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By W. R. Dengler, R. S. Brown

In 1974, Brunswick Mining and Smelting Corporation Limited started a 48 million dollar expansion programme at their property in Bathurst, New Brunswick. A portion of the expansion plans includes a 26 foot diameter 4,525 foot deep shaft, underground crusher and conveyor excavations and lower level access development. J. S. Redpath Limited was awarded the contract for the new shaft and associated rock work in May 1974. Brunswick Mining and Smelting Corporation Limited, a member of the Noranda Group, operate this 10,000 ton per day lead, zinc, copper plant with proven reserves in excess of 90 million tons. While most of the ore is provided by the underground operation at the Number 12 ore body, some tonnage is produced from the open pit at the Number 6 ore body. Long range plans indicate a phasing out of the open pit and an increase in production from the underground operation. Existing facilities at the underground mine could not provide additional tonnage, thus the requirement for a new shaft. (Figure 1) The new shaft will also provide access to ore below the 2,800 level which is currently the bottom level of the existing facility. The contract called for sinking a 26 foot inside diameter, nine compartment concrete shaft 4,525 feet deep (Figure 2). Station access and ramp development from existing workings would be required to the bottom of the new shaft. In addition, development work for new crushing and conveying facilities was needed simultaneous with the shaft sinking.

Jan 1, 1976

By Chandler Morse

RENEWABLE VS. NONRENEWABLE NATURAL RESOURCES Nonrenewable resources, such as minerals, are the inevitable center of attention in discussions of depletion and exhaustion. Nevertheless, it may well be proper to regard some nonrenewable resources as not subject to exhaustion, and renewable resources may sometimes be treated as if they were finite stocks. Thus, the availability of nonrenewable resources is not and probably never will be known completely Chap. 2.5A, and therefore is not subject to firm predictions concerning exhaustibility. Moreover, because exploration and discovery are more or less continuous processes it is often appropriate to regard mineral supplies as flows, and to treat the estimated reserves as working capital, an inventory, continually depleted by use and augmented by discoveries.23 The aggregate economically exploitable stocks of a given mineral are seldom estimated (or estimatable) with precision, as Chap. 2.5A shows, and even when they are, forecasts concerning years of remaining life can be and often are falsified by changes in one or more of the multidimensional conditions of supply and demand; or the productive services formerly derived from an exhausted stock may continue to provided without material impairment by one or more substitutes b Conversely, the renewable resources are all subject to depletion when the rate of use exceeds the natural or induced rate of replenishment, and cases of exhaustion or near exhaustion, as through soil erosion, overcuttmg of forest lands, and overfishing, are rather common c Where exhaustion is a clear possibility the resource may either be exploited on a consciously adopted "sustainable yield" basis or be treated as an exhausting asset." In some cases, conscious treatment

Jan 1, 1976

By G. W. Poling

Chemical and physical properties of thiol collectors are reexamined to compare the prospects of heavy metal-thiolate or disulphide surface reaction products acting as actual collector species. Recent evidences for the existence and importance of each of these types of adsorbed species on sulphide minerals are also discussed. A conclusion is reached that partial coverage by chemisorbed heavy metal thiolate is often sufficient to confer practical levels of hydrophobicity and floatability. Only on a few highly conducting and "noble" sulphides does adsorbed disulphide-type collector oxidation product appear to be significant.

Jan 1, 1976

By James A. Beck

Phosphorus is essential to all life processes and therefore to the existence of man. In this role, there are no substitutes for phosphorus. In a commercial sense, phosphorus and its compounds are important to our entire economy, both in agricultural and in nonagricultural applications. The world's phosphate requirements are met by mining phosphate rock. Two general types of phosphate ore deposits are commercially important-igneous and sedimentary. Igneous deposits generally are more difficult and more expensive to mine than sedimentary deposits and are of importance mainly in the USSR, North Vietnam, and South Africa. Approximately 15% of current world production comes from these deposits. Over 80% of world production is from the pellet sedimentary deposits of Florida, North Africa, and elsewhere. Guano, the second type of sedimentary deposit, is produced in South America but is declining in world importance. Production Production of phosphate rock was reported in 31 countries during 1972. However, about 80% of world output is produced in three countries: the United States, the USSR, and Morocco (Table 15.2A.1). Throughout the past 20 years, between 75% and 80% of world output has been produced by these three leading countries. Between 1948 and 1972 world production increased at an average rate of 10% per year, from 21.5 to 103.9 million tons. Growth was quite steady at 6% per year through 1963, but in the 5 years from 1963 to 1968 production increased 11 1/2% per year. Since 1968 production has increased about 91/2 % annually. Since 1948 several new phosphate mining ventures have been developed in Senegal, Togo, Israel, and North Vietnam. In the same period, only one important phosphate deposit, on Makatea Island, has been mined out and closed. A number of other phosphate mining ventures are in various stages of planning and development. The most important new venture in phosphate mining is in the Spanish Sahara. New mining capacity is expected also in Syria, and serious investigation is in progress in Peru, India, Turkey, and Australia. Major expansion of existing operations is expected in Morocco, Russia, Tunisia, Israel, and Jordan. Consumption Historical data on world consumption of phosphate rock are not available in detail, but world consumption of phosphate has closely paralleled world production in the past two decades. The United States is the world's largest user of phosphate rock, accounting for 30%

Jan 1, 1976

By A. E. Gooch

The Bureau of Mines conducted research in an attempt to provide a more sound basis for recommending improved artificial support during deepening of the main shaft of the Lucky Friday mine in the Coeur d'Alene mining district of northern Idaho. Field measurements of closure across the short axis of the 13-by 26-foot shaft were as high as 16 inches. Elastic/plastic finite-element (F/E) analyses were made, reducing the values of large-scale in situ rock mass properties until field closure measurements generally corresponded to displacements in the F/E analyses. Resulting plots of rock mass displacements, stresses, and areas of plastic failure display the results of creating openings (shaft, in this case) in deep mines in difficult ground conditions requiring artificial support.

Jan 1, 1976

By Ralbern H. Murray

The decline in deliverability of conventional natural gas supplies and the general energy crisis have resulted in national programs directed toward the commercialization of energy conversion technologies. Foremost among these efforts is the gasification of coal. Coal reserves represent our most abundant fossil fuel resource. Its utilization is hampered both by its form value and its pollution qualities. Coal gasification is commercially feasible today and projects requiring hundreds of millions of dollars and years of construction time are underway. This paper provides a perspective for the scope, time, and cost of these venture projects. Resource requirements, plant products, and coal gasification processes are discussed. Emphasis is placed on the effects of coal feedstock and prices on plant economics.

Jan 1, 1976

By William R. Groseclose, Kenneth D. Schoeman

The Buckskin Mountains Tunnel is a key link in the Bureau of Reclamation's Central Arizona Project. The 22-foot (6.7-m) diameter tunnel is being bored in a north-northwesterly direction through volcanic rock near Lake Havasu in western Arizona. The 6.9-mile (11-km) conveyance tunnel will carry up to 3,000 cfs (85 cu m per sec) of water through the Buckskin Mountains as part of the Granite Reef Aqueduct. The water for the project will be drawn from Lake Havasu behind Parker Dam on the Colorado River and pumped some 800 feet (244 m) above the lake to the inlet portal of the free flow tunnel where it begins its 190-mile (300-km) journey to Phoenix, Arizona, and beyond into Orme Reservoir (figure 1). Precast concrete segments are being used as a single system initial support and final lining in the tunnel being excavated by a tunnel boring machine specially designed and built for the job by The Robbins Company. J. F. Shea Company, Inc., of Walnut, California, is constructing the tunnel for the Bureau of Reclamation.

Jan 1, 1976

By Mehmet Guney

A series of experimental investigations was carried out in situ and in the laboratory with special emphasis on the gassy seams of the Kozlu District, Zonguldak Coalfield, Turkey. The nature of firedamp emission in the return airways of coal faces together with the individual parameters affecting the phnomenon were studied and the observations are discussed. The residual methane content of the lump coal samples was determined by the volumetric method. All the evidence obtained from the field and laboratory results indicate that certain coal seams under production in the Kozlu District of the Zonguldak Coalfield are very gassy in nature. There are cases where in the return airways of some coal faces the total emission of methane reached up to 3300 cu ft pure methane per ton of coal mined. From the impressions gained in the course of the present work and from available literature, retention and emission of methane are basically large-scale phenomena, dependent on exogenous and endogenous parameters in coal mine, which may effect to a greater or lesser degree actual firedamp incidents.

Jan 1, 1976

By Hanns J. Billmayer

This report, which covers the period from April 1975 to November 1975, describes the work performed in compliance with the requirements of Contract No. H0357091. The purpose of this contract was the development of protective canopy concepts applicable to rail haulage equipment used in underground coal mines.

Jan 1, 1976

By Joseph Sabatini

This report, covering the period January through December 1975, contains abstracts of articles concerning all phases of cost engineering and economics for chemicals processing, raining, and other mineral industries. The abstracts are collected from the following sources: 1. Chemical Engineering 2. Chemical Engineering Progress 3. Chemtech 4. Coal Arse 5. Coal Mining and Processing 6. Combustion 7. Drilling 8. Electrical World 9. Engineering and Mining Journal

Jan 1, 1976

By D. L. Paulson

The Bureau of Mines studied the feasibility of producing copper matte in an electric furnace from blends of copper concentrate similar to those currently smelted in a gas-fired reverberatory system at an installation in Tacoma, Wash. A 800-kva electric-arc furnace was used to determine the distribution of constituents when arseniferous concentrates are being smelted in an electric-arc furnace. Test results from smelting 40 tons of materials indicated that electric smelting is more like a conventional gas-fired system than originally expected. Although gas composition over the molten bath is much different in an electric furnace, the secondary constituents such as arsenic, lead, zinc, and antimony behaved the same as in a reverberatory furnace. The results established that an electric furnace would be compatible with sulfur and particulate recovery facilities that are being used.

Jan 1, 1976

The three main types of iron ore deposits in Australia are bedded, massive and residual. Some character- istics of iron ore, important in its process behaviour, are related to its mineralogy which is a result of its geological history. World iron ore resources are extremely large but there are problems in quantifying re- serves, defined as that part of re- sources from which a useable commodity can be extracted economically. The relationship between the discovery and exploitation of iron ore resources and the process of industrialization is examined in historical and present day contexts.

Jan 1, 1976

By P. H. Mutschler

The Bureau of Mines studied the Chattanooga Shale to determine the quantity and quality of the uranium resources present and to assess specific environmental effects of mining the shale. Geologic data and chemical analyses, mainly concerning a 12-county area of Tennessee, were compiled from previous published and unpublished reports. Uranium resources in the Gassaway Member of the Chattanooga Shale in this 12-county area were estimated to be between 4.2 and 5.1 million tons, contained in 76 to 91 billion tons of shale. These figures represent inground tonnages and do not allow for mining or processing losses. Depending upon efficiency of mining and processing systems, enough uranium could be available to satisfy a large part of the cumulative domestic and world demand through the year 2000. A model was developed which assesses the total tons or acres of shale to be mined if the Gassaway Member were to satisfy 1 percent of the United States demand for uranium in 1991. This partially demonstrates the environmental impact of mining the shale and is easily factorable to any specified demand.

Jan 1, 1976

The accuracy with which block values are known can have a fundamental effect on the success of an operation.From a geostatistical study the variance of the error in extending sample values to block values can be determined and the engineer must ensure that this is sufficiently small by adjusting the size of blocks or moreintensive sampling. A study is given for a deposit showing a high degree of anisotropy and it is shown that the shape of the block is not important in determining the estimates.

Jan 1, 1976

By Louis A. Mattson, Winthrop A. Rowe, John T. Cumberlidge, Victor M. Mejia

The parent ultramafic of Nickel Mountain is an alpine-peri-dotite. Compositional layering and late stage dunites suggest the intrusive crystallized in the upper mantle or lower crust. The ultramafic mass was fault emplaced in the upper crust, probably during upper Jurassic time. Soil, saprolite and silica boxwork nickeliferous ores were formed over the Nickel Mountain peridotite during the development and later destruction of the Klamath peneplane. A complex fault pattern was produced by irregular gravity displacements along fault surfaces during the relative uplift of Nickel Mountain. The majority of the ores occur in the fractured hanging wall of these gravity faults. Consequently, structure mapping is important for mining purposes. Ore types at Riddle are classified on the basis of MgO, Fe, and Si02 contents as well as textures. The chemical, mineralogical and textural differences of the various ore types reflect differences in weathering histories. Satellitic ore bodies occur peripherally to Nickel Mountain. These are erosional remnants of landslides and large gravity fault blocks from Nickel Mountain.

Jan 1, 1976

By F. G. Miller

In mid-1972 we determined that a fresh approach to coal mining research was needed for the industry as well as for Bethlehem. The reasons to us were obvious: Productivity was in the throes of a steady decline, and labor and maintenance costs were spiraling upward. Yet, despite this predicament, nowhere in the U.S. at that time was there a comprehensive and coordinated research and development plan in the offing. The Bureau of Mines had not yet been charged with such a responsibility, and industry was content to rely on machinery manufacturers for innovations. After studying our own mining practices, the state-of-the-art of mining research elsewhere, and development work by manufacturers, we presented a comprehensive research package to our management at the end of 1972. The ideas and experience of many operating and management personnel in our Corporation contributed to the formulation of the final plan as approved.

Jan 1, 1976

By Lynn B. Hales

The Supervisory Computer System at Cities Service copper mine and concentrator at Miami, Arizona was installed at Pinto Valley in the spring of 1975. Design and specification [l] of the digital system was initiated jointly by key plant personnel at Pinto Valley and staff of Cities Service Research and Development Company. The Pinto Valley digital system [2] may be classified as a supervisory control system of hierarchical design. There are three fully independent satellite computers which retrieve and reduce the raw plant data from each of the three main operating areas - the primary crushing plant, the fine crushing plant, and the grinding and flotation plant. While the three satellite computers are core resident systems, the master computer is a disc-based operating system which also interfaces with a computer controlled on-stream x-ray analyzer system. Figure 1 illustrates the basic system configuration [3]. The software systems required to support a large system are quite diverse and vary greatly in function. The philosophy followed in dividing the software into three categories was designed to: 1) fully utilize existing process knowledge of technical staff; 2) delegate certain software tasks to outside sources already skilled and trained in software development; and 3) maintain final control over the design and operation of each system.

Jan 1, 1976

By David Hoadley, Kenneth R. Maser, Ashok B. Boghani, James E. Billar, D. Randolph Berry, Mackenzie Burnett, Robert H. Trent

C 6 Automatic Elevator Control Systems An automatic elevator control system, consisting of position sensing devices and a control unit, can be used to control an emergency mine hoist. While automatic elevator control systems are assembled from standard components, they are typically custom designed to suit a given customer's application. Various manufacturers contacted indicated that the price range, less installation, for a simple two-stop control system begins at approximately $2500 and can increase depending upon the type of components used, shaft depth, the type of mechanical drive used, and the maximum operating speed A partial list of elevator control manufacturers follows. They should be contacted for further details. Marshall Elevator Company Pittsburgh, P A 412 -431 -1340 Armor Elevator Company, Inc. Louisville, KY 502-361 -7181

Jan 1, 1976

By H. W. Smith

This paper presents a review of developments to date in computer control practice, based in large part on Canadian experience. The basic problem examined is that of stabilizing control; matters considered are control strategies, hardware and software aspects of system implementation, reliability, human factors, and economic results.

Jan 1, 1976

By W. L. Freyberger, H. Alter, K. L. Woodruff, E. L. Michaels

Laboratory and pilot scale tests have been made to determine the utility of heavymedia separation, particularly a cone-type separator, as a means of recovering aluminum and other values from shredded municipal solid waste. The effect of the method of shredding on the behavior of aluminum in a heavy-media system was determined. Two-stage pilot-scale heavy-media separations were made with size fractions of shredded refuse. Recoveries of aluminum, as well as other components of the refuse, were measured and medium losses determined. The experimental results indicate that with certain reservations a heavy-media cone system can be utilized for aluminum separation and recovery from shredded and air-classified municipal solid waste. Observations made using two-stage heavy-media separation in a drum unit are included. Qualitatively, the results from the two types of separators are similar.

Jan 1, 1976