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By R. J. Yan

There was a plant equipped with a 32000t Hydraulic Press to be built, under which a box foundation of 22.5m x 15m x 14.25m (depth) with a base slab of, varying thickness was proposed. The subgrade reactions, bending moments and settlements needed to be determined by means of in-situ model test. A model of the same materials as the prototype scaled to l/10 was embedded in-situ with simulated depth in the bedrock. A lot of data obtained from 39 bench marks, 32 elongation measuring points, 30 couples of electric resistance strain gauges and 24 pressure cells attached to the model foundation enables all the quantities required to be found out. Since it was put into operation, the settlements measured has reasonably agreed with the test results and the foundation has been in good condition.

Jan 1, 2010

By Granville S. Borden

THE program for income tax legislation presented here proposes some diminution in the current tax burden on mineral producers but it will, if enacted, eventually increase the potential and current Government revenue from the mineral industry.

Jan 6, 1951

By F. T. Cawood

This paper reviews the Mineral and Petroleum Resources Royalty Bill of 2006, identifies potential areas that require further consideration by the National Treasury and, where appropriate, offers alternatives. At its basic level a royalty regime consists of two elements: the base and the rate that must be applied to the base. Deciding on an acceptable royalty rate is a complex matter and can be done only after extensive analysis of all variables affecting the competitiveness of the regime. The proposed royalty rates are in the range of zero to five per cent and are based on sales revenue. It is argued that future investment patterns are more likely to be influenced by market cycles and commodity prices than policy events. Inevitably the current boom in the minerals sector will come to an end and the success of the proposed regime will be known only when profit margins are under pressure. Policy makers must therefore have the long run in mind when developing policies that affect the ability of industry to do business, without the need to renegotiate each time there is a change in the market. A long-run policy must be sufficiently flexible to allow for consistently fair sharing ratios and splitting of revenues between government and industry. Although broadly in line with international practice, the current version cannot be regarded as internationally competitive and efficient. In order for the royalty bill to become internationally competitive, promote beneficiation of mineral production and adequately compensate the State for the loss of a national resource, the National Treasury should heed the following main recommendations in this review: 1. Abandon the notion that each mineral product must have its own royalty rate; 2. Introduce an NSR type royalty that allows for value-addition costs to be deducted from the base; and 3. Provide for automatic relief through the use of a sliding-scale mechanism based on ability to pay, e.g. the X-Factor used in the gold mining tax formula.

Jan 1, 2007

In the spring of 1944 the Congress passed Public Law 290 (58 Stat. 190, 30 U. S. C. Sec. 321) "authorizing the construction and operation of demonstration plants to produce synthetic liquid fuels from coal, oil shales, agricultural and forestry products, and other substances, in order to aid the prosecution of the war, to conserve and increase the oil resources of the Nation, and for other purposes." Section 2 reads: "In order to carry out the :purpose of this act, the Secretary of the Interior is authorized- (a) to conduct laboratory research and development work, and, with pilot plants and semi-works plants, to make careful process engineering studies, along with structural engineering studies, in order to ascertain lowest investment and operating costs necessary to determine the best demonstration plant designs and conditions of operation;

Jan 1, 1948

In the spring of 1944 the Congress passed Public Law 290 (58 Stat. 190, 30 U. S. C. Sec. 321) "authorizing the construction and operation of demonstration plants to produce synthetic liquid fuels from coal, oil shales, agricultural and forestry products, and other substances, in order to aid the prosecution of the war, to conserve and increase the oil resources of the Nation, and for other purposes." Section 2 reads: "In order to carry out the purpose of this act, the Secretary of the Interior is authorized- (a) to conduct laboratory research and development work, and, with pilot plants and semi-works plants, to make careful process engineering studies, along with structural engineering studies, in order to ascertain lowest investment and operating costs necessary to determine the best demonstration plant designs and conditions of operation;

Jan 1, 1948

By J. Leonard Frame

A coal-fired fluidized bed combustion (FBC) system will be installed at the Owatonna Tool Company, Owatonna, Minnesota. Two FBC combustors will burn solid fuels: coal, petroleum coke, and wood and paper wastes. Crushed dolomitic limestone will be used to control sulfur emissions to EPA limits. The combustors will supply indirectly heated hot air and hot water for paint drying operations, washing processes, and space heating. The program is sponsored by the United States Department of Energy and the Owatonna Tool Company, and is one of five programs designed to demonstrate industrial applications of coal-fired fluidized bed equipment. The paper will describe the combustion system and the results of development tests with dolomitic limestone for sulfur emission control.

Jan 1, 1978

By Walter F. Gries

AN ounce of prevention is worth A a pound of cure' is an old proverb that has sometimes been forgotten in programs having to do with the health of workmen. Realization of the truth of this maxim is increasing, however, and today the iron-mining industry, with which I am particularly concerned, is becoming more alive to the prevention of illness and the conservation of health, thus decreasing the need for treatment after diagnosis has established its necessity. The healthy workman is the happy, efficient workman, and new programs tending to make him more health-minded are being put into operation. Preventive medicine is less costly than corrective medicine, to say nothing of the better results obtained. Periodic physical examinations, with close follow-up attention when required, have reduced the time lost because of illness, workmen's compensation costs, and group-insurance benefits for nonindustrial disabilities.

Jan 1, 1939

By William J. Coulter

WITHIN the past thirty years the United States has been involved in two tragic, vicious, and costly world wars. To make the world safe for democracy was the reason given for our participation, but the confusion and misunderstanding that prevails all over the world today suggests that war is not the proper approach to the attainment of that utopia. These conflicts were conceived and prosecuted by nations far advanced in civilization and culture. Their best manhood was sacrificed, a staggering tax burden was saddled on their peoples, huge financial losses were incurred, destruction of property was appalling, and cultural and peaceful scientific advancement received a setback that may require centuries to retrieve. Therefore, some basis is established for the conclusion that progress in the past fifty years has been most outstanding in the development of instruments used for death and destruction, and that progress in this direction between the two World Wars would indicate that the next war will go far toward total destruction of world civilization.

Jan 1, 1946

By D. W. Ashman

Today the electrolytic zinc industry is facing unprecedented environmental pressure and low metal prices. Zinc plants have to decide how they will dispose of iron residues in an environmentally friendly way without major capital expenditures. Only low-cost producers will survive, so companies must continuously improve to stay competitive. Therefore, the challenge of the process engineer is to find innovative solutions to the industry's problems. This paper reviews the status of electrolytic zinc processing and provides some insight into how the industry will respond to the pressures facing it

Jan 1, 1993

By Norm Greenwald

The Environmental Protection Agency ("EPA") has been attempting to develop a federal regulatory program for mine waste under Subtitle D of the Resource Conservation and Recovery Act since 1986. Recent regulatory and legislative events are now bringing this goal closer to reality. This paper discusses the mining industry's perspective on a number of the issues currently being addressed at EPA's Policy Dialogue Committee and in Congressionally-sponsored negotiating sessions.

Jan 1, 1992

By Leping Liu, Sachin Urade, Li-Ting Chen, Pengbo Chu

This study aims to provide industrial perspectives on the current U.S. metal mining engineering education and areas for improvement. An online survey was designed to seek opinions from the U.S. mining industry. Findings indicated a shortage of qualified graduates from the current U.S. metal mining engineering education system. The qualifications that need to be improved include engineering sciences underlying mining methods, mining design experience, mining feasibility study, the connection between theory and practice, and understanding of the overall mining operation. The survey also identified future desired qualifications, such as the ability to acquire and apply new knowledge as needed and sufficient field experience. Respondents recommended enhancing collaborations between industry and academia.

Oct 1, 2023

By James R. Jones

The purpose of these opening remarks is to establish a viewpoint, which will form part of the basis for later discussion between panel members and between the panel and the audience. Important issues will be identified. These ideas in the form of questions and answers, hopefully, will provide the necessary background for the ensuing dialogue. Is There An Urgency? We do not believe there is the urgency for immediate control legislation that has been depicted by some Congressional sources, environmental groups, and certain segments of the press. Emissions of sulfur oxides in the United States have decreased 15% during the 19701s, even though the use of coal by electrical utility power plants increased nearly 80%. That trend will continue as the older plants are phased out of operation and are replaced with newer plants, which must meet the New Source Performance Standards (NSPS) requiring the use of "scrubbers" to reduce sulfur dioxide emissions by 70% or 90%. The present Clean Air Act Amendments of 1977, by allowing the logical progression of economic events- -depreciation, retirement, replacement, and growth--will produce approximately a 50 % reduction in SOX emissions by the year 2015.

Jan 1, 1984

By David P. Kimball, Dalva L. Moellenberg

On May 21, 1990, EPA released its Strawman II draft program for mining wastes. It proposes to expand RCRA regulation of mining operations to include materials other than wastes. Strawman I1 would establish strict standards for the states to follow, rather than technical guidance. It proposes to establish performance standards; design criteria; monitoring requirements; and corrective action, closure, post-closure, and financial assurance requirements. It suggests "pollution prevention" concepts for mining operations. This paper explores the Strawman II proposals, particularly the technical criteria, and addresses several of the important concerns raised by industry.

Jan 1, 1991

By III Kimball

Mining wastes have received individual attention under the Resource Conservation and Recovery Act (RCRA) since its inception, in recognition of the special characteristics that distinguish mining wastes from other solid wastes. The Environmental Protection Agency (EPA) has recognized that: - Mining wastes are generated in much larger volumes than other industrial wastes. Most material handled in mining is waste (over 99% in many cases) and not marketable product, whereas waste is a small portion of raw materials used in most industries. Consequently, controls used for hazardous wastes may be technically infeasible or economically impractical. - Nearly all mining waste is managed at the site of generation and is land-disposed. . - Mining wastes typically pose lower hazards than other industrial wastes. Mining operations are located predominantly in sparsely populated areas and in arid or semi-arid areas with little surface water runoff and deeper water tables.

Jan 1, 1990

By Susanne Hering, Brent Kirby, Charles D. Litton, Tracy Allen, Kirk R. Smith, Rufus Edwards

In developing countries, high levels of particle pollution from the use of coal and biomass fuels for household cooking and heating are a major cause of ill health and premature mortality. The cost and complexity of existing monitoring equipment, combined with the need to sample many locations, make routine quantification of household particle pollution levels difficult. Recent advances in technology, however, have enabled the development of a small, portable, data-logging particle monitor modified from commercial smoke alarm technology that can meet the needs of surveys in the developing world at reasonable cost. Laboratory comparisons of a prototype particle monitor developed at the University of California at Berkeley (UCB) with gravimetric filters, a tapered element oscillating microbalance, and a TSI DustTrak to quantify the UCB particle monitor response as a function of both concentration and particle size and to examine sensor response in relation to changes in temperature, relative humidity, and elevation are presented here. UCB particle monitors showed good linearity in response to different concentrations of laboratory-generated oleic acid aerosols with a coarse (mass median diameter, 2.1 µm) and fine (mass median diameter, 0.27-0.42 µm) size distributions (average r2 = 0.997 ± 0.005). The photoelectric and ionization chamber showed a wide range of responses based on particle size and, thus, require calibration with the aerosol of interest. The ionization chamber was five times more sensitive to fine rather than coarse particles, whereas the photoelectric chamber was five times more sensitive to coarse than fine. The ratio of the response between the two sensors has the potential for mass calibration of individual data points based on estimated parameters of the size distribution. The results demonstrate the significant potential of this monitor, which will facilitate the evaluation of interventions (improved fuels, stoves, and ventilation) on indoor air pollution levels and research on the impacts of indoor particle levels on health in developing countries.

By Takahiko Okura, Chiharu Tokoro, Shunta Shibuya

Copper concentrates bearing arsenic as enargite (Cu3AsS4) or tennantite (Cu12As4S13) have disadvantage on copper smelting environmentally and economically, so those concentrates should be treated decently. In this paper, some experiments of arsenic removal from several kinds of copper concentrates by heat treatment in an inert atmosphere were discussed. In this study, several samples in which arsenic contents varied 0.18 to 8.3 wt % were heated to the temperature range of 400 °C to 700 °C under argon gas flow during 1 hour. The heat residues and volatilized materials (V.M.) were analyzed by XRD, XRF, ICP-AES, XAFS and MLA to analyze residual concentration of arsenic and residual mineral composition. Experimental results showed that arsenic removal from copper concentrates advanced in 2 steps; at the temperature range of 500 ° C to 550 °C and of 550 °C to 650 °C, respectively. MLA analysis showed that a few of arsenic in enargite was removed by 550 °C heating and a majority of it was still combined with copper and sulfur as tennantite. On the other hand, arsenic in tennantite was removed almost completely by 650 °C heating. Furthermore, a particular type of arsenic mineral, such as Cobaltite (CoAsS) still remained after heating at 700 °C.

Jan 1, 2014

By Daniel Saramak

"Issues concerning effectiveness of the high-pressure comminution process in technological circuits of copper ore treatment were presented in the paper. Crushing processes taking place in high-pressure grinding rolls devices (HPGR) are currently one of the most efficient methods of hard ore size reduction in terms of the energy consumption. The HPGR products are characterized by a fine particle size and the micro-cracks formation in individual particles, which appear in downstream grinding processes, decreasing their energy consumption. The purpose of this paper was to analyse the effectiveness of a ball mill grinding process depending on the changeable conditions of run for the HPGR crushing process. The research programme carried out included crushing tests in the laboratory scale HPGR device at various settings of the operating pressure volume and selected qualitative properties of the feed material (i.e. particle size distribution). Particle size distribution analyses of all HPGR products were performed and in the next stage the material was a feed to the ball mill grinding process. Grinding process kinetics were investigated through the determination of mass recoveries of individual particle size fractions after defined grinding time intervals. The models, defining the grinding process effectiveness as a function of changeable conditions of HPGR process run, were determined on the basis of obtained results. Based on these models the optimal grinding time in a ball mill was specified which is, in turn, the basis for optimization of operation of the technological comminution circuits for a given material type. The obtained results proved that the application of HPGR devices in a given copper ore comminution circuit may improve the effectiveness of the downstream grinding process which leads to improvement of the entire circuit work efficiency through decreasing the process energy consumption and enhancing product size reduction."

Jan 1, 2014

By Snehamoy Chatterjee, Dharmasai Eshwar, Aref Majdara, Rennie Kaunda, HUGH MILLER

The U.S. mining industry has made progress in reducing accidents and injuries, but interpreting safety data remains difficult due to changes in workforce size and productivity. The Mine Safety and Health Administration (MSHA) uses tools like the pattern of violation (POV) and significant & substantial (S&S) calculator to monitor safety, though these have limitations. To address this, we developed an information entropybased risk (IER) index that combines various safety metrics, including citations, penalties and injuries. Using data from 2011 to 2020, the IER index was validated with statistical methods and clustering algorithms to ensure it accurately reflects risk levels. The analysis showed clear differences in risk across mining sites, proving the index’s usefulness. The IER index was then applied to a coal mine to demonstrate its effectiveness. This new tool can help mining companies better assess their safety risks and take action to improve workplace safety.

Nov 1, 2024

By A. Burkert, A. E. Hajj

"An information system has been developed for the use of companies considering developing a new mine which may be liable to secondary sulphide ignitions or by existing operations. The system uses the Comdale X expert system to analyze information about a particular mine. The system will indicate whether the mine is likely to experience ignitions and what precautions can be taken to reduce or prevent their occurrence. The advantage of an information system using expert system and artificial intelligence principles is that it can recommend action when there is an incomplete knowledge of all the system parameters. By interrogation of the user it can determine the state of knowledge and react accordingly. It is considered that such systems could be of significant use in mine planning for new and existing properties, especially where operators have limited expertise regarding secondary sulphide ignitions. IntroductionSulphide ignitions occur in the underground mines of several countries, including Australia, Canada, Finland, South Africa and the United States of America (1·3) and there has been a significant increase in their number and severity over the last decade(2.4). The basic causes of such ignitions are not well understood and man incidents are not reported or documented.Sulphide ignitions can pose a serious threat to the health and safety of mine workers and to the cost and efficiency of the mining operation (1-5). Byberg(6) described the three major problems associated with sulphide ignitions as:1. the force of the initial explosion can endanger workers and equipment;2. the intense heat of the ignition's flame front can endanger workers and equipment and may also ignite combustible material resulting in mine fires; and3. the sulphur dioxide produced by the ignition may be of such quantity and concentration to endanger workers, as was tragically demonstrated at Geco. In this incident in October 1985, a worker was killed at a position 2400 metres from the ignition point of a sulphide ignition at Manitouwadge, Ontario."

Jan 1, 1994

By M. G. Lipsett

"Mining properties are becoming increasingly remote, a challenging situation for operating and maintaining equipment. Logistics of transporting workers and materials can be alleviated by having timely, accurate information of equipment location and operating condition, and by automating some activities. This paper discusses an infrastructure for remote operations, with strategies for communicating different types of data, and a design method so that systems can interact with either an operator or another system. A remotely operated excavator prototype is described, with on-board performance and diagnostic monitoring systems now used on production equipment. IntroductionSyncrude Canada Ltd. operates an openpit oil sands mine near Fort McMurray, Alberta. For twenty years, draglines and bucketwheel reclaimers have fed conveyors that transport dry oil sand to an extraction and upgrading plant. In converting to a truck and shovel operation, Syncrude has developed slurry pipelines and bitumen froth pumping to allow more remote leases to be mined more than 30 km from the base plant.There are organizational and resourcing challenges in operating and maintaining equipment in three nearby, but separate, mines. The logistics of transporting workers and materials to production and support equipment become more difficult, and operations and maintenance personnel and facilities become more distributed. Supervising mine operations will rely even more on having timely, accurate information about equipment location and operational status.Syncrude is typical of an open-pit operation. Voice communications are the preferred way to exchange information for making immediate decisions about operations and maintenance. A large number of narrowband FM broadcast radio channels keep teams of miners working together. Haul truck drivers, shovel operators, and dispatchers talk on one channel while maintainers coordinate activities with the control tower on another. Cellular phones have become popular for supervisors who have to talk with planners and engineers in offices without radios."

Jan 1, 2000