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By John Jonkman

Two major changes occured during the last 5 years in the applications of computers. First, the cost of computer equipment decreased drastically in an era of high inflation. Second, technological breakthroughs in hardware and software have been applied successfully so that the average person can successfully utilize the computer without having to be a computer expert himself. The mining industry has recognized that computing technology has evolved to a point where it can be applied successfully to assist in improving productivity. Since equipment downtime is one of the major reasons for lost production, the Kennecott Minerals Company has developed a comprehensive maintenance information system which now assists the maintenance department in minimizing equipment downtimes. This paper discusses the primary features and functions of this system, the state-of-the-art technology that has been applied, and the benefits that resulted from using this system. Programs to support mobile equipment maintenance scheduling, which currently are under development, are reviewed and a summary of future applications is given.

Jan 1, 1982

By Y. C. Kim, I. S. Roditis, P. K. Medhi

The strongly skewed grade distributions and the need to estimate the local recoverable reserves in a selective mining environment are the two problems that ordinary kriging (OK) cannot easily handle. With the recent introduction of the non- parametric, distribution-free technique of indicator kriging (IK), the above problems can be solved. This paper describes the result of performance evaluation of IK in an open-pit gold-silver deposit. For performance evaluation, the predictions of local recoverable reserves using IK were compared with the actual reserves based on blasthole information. The IK estimator, although a bit optimistic (or overestimating), performed very well in predicting the total recoverable ounces of gold from each panel on a test bench. The OK estimator was also used to try to predict local recoverable reserves, by treating each panel as either waste or ore, depending on the panel's average grade. Under this criterion, OK was found to be quite biased and pessimistic (or underestimating).

Jan 1, 1988

By R. N. Rothan, V. Khunova, C. M. Liauw, G. C. Lees

The interphase modification activity of 1,3-phenylene dimaleimide (also known as m-phenylene bismaleimide (BMI)) has been studied in composites based on magnesium hydroxide (60% w/w) and a polypropylene block copolymer (PPBC) that featured an ethylene-rich elastomeric impact modifier phase. BMI was found to be a unique product that led to significant simultaneous improvements in composite strength and toughness, even at the high filler levels. BMI modification was found to promote encapsulation of filler particles with the elastomeric phase of the PPBC together with formation of a PP boundary layer of increased crystalline content.

Jan 1, 2003

By Ian J. Duckworth, Pierre F. X. Mousset-Jones

A detailed heat flow project was conducted at the Homestake Mine in Lead, South Dakota. This paper presents results obtained from a stope sensor system installed in the mine. The design and installation of the system are described in detail in a previous paper (Duckworth et al., 1992). The major project objective was the construction of a comprehensive heat flow data base to allow the design and testing of a new climate prediction model applicable to irregularly shaped underground excavations in non-homogeneous surrounding rock types. A mechanized cut-and-fill (MCF) stope contributes a substantial overall heat source in a mine, and the effect of this source on the working environment must be considered when planning future ventilation and refrigeration requirements. The relative magnitudes of the component heat sources encountered with the MCF mining technique are presented, having been computed from actual stope beat flow data collected over a one-month study period. The percentage of the overall heat load that is removed from the scope for each component heat sink is evaluated, and the overall energy balance is analyzed. A one-month study length was considered a sufficient period of time to allow stope monitoring for a complete range of mining conditions.

Jan 1, 1993

The price of copper has gone into the tank. So has gold. Environmental regulations are more restrictive. Global warming has world leaders and environmental groups seeking international regulations to keep the planet from heating up - mostly by restricting the use of fossil fuels. And the US Secretary of the Interior wants to make it more costly -prohibitively so for smaller companies - to mine hard rock metals in the United States. By rights, miners should be carrying around a pessimistic attitude about their industry. But miners are an optimistic lot, always believing that things will improve. That optimism was in evidence in Tucson, AZ in early December, when about 620 miners met at the Double- tree Hotel for the Annual Meeting of the Arizona Conference, put on by SME. Attendees listened as a United States congressman commented on the recent tax cut bill, mining regulations and the continuing need for the mining industry to improve its image in the eyes of the general public. Session speakers discussed how improved technology has made their processing operations at Sierrita and Morenci more efficient and cost-effective.

Jan 1, 1998

By S. Chander

The fundamentals of flotation are reviewed with an objective to understand the limitations in predicting the performance of a sulfide mineral flotation system and in its scale-up from laboratory studies to plant practice. The difficulties can often be traced back to complex interactions between chemical and physical parameters and nonequilibrium effects. The physical and chemical changes that occur during the long sojourn of sulfide minerals that begins with mining, continues through crushing and grinding, and ends when they emerge from the flotation cell as a concentrate, are reviewed. The benefits of new techniques that have become available in recent years to identify and estimate the amount of surface species are discussed.

Jan 1, 1999

By Andrzej Luszczkiewicz, Kazimierz S. Sztaba

Flotation tailing of Polish copper sulfide ores represents more than 90% of the mass of run-of-mine ore. The tailing contains mainly quartz, dolomite, clay minerals, traces of sulfides, and some accessory minerals. Almost all minerals of the tailing are well liberated and, therefore, any further beneficiation process applied to the tailing is expected to be inexpensive. In this work, results of investigations on utilization of flotation tailing using classification and gravity concentration are presented. It is shown that due to classification of flotation tailing in hydrocyclones, the coarse fraction becomes suitable material for gravity separation providing backfill material for underground mines as well as heavy minerals, a source of valuable rare elements. It was also found that heavy minerals separated by gravity methods contain a significant amount of rare elements such as zirconium, titanium, silver, rare earth metals, and uranium. The light fraction of the gravity separation contains well deslimed quartz particles and meets strict requirements for hydraulic filling material ked for structural support in underground mines. Evaluation of the cost of the proposed technology indicated that investment to implement the method would provide a return within 2-4 years.

Jan 1, 1995

By George E. Niewiadomski

The exposure of miners to radon gas and its airborne daughter products is a serious health problem which has long been recognized in the uranium mining industry. The association of high exposure to alpha particle emitters with incidence of lung cancer is well established. There continues to be a pressing need to reduce and eventually eliminate the high incidence of occupational lung cancer among uranium miners through the development of new and improved measurement and control technologies. This paper highlights the current efforts of the Bureau of Mines radiation hazards research program. It is aimed at obtaining a fundamental understanding of the behavior and transport of radon and radon daughters, developing more accurate and reliable instruments and measurement methods and developing cost-effective control techniques. Also discussed are the most recent accomplishments and the future research plans of the program.

Jan 1, 1981

By Richard B. Berg

Until its closure in 1999, the Antler was North America's only active chlorite mine. The mine is located 25 miles (40 km) southeast of Butte in the Silver Star district - an old Montana gold mining district. In 1975, two prospectors searching for talc re-examined a prospect showing a green, fine-grained mineral resembling talc. Following identification and testing of this magnesian chlorite (variety clinochlore), Cyprus Industrial Minerals began processing ore from this deposit in 1976. Chlorite veins ranging up to 30 feet (9 m) in thickness were formed by essentially complete replacement of Precambrian (Archean?) quartzofeldspathic gneiss. Chlorite replacement was controlled by near- vertical faults. These chlorite veins, typically surrounded by envelopes of sericitic alteration, were formed by the introduction of magnesium-rich hydrothermal fluids, probably related to the Proterozoic talc-forming event in southwestern Montana. Luzenac America, Inc. acquired Cyprus' talc operations in 1992, and continued to mine this deposit until the ore body was mined out in March 1999, and the mine was reclaimed. Total sorted ore production from this deposit is about 250,000 short tons (st) (227,000 metric tons [mt]). Chlorite from this deposit was primarily used in ceramic and paint applications.

Jan 1, 2001

By A. M. Marabini, G. Belardi, E. Spaziani

The objective of this research was to investigate the possible application of integrated circuits to the concentration of talc from the Valmalenco mine, located in northern Italy. The investigation was aimed at producing a high-grade product (low in impurities such as iron and carbonate) that would be suitable for industrial applications. Because of the presence of accessory minerals, the talc concentrate from this ore is not, at the present time, suitable for industrial applications.

Jan 1, 1996

By R. Hogg, R. C. Klimpel, D. T. Ray

The sedimentation and dewatering characteristics of flocculated slurries are determined by the size and density of the flocs. Studies of the formation and growth of flocs reveal that floc size is limited by breakage of the agglomerates due to shear in the suspension. Floc density measurements indicate that there is an inverse relationship between size and density. This relationship appears to be determined primarily by the nature of the solid particles, especially the size distribution, but it appears that agitation of the suspension can lead to some densification of the flocs, in addition to breakage. It follows that both size and density can be controlled to a significant extent by regulating the physical conditions (agitation, method of flocculant addition, etc.) during flocculation. The use of physical floc conditioning to control the sedimentation and dewatering (filtration) behavior of flocculated, fine-particle suspensions is evaluated in terms of its effects on floc size and density.

Jan 1, 1988

By Andrew I. Hustrulid

The Internet and World Wide Web create multiple opportunities to advance and change an industry. Scandura Conveyor Belting, a mid-sized manufacturing company supplying the mining industry, has embraced several of these opportunities that add value to the sale and service of the manufactured product. This paper presents a technical overview of available technology and how it is being applied to advance the conveyor belt industry. These technologies are used to provide historic catalog information, interactive troubleshooting, product installation and service instructions, detailed product information, technical calculations for the proper conveyor belt selection, and on-line site surveys and maintenance logs.

Jan 1, 2002

By W. M. Kidd

INTRODUCTION Uranium mine inspection in Canada forms one element of the enforcement of the Atomic Energy Control Act; it is under this Act that all Canadian uranium mines and mills are licensed to operate. Inspection duties are carried out by a small core staff of federal government inspectors (working for the Atomic Energy Control Board (AECB)) largely supplemented by provincial mine inspectors working on behalf of the AECB. Unlike most resource extraction in Canada, uranium mining is under federal jurisdiction and consequently it was the AECB who decided in 1975 that changes in the Canadian uranium mining industry, particularly its expansion and the expanding role of the mine inspector in the limiting of exposures, warranted the offering of a special radiation protection training course. The Uranium Mine Inspector Training Course (UMITC) was first conducted in 1976 at the Elliot Lake Centre in Elliot Lake, Ontario. Subscription for the course was not limited to mine inspectors to enable union stewards, management personnel and provincial/federal labour inspectors to attend. This paper will present an outline of the course content, the format of its presentation and non-curriculum aspects of running a course of this type in uranium-producing community. The core lecturers for UMITC are drawn from the Radiation Protection and Uranium Mine Divisions of the AECB. In addition, guest lecturers are invited from universities and medical research centres together with industry professionals and government researchers. In all some twenty-four plus presentations are made over the first five days of lectures. The program topic areas, hazards, controls, measurements, record-keeping and health effects are preceded by an intensive half-day session on radiation fundamentals. TOPICS Hazards [Dust] A review of the dynamics of airborne particles including the effects of particle size, gravity and wake-turbulence on the behaviour of dust clouds. Associated topics are migrational aspects of dust particles and specific dust-generating mine operations. [Radiation] Canadian uranium mines are increasingly diverse in nature ranging from large scale low-grade underground operations in Elliot Lake to smaller high-grade open pits in Saskatchewan. Papers are presented on assessments of internal and external exposure, the metabolic pathways of ingested or inhaled radiation and the specifics of mine and mill hazards. Radiation hazards are further broken down into gamma surveys of uranium mines, radon daughter concentrations and problem areas. Controls The relationship between mining methods and the operating environment is critically important to ensuring safe working conditions. This refers to both the selection of machinery/devices, etc., and to engineering controls which are instituted to remedy problems created by new technology. UMITC examines a number of possible mining techniques, their criteria for selection and impact on the working environment. Control measures, ventilation practices and design, the need for continuous water misting and special open-pit precautions are presented. These lectures frequently conclude with suggestions for better operating guidelines for mine ventilation systems and the need for greater co-operation between the ventilation department and the underground crews. Measurements Uranium mining regulations stress the need for a high standard of exposure monitoring, statistical planning and record-keeping. [Statistics] Although many course participants are well versed in statistics, certain fundamentals are repeated and include, the concepts of mean, variance, standard deviation and standard deviation of the mean. Confidence levels, decision-making based on sample statistics and statistical records are also discussed. [Dust Measurement] Dust measurement is particularly critical in the mines where the high silica content of the ore body, such as those at Elliot Lake, results in the continuous generation of dust. Sampling practices, filtration, impaction, thermal impaction and electrostatic precipitation are explained together with the methods of counting samples to determine free silica. Konimetric and gravimetric techniques for dust sampling are compared and contrasted. [Radiation Measurements] Both collective and personal dosimetry systems are used in the Canadian uranium mining industry and lectures are presented on each. Techniques and possible sources of error are discussed for a variety of radon and radon daughter measurement methods - Lucas method, Tsivoglou and modified Tsivoglou, Kusnetz, Rolle. Instant working level meters and personal alpha dosimeters are explained in terms of calibration, maintenance, readout and estimation of accuracy. A lecture outlining dose estimation by means of bio-assay, whole-body counting and the use of TLD's concludes the topic. Record-Keeping An overview of the problems of changing limits,

Jan 1, 1981

By Merrill P. Allen

The Vernal phosphate rock concentrator is located in the Uinta Mountains near Vernal, Utah. Ore is sedimentary rock from the Phosphoria Formation. Truck and shovel mining is done at a rate of 11,500 TPD. Run of mine ore is crushed and then milled through a SAG mill and ball mill to minus 16 mesh. Milled ore is deslimed using cyclones and hydrosizers. Sands are conditioned with fatty acid, petroleum sulfonate, diesel fuel and frother prior to primary rougher and cleaner flotation. Primary flotation tailing is milled to 95% minus 48 mesh, deslimed in cyclones, conditioned using reagents previously described, and then processed through rougher and cleaner scavenger flotation. Product of scavenger cleaner concentrate is upgraded by reverse flotation of dolomite. Flotation concentrates are combined and dewatered, pulp being milled to 99.5% minus 65 mesh and then thickened to 65% solids. Product is pumped from storage through a 10 inch, 94 mile pipeline to a conversion plant at Rock Springs, Wyoming. Mill tailing is stored behind an earthen dam, water from the settled tailing being reclaimed for mill use.

Jan 1, 1993

By N. Colvin, J. W. Gulyas

HISTORY The Surigao Nickel Refinery of Marinduque Mining and Industrial Corporation is located on Nonoc Island off the northwestern coast of Mindanao in the Philippines. Nonoc Island is part of the Surigao Mineral Reservation which had been identified as early as 1912. Initial interest in these deposits was due to their iron content, and their value as a nickel deposit was not seriously entertained until the late 1950's. The Philippine government undertook extensive test pitting and sampling programmes at that time and in the early sixties Marinduque became involved in helping to establish firmer ore reserves. Evaluations of the test pitting programme indicated reserves of 75,000,000 tonnes of ore averaging 1.22% Ni, 0.1% Co and 38.5% Fe. The Philippine government called for bids on the reservation in 1962 and Marinduque and Sherritt Gordon carried out some feasibility studies for the recovery of nickel from the deposit. However, it was not until 1968 that Marinduque was granted proper authority to exploit the Surigao deposits. Marinduque and Sherritt then entered into an agreement which allowed Marinduque to utilize a process developed by Sherritt for treating lateritic ores. During 1968, a 25 st/d pilot plant was erected in Fort Saskatchewan, Alberta for the purpose of modelling all process steps. A 10,000 tonne ore sample was sent from Nonoc as feed stock for the pilot plant.

Jan 1, 1979

By Zsolt Csillag, Dragorad Ivankovic, Miomir Ceh, Anna Csordás-Tóth

Results of the common research work of ALUTERV-FKI and RI in field of ore dressing are presented here. Although monohydrate types of bauxites consist of finely dispersed minerals, however, in some cases certain contaminants (carbonates mainly), can be reduced by physical methods before Bayer process. Electronmicroscopy combined with computerized data processing is proven to determine the possibility of beneficiation and to control the different stages of ore dressing. Test results gained by Hungarian and Yougoslavian bauxite samples, contaminated by calcite, dolomite, siderite and pyrite, are discussed. Basic operations were: grinding (mostly dry) and classification, magnetic separation (mostly wet) and selective agglomeration. Only simple processes, having high efficiency and mostly dry ore dressing technique may meet the requirement of economical criteria. 1. [CONDITIONS OF ADAPTING THE BAUXITE DRESSING METHOD] Bauxite is a relatively cheap raw material, occurring in great bulks. Bauxite deposits may often lay far from the traditional ore processing plants, and in such cases the ore reaches the plants after long transportation. Some of these plants must face the difficulty that the resources of high quality ore are exhausted, they fall short of supply and, consequently, they must decide on whether to utilize the existing resources of poorer

Jan 1, 1984

By S. K. Kawatra, M. T. Rusesky, T. C. Eisele

An on-line monitoring system for apparent slurry viscosity has been developed at Michigan Technological University. It utilizes a vibrating sphere viscometer in conjunction with a special slurry presentation system to reduce particle settling and turbulence effects. It has proven to give accurate, reproducible results in an on-line hydrocyclone installation. Its performance shows that it can be an effective instrument on an industrial scale, particularly in grinding circuits. Development of the sensor and the importance of rheology in grinding are also discussed.

Jan 1, 1992

By W. J. Wuest, M. J. DeMarco, J. R. Koehler

Yield-pillar-based gate-road designs often fail to provide mine operators with adequate ground control. This is because of the unknowing m is employment of "critically" sized pillars. A "critical” pillar is one that is too large to either yield nonviolently or to yield before the roof and floor sustain permanent damage and is too small to support full abutment loads. To demonstrate the critical pillar concept, afield study of a tapering gate road was conducted by the US Bureau of Mines at the Sunnyside Coal Mines, Sunnyside, UT. Extreme pillar stresses and associated coal bumps characterize the response to first panel mining of a 16.8-m (55.1-ft) wide critical design. Significantly lower pillar stresses, early yielding of the pillar and adjacent panel rib, and an absence of coal bumps suggest that a narrower 12.2-m (40-ft) wide design more closely approaches proper yield pillar dimensions. A probe hole in several 10.6-m (34.8-ft) wide pillars revealed low stress levels and substantial pillar and panel rib yielding prior to abutment onset, indicating a properly functioning yield pillar design.

Jan 1, 1997

By M. Jack Snyder

The problem of effective utilization of fly ash has been given wide attention for a number of years. Although the effort devoted to the problem has led to some applications of demonstrated usefulness, the full utilization of fly ash has been held back by lack of concerted research and development activity, by lack of effective dissemination to potential users of fly ash of the knowledge that is available from laboratory and field studies, and by the obvious variability of the product. Because of the variability in fly ash from one power plant to another and from time-to-time in the same plant, specifications have been set up defining compositional or property limits within which a fly ash must fall to be used in certain applications. This paper discusses the bases for such specifications and examines them in the light of recent research on the characterization of fly ash. Other limitations and restrictions on the use of fly ash and what is being done to overcome them are also discussed.

Jan 1, 1968

By Darold Woodward, Stefan Haydn, Petr Pospisil

Most fatalities in tunnel fires are caused by the spread of toxic smoke. Controlling the spread of smoke is crucial to provide a survivable environment for emergency egress. A properly designed and tuned feedback control loop is required to achieve a target flow that is slow enough to allow pedestrians to escape under different boundary conditions. Feedback control loops are also helpful in optimizing energy consumption under moving traffic conditions. A reliable feedback flow control system requires sophisticated engineering knowhow and experience, careful selection of instruments and controlled variables, and thoughtful implementation from design through field testing and commissioning.

Dec 1, 2022