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By Charles LeMoyne

The Cable belt Company has been building single flight conveyors for a number of years. The simple design concepts of this type conveyor, introduced over thirty years ago, when distances of one to two miles were considered major advances in technology, remain relatively unchanged. Conveyors that are 6 to 20 miles (9.0 to 32 kilometers) long are being built and are presently in operation through- out the free world. The Cable Belt conveyor is not conventional in its construction. Cable welt differs from conventional troughed idler conveyors in that the driving medium and carrying medium are separated. Motion is provided by two endless steel cables running the length of the conveyor. The cables are driven by a single drive unit incorporating a differential gear which insures identical cable linear speeds and equal tension in both cables at all times. The belting is located and supported by "V" shaped shoeforms moulded to the belt which form a wedging action. The friction between the belting and rope is sufficient to prevent slippage (See figure 01).

Jan 1, 1983

In 1976, The Zinc Corporation Limited Broken Hill set up a plant to re-process a hill of tailing (Mt. Keast) from the original treatment operations. With the likely disappearance of this source of feed in 1985, an investigation was initiated to determine what other feed sources might be available. This involved searching through old records and photographs as well as a subsequent drilling campaign. The paper briefly covers the history of treatment operations and describes, as a result of the information obtained, the likely future sources of feed.

Jan 1, 1983

By Thomas J. Peters

A mineral survey of the Sill Hill RARE II area (No. 5304), covering 5,200 acres (2,100 ha) of the Cleveland National Forest, San Diego County, California, was conducted by the U.S. Bureau of Mines and the U.S. Geological Survey. This survey was in conformance with the Resource Planning Act (RPA) of 1974, as amended by the National Forest Management Act of 1976, to provide mineral resource information for study area classification. Bureau of Mines personnel made an economic appraisal of mineral deposits by searching pertinent geological and mining publications as well as U.S. Bureau of Land Management, U.S. Forest Service, and U.S. Bureau of Mines files and records. Known mines, prospects, and mineralized localities were examined during 1981, and sampling and mapping were done where warranted. The Geological Survey 'did geologic mapping, geochemical sampling, and geophysical surveys to aid this study.

Jan 1, 1983

By Robert B. Parsons

"Recent amendments to the so-called ""flow-through share"" rules in our income tax legislation have given a new lease on life to this once popular investment vehicle.The original ""Dome funds"" for exploration in the Beaufort sea recognized the usefulness of flow-through share arrangements, but, by and large, flow-through shares have until recently not been able to compete effectively with other tax shelter instruments-mainly , limited partnership interests.This month, Tax Notes examines the new tax rules for investing in flow-through shares.IntroductionRecent income tax amendments have helped to rekindle investor and industry interest in so-called ""flow-through shares"" as a mechanism for mobilizing funds toward mineral exploration and development activities. In competing for investment funds, flow-through shares have historically placed a distant second in terms of investor popularity, being unable to compete with the more attractive features of limited partnership arrangements. However, primarily as a result of favourable changes to the income tax law, flow-through shares may be well poised for a comeback.This article examines the income tax considerations pertaining to issuing and investing in flow-through shares, and compares the former and the new income tax rules relating thereto. Of course, inasmuch as a flow-through share issue can involve various contractual arrangements between the investor and the issuer, there is a wide range of legal and business factors that generally have to be taken into account. A discussion of these matter s is beyond the scope of this paper, which is restricted to a summary of the special income tax factors attributable to flow-through shares."

Jan 1, 1983

This report discusses the nonfuel critical minerals position of the United States-both current and future (to the year 2000). We have assumed that there will be no major global disturbances-military, political, or economic-during the rest of this century. However, international relationships, strategies, and conditions that affect the supply of minerals are very tenuous, normal trading patterns can be easily upset, and national and ideological objectives can and do interfere with "normal" free market conditions. For example, the Department of Defense has reported that the Soviet Union is engaged in a strategy designed to reduce the availability of strategic minerals, through either physical disruption, market manipulation, or domination of producing or neighboring states. Although such a strategy poses serious concerns for the United States and the free world, the impacts of disruptions are not covered in this publication. Historical Perspective The modern industrial economy of the United States is founded on the production and use of minerals.* Two hundred years ago our forebears began taming a raw continent, developing a base for agriculture and a rudimentary minerals producing system. In the 19th century, with the aid of imported labor and capital, the development of America's vast natural resources was undertaken, and the transition from an agricultural to industrial society was underway. By the century's close, the United States had emerged as a great industrial power, partly through the development of such mineral resources as iron in Minnesota and coal in Pennsylvania.

Jan 1, 1983

Utah's Blackwater mine began operations in 1967. The four CQCA mines controlled by Utah followed over the period 1971 to 1979. Project feasibility studies for all these were based on open cut mining to overburden depths of 60 metres, with typical project lives of 12 to 16 years, depending on reserves Further studies, initiated after the mines had started, showed that continuation of open cut mining beyond the 60 metre highwall was viable. In 1973, the Deep Stripping Project (DSP) was launched to define the scope for stripping deeper, to determine what the additional equipment needs might be, and to pu forward proposals for a full scale trial system. The project commenced at grass roots with a literature survey, proceeded through a sequence of equipment evaluation, specification, design and manufacture to the commissioning of the Goonyella BWE system. Studies are continuing to assess the future deep stripping requirements for all Utah's Bowen Basin mines.

Jan 1, 1983

By D. Menne

A comminution model and a quick laboratory milling test procedure are presented. These allow the determination of milling parameters for the - optimization of ball size and pulp density in operating mills estimation of the performance of new feed stocks in an existing mill - estimation of the expected milling performance for a new project. Information on the estimation of the size of mills to deliver specified amounts of comminution energy, and amount of expected ball, rod, and liner wear to allow cost estimates for new projects, is also included.

Jan 1, 1983

By Hart G. H

In tectonically disturbed zones within coal seams, decreases in the amount of kaolinite in the cellular structure of inertiniterich coal are accompanied by increasing kaolinite contents in fractures within the coal and/or rocks of immediately overlying horizons. This is due to fracturing of the inertinite microstructure by tectonic disturbance and remobilization and redistribution of free, fine-grained material (kaolinite and/or inertodetrinite.) Ascending waters are believed to transport the kaolinite in suspension, and redeposit it in the fractures and pores in the overlying horizons. This removal of material from the inertinite-rich coal leads to an increase in porosity (higher free gas storage), a presumed reduction in coal strength and an apparent increased proneness to instantaneous outbursts of coal and gas.

Jan 1, 1983

By J. H. Perry, D. W. Houseknecth, C. A. Kertis, A. T. Iannacchione

Major problems facing the development of coal and gas resources of the Hartshorne Coalbeds include the complex distribution of minable and unminable coal, high methane content and bed pressure, faulting, variations in degree of dip, presence of natural gas fields in associated sandstones, and legal problems, caused by local geologic characteris- tics, in identifying gas origin. This Bureau of Mines study provides pertinent geologic information for long-range planning of subsurface coal and gas production from the Hartshorne Coalbeds. Pittsburg, Coal, Hughes, and Atoka Counties, OK, have approximately 1 billion metric tons (1.1 billion short tons) of Hartshorne coal in place. The methane resource of Hartshorne Coalbeds is estimated at 9.2 billion m3 (325 billion ft3) and varies with overburden and rank, These estimates were compiled from gas well density logs, coal-core data, out- crop measurements, abandoned mine maps, and the literature. The Hartshorne Coalbeds represent a valuable coal and gas resource which at present is contributing nothing to coal and gas production. This report discusses potential problems and serves as a reference for future exploration and development work. Recognition of these potential geologically related problems prior to development of this basin will reduce hazards and allow for an economic recovery of these resources.

Jan 1, 1983

By Paul G. Swanson

This manual of practice is to be used in combination with the final reports for the study of spoil stability in the Eastern Coal Province. The manual applies the predictive matrices developed in the parent study for use in evaluating the stability of typical mine spoil slopes. The values of internal friction and pore pressure coefficient are derived for many varied slope conditions. The results can be used in conventional stability analysis equations to assist the mine operator or regulatory personnel in evaluating spoil stability from very limited information.

Jan 1, 1983

By Leslie S. Halasz

This paper describes the techniques implemented at Randfontein Estates to develop twin-haulages at 'high speed'. An operation which culminated in the world record advance for twin-end multiblast cyclic development in hard abrasive quartzites. A major expansion project was planned for the mine, with the sinking of a third twin-shaft system (to be known as Cooke No. 3), to raise the level of ore production from 3 500 000 to 5 000 000 tonnes per alumm. Subsequent redesign of the proposed shaft system as a single 9 m brattice wall shaft took place, reducing the planned shaft sinking period by 12 months and saving an estimated R 250 000 (U.S. $ 330 000) in sinking costs. The advancement of the Cooke No. 3 Shaft sinking and development programme necessitated a rapid excavation schedule for two interconnecting twin-haulages from the existing Cooke No. 2 twin shaft complex to provide a second means of egress. An early holing between the two shafts would provide significant financial and technical benefits. Pre-development and equipping of shaft pillar excavations would enable a rapid shaft production build up and blocking out of at least one year's ore-reserves.

Jan 1, 1983

By Levent Ozdemir, Robert J. Evans

An ongoing research program at the Colorado School of Mines is investigating the application of low to moderate pressure water jets to assist the cutting performance of drag type cutter bits commonly used on coal mine cutting machinery. The results to date indicate that a water jet directed to impinge the rock in the immediate vicinity of cutter tip can provide significant benefits in terms of reduced cutting forces, prolonged bit life and less airborne dust, as well as reduced tendency of sparking during cutting. This paper describes the findings of this research effort designed to fully evaluate and optimize the parameters affecting the performance of a combined water jet assisted drag bit cutting system for coal mine applications.

Jan 1, 1983

By Christopher J. Bise

Traditionally, mine drainage systems have not received the high level of emphasis on careful engineering design which has been rendered to many of the other auxillary operations. This may be due, in part, to the situation-response approach toward dealing with an influx of water. When the installed system becomes inadequate, costly alterations to the pump, such as staging or speed increases, are considered expedient solutions. In order to rectify this situation, computer-aided solutions to mine drainage problems could represent an efficient alternative to the methods presently used. This paper will consider the application of microcomputer technology to mine drainage problems and will show how the relative economy and convenience of microcomputers can make them become valuable analytic tools at any mine site.

Jan 1, 1983

This paper sets out to discuss some of the more common forms of geological data abuse in project development. The paper illustrates various types of abuse and the reasons behind that misuse of data. This paper is only a brief introduction to a very large subject.

Jan 1, 1983

By H. W. Peirce

Identified and utilized Arizona salt deposits are of two ages: 1) Permian in the Colorado Plateau, and 2) Tertiary in the Basin and Range country. Uses include: a) storage of energy fluids in man-made solution cavities in both Permian (Supai Formation) and Tertiary (Luke salt body) salt and b) production of marketable products by solution and evaporation of tertiary salt. The two liquid petroleum storage Projects have a combined storage capacity in excess of 380 million L (100 million gal). Current production of salt products approximates 32 kt/a (32,000 stpy). Increasing demand for both storage and salt products is anticipated.

Jan 1, 1983

By Romeo S. Jurani

Bulkspray cooling has been economically applied in cooling the hot environment of South African gold mines for the past two decades. Its success in that country led to its introduction at Gulf Mineral Resources Co.'s Mt. Taylor Mine in 1981 when increased drifting imposed additional cooling requirements. The bulkspray cooler developed and used at Mt. Taylor has a heat transfer capability of about 500 to 1500 kW. It is compact and portable, designed to be moved as required to maintain working temperatures in the advancing drift faces.

Jan 1, 1983

By Kazumasa Taguchi

At the Kakogawa works of Kobe Steel. Ltd., the agglomeration facilities are composed of a pelletizing plant and sintering plant. This aim is to utilize raw materials efficiently and stabilize the raw material resources. Therefore at Kakogawa works, the blast furnaces (BF) have been operated with high pellet ratio and various developments for pellet properties have been achieved to improve the blast furnace performance. These developments include dolomite-fluxed pellets, new-porous pellets and crushed pellets. As a results of these improvements, pellets have achieved almost the same performance as sinter at high temperature regarding properties such as the softening, melting and reduction behaviour. However, some problems on shape have remained to be solved. Spherical pellets flow easily into the center of the furnace and form mixed layers of pellets and cokes. Therefore, in BF operations with these pellets it becomes more difficult to keep proper and stable gas distribution.

Jan 1, 1983

By J. Phillip Neal, Kefton H. Teague, Carroll P. Rogers

Feldspars, the most abundant minerals of the igneous rocks, occur in numerous forms and mixtures. The feldspars of commercial significance are found in widely distributed pegmatites as large crystals usually free of iron-bearing impurities and thus suitable for hand-cobbing, and also in larger bodies where the ore contains various types of feldspar intermingled with quartz and relatively free of iron-bearing impurities, or at least readily unlocked from impurities present at relatively coarse mesh. The latter type of ore includes some pegmatites, and the "alaskite" bodies so common in the Spruce Pine district of North Carolina. On the west coast of the US and in Oklahoma there is-or has been-commercial recovery of natural feldspathic sand as a source of alumina in glass and ceramics. "Aplite" in commercial terminology is a light-colored igneous rock with a granitic composition and a fine sugary texture, often banded with readily removable iron impurities. Only one area in Virginia produces aplite for the glass industry; it is located near Montpelier in Hanover County. According to Deer et al. (1966) the word feldspar derives from the Swedish feldt or jolt (field) and "spath:" chunks of rock appearing in tilled ground overlying granite. Castle and Gillson (1960) indicate a Germanic origin, citing "spat," which is said to refer to any transparent or translucent material which is readily cleavable. The term "spar" has in the past been applied to minerals other than feldspar, such as barite, calcite, and fluorite. It is correct to call the latter "fluorspar." There is a true barium feldspar, but it is rare and of no present economic importance. What is recognized as feldspar or "spar" by present producers and consumers consists of three silicate minerals which, if pure, would have the formulas KA1Si3O8 (microcline or orthoclase), NaAlSi3O8 (albite), and CaAl2Si2O8 (anorthite). These are almost never found in pure form in nature, but occur together in great abundance in a three-component system. A considerable number of different combined ratios of these three exists, with the exception that isomorphism between potassium spar and calcium spar is very limited. User specifications for feldspar products are largely built around the prevalent naturally occurring ratios. Passages following will refer to "K-spar," "Naspar," or "Ca-spar." Nomenclature and Descriptive Terms Relating to both the mineralogy and the economics of feldspar are certain terms whose coverage it is useful to specify. Commercially, aplite is a feldspathic rock mined and beneficiated in one location in Virginia, in which both titanium and feldspar minerals are present-the latter now being the major, if not the only, economic product. Technically, the term aplite when applied to this rock is of questionable accuracy. But, in light of accepted commercial usage, the term will be here used to designate it. Regarding the Virginia rock, Ross (1941) is cited. Alaskite is another term requiring understanding if not precise use. A distinctive rock type customarily called by this name is found near Spruce Pine, Mitchell County, North Carolina. An important major feldspar source, it contains somewhat higher levels of plagioclase feldspar and quartz than alaskite as defined in the Glossary of Geology and Related Sciences, which states that `orthoclase, microcline, and subordinate quartz are the principal

Jan 1, 1983

By Brian H. Kaye

Efficient design of grinding circuits for efficient production of ultrafine material requires rapid feedback of information concerning the fineness of material leaving the grinding device Generating this information requires efficient sampling and adequate rapid characterization of the material leaving the grinding machinery Recent developments in electrooptic inspection of dry and wet material leaving a grinding device are critically reviewed New methods for characterizing ultrafines are discussed A rapid operating automated cybernetic (intelligent) permeability device for automatic control of grinding circuits using Blaine Index and other fineness indices is described

Jan 1, 1983

Develop technology that can reduce the dust exposure of a mine worker at the tailgate end of the longwall face by providing him with a clean split of air. Approach Use the jet spray air mover (JSAM) developed under a Bureau of Mines contract (refer to Technology News No. 117 for details on the development), to clean a small portion of the face air and to discharge the clean air behind a brattice partition. How It Works At most longwalls, air flows along the face from head-to-tail. Most of the airborne respirable dust generated along the face during mining is transported to the tailgate with the airflow. Any miner required to work at the tailgate is exposed to this dust. The only practical means of removing airborne respirable dust is with a scrubber. Simplicity and size made the JSAM the best choice for cleaning a portion of the tailgate air. The scrubber has no moving parts and is operated by water at low flow rates (<10 gpm) and fairly high pressures (250-500 psig). Many longwalls have sufficient water systems to supply the JSAM with adequate water pressures and flow rates. Also, the JSAM&apos;s size (4&apos;x 2&apos;x 1&apos;) allows it to be hung on one of the tailgate&apos;s shields or at some other convenient location. A clean split can be maintained at the tailgate by discharging the cleaned air behind a brattice partition at the work area. This should effectively seal off the clean air from the dusty air and provide the tailgate worker with a less dusty work environment.

Jan 1, 1983