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By Jr. Flynn

The filtration process has long been utilized in the mining industry and typically associated with processes where clear solutions are required. One definition of filtration states that it is utilized to affect a more complete separation of liquid and solid phases than is possible with settling alone. The development of Diatomaceous Earth filter aids has added a new dimension to filtration technology in the mining industry. It makes possible the filtration of slimes with almost perfect clarity, and at rates that become economical.

Jan 1, 1980

By G. W. Poling

"Construction, equipping and planned operation of a new laboratory for engineering-teaching and research in coal and mineral processing is described. This facility will provide approximately 1860 m2 (20,000 ft. 2 ) of laboratory space with nearly half devoted to a new venture in coal preparation. Two high-bay, overhead crane-accessed areas will accommodate major unit operations for each of the ""coal"" and ""mineral"" laboratories. COAL PREPARATION FACILITIES:The coal facility provides three main functional areas:(1) Sample preparation (drying, blending, crushing, screening) and sink-float washability testing.(2) Unit operations U1igh-bay, serviced by crane).(3) Analytical laboratories.(l) Sample Preparation and Sink-Float TestingBreaking or comminution of coal will be accomplished using a rolls crusher, a hammer mill, a jaw crusher, or a pulverizer. Capacity to prepare coal at rates of up to approximately 4 tph will be provided by some of these units. Large diameter (~0.5m) baths of heavy organic liquids will be available for sink-float washability tests on coal samples of several kg. Particle sizes of up to 25 mm can be tested in these baths. Smaller scale washability tests on finer samples will be accelerated by centrifuges."

Jan 1, 1980

By R. Marshall

Electrical trailing cable handling techniques and practices used in metal and non-metal surface mines were investigated by obtaining information through actual visits to the mine properties located in a variety of geological areas and climatic conditions. An analysis was made of all accidents related to cable handling which are cataloged by HSAC* for the period from 1971, through June 1980. Information was also collected from mine operators concerning near accidents and non-reported accidents. The results of this investigation were presented to the U.S. Bureau of Mines in an effort to outline recommended practices for cable handling in surface mines and to recommend additions and/or changes in the present regulations now being enforced by MSHA** field inspectors. These recommendations are also intended to assist the U.S. Bureau of Mines in evaluating the need for assisting the mine operators in the areas of training and distribution of information related to material handling of trailing cable. * Health Safety Analysis Center ** Mine Safety & Health Administration

Jan 1, 1980

By Gary E. McIntosh

This paper will discuss a US Bureau of Mines project designed to assess and predict the impacts which surface coal mining will have on the regional shallow groundwater systems in the Powder River Basin. The primary objective will be met through the accomplishment of the following: (1) The design and establishment of a regional network for monitoring shallow groundwater systems in the basin; (2) monitoring the direction and rate of flow, water quality, and aquifer characteristics of the shallow groundwater systems; and (3) development of a regional groundwater simulation model, with appurtenant subroutines to determine local effects.

Jan 1, 1980

Provide an improved, rugged, reliable, cost-effective automatic fire protection for mine haulage trucks. Approach Systems that automatically sense and extinguish fires on haulage trucks were designed, built, and in-mine tested. How It Works Temperature sensors mounted above the engine of the truck detect the heat from a fire while it is still small and controllable. A cab-mounted control panel warns the operator of the fire emergency and then automatically triggers the discharge of 60 pounds of multipurpose dry chemical extinguishing agent (from storage tanks through hoses and nozzles) into the engine compartment. If desired, the control panel can be field-adjusted by changing one resistor to delay the discharge for up to 60 seconds to allow time for the operator to stop the truck and shut down the engine. The system can be assembled with either pressurized storage tanks, or a combination of non-pressurized storage tanks plus separate pressure cartridges. This pressure source option is one of the improvements of this system over the earlier systems described in Technology News No. 11. Other improvements are a simplified control circuit and an improved sensor.

Jan 1, 1980

By E. S. Smith, Sunirmal Banerjee

INTRODUCTION Social awareness of the detrimental impact of man-made wastes on our environment has grown considerably during the last two decades. Increased public and institutional concerns have resulted in the implementation of a wide variety of regulatory controls of disposal of wastes. These regulations have often reflected significant conservatism in expecting guaranteed elimination of pollution risks. This sort of expectation assumed a state of knowledge which was not readily available to the major producers of wastes. The mining industry, in particular, has been affected by such regulations in terms of excessive costs and loss of benefit. As a result, investigations are in progress (1) to generate newer methods for satisfactory stabilization of mine and mill wastes and (2) to apply the available technology to achieve the standards set by the regulatory agencies at reasonable costs. This paper presents a conceptual scheme for stabilization of mill wastes by suitable management of operations and accelerated consolidation of tailings slurries. The main discussion in this paper is aimed at the ability of the proposed scheme to address the major considerations in effective disposal. Comparison in both cost and effectiveness are also made between the proposed scheme and various other currently used disposal concepts. MAJOR CONSIDERATIONS IN EFFECTIVE DISPOSAL The primary objective of an effective tailings disposal scheme is to provide containment of the contaminants in such a manner that the undesirable impact of the wastes on the three basic elements of our environment--land, air, and water-would be minimal. Bearing the above objective in mind, one may justifiably list the major considerations in the choice of the disposal scheme in terms of its effects on land, air, and water (Bromwell, 1976) as follows: Effects on Land (1) whether the scheme makes optimal use of land.

Jan 1, 1980

INTRODUCTION The preceding chapters have brought us to a point in the mineral appraisal process where the composited sample values can now be used to estimate the grade and tonnage of the total mineral deposit. There are many techniques whereby drill hole composites and/or other sample data are used to assign grade and estimates to the surrounding rock. Matheron and his students have properly called such techniques extension functions. Before embarking upon a detailed discussion of extension functions, it is necessary that we take time to consider the concept of geostatistics as advocated by George Matheron who developed the "Theory of Regionalized Variables," which he published in 1962 (Matheron, 1971). The concept of regionalized variables has important application in the techniques of mineral appraisal. The position or location of a mineral sample within a deposit can be almost as important as its value. Geostatistics, when defined as "the application of the theory of regionalized variables* to the study of mineralized volumes of rock," takes into consideration the position as well as the magnitude of the value of the sample. The principles of geostatistics, as outlined by Matheron, represent a major step forward in the mineral evaluation process, because they provide a sound theoretical and practical basis for quantifying the geological concepts of (1) area of influence of a sample, (2) the continuity or lack of continuity of mineralization within the ore body, and (3) the lateral changes in mineralization according to the trend direction of an ore body and its orthogonal components; or in other words, a measure of the anisotropy of the deposit. Royle (1971) has defined the objects of geostatistic as being: "1. To estimate the most likely value of blocks of ore, or the values of the whole deposit; and 2. to estimate the errors of such estimates. This latter is important as, in addition to providing a check on unwarranted optimism, it shows where more valuation work may be needed." Because of the great importance of these concepts in mineral evaluation, an introduction into the theory of regionalized variables, and the study of a practical approach to its application is outlined here. REGIONALIZED VARIABLES VS. RANDOM VARIABLES Classical statistics, as discussed in earlier chapters, grew out of the study and application of probability theory. Probability is concerned with the outcome of random events and therefore classical statistics is built upon the theory of random variables, i.e., the probability of independent events. The validity of most statistical inferences depends upon sample randomness being assured for unbiased results. Where independent events cannot be assumed the results of statistical inference becomes suspect. On the other hand, geostatistics is concerned with variables that have position in space as well as magnitude, hence the term regionalized variables. Mineral deposits are not the only field to which the theory of regionalized variables is applicable. Many natural phenomena that demonstrate a relationship between change in magnitude and position in space are amenable to application of geostatistical techniques. Mineral deposits vary greatly in their geosta-

Jan 1, 1980

By T. E. Walsh

Introduction I will address two important alternative energy resources, solar and geothermal, with emphasis on their potential application in electric power generation. As a result of this presentation, I hope to leave you with a realistic view of the principal technology options that are being developed or that are available. Solar Types of Collection In terrestrial solar applications, the biggest challenge is to find ways of collecting the sun’s relatively low intensity energy so it can be converted economically to useful thermal or electric energy. Fig. 1 shows that there are both natural and technological ways of collecting solar energy. In nature we find that solar energy aids in the production of biological growth, rainfall, and wind, all of which can, in one form or another, be put to use in the production of heat or electric power. The sun’s rays also are collected and stored naturally in the form of heat in the upper layers of the ocean which can be put to use in the production of electric energy by means of ocean thermal energy conversion (OTEC) approaches. On the technological side, the sun’s rays can be intercepted by materials that directly absorb and convert its energy to low-grade heat, or by mirrors or lenses that focus the rays onto a material to produce high-temperature heat. The higher temperature systems can be used to drive efficient heat engines in the production of electricityy. The sun’s rays also can be collected on photosensitive materials, in either a direct or concentrated form to generate DC electricity directly. The systems I will discuss employ all of these means of collection and conversion, excluding biological and hydroelectric. The former is too ex

Jan 1, 1980

By V. J. Sopuck, O. P. Lavin, Ian Nichol

"A major challenge of contemporary exploration geochemistry is the development of procedures that can locate blind mineralization or mineralization that sub-crops below a cover of transported overburden, the composition of which bears no relation to the underlying mineralization. Over the past few years, the possible existence of diagnostic geochemical features in the country rock associated with volcanogenic massive sulphide deposits has attracted increasing attention both on the local mine scale and on the regional scale. In the present investigation, the nature of the geochemistry of a number of Archean greenstone belts of the Canadian Shield is examined to determine the feasibility of distinguishing productive from non-productive areas of copper-zinc mineralization. The results indicate that productive areas are distinguishable from non-productive areas providing consideration is given to the effects of igneous differentiation on rock compositionIntroductionArchean massive sulphide deposits are an important source of copper and zinc, and to a lesser extent silver and gold, particularly in Canada. As in the case of most other forms of mineralization, there is a continual need to develop new techniques that will improve the chances of success in the search for these deposits. The majority of Archean areas in the northern latitudes are overlain by a variable cover of glacial overburden. Considerable progress has been made in the development of new geochemical exploration techniques for use in glaciated terrain, based on the detection of anomalous dispersion in the glacial overburden. In certain situations, however, as in the search for blind deposits or in areas covered by glaciolacustrine deposits, overburden geochemistry offers little hope for success. In the case of massive sulphide deposits, one possible solution may lie in the detection of anomalous geochemical signatures in the bedrock. Recognizing this possibility, attention has been directed to the investigation of the nature of lithogeochemical dispersion associated with massive sulphide deposits on both regional and local scales, to establish the potential of lithogeochemistry as an aid in the search for these deposits."

Jan 1, 1980

By H. W. Smith, D. Guerin

"This paper describes the development of a dynamic model for a full- scale (64 tonnes/hr) grinding circuit consisting of an open-circuit rod mill feeding a ball mill operating in closed circuit. The object of constructing such a model is to investigate the static and dynamic behaviour of potential control schemes. Model selection, data processing and parameter estimation are discussed, and static and dynamic results of simulations are presented. Conclusions are drawn with regard to the adequacy of the model for such studies, and likely limitations on control of such circuits.IntroductionThe model developed here is intended to represent the grinding behaviour of the grinding circuit at the Lake Dufault division of Falconbridge Copper Mines Ltd. This circuit has been fully described elsewhere. At the time of the work described, the ball mill discharge was fed to a four-cell flotation bank , the tailings of which are combined with the rod mill discharge in the cyclone feed pump sump. As the emphasis in this study is on grinding behaviour, and as only I per cent of cyclone feed material is removed in these cells, no attempt has been made to include flotation behaviour in the simulation. One effect of the presence of flotation cells in the grinding circuit is, however, to necessitate somewhat finer grinding than might otherwise be needed: this will have effects on mill parameters.The paper is organized as follows. First the selection of models is discussed, paying particular attention to the problem of selecting simple, yet adequate, flow models for the mills. Then data gathering is described. The method of deriving mill model parameters is explained, and the results presented. Mass balancing of cyclone data and the determination of cyclone model parameters are described. The linking of the models into a full simulation is outlined, and sta tic and dynamic results presented. Finally, the results are discussed and conclusions drawn ."

Jan 1, 1980

As part of the Bureau of Mines subactivity in secondary resource recovery and to expand the Nation's mineral base, the Tuscaloosa Research Center made characterization and preliminary beneficiation studies of the waste residues from various coal-conversion processes: from pilot plant tests of the Synthane process for coal gasification, the Synthoil process for coal liquefaction, and the solvent-refined coal (SRC) process for sulfur removal from coal. Those coal conversion processes selected for this study were based on the availability of pilot plant samples. Physical, chemical, and mineralogical examinations of the wastes made to determine the mineral content prior to physical beneficiation tests indicated that in addition to significant quantities of carbon, some trace elements offer potential for concentration.

Jan 1, 1980

By H. M. Friede

Mining was a widespread economic activity in the African Iron Age. This paper reviews the available evidence on, the archaeological, historical, ethnological, and technological aspects of early mining in the Transvaal. A number of analyses of ores found at archaeological sites (especially at Broederstroom) are reported, and an interpretation of the analytical results is suggested. Descriptions of Iron Age copper- and tin-mining complexes, and of iron-ore workings, are given, and techniques of Iron Age mining are discussed. The evidence of gold mining in Iron Age Transvaal is examined.

Jan 1, 1980

By Hoskings R

Conceptual studies of the run of mine stockpiling and reclaiming requirements com- menced in 1975. Final selection of equipment was made in 1978 and the equipment was commissioned in June, 1979. Equipment selection was made after extensive investigation and visits to existing facilities throughout the world. The equipment selected is described and com- pared with the alternatives. Foundations were designed to minimise clean up effort and to ensure stability of equipment under design wind loading without storm bays. Program- mable logic control enables the stacking and reclaiming facility to provide a blended feed to the coal preparation plant.

Jan 1, 1980

By Eugene C. Spilker

Cross country belt conveyors are becoming the preferred method of bulk material handling in the industrial complex. Installed cost, maintenance, reliability, simplicity and operating expense enhance this choice, especially when faced with rising cost and questionable availability of liquid fuels. Conveyor flights are getting longer, faster, and higher in capacity, and are being installed in rugged terrain. Rights of way are often difficult to obtain. All these considerations lead up to design aspects well beyond those for in-plant conveyors. This paper points out some of the aspects that lead to the successful design of a cross country belt conveyor system.

Jan 1, 1980

By Werner Unland, Nick Holl

"The paper presents the engineering design and experience gained so far with a dewatering system for an open-pit uranium mine planned at Key Lake in Northern Saskatchewan.The results of hydrogeological investigations preceding engineering exhibit an extensive unconfined overburden aquifer hydraulically connected with the underlying Athabasca Formation and basement rocks, both of relatively low hydraulic conductivity. The overburden aquifer is embedded in a bedrock trough, with the deepest depression between the planned pits. The hydrogeological data were used in a numerical dewatering model simulating groundwater flow atdifferent stages of the pit development.Based on the model results, the engineering design had to provide for different pumping rates, varying between 1.0 and 0.21 ms/sec. This problem was solved by using a double line pressure system. The design concept for the complete peripheral discharge system and the well design used for 26dewatering wells are discussed.Experience with reverse-circulation techniques applied for the construction of the dewatering wells is presented. Theoretical and practical considerations which led to the constructionof wells of different diameters are discussed.The design of the in-pit dewatering system provides for seepage ditches, horizontal drains, pit-bottom sumps and inpit dewatering wells where required."

Jan 1, 1980

Duty on Lead Reduced. -On December 28, the President signed H.R. 5047 which reduces the duty on unwrought lead from 3.5% ad valorem to 3% ad valorem, with a floor level of 1.0625 cents per pound, effective retroactively from January 1, 1980, through June 30, 1983. Pacific Northwest Power Bill Passed. -On December 5, the President signed S. 885 which will enable the Bonneville Power Administration to guarantee 20-year contracts to its 15 major industrial customers in exchange for higher rates. In effect, the bill will have industrial customers pay some of the costs of building additional generating facilities in the Northwest, of which thermal units are expected to be a major part. BPA supplies power to six primary aluminum producers which operate eleven plants having over 30% of the primary aluminum capacity in the United States.

Jan 1, 1980

By D. W. Kestner

Recent developments and trends in the state of the art as being commercially applied to the pelletizing and sintering of metallic ores, concentrates and reverts will be reviewed. Both ferrous and non-ferrous materials will be covered. The influence of environmental considerations on the decision to build, the process selection, and design of the plants will be discussed. Use of coal in iron ore pellet induration will also be reviewed as the availability and price structure of oil and gas becomes a consideration to the plant operators.

Jan 1, 1980

By Clyde Orr

INTRODUCTION Cracks, crevices, holes, and fissures -- here collectively termed pores -- occur in all manner of substances in sizes from those evident to the unaided eye to those well below electron microscopic levels of detection. Naturally occurring materials having varying degrees of porosity are represented by wood, rock, soil, and mineral formations. Man-made materials that are porous include ceramics, sintered metals, catalysts, adsorbents, filters, and various compacted objects. The extent of their porosity greatly influences the hardness, rigidity, integrity, and general usefulness of such materials, and assessing both their pore volume and size is becoming increasingly necessary. Means by which this pore information can be obtained is the subject here. No attempt will be made to include all techniques and variations of them that have been suggested, but, hopefully, those of most general applicability will be described in sufficient detail to enable a potential user to judge their merit for a particular need. The results of pore measurements are made useful by relating them through other tests to performance criteria such as weatherability, water penetration, frost damage, oil recovery, strength, or thermal or electrical conductivity. These tests, of course, are outside the bounds for inclusion here. A pore is variously defined in dictionaries as "a minute opening", "a small interstice admitting passage of liquid", and "an interspace between particles". Clearly any object through which it is possible to find a continuous path from one side to the other either for a liquid or a gas must be regarded as porous. Passageways are not necessary for porosity to exist, however. There are so-called blind

Jan 1, 1980

The Nelson province was chosen as the prime area for rhenium sampling, based on its mineral associations. Sample preparation involved benefication by grinding and flotation A modification of published procedures for rhenium analysis was developed and the results compared with those obtained for molybdenum on the same samples using atomic absorption spectroscopy. The results of the analysis for both metals is discussed and the relationships between rhenium and the molybdenum mineralisa- tion of this region is commented on. A metal- 1ngenic province is defined for molybdenum and r'.ienium and the tectonic setting for this is discussed. Some consideration has been given to rhenium possibilities in Fiordland and the Coromandel Range.

Jan 1, 1980

By R. D. Brown

"Concerns over possible additional involvement of governments in Canada's mining industry and its adverse effects on the industry 's growth were a frequent topic of conversation at the recent Annual General Meeting of the CIM.Still painfully fresh in the minds of industry leaders are the disastrous results of the federal/provincial scramble over resource revenues which followed the relatively high metal prices witnessed in 1973/1974. At current metal prices, it is not surprising, then, that a nagging fear persists that these governments may once again restructure tax and other rules to the detriment of the industry and the country.This month, Tax Notes recalls some of the progress which the industry and governments have made in 1979 in the taxation of the resource sector, and urges that higher metal prices be viewed in light of the costly exploration, development and production efforts which will be required for the industry to continue to play its important role in our economy.IntroductionAt the Annual General Meeting of The Canadian Institute of Mining and Metallurgy, held in April, 1980, it was abundantly clear that there is widespread concern in Canada's mining industry that this country's tax regime may once again be blasted by ill winds of change.A stable and more favourable tax climate, as well as higher metal prices and profits, made 1979 almost a golden year for Canadian mining. However, from the tax viewpoint at least, there are some spots on the silver lining as apprehensions grow that the well-heralded battle between federal and provincial governments over oil and gas may spread to the mining sector, with serious damage to the industry and its newfound federal-provincial cooperation."

Jan 1, 1980