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By Turan Uysal, Thierno Saidou Barry, MURAT ERDEMOGLU, Mustafa Birinci

Nonbauxite ores such as aluminum silicate clays and coal fly ashes have been widely considered as potential resources of alumina (Al2O3). The interest focused on these ores is due to their high alumina content. Over the years, in countries where there are little or no bauxite reserves or where the recovery of existing bauxite ores to produce alumina with the Bayer process is not economical, alternative processes have been explored. Among these processes, acid leaching is seen as the most attractive process. In the acid leaching process, heat treatment for thermal activation to destruct the refractory structure of the minerals in the ores is generally recommended as a pretreatment method. Recently, the applicability of high energy ball mills, which are useful for mechanical activation as a pretreatment method before leaching, has attracted much attention. This is a short summary of our previous review [1], giving the details of alumina manufacturing from thermally and mechanically activated clays and coal fly ashes by acid leaching.

By D. J. Rose

The San Miguel Mine is owned by San Miguel Electrical Cooperative, Inc. and operated by Atascosa Mining Company, a wholly-owned subsidiary of Morrison-Knudsen Company, Inc. This multiseam, single-zone lignite surface mine is located near Jourdanton, Texas, 110 kilometers (68 miles) south of San Antonio. Lignite extracted from four closely-spaced seams is used to fuel the 400-MW San Miguel Power Plant. Recovery depths range from 7 to 37 meters (25 to 120 feet). The mine began stripping operations in the spring of 1980 and now produces approximately 2.5 million tonnes (2.8 million tons) of lignite annually. Atascosa Mining Company is responsible for production, maintenance, engineering, and management services. Production responsibilities include topsoil removal, overburden removal, lignite mining, spoil pile regrading and topsoil replacement, as well as ash disposal and construction and maintenance of water retention and diversion facilities.

Jan 1, 1984

By Peter I. Brooker

The turning bands method for the simulation of spatially correlated data in two or three dimensions requires that the relation- ship between the covariance obeyed by the realizations first generated on lines, and the covariance of the two or three dimensional process must be solved. In three dimensions the solution is immediate, but in two dimensions the integral equation relating the covariances of the one and two dimensional processes is more complex. This is solved in this paper and is applied to the most common model used in ore deposit description, the spherical covariance.

Jan 1, 1984

By W. H. Jang

Although surface chemistry fundamentals of semi-soluble minerals have been studied by many researchers, detailed understanding of these systems is still incomplete. In-situ FT-IR/IRS techniques have recently been used to successfully describe the adsorption of carboxylates at semi-soluble mineral surfaces. However, the wetting characteristics of these adsorbed films require further consideration. In this regard, the hydrophobicity and stability of transferred Langmuir-Blodgett (LB) monolayers of fatty acids at fluorite and calcite surfaces has been studied by contact angle measurements with polar and apolar liquids. Generally, it was found that the transferred LB monolayers of fatty acids at a calcite surface are unstable whereas such monolayers transferred at a fluorite surface are stable, as revealed from advancing and receding contact angle measurements. These results are believed to be due to the incomplete reaction of fatty acid monolayer at the calcite surface. In addition it was found that a closely packed well-ordered stearate monolayer with good hydrophobicity, equivalent to that of a transferred LB monolayer, can be formed at fluorite surfaces by spontaneous adsorption and self-assembly from aqueous solutions.

Jan 1, 1995

By Yi Zheng

Under normal circumstances, methane released along a longwall face represents only 10%-20% of the total me- thane emitted from the entire longwall panel. However, there might be a sudden surge of methane at the face which may cause a potential problem because the friction from shearer cutting, support movement, and scraper conveyor dragging can be ready ignition sources. Therefore, to predict the distribution of methane will be critical to prevent possible explosions. In this paper, methane dispersion patterns along a lognwall face are simulated under normal and abnormal conditions. With the simulation of methane released from the face, around shearer drum, and from the broken coal on the conveyor, places with possible high methane content can be identified by different phases of working process and shearer positions. Local ventilation measures are evaluated so precautionary measures can be planned ahead.

Jan 1, 2012

By Ulrich Benatzky

Rheinbraun AG, Germany, is the management company of the mining and raw materials division of RWE AG. Rheinbraun's core business and major functional area is opencast lignite mining in the Rhineland. The characteristic feature of opencast mining is continuous operation using bucket-wheel excavators, belt conveyors, and spreaders. The report gives a survey of the conveyor systems used. In addition to the general performance data of these belt conveyors, this report will deal in particular with major components, such as drive stations and individual mechanical components (e.g., conveyor belts, pulleys, gears, couplings, brakes, scrapers), as well as monitoring systems. Finally, an assessment of the conveyor systems, together with future developments, will be given.

Jan 1, 2000

By G. Montgomery

This is a summary of what has happened to the domestic production of two industrial minerals vital to a healthy US economy: fluorspar and barite. A few years ago we were self-sufficient in both minerals and good ore reserves still exist. FLUORSPAR Some 9% of the fluorspar presently being consumed in the US is imported, whereas the use of fluorspar has not declined proportionately. Several factors can be mentioned.

Jan 1, 1986

By S. F. Willey

The difficulties encountered in justifying replacements for over-age mobile mine equipment at the Gay Mine are common to most mining operations. More critical management reviews, resulting from ever rising capital expenses, increased such difficulties. These increased difficulties are especially apparent to those who are primarily operators and are not statisticians, mathematicians, or computer oriented. The Gay Mine is located 17 miles east of the town of Fort Hall in southern Idaho. This open pit operation annually supplies the J. R. Simplot Company and the FMC Corporation with 1.5 MM - 2.0 MM tons of phosphate ore. Stripping ratios average approximately three bank cubic yards of waste per ton of ore mined. The mobile mine equipment fleet consists of ten 24 yard scrapers; twenty-one 30-50 ton end dump trucks; four 32 42 yard shovels; fifteen dozers in the D-8 and D-9 classes; and three road patrols. Equipment replacement is based on the results of evaluations made on individual units. Authorization of capital expenditures for equipment replacement is dependent upon a favorable profitability index (true rate of return on investment) plus a favorable payout time. The system is based on cash flows and requires the determination of (1) the net cash outflows in the form of capital expenses plus (2) the expected cash inflows resulting from reduced expenses and depreciation tax credits. After adjustments for taxes and the time value of money, the net amounts are used to calculate the required indices. The basic elements for the system related to the replacement of mobile mine equipment include: (1) the determination of dollar penalties to be expected from the continued use of aging equipment; (2) the selection of equipment that will provide the greatest return on the investment dollars; (3) the quantification of the expected savings; and (4) the calculations of the prescribed indices. Inadequacies inherent in previous evaluating methods led to the search for more

Jan 1, 1972

By William E. Mead

A regional investigation to find large supplies of potable ground water was carried out at elevations exceeding 12,000 feet above sea level on the Bolivian Altiplano. The program marked the first application of modern ground water search and development technology in the region, and ended a history of unsuccessful exploration efforts to locate important supplies of fresh water from underground sources. Oruro, a population center of 90,000 inhabitants, and its primary supporting industry - mining, both derived major direct benefit from the results of this program.

Jan 1, 1970

By Brendan Demich, Linda L. Chasko, Brendan Macdonald, Timothy J. Orr, Jessie J. Mechling, Cassandra Hoebbel, Jason Navoyski, William Helfrich, Jessica Cohen, Paul E. Schmidt, Jennica L. Bellanca

The National Institute for Occupational Safety and Health (NIOSH) in partnership with the Mine Safety and Health Administration (MSHA) developed VR Mine Rescue Training (VR-MRT). It is a training platform that allows mine rescue team members to explore virtual emergency scenarios collaboratively. Team members use a head-mounted display to visualize and interact together with equipment, hazards, and dynamic ventilation. All player actions are recorded and displayed for debriefing. Researchers at NIOSH demonstrated the training platform at various mine rescue competitions, including the International Mine Rescue Competition, and collected feedback. Participants’ responses were overwhelmingly positive. This paper describes the development of the software platform and the results of the usability surveys and interviews.

Jun 25, 2023

By James L. Withiam, P. C. Kelsall

The manuscript of this paper was not available for publication when the Proceedings went to press. Should the authors elect, they may distribute copies at the time of the Symposium.

Jan 1, 1986

By J. J. Reilly

The Vesta Mines of the Jones & Laughlin Steel Corporation operate in the Pittsburgh Seam in Washington County, Pennsylvania. This seam is overlain with a drawslate, 12" to 16" in thickness, which slimes readily when wet. Because of the need for a uniformly good quality metallurgical coal, the amount of reject, together with the top and particle sizes of the raw coal feed, is a serious problem at the Vesta Preparation Plant. The Preparation Plant operates two, seven and one-quarter hour shifts per day and processes 2,100 tons per hour of raw coal feed. The third shift is, used for planned maintenance of equipment. Since the water clarification equipment is so vital in insuring a uniform product, there is no alternative but that it be in operation at all times. To insure this continuous operation,. well-planned maintenance is a necessity. For years, Plant Management has kept performance records of the various units to determine the renewal dates of vital component parts, the length of wear, the various materials used in the manufacture of the equipment, and the labor cost for renewal. These records have been of inestimable help in planning an effective maintenance program to insure continuous operation of the various units.

Jan 1, 1959

By P. W. Finck

Detailed mapping, using a large diameter diamond-drill in conjunction with high resolution reflection seismics, has increased known resources of kaolin clay and glass-grade silica sand from scattered deposits generally < 1 km2 to large areas of Cretaceous valley fill up to 130 m thick. Detailed chemical and physical analysis of drill core is presently underway. Silica sand deposits intersected in this study are up to 99.4 % SiO2 without beneficiation. Light grey to white kaolin clays identified by XRD and DT A have concentrations values (without beneficiation) up to 47.28% SiO2, 37.44% Al2O3, 0.45% Fe2O3, 0.49% K2O, 0.07% Nap, 0.07% CaO and 0.39% MgO.

Jan 1, 1996

By Akram Marseet, Andrew J. Petruska, Rik Banerjee

Event cameras are used for their performance in high dynamic-range lighting conditions which are canonical to active mining environments. Direct labeling of event-based image data to train a model to perform semantic segmentation using traditional methods is slow and error-prone. This study proposes a framework to use roughly hand-labeled color images from a mine as an input to an intermediary probabilistic algorithm called alphamatting to generate a ground-truth data set. These high-fidelity labels can be used to train a semantic segmentation model to differentiate the support strap from the roof. This model can then be leveraged to segment an event-based scene to enable autonomous roof bolting. This pipeline has been shown to achieve an accuracy of 88% with a false positive rate of 3%.

Feb 1, 2024

By W. Edwin Dill

For the mining industry, the Internal Revenue Code and regulations offer a range of choices in arriving at the allowable depletion. Each case is essentially unique. Two prerequisites can optimize these opportunities: communications between the mining company&apos;s tax specialists and its technical staff; and an understanding of IRS definitions. For the latter, a logical starting point is consideration of exploration and development, since they precede production and depletion is unallowable prior to production. Criteria for selecting engineering and accounting options for exploration and development indicate the necessity of interaction between these company functions to achieve the most favorable tax position.

Jan 1, 1982

By S. Frimpong, G. Galecki

Dump truck tires are often used in long-haul roads in rugged terrain, with high rolling and grade resistances. These conditions increase the ton-kilometer-per-hour (tkm/hr) or short-ton-mile-per-hour (stmph)rating of tires, leading to tread wear, cuts and complete failures. The load-bearing capacities of these tires are sometimes exceeded, with truck overloading, overstressing, heating and subsequent failures. In addition, truck tire demand far exceeds the current supply capacity, with long lead ordering time. This condition has caused severe tire shortage, and the problem is expected to be sustained in the long-term. Industry has taken extensive practical measures to prolong tire service life with significant results. However, this problem can be solved through fundamental and applied research initiatives. This paper pioneers a research effort in tire service life using multibody physics, fatigue failure modes and soil failure dynamics to develop tire-road contact force dynamics. A virtual prototype simulator of the tire-road contact, using the CAT 775E (with standard tire 24.00R35) was developed and simulated within the MSC.ADAMS/NASTRAN environments. The results show the areas of the loaded tires with maximum Von Mises, principal and shear stresses, which could result in fatigue failure, tire wear and tear and blowouts. The maximum Von Mises stresses on the six truck tires are between 35 and 58 MPa. The maximum shear stresses are also between 19 and 33 MPa. These stresses will cause early tire failures given an average operating schedule of between 20 and 24 hours per day. The isolated areas with maximum stresses will be subjected to further studies to reduce stress intensity while preserving tire performance.

Jan 1, 2012

By S. A. Lang

Mine management in general, and mine maintenance in particular, has lagged in using computers as an effective management tool. SF Coal Corporation, in conjunction with the development of the new Lee Ranch Mine, is developing a computer-based maintenance system as an integral part of a total mine management information system. The system includes the ability to schedule and plan preventative maintenance on all rolling stock and mine facilities, project and track component life, and evaluate and schedule manpower requirements. The system hardware, shared by accounting, warehousing, engineering, production and management, consists of a multi-user, multi-processor micro-computer.

Jan 1, 1985

By L. Barnewold, A. Merchiers, M. Pütz, P. Jeschke, M. Dammers

The mining industry faces many difficult challenges, for example, lower ore grades, smaller and deeper deposits, and longer transportation distances. In the past, there have been remarkable innovations in both equipment and the types of mining methods for which it is used, which have resulted in economies of scale. This has led to an increased use of bulk mining methods, like sublevel and block caving, which has increased productivity and reduced costs. Haulage alone plays a major role. Current haulage techniques are a significant cost driver, which account for between 15 and 30% of the overall capital investment (capex) in a mine and are an increasingly part of the operating costs (opex). The paper introduces a simulation tool of main haulage system in underground mining. Therefore, performances and the costs of the three most common underground main haulage systems, rail, truck, and conveyor, are calculated using a developed modeling tool. The tool was applied and validated in a case study carried out with the LKAB Kiruna Mine in northern Sweden.

By S. S. Huyett

The opportunity to cooperate with the Mining Department of the Pennsylvania State University in their Student-Trainee Program is accepted by The New Jersey Zinc Company who believes that the participation in this type of a program will lead to a larger supply of high calibre engineers in mining. Trainees compete with other employees to earn the cost of their education while gaining practical experience in the mining industry. The practical experience is arranged to complement the technical education through a variety of work assignments. Job opportunities for the trainee are related to the work requirements of the Company and to the performance of the trainee. Management must consider and deal with a good many problems uncommon with regular, full &apos;time employees. For a number of reasons this program is recommended to other companies as a means to encourage outstanding young men who are interested in a career in the mineral industry to obtain a professiona1 education.

Jan 1, 1963

By Thomas W. Smelser

A full-scale geotechnical model of a 15-foot (4.6 m) wide coal mine entry in correlation with computer finite-element analysis (FEA) is being employed at the Bureau of Mines Spokane Research Center for basic research on roof-bolt support systems. Physical and computer modeling of various coal mine roof-bolt reinforcement systems will increase our basic knowledge of how roof supports function. This information, in correlation with computer FEA and underground verification tests, will provide a basis for establishing safer, more cost- effective roof control plans and help establish guidelines for employing fully grouted and conventional bolting systems. The basic rationale for the research, research approach, methods and equipment employed, results to date, and future research plans are described in this paper.

Jan 1, 1982