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Perhaps one of the most important conferences or symposia which our Institute has conducted, was the joint Aus. LM.M./AJ.M.E. meeting held in Canberra in May 1978, with the theme International Resource Management (Woodcock, 1978).We were privileged to witness active participation in the meeting by outstanding personalities from the mining and metallurgical industries of Australia and New Zealand, the United States of America, Canada and the United Kingdom and to hear addresses on subjects of international significance to the mining and metallurgical industries.Our Institute is one concerned with professionalism.The principal objects of The Institute as described by our founders include, "promoting the arts and sciences connected with the economical production of the useful minerals and metals, and the welfare of those in the industries, by meetings for social intercourse, and the reading and discussion of professional papers, and to circulate by means of publications amongst its members and associates, the information thus obtained".Sir Maurice Mawby (1968) said in his Presidential Address to the Institite, "the most important aspect of these objects was the promotion of the arts and sciences of the mining industry".Why is it then, that a large proportion of the papers given at the meeting in Canberra dealt with world wide social aspects of the mining and metallurgical industries, rather than the technology, the arts and sciences of mining and metallurgy as principal factors in international resource management?The answer is quite simple of course, and that is that the social and political factors are the principal factors which create the demand for basic raw materials and in the long term determine the costs and prices of the commodities which our professional abilities are drawn upon to produce.

Jan 1, 1979

By George W. Toth

This chapter describes the development of a computer code which rapidly estimates the cost of producing coal from either surface or underground mining situations. The computer code, termed the coal production cost (CPC) code, was developed under an NUS corporate research grant and was based on the findings of several coal mining and cost research analyses performed by NUS over a three-year period. The studies which served as the primary basis for the CPC code were the coal mining cost models developed by NUS for the Electric Power Research Institute. These models were designed for use in manual analyses and have been published by EPRI (Toth, 1977; and Stinnett, 1977).

Jan 1, 1979

By Lex L. Udy

External-detonation-generated plasmas, highly ionized zones of reacting material ejected from the surface of detonating explosive charges, are shown to be the cause of channel desensitization, i.e., the self-quenching of a detonating explosive column loaded in a borehole with an air annulus between the explosive and the borehole wall. The effects of this phenomenon on several explosive compositions and types are demonstrated and discussed. The explosives tested include aluminum-sensitized and explosive-sensitized slurries, ANFO, liquid explosives and dynamites. Various techniques are described that can be used to reduce or eliminate the plasma effect.

Jan 1, 1979

By J. E. Furze

World-wide hikes in the oil price and the prospect of future scar cities of liquid and gaseous fuels have given enhanced status to the South African coal industry. It is thus understandable that the colloquium held at Wit bank on 3rd and 4th October, 1979, and organized jointly by the South African Institute of Mining and Metallurgy and the South African Coal Processing Society should have attracted more than 400 delegates.

Jan 1, 1979

By R. V. Ramani, R. M. Mishra, Y. J. Wang

The validity of the concept of mine resistance in ventilation systems is examined. Mine resistance is the proportionality constant relating the head generated by a fan and the quantity flowing through it when the fan is connected to a mine circuit. It is the total effect of all branches in the mine ventilation circuit. Its importance lies in the fact that for new mine projections, and in the extensions of existing mines, ventilation calculations are usually based upon adjustments of the mine resistance. In ventilation circuits with regulation, and/or with multi-fans, simple adjustments of the mine resistance curve do not lead to correct solution. A ventilation system consists of several interconnected subsystems where one subsystem behavior affects that of the others, and the total system. Through a series of simple but realistic examples, the authors demonstrate the importance of the systems concept in mine ventilation, and its practical application to coal mine ventilation planning. Starting from an initial system with no leakage and one fan, more complex ventilation networks with several leakages, sections and fans, are analyzed to show that ventilation system design on the basis of total systems approach is the correct procedure.

Jan 1, 1979

By D. D. Downing

This paper is a review of material selection considerations concerning protective coatings in the mining industry. The discussion will cover both capital-dollar projects and maintenance requirements. Emphasis will be on industrial finishes for structural steel and process equipment subjected to aggressive atmospheres. The presentation will cover the total needs of a job, emphasizing not only the owner's requirement for a cost-effective system during plant operations, but also taking into consideration the short-term requirements of general contractors, steel fabricators, erection firms and paint contractors.

Jan 1, 1979

Permit visual inspection of underground cavities dam the surface. Approach A closed circuit TV camera and a 35mm still camera are lowered down a borehole, and remotely operated. How It Works A platform holding the cameras, and other equipment is lowered on a graduated cable until the depth of interest is reached. Then a quartz lamp and the TV camera are turned on. The television picture is monitored at the surface and recorded on video tape. Areas of special interest are photographed with a 35mm still camera. These photographs contain more detail than TV images because photographic film is capable of higher resolution than a TV transmission.

Jan 1, 1979

By Delon Hampton, Francis K. Mensah-Dwumah

INTRODUCTION The state-of-the art in the area of soil-structure interaction is not sufficiently developed that one can accurately predict the earth load distribution on buried structures. This lack of knowledge has led to the use of high factors of safety in their design and conservative assumptions for the loading diagrams. As a step towards the improvement of the design methodology for buried structures, it is important to be able to apply new analytical techniques and monitor the performance data obtained on full-size buried structures. The performance data should preferably include: 1) the actual stress distribution on the buried structure, 2) stress distribution in the buried structure and surrounding soil media, 3) vertical and lateral movements in the soil adjacent to the buried structure, and 4) deflection of the buried structure. Brown (1967), Davis (1972), Krizek, et al (1974), Krizek and MacQuade (1978), and some few others have compared the performance of full-size culverts with finite element results. Despite all these efforts, a complete understanding of the soil-structure interaction problem has not yet been fully achieved. In an effort to make improvements in the existing design procedures for buried structures constructed in an open-cut, the Department of Environmental Services (DES), Washington, D.C., in conjunction with Howard University, undertook a detailed study of Section II of the Capitol Hill Relief Sewer (CHRS). Inclinometers were used to measure lateral movements of the excavation wall and the total normal interface stresses acting on the concrete sewer were obtained using glotzl total pressure cells. This paper describes the results of the field instrumentation program for acquisition of data, their comparison with the design assumptions, and the results of a series of post-construction finite element analyses of the CHRS project.

Jan 1, 1979

By Peter A. Burger

The Greenvale Orebody comprises a series of contiguous lateriteprofiles developed terrace-like during the Cainozoic over a serpentinized harzburgite intrusive emplaced within Proterozoic schists. Each terrace displays individual characteristics of metal distribution. Topographically higher (older) profiles have been partially eroded and metal concentrations reworked. Within the laterite profile, metals have been concentrated or depleted according to their relative solubilities. At tropical temperatures, acidic meteoric waters have progressively depleted the ultrabasic parent rock of Si and Mg, leaving A1 and Fe to form a surface duricrust. Ni, Co, Mn and Cr have accumulated in the lower and middle levels of the weathering mantle. Only Ni and Co have accumulated to exploitable grades. Lateritization has evidently proceeded over a considerable portion of the Cainozoic and may be still continuing.

Jan 1, 1979

By T. R. Heflin

The paper provides a comprehensive discussion of pump selection for the hydrometallurgical industry. Material suitability, in addition to proper size and design, will provide extended life for pumps in erosion /corrosion service.

Jan 1, 1979

By A. J. Brown

This paper presents an economic evaluation of resin ion exchange and solvent extraction for the purification and concentration of uraniferous solutions derived from sulphuric acid leaching operations. Capital and operating costs are related to the uranium tenors of pregnant solutions. The conclusions drawn herein apply only to cases where resin and liquid ion exchange are technically feasible process alternatives. It is shown that solvent extraction is economically favoured for pregnant solutions at tenors greater than 0.90 gpl U3O8. Pregnant solutions with tenors below 0.35 gpl U3O8 are best treated by resin ion exchange. Between these concentrations, the economics are marginal and the favoured process is indistinguishable within the limits of accuracy of this study.

Jan 1, 1979

By Håkan Stille, Kjeld Boye-Møller, Lars Lundström

BACKGROUND Forsmark Power Station is a nuclear power plant under construction at the Baltic abt 120 km north of Stockholm. Investigations on the Site were started in 1969. Areas were reserved for a maximum of 6 units of which the buildings for two of them, Unit 1 and 2, were nearly finished in 1976, when the investigation for Unit [3], here presented, was carried out, cf Fig. 1. [ ]

Jan 1, 1979

By Vytas Svalbonas

Sophisticated computer analysis methods such as finite elements, finite differences, and numerical integration have become tools in the mineral processing industry for design of large mill shells. While use of such methods allows the analyst-designer to take new freedoms with his designed structure, there are also pitfalls and dangers which must be recognized for the proper use of such sophisticated tools. One of the worst of these is treating any computer answers as "gospel truth". The present paper discusses the knowledge required by the analyst-designer for proper use of computer analysis, as well as explaining to the layman how to identify questionable areas in such structural analyses.

Jan 1, 1979

By John D. Morton, J. H. LaVerne Palmer, Douglas J. Belshaw

An extensive programme of ground instrumentation and observation was carried out for the West Duff in Outfall Sewer tunnel project prior to and during construction, to establish the performance characteristics of the rock through which the tunnel and appurtenant openings were dug and to examine the nature of the lining-to-ground interaction. The existence of high horizontal residual ground stresses was confirmed, and values established by overcoring. Rock deformations and stress changes were monitored during tunnelling. Permanent stress and strain monitoring devices were set into the final lining and these are continuing to operate. INTRODUCTION The site is located on the north shore of Lake Ontario at Pickering, some 20 miles (32 kilometres) east of Toronto, Canada where a variable thickness of glacial or interglacial sediments overlies bituminous shale bedrock of. the Collingwood Formation which is lower Ordovician age. Approximately 50 feet (15 metres) of glacial cover exists at the shaft, though this thins abruptly at the regressing cliffed shoreline such that several small areas of exposed bedrock exist in the lakebed. The general location, overall geological section and detailed site plan and profile are illustrated in Figs.1,2 and 3 respectively. General properties of the rock as established during an extensive test drilling and site investigation programme are listed in Table 1, while stress determination by USER overcoring stress meter device are given in Table ll. These data formed the basis of analyses which were done to examine the intended outfall design, and to detail the construction procedure and the observational instrumentation programme.

Jan 1, 1979

By Raymond E. Zimmerman

The Swirl Cyclone developed in Japan, although based upon the same principles as the standard cyclones for heavy-media or water-only cyclones for cleaning coal, is novel in that it is invested with the apex on top, discharging rejects at the top, and clean coal at the bottom. It also uses a variable air vent tube for controlling the vortex. Tests conducted indicate that its efficiency is not only as sharp as standard cyclones but it also performs using a much coarser grain magnetite, promising higher magnetite recovery. The author describes the results of tests conducted in Japan on a very difficult coal.

Jan 1, 1979

By J. P. Matoney, E. J. Sandy, D. A. Dahlstorm

INTRODUCTION Before an understandable discussion concerning coal dewatering processes can be initiated, it is necessary to define some terms of usage. The many different meanings and interpretations of terms preclude development of standard definitions so the terms defined in this chapter should be regarded primarily as working terms intended to facilitate communication.

Jan 1, 1979

By S. O. Warren

From the contractor's viewpoint, suggesting what is now a theoretical industrial approach to safety and a proposal for realistic reformation to accomplish the intended goals, is the tri-parte adversary formula productive, unproductive, or counter-productive? Can industrial safety be regulated and penalized to effectiveness? No manuscript received

Jan 1, 1979

By K. D. Hester

This paper will review the metallurgical aspects of the completed expansion program at Quirke, and the current rehabilitation and refurbishing program at Panel. During the Quirke program, completed at the end of 1977, the plant capacity was increased from a nominal 4,500 to 7,000 short tons per milling day. The expansion of crushing, grinding, neutral thickening and filtering, leaching, partial neutralization, sand-slime separation, sand washing, C.C.D., clarification, ion exchange, mine water treatment, and tailings neutralization and pumping will be considered. The application of Enviro-Clear thickeners in the mine water treatment circuit and in the C.C.D. will be briefly reviewed. An automatic grinding and classification circuit for limestone will also be covered. The refurbishing program underway at Panel will be discussed. The Quirke and Panel plants will be contrasted and compared. In particular, reference will be made to environmental considerations. The innovative system for producing yellow cake at Panel, LAMIX, will be considered as well as the proposed treatment system for Panel tailings.

Jan 1, 1979

By L. G. Tejada, T. Sjursen

In the production of ferronickel at Falconbridge Dominicana's plant in the Dominican Republic the Reduction Plant plays a vital role by partially reducing the nickeliferous oxide ore, and pre- heating the charge to the electric furnaces. Ore is agglomerated in the form of pillow-shaped briquettes which are screened and fed to 12 open-top shaft furnaces. Hot (over 1250°C) reducing gases are partially cooled (less than 1150°C) and introduced through a set of primary tuyeres. The reducing gas rises counter-currently to the flow of solids. A portion of the partially spent reducing gas is withdrawn at the furnace top and recirculated through a set of secondary tuyeres, 1800 nrm above the primary tuyeres. Together with the recycle gas a controlled amount of air is also added to react with the partially spent reducing gas in order to preheat and dry the charge in the upper part of the shaft furnaces. The calcine is discharged through three discharge legs and pusher block assemblies into open-top refractory lined cars. These cars are then hauled to the electric furnace, parked over selected feed ports, and discharged through bottom gates. The furnace exhaust gas is de-dusted in cyclones and then passed through Venturi scrubbers. The slurry is fed to a thickener, filtered, and recycled to the ore receiving hopper in the ore preparation area. Dust generated throughout the plant is collected, wetted to conform with briquette press feed, and recirculated in a controlled manner through the feed system.

Jan 1, 1979

Mitsui Aluminium Co. of Japan announced that it would finance 25 percent of the construction costs for the 217,000 ton-per-year primary aluminum smelter being built by Alumax, Inc. at Holly, SC. Mitsui would receive 25 percent of the plant's production in return. Construction on the smelter began early in 1978, and is scheduled to be completed in 1981. The Aluminum Company of America (Alcoa) announced plans to restart a third potline at its Point Comfort, TX primary aluminum smelter in July. The company previously announced plans to restart two potlines at the facility in May. Reynolds Metals Co. began preparations to restart primary aluminum production in May in one of two 57,000 ton-per-year potlines at its Corpus Christi, TX smelter. The plant has been closed since 1975.

Jan 1, 1979