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By G. Kinder, R. Gilges, W. Stoker, R. Davey

The Bingham Canyon Mine, located 48 km (30 mi) southwest of Salt Lake City, Utah, is operated by Kennecott Copper Corporation's Utah Copper Division. This operation is the world's largest open-pit copper mine and produces 96 000 tons (106,000 st) ore and 327 000 tons (360,000 st) waste each day. This material is loaded by large electric shovels and transported by both truck and rail haulage. To meet the requirements of the Clean Air Act of 1970 (as amended), new facilities for the control of smelter emissions were required and are now nearing the final stages of construction. The facility will be capable of treating all the output from the mine, some 2,530 tons (2,789 st) per day of combined concentrate and precipitate. Costing $280 million and necessitating the replacement of reverberatory furnaces with continuous smelting vessels, the plant, with its massive and complex gas handling and acid-making facility, is required to remain on-stream with the minimum of pollution control equipment outages to conform with Federal Regulation 52.2325. As part of this giant effort, the smelter planning team and supervisory staff considered that new, well organized, highly flexible, readily available maintenance information was essential to assist the maintenance personnel in the performance of their duties.

Jan 1, 1979

By Ben L. Seegmiller

Introduction The profitability of an open pit operation depends to a large extent on the use of the steepest pit slopes possible, provided they do not fail during the life of the mine Optimum pit slopes can be designed by using rock mechanics technology. Such technology includes gathering and analyzing pertinent data prior to pit design, rigorous application of rock mechanics principles during the design process, remedial actions to improve slope stability, and monitoring slopes during the life of the mine. Ignoring rock mechanics technology in pit design may place the entire mining enter- prise in jeopardy Disruption of mining operations and safety hazards caused by slope instability can be severe. A classic case in point is the major slope failure (Seegmiller, 1972) that occurred at a southwestern US copper mining operation in 1970-1971 Minor slope stability problems initially amounted to no more than a nuisance, but in time, the unstable zones became larger, causing greater disruption of production and threatening safety Mining at or near the slide toe had continued throughout the period of slope failure, aggravating the already unstable condition The original plan for this pit called for mining the overall pit slope to 37.5" Mine operators were forced to lessen the back- slope angle in the hope that the failing rock mass would stabilize. However, stabilization did not take place, and when mining in the area of failure was completed, the overall slope had been reduced to approximately 27" Mining had been successful in removing only a small portion of the ore body at a high stripping ratio.

Jan 1, 1979

By Michael H. Inglis

The Technology Application Center, in conjunction with the U.S. Bureau of Mines Liaison Program, is studying the use of Landsat data for the monitoring of coal surface mine reclamation activities. Landsat may provide sufficient information to reduce the number of on-site inspections now required. The focus of the project has been the Navajo Coal Mine located in north- western New Mexico and operated by Utah International, Inc. On October 15, 1977, a field team recorded spectral measurements at the mine during the time of Landsat's overpass and a corresponding aerial photographic flight. Training sets were selected from the ground and aircraft data representing vegetated, graded, ungraded and natural environments. A supervised classification of the data was performed by the Stanford University Remote Sensing Laboratory then correlated to aerial photos and mine maps. The results, to date, have been very encouraging.

Jan 1, 1979

By E. LaRocque

"Denison Mines Limited has been processing uranium ore in the Elliot Lake area since May of 1957. The ore body is located i11 the Huronion sediments on the north limb of the Quirke Lake syncline. Minerals of metallurgical significance are brannerite, uraninite and monazite. Gangue minerals include quartz, chlorite, sericite, pyrite, pyrrhotite and rutile. Silica content of the ore is greater than 75 % and pyrite-pyrrhotite content around 7 %. Specific gravity of the ore is 2.75.The Denison flowsheet is based on sulphuric acid leaching to extract the uranium values from the ore followed by liquid-solid separation to wash the uranium-bearing solution from the barren ore. The resultant pregnant solution is concentrated and purified by ion exchange followed by two-stage precipitation with ammonia to produce an ammonium yellow-cake.Elliot Lake ores require high acid concentrations and high temperatures to extract the uranium from brannerite and monazite. Uraninite will leach at low acid concentrations as long as oxiclizing conditions exist. The whole ore must be treated so that these conditions do exist.This paper provides a description of the leaching process equipment as originally installed and major changes in that equipment to date. Process control refinements to economically improve extraction are also discussed."

Jan 1, 1979

By A. H. Marquis

Since the start-up of its first Direct Reduction Module in April 1973, S1DBEC has produced over 2 million tons of prereduced iron. During this period, SIDBEC has acquired comprehensive experience in the operation of the direct reduction process and at the same time has learned to recognize the characteristics that the oxide should have to constitute an adequate feed for the process. A comparison is made as to the design and operation of the two direct reduction units now operating at Contrecoeur, Que. A description is given of a method of evaluation of a direct reduction unit, which takes into account the main process variable sand which permits comparison ofthe results on a daily basis. The paper defines the characteristics that the iron oxide and the prereduced iron pellets must have to meet the specific requirements of the direct reduction and the electric arc furnace processes. A simple model makes possible a rapid evaluation of the technical and economic effect related to the use of a given raw material. Finally, the paper outlines the advantages of prereduced iron in the steelmaking process and on the quality of the steel products.

Jan 1, 1979

By P. J. D. Lloyd

An account is given of the development of a process to concentrate gold and other valuable minerals and to produce a discardable waste. In this process, the ore is coarsely milled, a bulk flotation concentrate is prepared, and the flotation tailing is scavenged in a hydrocyclone, which returns coarse gangue, moderately coarse valuable minerals, and locked valuable minerals back to the mill. The engineering developments required by this circuit in order that it will fit underground, and the progress made towards the achievement of those requirements, are reviewed. If the waste is to be suitable for use as a backfill in a deep-level, flat tabular excavation, it should be capable of being placed hydraulically, and should have both low voidage and high rates of drainage. Such a material could be prepared by the fine screening of the overflow from the cyclone in the proposed circuit. Possible methods for the handling of the concentrate and the recovery of its valuable constituents are described. The paper concludes with a discussion of the possible benefits from the use, in deep-level Witwatersrand mines, of a system involving concentration underground, extensive backfilling using the tailings from the concentration process, and hydraulic hoisting of the concentrate.

Jan 1, 1979

By Jacques Nantel

Mechanical-electrical personnel are present in all phases of the mining industry; the coverage is broad and diversified. Concepts of energy accounting are reviewed to pinpoint the sectors with a large energy consumption. Four sectors are reviewed: underground hard-rock mines, underground soft-rock mines, open-pit mines and mineral processing. In each sector, five or six technical innovations are analyzed as to their contribution to a more efficient use of energy.

Jan 1, 1979

By Jean-Claude Bianchini, Paul Bauernfeind, Erwin Gartung

Introduction The city of Nuremberg, located in Bavaria in the Federal Republic of Germany, started building a subway in 1967. The construction operations began in a southern suburb, where no complications were encountered in the design and execution of the job. As the first subway line approached the downtown area of the city, the civil engineering challenges increased rapidly. Tunnels had to be excavated next to, or below precious historical buildings, and the work of the responsible engineers was closely watched by the public, who were very anxious about any damage to the existing beautiful old houses and churches. The job has been handled successfully to date in cooperation with the owner-designer, the geotechnical consultant and the contractors, who jointly went through a process of systematic learning and gathering of experience, and who developed a modern tunneling technique specifically tailored to the natural properties of the encountered ground conditions and the requirements of the city of Nuremberg. The application of scientific methods has been an important part of this development. Research into the geotechnical properties of the predominantly encountered soft Keuper sandstone, studies of the geomechanical performance of grout reinforced sand sections and finite element analyses of various tunnel problems for the prediction of displacements, for the assessment of stability, or

Jan 1, 1979

By Guy D. Bruno

Through the remainder of this century, world consumption of fluorine per ton of primary aluminum produced will continue to be substantially reduced. Growth of the primary industry will offset some of the unit consumption, but demand for new fluorine sources will decline sharply. Continued application of dry fume scrubbing system will be the most significant factor in reducing demand.

Jan 1, 1979

By J. J. Emery

There is an increasing awareness on an international level of the potential for utilizing many wastes and by-products as construction materials. This has resulted in recent major reviews by OECD and RILEM to supplement national activities by agencies such as CANMET, USBM, BRE and LCPC. Much of this international and national work was reported during an International Conference on the use of by-products and wastes in civil engineering held in November 1978 in Paris. Based on participation in the OECD and RILEM reviews, and the Paris conference, developments in waste and byproduct utilization of particular concern to Canada are described. The major technical and economic constraints involved are also reviewed, so that the over-all evaluation reflects important factors such as inherent variability and transport logistics. Areas requiring further research and development are also identified. Particular emphasis is placed on slags, salvaged asphaltic concrete and surplus sulphur. "Due to the rapid development of China's industry, more than a hundred million tons of industrial wastes are generated annually, which occupy lots of land for storing, bring about environmental pollution, obstruct industrial and agricultural production and cause harm to people 's living. Therefore we must utilize them effectively to create wealth for our country. "

Jan 1, 1979

By J. Wyn Prior

The seismic refraction technique is probably the most popular geophysical method of bedrock profiling in geotechnical site investigations but is somewhat restricted by the inherent assumptions in the method. This paper describes how Hales' method of profile interpretation is modified to overcome the assumptions of increasing velocity and layer thickness with depth when only first arrival data is available. A further expansion of Hales' method enables presentation of refraction data in a form whereby bedrock features, such as changes in velocity, relief and dip in particular, are more readily recognized. Characteristic curves of the more common bedrock features are presented as an aid to bedrock feature recognition.

Jan 1, 1979

By W. Belobraidich

Kennecott's Ray mine is located about 145 km (90 miles) north of Tucson in the Mineral Creek mining district of central Arizona. Mining in the district started in the late 1800's. The Ray mine itself was first mined by under- ground methods in 1911 and was changed to an open-pit operation in 1952. Mineralization is complex and includes sulfide, silicate, and native copper mineralization, as well as minor amounts of molybdenite. Sulfide ore, mined at Ray, is shipped by rail to Kennecott's concentrator and smelter at Hayden, 32 km (20 miies) away. Silicate ore, mostly chrysocolla, is processed near the mine in a vat leaching-electro- winning plant. The mine consists of two sulfide areas: (1) the West pit and the Central pit (the original Pearl Handle pit) and (2) a silicate area on the northeast perimeter of the Central pit. The pit now is over 304 m (1000 ft) deep and approximately 3048 m (10,000 ft) long. Roads within the ultimate pit are limited to a grade of 10%, while those outside the pit are limited to 8%. The mining equipment consists of 40 Wabco 1094 (120-st) haulage trucks [ranging from 109 to 227 t (120 to 250 st)], 12 electric shovels [ranging from 6 to 23 m (7 to 25 yd)], and 3 11-m (12-yd) Dart production loaders.

Jan 1, 1979

NIM reports Report no. 1970 List of unrestricted NIM publications issued from 1966 to 1978. (30th Jun., 1978). Report no. 1976 The preparation and certification of two samples of chromium ore. (9th Sep., 1978). Report no. 1982 The resistivity of mixtures of Mamatwan manganese ore and reducing agents. (31st Aug., 1978). Report no. 1984 Commissioning of the AEI MS702 mass spectrometer. 31st Aug., 1978). Metallurgical slags The Basic Science Section of the Canadian Institute of Mining and Metallurgy is sponsoring an International Symposium on Metallurgical Slags, which is to be held in Halifax, Nova Scotia, during 24th to 28th August, 1980. Mining machinery An international conference on mining machinery is to be held in Brisbane, Australia, from 2nd to 6th July, 1979.

Jan 1, 1979

By D. M. Thayer

Dry magnetic separation of feebly magnetic minerals and wet magnetic separators suitable for highly magnetic minerals have been commercially utilized for a number of years. The beneficiation of magnetic taconite ores by conventional, low intensity magnetic separators in combination with flotation is well established technology (1). However, over the past decade much effort has been expended in developing techniques for the upgrading of feebly magnetic oxidized iron ores (2,5). Such research and development have been stimulated by the limitations of the above-mentioned techniques in application to ores containing fine material; for example, ores requiring fine grinding for liberation or slime-forming ores such as the oxidized taconites or semi-taconites. Wet separation has allowed the reduction of the minim particle size that can be effectively treated from that allowable for high intensity dry magnetic separation. Consequently, the development of high intensity wet magnetic separation methods has received much attention in the search for an effective method to treat the weakly magnetic minerals. Recently Lawver and Hopstock (5) have provided an excellent review of the state of know- ledge of this technology. In addition, a valuable compendium of available laboratory and commercial devices is included. Nonetheless, the feasibility of the use of high intensity magnetic separation in a particular application is largly empirical in nature and requires experimentation to chazacterize the response of a particular ore. The purpose of this paper is to assess the incorporation of high intensity magnetic separation for the beneficiation of a non- sliming specular Michigan hematite. Particular attention is focused on the existence of a lower limit of particle size that can be treated effectively and is inherent in the use of these techniques. Additionally, a rationalization of various models presented in the literature is attempted.

Jan 1, 1979

By L. W. Hamel

"Two 35 foot diameter enviro clear thickeners were tested in series as CCD units from June until October, 1978. Up to shutdown in July, we ran with automatic bed level control via the level probes and underflow pinch valves. Despite extensive efforts, we were unable to eliminate the surges created between the units by the opening and closing of the pinch valves. Early in July, the best rake speed and gap setting were determined. After shutdown, the enviro clears were run by manually controlling the pinch valves. These efforts were successful.A few mechanical problems were encountered while operating the thickeners. New units should incorporate more support for the drive coupling and a rubber feed seal. A few modifications of the instrumentation control scheme will be required before the units can be fully automated. A less sophisticated automatic flocculant addition system will accomplish the desired results. Control of the underflow withdrawal via the pinch valve should be investigated further. Our best results were obtained by keeping the feed volume to the No. 1 enviro clear constant. Surges were controlled by opening or closing both underflow valves proportionately.Capacity of the enviro clears is dependent of many variables. The ore treated during the test program was much finer than that reported on in R & D Project Report 76-02. Conditions were never steady enough to determine best flocculant dosage or addition point(s). The lowest soluble losses were obtained at very high wash rates. The underflow densities drop but the soluble losses also drop. Regression equations were developed in order to assess the effect of the various parameters. Within the range studied, these equations will predict the performance of enviro clear thickeners as CCD units on Elliot Lake ores. Our results show that the enviro clear thickeners are a viable alternative to the conventional CCD thickener."

Jan 1, 1979

"Status of the Mineral Industries" provides a written and graphic view of the Nation's mineral position and its mineral industries. The report, issued annually by the Bureau of Mines, U.S. Department of the Interior, describes recent activities in mineral production, consumption, imports, exports, and uses of significant minerals and mineral raw materials. Charts profile trends for the past 28 years in supplies and uses of iron, steel, major nonferrous metals, primary nonmetallic construction raw materials, fertilizers, and plastics. Also included are current and historical financial data on the mineral industries, such as debt-equity ratios, asset-to-liability ratios, and plant and equipment expenditures.

Jan 1, 1979

By H. O. McDonald

The Bureau of Mines reviewed the chemical vapor deposition (CVD) literature of the group IVB, VB, and VIR elements. This review was utilized in the Bureau's research to provide erosion-, abrasion-, and corrosion-resistant coatings for valve components used in coal gasification units. This report attempts to bring together the many CVD references that have been published since 1966. Each of the group IVB, VB, and VLB metal coatings were reviewed, and some of their preparation methods, uses, and properties are given. A total of 160 references were found for the nine elements. Isotope separation, stronger steels, solar absorbers, alloys, superconductors, optical fibers, and coatings to increase the life of materials are some of the new uses for CVD.

Jan 1, 1979

By Raymond H. Young, Paul Sennett

INTRODUCTION Kaolin clay, consisting largely of the mineral kaolinite, is widely used as a white pigment. In the United States, for instance, pigment kaolin production was nearly 6,000,000 tons in 1976 (1). Production for this year should be significantly above this level. Current prices for kaolinite 'pigments range from about $20.00/ ton to$260.00/tony,depending on the amount of processing needed to make the final product. Although much of this pigment kaolinite is used as an inert filler where product specifications are not very rigid, a large quantity of kaolinite is converted to products where very restrictive specifications exist. These specifications set severe limits on such properties as viscosity in a water suspension, particle size distribution, color, and brightness. This discussion will concentrate on methods available to improve the color and brightness of pigment kaolin and will review the advantages and problems associated with these various methods. The term "brightness" refers to the reflectance of the pigment to blue light (2). Since even the brightest commercial kaolins have a somewhat yellowish color, the blue reflectance (or brightness) is a reasonably good measure of their nearness to a perfectly white material. I KAOLINITE STRUCTURE AND SOURCES The mineral kaolinite is an aluminum silicate and can be represented by the formula (OH) 8Si4A14010. The formula is frequently written

Jan 1, 1979

By W C. Burkle

A rather common observation over the last several decades at least has been that rock or ore properties influence blasting results more than does the explosive type that has been used in the blast. It we accept that premise than it is held here that the material to be blasted should receive even closer attention as to its properties. Several years ago, Dr. Richard Ash published papers that pointed out the rock properties that mostly influence blasting. These principles are given attention in this paper. We have gone somewhat further - or lets say expanded this subject in regard to the role of rock structure in open pit blasting. Though open pit work is given some prominence, we believe that much can be observed and applied to underground mining.

Jan 1, 1979

By James H. Cobbs

Blind boring of shafts is becoming an increasingly important part of shaft sinking. Blind-bored shafts have reached diameters of 25 It in Europe and 16-1/2 ft in the United States. Much of the technology developed for blind boring has evolved from the technology of drilling wells for oil and gas production. Blind boring offers economic advantage in a number of situations where conventional shaft sinking either is extremely difficult or very expensive by virtue of large-capacity aquifers which must be penetrated, unstable ground or where very rapid sinking is required. In sedimentary rocks, blind boring is cost competitive with conventional sinking, in diameters of about 12 ft or less. Blind boring is not competitive with raise boring where conditions are favourable for raise boring. Blind boring does, however, offer greater flexibility than raise boring and can be performed in situations where raise boring is inefficient or impossible. Combination machinery has been developed to perform both blind boring and raise boring, so that the machine can be used effectively in situations where only the near-surface portions of the shaft are unfavourable for raise boring. Development work is being supported by the United States Bureau of Mines for blind boring equipment capable of boring shafts up to 30 feet in diameter.

Jan 1, 1979