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By Michael Fellows

Epidote is a common hydrothermal alteration product in many copper deposits of the southwestern United States. In many of these deposits epidote, along with calcite and chlorite, generally characterize a distal or halo propylitic alteration assemblage, but the mineral can occur within the central potassic alteration zone as well. Epidote is also a common alteration mineral in deposits formed in calcareous host rocks -- the skarn or pyrometasomatic ore bodies. Within the past 15 years, studies of the major and trace element composition of other alteration phases, principally biotite, associated with base metal ore deposits have demonstrated that some hydrothermal alteration minerals are compositional distinct from their igneous or metamorphic counterparts: However, the use of major and minor element content to identify and zero in on mineral¬ized areas does not appear to be very promising. Little work has been published upon the geochemistry of epidote from this standpoint and the results of my work suggest that a similar conclusion can be applied to epidote. My work (Fellows, 1976) suggests that epidote minerals in hydrothermal alteration suites from porphyry copper deposits in the southwestern United States are generally iron-rich rather than aluminum-rich. As a group, these alteration minerals differ compositionally from epidotes of regional metamorphic terrains. I ascribe these differences to the variations in the oxidation character of the respective environments. However, it appears as though the use of major element compositional variations of epidotes as an exploration tool is severely limited. Epidote is a complex calcium-aluminum silicate. Replacement of aluminum by ferric iron establishes a solid solution series between

Jan 1, 1977

By Gerry Norton

The purpose of this paper is to make the most complete assessment of coal cleaning methods, both process and equipment related to modern-day production and environmental requirements. In order to achieve this primary objective, a number of interdependent aspects of coal cleaning technology require evaluation and analysis. 1.0 CLASSIFICATION OF SEPARATION PROCESSES Processes and cleaning equipment can be categorized according to the important parameters of 1) mechanics of separation, 2) size range application, 3) range or variance in accuracy of separation related to 2) above, and 4) feed-size ratio affecting 3) above.

Jan 1, 1977

By Byron S. Gottfried

This Bureau of Mines report presents a method for combining the distribution curves at different specific gravities of separation, for a given piece of coal-cleaning equipment and a given raw coal feed, into a single, generalized distribution curve normalized with respect to specific gravity and, therefore, independent of the specific gravity of separation. Illustrative generalized distribution curves, based upon Bureau of Mines collected data on industrial operations, are presented for five different types of coal-cleaning equipment. The well-known concept of probable error is extended to the generalized distribution curve. It is shown that the conventional probable error is directly proportional to the specific gravity of separation. A number of sample calculations, illustrating the use of the generalized distribution curve and generalized probable error, are presented in the appendix.

Jan 1, 1977

By Charles L. Hosler

My function here today is not to illuminate any particular subject but simply to welcome you to Penn State and to the College of Earth and Mineral Sciences. Our college is, of course, dedicated to the same thing to which most of you have dedicated your lives--the exploration of the earth, the extraction of materials from it, and the production of useful things from those materials. We have about 2,000 students engaged in studying in preparation for service in these activities at the present time. Like other colleges of our type, we've undergone a great expansion just at a time when university budgets are contracting. This creates an interesting situation as to how we can best use our resources. This, of course, is the thing a lot of you are going to be talking about here--how we can best use the world's resources. As you well know, the expectations of the people of the world are rising, and, with the numbers of people increasing and with finite resources, there never was a time in history when it was more important that we become "quantitative" in our discovery, estimation, extraction, and utilization of those resources. I think it is admirable and very timely that you are gathered together to discuss your various approaches to this particu¬lar problem of quantifying and making most efficient use of the resources of the world. Yours is sort of a hidden profession, not just because you actually go underground, but because the public in general is not aware of where the materials they use come from. If you are successful in your professions the public will continue to be unaware. Only if you fail will your essential function become patently obvious. I wish you success both in your professional pursuits and in this particular meeting.

Jan 1, 1977

By Keith Whitworth

The USSR, over the last 20 years, has continued to increase its out-put year by year and it is now almost four times what it was at the end of the Second World War. In 1975, it exceeded 700 million tons of run-oi-mine coal (all ranks) which amounts to over 20 percent of world output. This rapid progress has been due to modernization of the industry, by means of increased mechanization and automation and the development of new machines and systems for underground workings and by the expansion of open-pit workings and the development and implementation of larger earthmoving machines.

Jan 1, 1977

By R. Gilges

The implementation of effective techniques for meeting the maintenance requirements of the new Utah Copper Division smelter, one of the largest in the Western Hemisphere, is a goal of the smelter management and supervisory personnel. Kennecott's Metal Mining Division Computing Center has been working with smelter personnel to implement a computer program to provide instantaneous access to equipment specifications, maintenance and cost histories, spare parts, preventive maintenance scheddes, etc. for several hundred pieces of equipment. This information will be available to all smelter personnel via visual display terminals. The system will dramatically reduce the time now spent in search of pertinent information required in effectively performing the maintenance functions. It will also be used to analyze practices, detect trends, prepare budgets, and substantially reduce the paper work normally associated with the running of a large and complex maintenance organization.

Jan 1, 1977

By R. H. Roberts

The Environment Weipa is located at 12° south latitude on the west coast of Cape York Peninsula, North Queensland, Australia. The climate is tropical with most of the 1 600 mm. average annual rainfall falling between November and March. During the short winter months (May/ August) the weather is clear and pleasant, with temperatures seldom exceeding 27°C.Throughout the remainder of the year, conditions are frequently oppressive due to consistent high ambient temperatures accompanied by high humidity. The terrain is of low relief, and generally not more than 6 to 10m. above mean sea level adjacent to the coast. The coastline features numerous short estuaries which discharge run-off from the heavy rains collected by creeks and rivers. The whole area is covered by an open forest, the predominant species of which is Eucalyptus tetradonta. These eucalypts have only limited commercial value and are heavily infested with termites. Despite the fact that Weipa is close to the location of the first reported sighting of the Australian coastline by a European (William Janz - 1606), it remains very isolated. There is no developed road or rail connection to centres of population, so that transport of practically all products, personnel and materials to and from Weipa is by sea and air. Cairns (population 49 000) is 580 km. by air and 670 nautical miles by sea; Brisbane, the

Jan 1, 1977

By Richard E. Beane

For several decades, the minerals industry has used leaching techniques to extract metals from rocks whose grade was too low to be treated profitably using conventional metallurgical techniques, and, as of 1972, about 15% of domestic copper production was derived using leaching methods (Beall 1). Increasing interest is currently being directed toward solution mining, particularly with respect to copper, for basically two reasons. In the first place, geological exploration has outlined several copper deposits of large tonnage and 1m', grade which are buried at sufficient depth to preclude open-pit mining which would make such mineral deposits ore deposits. Nevertheless, these occurrences provide significant potential if they could be treated by chemical leaching in situ. Secondly, the porphyry deposits of the western united States, which provide by far the largest percentage of domestic copper, do not terminate geometrically with sharp borders. These large disseminated bodies commonly decrease in grade laterally away from volumes of rock containing ore grade metallization, and the distinction between ore and waste is strictly economic. In order to extract ore grade material from the ground, a significant amount of rock containing sub-ore-grade copper must also be removed which, when placed on dumps, is amenable to solution mining. These two considerations clearly indicate the reasons for the growing interest in solution , leaching techniques--namely the ability to exploit deeply buried low grade deposits and the expansion of reserves in deposits currently under production.

Jan 1, 1977

By R. V. Ramani

The industrial hygiene and safety aspects with internal combustion engines in mining systems is truly interdisciplinary and encompasses many fields such as mine ventilation, exhaust gas and particulate analyses, mine atmospheric environment monitoring, mathematical modeling of generation, dilution and dispersion of pollutants in ventilation systems, and engine testing and approval. This bibliography, therefore, is a compilation of references from interdisciplinary sources pertaining to diesels and related areas. Related areas are defined as those concerned with: (i) mine ventilation system design and operation; (ii) description, measurement, modeling and monitoring of mine atmosphere contaminants, and (iii) tests, standards, selection procedures, and operational practices for internal combustion engines in underground mines. References cited from source materials span the years 1900 to early 1977. Total number of references cited is 511. Subjective criteria governed the definition and selection of references. Therefore, this bibliography is not claimed to be all-inclusive nor does it purport to be an exhaustive search of all sources.

Jan 1, 1977

By L. R. Hougen

The Falconbridge Matte Leach Process yields high-purity nickel chloride by selectively dissolving nickel from copper-nickel converter matte with hydrochloric acid , purifying the solution by solvent extraction and crystallizing NiCl2 4H2O by further acidifying the purified leach liquor. In the Kristiansand Matte Leach Plant, a granular oxide is produced by high-temperature hydrolysis of the nickel chloride for subsequent reduction to a high-purity granular metal product, designated NICKEL 98. This paper describes the investigation of on alternate route to processing nickel chloride in which high-quality cathode nickel is produced by electrowinning from all- chloride electrolyte. The investigation was made in a pilot circuit containing two production-size electrowinning tanks operated in conjunction with the commercial-scale leach plant.

Jan 1, 1977

By Donn W. Leva

In North America, pipelines move more material than any other form of transportation. 1 Pipelines have been used principally for the transportation of liquids and gases; however, slurry pipelines have made notable gains in recent years enabling solid materials to be moved efficiently by pipelines. The obvious advantages of pipe-lines --low maintenance, low operating costs, minimal impact on the environment, greater land use, low labor intensity, safety and high operating factor --have stimulated researchers in England, West Germany, Japan, USSR and the USA during the past ten years to develop pneumatic capsule pipelines for the movement of bulk materials in large quantities. As a result of this work, pneumatic capsule pipelines are now available for the movement of dense bulk materials. Through these pneumatic capsule pipelines, material is moved in wheeled capsules which are pushed through the pipeline by flowing air. In this paper, a capsule pipeline system developed by the Georgia Institute of Technology and Tubexpress Systems, Inc. of Houston, Texas is discussed. The Tubexpress System Major Components The pipe used for a Tubexpress capsule system is standard thin wall welded steel pipe. Since pressures in the system generally do not exceed one atmosphere, the controlling design criteria for wall thickness of the pipeline is pressure from the overburden of the backfill if the line is buried or the structural requirements for supporting itself and the load if it is suspended or supported on piers. The air pumping system for Tubexpress is a combination of

Jan 1, 1977

The Bureau of Mines conducted a field study of respirable dust concentrations at an underground room-and-pillar oil shale mine and at the aboveground milling facility to determine the dust generation sources, personal respirable exposure, characteristic minerals, and size distribution of the dust. Major dust sources in the mine were the scaling and blasthole drilling operations, and major dust sources in the processing mill were the screening and crushing operations. Principal minerals found in the airborne respirable dust were albite, analcite, calcite, dolomite, quartz, and orthoclase. The average alpha-quartz content of mine and mill respirable dust samples was 4.1 pct and 15.5 pct, respectively. Carbonaceous material such as diesel particulate accounted for approximately 75 pct of the respirable particulate found in the mine. The average coefficient of variance of respirable dust concentrations measured with approved personal dust samplers in the mine and mill was 7.6 pct, the best precision observed to date with the personal dust sampler operated in the field.

Jan 1, 1977

By Thomas N. Walthier

Exploration is the systematically financed and technically oriented search for mineral wealth. Almost all established mining companies have an exploration department. The size of a company's search varies over the years as the company's profits, or the corporate philosophy change. While the established mining companies have exploration departments, they are also alert to acquiring discoveries made by others -- especially by prospectors and small companies without the resources to develop their find. The emphasis in some large companies stresses self-generated discoveries while others rely heavily on acquisitions; again, over the years the emphasis may alternate. In the last analysis, essentially all new mineral wealth was found through someone's exploration effort. Before we discuss how exploration is financed, it will be informative to analyze how discoveries have been made and by whom. Recently, the author conducted a survey of randomly selected major mining companies to answer these questions. Most companies responded and many went to considerable effort to give complete and detailed answers. I thank all for their help and cooperation. The questionnaire is attached as Appendix I. Appendix II is a list of the 400 companies that replied in a complete enough manner and format to be analyzed here. The results of the questionnaire are given in Table 1. Over 57% of the new orebodies acquired by 40 major mining companies during the past quarter of a century were generated

Jan 1, 1977

By David Schlain

The Bureau of Mines investigated methods for electrodepositing platinum-group metals from molten cyanide baths. The preparation of thick, protective coatings on molybdenum, Inconel, graphite, stainless steel, copper, and other structural metals were studied, as well as the electroforming of platinum and iridium crucibles. Iridium, rhodium, and ruthenium can be electrodeposited under an inert atmosphere, while platinum and palladium require the presence of air. Electrolytes may be prepared by direct-current electrolysis in NaCN or mixtures of NaCN and KCN using anodes of the particular platinum-group metal. When the concentration of metal increases to about 0.3 or 0.4 percent, the deposits become bright, adherent, and coherent. Current densities may be 10 to 25 ma/cm2, and plating rates are often 0.5 mil/hr. Platinum and palladium baths deteriorate because of the oxidation of cyanide to cyanate and carbonate, and the precipitation of metal. Changes in the platinum cyanide bath are relatively slow. The protection against oxidation afforded by the platinum-group metal coatings is evaluated by testing encapsulated specimens in a thermogravimetric balance. Surface pretreatment and the use of undercoats are discussed.

Jan 1, 1977

By Leonard Sugin

The requirements of today's and tomorrow's markets led to a new generation of facilities which handles large tonnages annually, loading them into larger vessels, at higher rates, efficiently and reliably, with minimum labor input, and significantly greater attention to the environment. A great variety of products are handled, including various grades of metallurgical and steaming coal, coke, iron ore in its many forms, shapes and moisture content, phosphates and fertilizer products, bauxite and alumina ores, limestone, sugar and grains, cement and many other products. When we examine the annual tonnages involved in these movements the economic value of handling these products on a bulk basis can be readily seen. Although nearly all these products have been handled by continuous bulk conveyors for many years, recent governmental response to environmental concerns require a re-evaluation of previous procedures. Most air pollution and emission control regulations and ordinances have recognized several specific sources of pollution. Detailed regulations and requirements have been developed concerning smoke emissions, emissions of visible air contaminants and particulate matter from power plants, heating plants, refuse burning equipment, coke ovens, steel furnaces, kilns, and other industrial installations. Although fugitive dust is also an environmental pollutant it is governed by regulations that are more general and therefore, more difficult to apply. A general definition of a "fugitive particle" is any matter which escapes or becomes airborne from an operation or which is emitted into the atmosphere without passing or being conducted through a flue, pipe, stack or other structure designed for the purpose of emitting air pollutants into the atmosphere. This paper deals with the aspects of fugitive dust emissions as they apply to shiploading. Fugitive dust emissions control is important not only because of environmental regulations but also to prevent the loss of valuable product, reduce housekeeping, and reduce breakdown and maintenance problems to land and vessel equipment. The environmental controls for a belt conveyor system are those which will restrict the emission of fugitive dust particles and can be considered as follows:

Jan 1, 1977

By Martin Hertzberg

The early and reliable detection of the self-heating of combustible substances in mines is of considerable importance to the mining community. This Bureau of Mines report describes the results of a variety of studies of incipient combustion and its detection. Heated samples of coal, wood, and various polymers were used to evaluate the relative sensitivities of several types of detectors. The laboratory results indicate that submicrometer particulate detection is the most universal and sensitive method. Carbon monoxide detection was as sensitive as submicrometer particulate detection for pyrolyzing coal but was relatively insensitive to pyrolyzing wood or plastics. The conventional type of ionization smoke detector was the least sensitive for coal and of intermediate sensitivity for wood and plastics. Self-heating experiments with Pittsburgh seam coal piles of varying particle sizes gave ignition temperatures of 170° C for 4-to 7-µm dust, which increased monotonically with particle size. The measured heating rates were compared with data from an adiabatic calorimeter to obtain preexponential rate constants. The preexponential rate constants varied linearly with the surface area per unit mass of sample as would be expected for heterogeneous surface oxidation. The propagation behavior of ignition waves and the overall self-heating appears to depend critically on the magnitude of the convective flows induced, which counteract the depletion of oxygen in the void spaces of the pile. Classical theories of thermal ignition require substantial modification to be applied reliably to such cases.

Jan 1, 1977

By William N. Poundstone

Consolidation Coal Company, through the mining research division of Continental Oil Company, is now undertaking the installation of a full-scale hydraulic transportation system to carry coarse coal from the mine face to the preparation plant. The facility will include all elements of a fully integrated haulage system including face haulage for both longwall and continuous miner sections, multiple slurry feeds, hydraulic hoisting and 2.4 miles of overland slurry transport. This undertaking is a result of more than six years of extensive research and testing, some of which has been previously releasted to the literature. To provide a reference framework for system description, a brief history of recent coal mining technological developments will be discussed. Following World War II, mechanization resulted in mining machines that were bigger, faster, more powerful, and more reliable. These changes were essentially refinements in an established mining system. They made mining more efficient than before, but they did not change the system itself. By about the mid-1960's, it was apparent that further improvements in the extraction machinery would have a declining payoff, simply because .the worst bottlenecks were in other components of the mining system. A modern continuous miner cannot be run continuously because other operations underground cannot keep pace. In fact, most continuous miners today run at less than 20% of capacity. Consequently, in 1969 Consol and its parent company, Continental Oil, undertook a long-range R&D program to try to change the basic haulage system for the better. Most coal at present is removed from the mine by a hand-off system in which the coal is transferred from the continuous miner to a shuttle car, often with the aid of a separate loader; then from the shuttle car to a system of conveyor belts; and finally from the conveyors to rail cars. The system involves a large amount of moving equipment underground, many transfer points, and the everpresent chance of operational delays and safety hazards. By removing the haulage bottleneck, we believe we can speed up underground operations substantially; and perhaps more important, we could make it feasible to develop a whole new generation of mining equipment that is inherently safer. What we wanted was a truly flexible, continuous haulage system with inherent safety advantages. Ideally the system had to meet three major requirements: First, the coal had to enter the transport system at the face, and remain in that same system all the way to the preparation plant. Second, the system had to be flexible and extensible so that it could- follow the mining machine as it advances and retracts. And, third, the system must be inherently safer than current haulage technology.

Jan 1, 1977

By Young C. Kim

Introduction and Objective of This Paper Computerized open pit mine models* are more and more used today for feasi¬bility studies as well as for long range mine planning. In fact, using these models is becoming an enforced practice due to various reasons. One main reason is its capacity to evaluate several designs in a fraction of time required by manual effort. Another reason is the necessity to evaluate several. pit designs due to ever decreasing grade of the orebody and increasing financial risk due to smaller profitability margin. In spite of today's accepted use of computer models, very little guidelines are available which the average practitioner can follow either to choose or to build the type of model best suited for his need. Consequently, the objectives of this paper are: 1. To review the current state of the art in the computerized open pit mine models. 2. To provide some suggestions for model selection. 3. To share our experiences in developing a model for a highly irregular copper ore deposit (see Appendix).

Jan 1, 1977

By E. M. Cameron

Reconnaissance radiometric and geochemical data have been obtained for an area on the western shore of Wollaston Lake that includes the Rabbit Lake uranium deposit. The study area is extensively drift cover ed. The geochemical data were obtained by analysis of center-lake sediments and surface waters for a variety of elements and other constituents. The airborne radiometric data comprise measurements of eU, eTh and K obtained with a .50,000-cc NaI (Tl) detector at a mean terrain clearance of 120 m and 5-km flight-line spacing. Uranium in lake sediments and uranium in waters are the most effective geochemical indicators of uranium mineralization; the other elements measured are not notably anomalous. A sample site density of one per 1 8 km 2 is more than adequate for identification of the mineralized area. Because many water samples contain close to or below the current analytical detection limit of 0.05 ppb U, the use of sediments is generally favoured. for broad-scale reconnaissance in the region. Uranium in these lake sediments appears to be little influenced by variations in the organic or iron and manganese content. The most effective radiometric indicator of the mineralization is the eU/eTh ratio. This parameter is less influenced by environmental variation on the ground beneath the flight line than eU alone . The eTh/K ratio is anomalous under the Athabasca Formation unconformity where, in places, the uranium mineralization is localized.

Jan 1, 1977

By Donald R. Williamson

Statistical studies at Cyprus Pima Mine indicate that samples from 22 blastholes are necessary for determining average copper grades, within a desired range of precision, for mine-model blocks by arithmetic averaging. The average number of holes in such blocks is 14. Many considerations show that more holes will not be drilled for sampling. A way to determine block grades more reliably than by" arithmetic averaging was sought. Thus far arithmetic averaging has proven to be the best procedure for the particular operation characteristics despite the small number of samples. It naturally follows that expenditure of great effort in sampling blasthole cuttings is unwise.

Jan 1, 1977