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By D. A. Dahlstrom

Energy costs have had a serious impact on all basic industries today. This is due to the significant amount of energy that is used to convert natural resources into usable products. Other factors such as transportation with its major energy requirement and materials employed in processing that have already required significant energy input for their manufacture accordingly influence delivered cost to the user. The farmer is a good example of this. While his large capital investment for land, machines, and buildings is highly impacted by today's interest rates, his chemical fertilizer, herbicides, and pesticides as well as those same machines and transportation costs for his products have also been seriously affected by energy costs. With the many unit operations involved in mining and mineral processing, several of which require significant inputs of energy, one can only conclude that this industry has experienced a great increase in percentage of total cost for energy alone. Fuerstenau (1975) indicated that the minerals industry used about 12.5% of the total energy produced in the US. McNulty (1983) listed the total energy requirements for the production of 0.9 t (1 st) of various metals including the energy consumed in the manufacture of supplies employed, such as tires, explosives, chemicals, grinding media, etc. (Table 1).

Jan 1, 1987

By Joe W. Cotton, Thomas A. Wheeler

This paper briefly covers theories behind caking of crystalline salt particles, and methods of its prevention. The main factors that influence the extent of caking are humidity, storage pressure, temperature variations, and length of storage time. Careful adherence to control- ling these variables are more critical than the addition of even the most efficient anticaking reagent. The principle characteristics that a successful anticaking reagent must possess are: high retention at the temperature of application, good coating of reagent on the particle surface, capability of in- creasing the hydrophobicity of the particle, reducing the surface tension of liquids, and/or creating of a barrier between particles that prevent contact between particles, and modifying the crystal structure of the salt between the particles. Methods to evaluate the reduction of caking tenacity with the application of various anticaking reagents, reagent volatility and reagent degradation in plant and laboratory scales are discussed. Various types of anticake reagents used today in industry are organic active and inactive reagents, inorganic inert and inorganic salt crystal modifying re- agents.

Jan 1, 1986

By Jim Armbrust

JAMIE DAVIS: Our next speaker is Jim Armbrust, maintenance manager at Phelps Dodge, Morenci. Jim's presentation is titled "We Need More Training-How to Get the Biggest Bang for the Buck." We've talked a lot about preventative maintenance and we've heard several people talk about training. How do we train to use all these systems? How do we educate people? This will be a nice little wrap-up for us. JIM ARMBRUST: One common theme from this morning's talk is that we need more training. That's exactly what we'll be talking about for the next few minutes.

Jan 1, 1998

By J. I. Schoenherr, T. A. Baloun

Mixed cable waste, which amounts to more than 200,000 tpy in Germany, is subjected to recycling. In most cases cable recycling means only recovering copper and/or aluminum metals. The remaining cable waste contains nearly 3-8% of the reusable materials, and is disposed of in landfills. Aluminum is recovered within copper products and leads to lower product prices. Preliminary laboratory tests show that the use of shaking hydro-tables as well as electrostatic separators result in less than 1 % of metals in the residual material. The products are high in grade at metal recoveries of more than 85%. Furthermore, applying a modified electrostatic separator may also lead to an efficient Cu-Al separation. The separation efficiency amounts to up to 95%.

Jan 1, 2002

By Z. Kowalski

Landfilling of waste causes the degradation of natural environment, not only due to land occupation, but also due to pollution of air, water and soil. The flotation waste from zinc-lead industry also poses such problem. There is a need to find the way to utilise substantial amount of these wastes and backfilling seems to be a good solution. Recently, in Poland only sand was used for backfilling. However, it will be more beneficial to substitute the sand with the industrial solid waste, especially flotation waste. The tests were performed in the laboratory to examine the use of flotation waste as a main ingredient for backfilling. The use of flotation waste is possible only when it is combined with other waste with specific bonding properties, especially regarding the prevention of leakage. The outcome of tests shows that flotation waste combined with cement and fly ashes can be used as a backfilling material. This paper presents the preparation of flotation waste for using it for backfilling.

Jan 1, 2006

By J. R. England, W. J. Taylor

The Sudbury Basin is the scene of the mining operations of the Ontario Division of the International Nickel Company of Canada, Limited. Around the rim of the geological formation and within thirty miles of the City of Sudbury are located twelve operating mines and one open pit operated by the Company. The City, with a metropolitan population of some 100,000 lies 240 miles Northwest of Toronto. In addition, there is one mine in Northwestern Ontario, at Shebandowan, 700 miles Northwest of Sudbury. In 1973 these mines produced 16.5 million short tons of ore of which 14.9 million tons were from underground and the balance from open pit operations. Mining methods include blasthole, sublevel caving, induced caving, shrinkage, cut-and-fill and undercut-and-fill. Raise boring commenced at Inco in 1964 and is now applied at all mines in the Sudbury District (Figure 1). [ ]

Jan 1, 1974

By Leo Langland

One of the primary functions of the Geotechnical Services-Materials section of the Arizona Department of Transportation (ADOT) is locating, sampling, and evaluating potential aggregate deposits throughout the State. This information is essential in designing, estimating, and bidding highway construction projects. The nature of materials used for aggregate varies greatly within Arizona. The northeastern or plateau section is famous for its scenic sedimentary formations that are, how- ever, too soft to make suitable aggregate. Volcanic materials are widely used in place of more conventional geologic units. In contrast, the southwestern, or Basin-and-Range section, contains a relative abundance of good aggregate, especially a diversity of gravels. The paper will review the off ice, field, and laboratory methods used by the ADOT Materials Section in satisfying its needs for aggregate information in Arizona.

Jan 1, 1987

By A. C. Ruckman, Allen G. D., G. H. Beckwith

This paper describes the design and operational features of several asphaltic concrete gold heap leach pads which have been constructed in the United States over the past 12 years.

Jan 1, 1988

By S. Chander, A. Briceno

The properties of surface films on pyrite have been studied through electrochemical techniques of cyclic voltammetry and AC impedance, measurements. The characteristics of the surface films depend on the conditions of oxidation and the source of pyrite. At potentials near 0.0 V, some pyrites have large values of polarization resistance, showing a certain degree of passivity. Some pyrites show more passivation than others, however. On oxidation, meta- stable phases of Fe(OH)2 and Fe(OH)3 form that transform to more stable phases on aging. The growth of surface films near the corrosion potential of pyrite follows a linear kinetics that is attributed to a chemical (or an electrochemical) reaction as the rate determining step. The surface film is considered to be a hydroxide or an oxide because it is hydrophilic. This study has also demonstrated that AC impedance ,measurements can be used to study the growth characteristics of films at mineral/solution interfaces.

Jan 1, 1988

By Susanne Pignolet-Brandom

This paper examines the viability of using the QEM*SEM automated scanning electron microscope for the determination iron sulfide and calcite volumetric percentages. The analytical reliability was verified by comparing elemental abundances calculated for fourteen samples using the QEM*SEM volumetric percentages and appropriate mineral compositions and elemental abundances determined by standard laboratory procedures. The abundances were comparable, thus demonstrating suitability of this technique for evaluation of the acid neutralization and generation potentials of mining wastes.

Jan 1, 1990

By Alwyn Protheroe, Steve Smith, Herbert Jr. Gibson

In September of 2000, Cowin and Company, Inc., contracted with Paramont Coal Corporation to construct a large decline approximately 820 m (2,700 feet) in overall length at a grade of 8 degrees to the Lower Banner Coal Seam. This paper will discuss the methods used by the contractor and owner to overcome the unique problems required to construct this tunnel in a coal mine environment. The problems include, initial design considerations, equipment selection, ventilation, ground control, control of water in?ows, and placement of concrete.

Jan 1, 2003

By Vanessa M. Torres, Renato S. Costa

This work presents the experience of Cia. Vale do Rio Doce in using Diagnostic Leaching tests to characterize refractory ores and CIP tailings. With the diagnostic leaching results of the highly refractory gold ore from Maria Preta Mine (Brazil), a process flowsheet was defined for a feasibility study of possible process modification on the existing plant. With CIP tailings from its Fazenda Brasileiro and Caué operations the amount of cyanidable gold was determined to aid plant optimization.

Jan 1, 1995

By Russell G. Slayback

Feasibility investigations for prospective gold mines too often neglect to consider ground water. Simple observations and tests during drilling exploration can provide useful data on probable water conditions. As the prospect becomes more serious, more detailed investigation of ground water and dewatering needs may be warranted. Ignoring ground-water conditions can lead to costly mistakes.

Jan 1, 1987

By R. Krishna, L. A. Kumar

The paper suggests a new empirical model for predicting mining subsidence. The parameters considered are Lithological Factor, which in this context meant percentage of sandstone, Rock Mass Factor (depending upon the RQD value of drill-hole cores), width: depth ratio and percentage extraction of coal. More than 250 drill-hole cores from seven longwall panels and 11 bord-and pillar (room-and-pillar) workings were analyzed from an extensive data bank of Singareni Collieries Company Ltd. (S.C.Co.), Andhra Pradesh, India. Excellent subsidence agreement was found with the suggested model.

Jan 1, 1993

By Olice C. Carter, B. J. Scheiner

The Bureau of Mines investigated the removal of two toxic/heavy metals (cadmium (Cd) and lead (Pb)) from brass foundry wastewater. Polymers, copolymers, guars, and gums were used in conjunction with calcium hydroxide (Ca(OH)2) and magnesium oxide (MgO) to remove the metals from solution. Several polymers were successful in removing Cd and Pb from the wastewater. The concentrations of Cd and Pb were lowered from 19 to 0.01 ppm and from 20 to less than 0.01 ppm, respectively. The methods investigated could easily be adapted to many existing wastewater treatment facilities and/or be used independently.

Jan 1, 1991

By Jane Morrison

Permanent magnets are used in most electromechanical and electronic devices to convert electrical to mechanical energy and vice versa. More than fifty are commonly found in the average American home and car. A new species of permanent magnet composed of iron, neodymium, and boron has recently been developed which combines superior magnetic properties with compact size. The reduced size of the magnets has enabled significant new developments in such areas as robotics and consumer electronic, among others. The objective of the present work is to efficiently and economically separate valuable rare earth materials from the relatively worthless iron constituent in NdFeB magnet scrap. Several magnet producers have expressed interest in the development of such a process and have provided information and scrap samples to aid in research. Scrap is generated in a variety of forms from different stages in the processing stream. Pieces of magnetic and non-magnetic metal as well as sludge and ribbon from jet casting must all be treated. Beneficiation techniques have been studied and size distributions developed for the different scrap types. Slag from the casting process is resistant to crushing and may need to be embrittled first, but all other types are amenable to crushing and ball mill grinding using stainless steel balls and water. Tabling was found to be useful in classification of magnet sludge. Two major techniques for separation of rare earths have been studied:

Jan 1, 1990

By B. K. Mishra, R. K. Rajamani, A. D. Joshi

The liners are the most important part in the SAG mill operation. Hence, the liners and their design parameters are primarily studied to see its effect on SAG mill operations. Effective liner designs are directed to reduce downtimes, which is needed for the replacement of worn liners. There exists constant chance of improvement in the capacity of mill by studying the effect of liner design on the charge motion inside the mill. This need is satisfied by three-dimensional discrete element code "Millsoft", which uses Discrete Element Method (DEM) to analyze the motion of charge. This simulation of SAG mill keeps track of all the moving bodies like ball and rock and observes its interaction with liners and lifters. The recent work done on this software helps generating mill to more reality by putting conical wall at feed and discharge end, over the earlier flat walls. Millsoft is an effective tool to watch the change in the motion of the charge due to different types of lifter bars and different design parameters. It was concluded that by simply increasing chord length between the lifters and increasing the face angle of the lifters, capacity of the mill could be increased. On the other hand, this software can also be used to get power draft at the respective mill design.

Jan 1, 2002

By C. Zografidis

Environmental protection, economic prosperity and respect of the need for social equity promotion, constitute a prerequisite for any modern industry aiming to operate in a sustainable manner. The Natural Stone industry in Europe, a sector comprising mainly of SMEs, despite the fact that consists a dynamic extraction sector, often lucks the resources to apply novel techniques and management schemes towards achieving sustainable performance. I-STONE, an EU Integrated Project funded by the 6th Framework Programme, is aiming to contribute in the improved performance of the Natural Stone industry. A primary project objective is the re-engineering of the stone production chain, in order among others to considerably in-crease its efficiency and productivity, and minimise the amount of stone wastes disposed. The present paper, resulting from the research con-ducted on environmental management within I-STONE, is focusing on the use of sustainable indicators as a tool for the assessment of the stone industry?s performance. Based on Commission Decisions and reported studies, a list of indicators was selected and used within I-STONE, including environmental and socio-economic indicators. A set of selected environmental indicators were quantified based on operational data of a number of Greek and Portuguese quarries examined as case studies. The analysis indicated that an integrated strategy, including the application of novel operation techniques and equipment, waste minimization and systematic environmental monitoring and reporting, constitute key factors for the sustainable operation of natural stone industry.

Jan 1, 2007

By J. Stachurski, N. A. Abdel-Khalek

Flotation tests were carried out on six coal samples of different rank as well as their oxidized samples. A mixture of diesel oil and alcohols was used in these tests. Surface oxidation caused a distinct decrease during flotation recovery with some improvement in the grade. The reduction in the recovery increased with increasing concentration of the oxidizing agent. The floatability of low rank coals was affected by oxidation to a higher degree than the floatability of medium and high rank coals. The recovery-size curves of oxidized samples were similar in shape to the recovery-size curves of non-oxidized coals.

Jan 1, 1991

By Dennis A. Giardino, Leonard C. Marraccini

This paper surveys noise levels, noise exposure patterns, and frequency spectra found in the mining environment; the effects of mining noise on the working population; and the quantification of hearing loss in the coal mining industry. Federal mining noise regulations and the present state of the industry, with respect to noise control technology, are discussed. Examples of proven noise controls for mining are included along with measured noise reductions.

Jan 1, 1986