineral industries of 168 countries. Data are also provided on the minerals industry on the State and county level. The specialists analyze information to identify trends and problems, forecast future U.S. and world supply and demand for the nonfuel minerals, and relate trends and developments to their impact on the domestic minerals industry. Data Sources and Publications The primary sources of data concerning the domestic minerals industry are the companies that produce, use, and trade in these minerals. Approximately 60,000 survey forms are sent to industry, on a monthly, quarterly, semiannual, or annual basis, to obtain the data. Domestic trade data are provided by the Bureau of the Census, U.S. Department of Commerce. Information on mineral developments abroad is developed by Bureau specialists from mineral reports supplied by U.S. embassies worldwide, from primary source documents, from a review of the technical mining literature, and from onsite mine and plant visits in foreign countries. The information is disseminated through a number of Bureau publications: "Mineral Industry Surveys" provide aggregated data on a monthly. quarterly, or semiannual basis to give timely information on the most important mineral commodities. "Mineral Commodity Summaries," published each January, provides preliminary annual data on supply and demand and discusses significant events of the previous year. The final data are published later in the "Minerals Yearbook," which is the definitive historical record for mineral statistics. "Mineral Facts and Problems," an encyclopedic work issued every 5 years, covers industry structure, technology, supply-demand analysis. economic factors, reserves, and forecasts of U.S. and world demand for individual commodities. "Mineral Perspectives" and "Mineral Issues" cover important international mineral developments and significant issues of current U.S. policy as they relate to minerals. Discussions and analyses of mineral trends and developments also appear in other Bureau publications, such as "Minerals and Materials" and "Information Circulars." These publications provide the basis for analysis and policy determinations by the Bureau and by virtually every Federal agency concerned with minerals, defense issues, the national economy, and foreign relations. The data are also used by industry in planning capital investments in mines and processing plants, by financial analysts, by U.S. delegations in their work with international commodity groups, and by a host of other minerals related organizations. Data Bases The data bases used by the specialists for preparing publications or in response to a continuous stream of inquiries include both those that contain individual commodity data from respondents, and those that are summary data bases on production, trade, capacity, employment and a number of other minerals-related items, not all of which are derived from data reported to the Bureau of Mines. The data bases maintained on the mainframes are not accessible by non- Bureau users. A 10-year data base of supply- demand data, published each year as an update of tables that appear for each commodity in Mineral Facts and Problems, is available on a floppy

Jan 1, 1987

By Keith Olson

In the heart of Appalachia, where coal mining has shaped communities and economies for generations, Bluefield State University (BSU) has made a landmark decision to reestablish its mining engineering technology program. This move comes at a critical juncture for both the university and the mining industry, which faces significant workforce challenges amid evolving technological demands and an aging professional demographic. The program’s revival represents an educational initiative and a strategic response to industry needs and regional economic development. Nestled in the mountains of southern West Virginia, BSU has a storied history intertwined with the region’s mining heritage. The institution’s decision to bring back this specialized program after a hiatus of several years signals a renewed commitment to serving both regional industry demands and providing career pathways for students in an area where the cyclical nature of resource extraction economies has often limited economic opportunities. “This program’s return reflects our deep understanding of this region’s needs and our commitment to preparing graduates for meaningful careers that support our local industries,” said Darrin Martin, president of Bluefield State University. “We’re bridging the gap between education and industry with a modernized curriculum that addresses today’s mining challenges while preparing for tomorrow’s innovations.”

Jun 1, 2025

By Hisashi Takahasi, Hironobu Yamazaki

INTRODUCTION The slurry shield method was developed in Japan in 1963 and its experimental tunnelling work was performed in 1965. Although the history of this method is short compared with the conventional shield method in Japan, many companies such as Tekken Construction, Okumura Gumi, Nishimatsu Kensetsu, etc. are engaged at present in developing their own unique system of the slurry shield method. The ground of Japan is generally pervaded with ground water and a large number of districts are covered with soft ground, which is composed of fine sand, silt and clay, etc. Therefore, the conventional shield method has always used compressed air with various kinds of auxiliary methods. However, with this method there have been experienced numerous troubles such as ground settlements, lowering of ground water, oxygen shortage within the tunnel, and so forth. The slurry shield method has been developed with the above background. In recent years remarkable progress has been made from the engineering viewpoint in applying this method to driving various kinds of tunnels such as road tunnels, subways, water supply and sewer tunnels, and other tunnels. Apart from Japan, the slurry shield process using bentonite is carried out in England and Germany. OUTLINE OF SLURRY SHIELD METHOD (1) System of Slurry Shield Method Since the conventional shield method drives tunnels using com-

Jan 1, 1976

By W. A. Heitbrink, M. Schmitz, J. A. Organiscak, A. B. Cecala, E. Ahrenholtz

Mobile excavation equipment operators at surface mines generally have the highest exposure to airborne respirable silica dust. Operator cabs on newer equipment are usually enclosed and equipped with heating and air conditioning systems. Many newer cabs are also equipped with air filtration systems. However, some newer cabs and many older cabs have either inefficient or no air filtration systems. The U. S. surface mining industry is still populated with older equipment and many of these have cabs that provide little or no respirable silica dust protection. Collaborative field studies were conducted as part of a partnership involving NIOSH, Clean Air Filter®, Red Dot, MSHA, and several mine operators to demonstrate that effective dust protection can be provided by these cabs at a nominal cost to mine operators. This effort encompassed adding an external make-up air fan and filter system to a retrofitted roof-mounted heating and air conditioning system in three older equipment cabs, and attempting to seal the cab enclosures to achieve interior cab pressurization. Abetter than 90 percent dust reduction was measured inside two of the three enclosed equipment cabs. It was possible to achieve positive cab pressurization inside these two cabs. A less significant dust reduction was measured inside the third cab, where positive pressurization was not achieved. These field studies demonstrate the key elements needed to improve enclosed cab dust protection in a cost-effective manner.

Jan 1, 2003

By M. C. Manderson

While the United States has been the world's largest volume producer and marketer of phosphatic fertilizers for many years, it has recently suffered heavy losses for a variety of reasons. While improved economic performance is expected, it is still at least a year or two away. But when recovery does manifest itself, it will likely yield only mediocre profits, due in part to the fact that about 50 percent of output is export-dependent. Therefore, there appears to be limited likelihood that profits will be adequate to justify the further outlay of large amounts of capital for expansion.

Jan 1, 1986

Effective tools are not only essential for the design of practical and efficient underground mine ventilation systems but must also play an integral part in the operation of the mine. One such tool is VUMA-coal ventilation simulation software. VUMA-coal is Windows-based and has been specially designed for the simulation of underground coal mines and includes user-friendly coal specific interfaces and three-dimensional graphics designed to facilitate in the construction and analysis of networks. VUMA-coal can be utilised during the design phase of new collieries, be used to conduct ?what-if? and optimisation studies, and be integrated into the ?day-to-day? ventilation related operations. In addition, VUMA-coal can be used to simulate dust and gas distribution in a ventilation network, as well as predict the impact of control measures. This paper describes the interactive VUMA-coal ventilation simulation software and its underlying design features and outlines a case study of how VUMA-coal has been integrated into Anglo Coal?s Ventilation and Occupational Hygiene Engineering [VOHE] department as part of the standard planning and evaluation process in their operational mines as well as long term planning and future mining operations.

Jan 1, 2009

By Kenneth S. Johnson

Large reserves of high-purity Permian gypsum crop out and are at shallow depth in three regions of western Oklahoma, Gypsum beds in the Blaine Formation are 10 to 30 feet thick and are generally 95 to 99 percent pure, whereas the massive Cloud Chief Gypsum is 20 to 100 feet thick and is 92 to 97 percent pure. Reserves are estimated at 48 billion short tons. Eight companies in the State currently mine about 1 million tons of gypsum each year for wall- board, for plaster, as a retarder in portland cement, and as a soil conditioner. Future uses, under more favorable market conditions, may be in the chemical industries, largely because of gypsum's potential as a source of sulfur. Three thick sequences of Permian rock salt underlie most of western Oklahoma at depths of 30 to 3,000 feet. Individual salt beds 5 to 30 feet thick are interbedded with thinner layers of shale and anhydrite. Five large salt plains, fed by natural springs of saturated brine constitute additional resources of salt. Reserves, estimated at 20 trillion short tons, are virtually untapped, and, ironically, about 90 percent of the salt used in Oklahoma is imported. Chemical data on the rock salt are lacking, but evaporated salt produced from brines is generally 97 to 99 percent pure. Current production from three solar-evaporation plants is used mainly for stockfeed, recharging water softeners, and deicing roads. Potential uses are in the chemical industries, where salt or brine is a necessary raw material.

Jan 1, 1973

By B. M. Davis

The problem of assessing uncertainty in grade estimates has been a topic of research and debate since kriging was first introduced. Use of the kriging variance was originally touted as all that was necessary in order to produce confidence limits for grade estimates. Since then the prudence of using the kriging variance for confidence interval estimation has been questioned, and techniques such as the jackknife and conditional simulation have been proposed to develop "true" interval estimates. This paper compares the differences between interval estimates produced by the three methods and makes conclusions about the performance of confidence intervals produced by the different methods.

Jan 1, 1997