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By G. C. McKerrow

"Mr. G.C. McKerrow, Assistant Manager of Noranda Mines and formerly Smelter Superintendent attended the meeting to answer questions as to why smelters imposed penalties for too much zinc in a copper concentrate or too much copper in a zinc concentrate, etc.D.W. Bridges -Mattagami Lake MinesWhat limits do you set on zinc and lead in a copper concentrate?G.C. McKerrow - At Noranda, we allow 5% zinc free and charge 25 cents for every unit above that. For lead, it is 1% free and 25 cents per unit above that. Lead is a much more harmful impurity than zinc because it tends to recycle more in the smelter circuit and creates a greater health hazard in the plant.E. Thornton - Sullivan GroupWHat harm does fluorine do in the smelting process?G.C. McKerrow - Fluorine usually does not occur in harmful concentrations in non-ferrous smelters. Fluorides are present in exhaust gases in the aluminum and phosphate industries. If these fumes escape into the atmosphere, they may settle out on forage grasses in concentrations that are harmful to livestock.Thorton - Sullivan GroupI have asked this question other places and have been told that it is hard on brick linings and causes gold and silver to be lost up the stack.G.C. McKerrow - Almost any volatile constituent in a smelter charge will aid in carrying other metal values. To this extent it may be harmful.E. Thornton - Sullivan GroupMr. Tait mentioned before a smelter where they have a copper-tin ore and they pay for copper, tin, bismuth and silver but object strongly to indium in the concentrate. Why would this be?G.G. McKerrow - 1 can't see why indium would be a serious impurity. It does tend to concentrate in flu dusts and if you get enough of it you can recover it and sell it but I have never heard of anyone putting a penalty on it.Question - I once ran into a small copper mine in Peru that had cadmium in the copper concentrate but no zinc. The copper smelter charged a penalty for the cadmium. Why would this be?"

Jan 1, 1971

By M. W. Bates, A. L. Mular

This paper, based on work carried out at Queen's University, describes the development and use of mathematical models of the parallel cyclone classifiers being used in the Strathcona mill of Falconbridge Nickel Min.es Ltd.

Jan 1, 1971

By D. J. McLaren

"Arctic Canada is one of the largest undeveloped terrains remaining in the world, and is in many ways unique. The ecological balance of the region is more delicate than tropical or temperate regions of similar size. This region is likely to be developed by research for and production of resources, primarily petroleum, in the immediate future. As well as sensitive terrain surface caused by permafrost in some areas, many large and small mammals and birds are also in a delicate balance with the environment. Small changes in this balance can have large effects.The probability of finding petroleum in different regions varies widely, but already there are good indications on the mainland and in the Islands that both oil and gas are present. Geophysical work in the offshore, particularly the Beaufort Sea, suggests further promising potential. Possible reserves in the Islands and mainland Arctic may amount to 50 or more billion barrels.A responsible approach to problems facing exploitation in an Arctic environment includes the careful monitoring by industry of likely effects of their activities. The Mackenzie Valley Pipeline Research Association test loop at Inuvik provides an example of such monitoring. Outside Canada, the operations at Prudhoe Bay on the north coast of Alaska show how major companies may operate responsibly and reduce environmental interference to a minim'.::at. Nevertheless, four variables must affect any decisions to be made concerning energy resource exploitation in the Arctic. These are man's need for energy, economic and industrial pressures to develop energy sources, the desire to preserve a deteriorating environment, and the role of government as representing all individuals in the country and their several points of view. Factors that must be taken into account in making any decisions include the importance of Canadian oil in a world picture, the need for alternative sources of energy in the near future, the depletion of nonrenewable resources at an accelerating rate and the increasing awareness that the major problems facing man have no direct technical solution and that social or political decisions must precede further techno-logical development."

Jan 1, 1971

By C. L. Lewis

"The development of computer process control at the Lake Dufault concentrator is reviewed and the on-stream X-ray analysis -computer system is described briefly. Some applications of the computer in metallurgical process control are described.The computer sequences slurry sample streams to the analyzer and translates the analytical results from voltage signals to elemental percentages. The required flotation reagent flow rates are calculated from analyses and mill-feed tonnage rates and the reagent feeders are set automatically to provide such flow rates. X-ray calibration time has been reduced from about 45 minutes to 15 minutes by the use of a computer program. Metallurgical and operating personnel have acquired the ability to program the computer and have extended the system capability to allow the calculation of recoveries, averaging of mill data, application of ore specific gravity in grinding control, control of oxidized ore flotation and the development of an economic recovery program."

Jan 1, 1971

By D. W. Duncan, A. Bruynesteyn

Acidic mine waters containing solubilized uranium have been observed in many uranium and some copper mines. In every case, the sulphide and iron oxidizing bacterium, Thiobacillus ferrooxidans, was also present. This bacterium provides the ferric iron required to oxidize u+4, both by oxidizing available ferrous iron and by oxidizing pyrite or other available sulphide minerals. This latter oxidation also provides sulphuric acid and may increase extraction by exposing more uranium. The enhancement of bacterial activity and the results of some field tests are discussed.

Jan 1, 1971

By B. J. Cunliffe

"Filter cloth in the mining industry is an ambiguous title asthis suggests filter cloth use from underground ventilation to the refining processes. The time allowed for this paper would be better served in con-centrating on vacuum filters common to all mine mills and to offer some simple guide lines to the mill metallurgists in the choice of filter cloth for this type of filter.The requirement of the filter cloth is to separate solids from liquids under a vacuum head by forming a permeable layer of solids or cake, through which liquids can flow until the panel or disc sector leave the slurry tank and to continue to pass residual moisture from the cake formed during the cake drying cycle, and to discharge the cake on air-blow so that the cycle can be repeated.Whilst the mill metallurgist should not be expected to under¬stand all aspects of filter cloth manufacturer, it is however, advantageous for him to understand a little of the textile language associated with filter cloth for his own protection against ""trial-and-error"" methods, which are both time consuming and costly.If improvements are to be made over existing filter cloth in use an examination of the limiting factors of the cloth used should be made and the major causes for removal determined, e.g. cloth blinding, high moisture in cake, poor cake discharge on air blow, mechanical damage to cloth.As each of the limiting factors mentioned has a bearing on the choice of fibre used, the yarn type and weave of a suitable cloth, an under-standing of these points will assist the mill metallurgist in avoiding repetitive trials offering little degree of success."

Jan 1, 1971

By D. R. Pyke, R. S. Middleton

"Three main types of base metal sulphide mineralization are present in the Timmins area:(1) -Massive and stringer-type copper-zinc deposits occurring mainly in pyroclastic rocks, as typified by the mines of Kam-Kotia, Jameland and Canadian Jamieson, or within or close to possible breccia pipes as shown by the Genex and Kidd Creek mines. With the exception of the Kidd Creek mine, all of these orebodies occur northwest of Timmins (Kamiskotia area) and appear to lie within or close to a major center of volcanic activity characterized by a thick accumulation of felsic pyroclastic rocks and subordinate epizonal intrusions. The margins of the rhyolitic pile are interfingered with mafic volcanics; overlying sedi-ments mark the termination of a vol-canic cycle. The copper-zinc deposits in the Kamiskotia area are confined to a particular stratigraphic unit. Ore-bearing solutions were probably derived from the intrusive complex of the volcanic pile.(2) -Porphyry copper deposit of the Mcintyre mine. The deposit occurs in a quarz porphyry intrusion related to the volcanism in the area (Hurst, 1936). Mineralization was probably introduced at the time of intrusion, and subsequently redistributed within the porphyry during deformation. (3) -Massive and disseminated nickel mineralization, associated with serpentinized alpine-type ultramafic intrusions, as shown by the Alexo, McWatters, Hart, Inco and Texmont deposits. The nickel mineralization occurs at or near contacts of the serpentinites with felsic or mafic volcanics, or sulphide-bearing iron formations. The nickel deposits south of Timmins are confined to a particular stratigraphic unit along the margins of domical-shaped structures which appear to outline former volcanic centers. Sulphurization as pro-posed by Naldrett (1966) appears to be a workable hypothesis for the formation of some of the deposits."

Jan 1, 1971

By Kim H. Shikaze, John R. Hawley

"Even though acid mine drainage is an old problem, particularly in coal mining areas, its appearance in the form of a major environmental hazard in the hardrock mining districts of Ontario was unexpected. The yellow and amber coloured wastes that characterize an acid mine drainage situation were first noted by the Ontario Water Resources Commission in the uranium mining Elliot Lake district. Problems of a similar nature were also noted in the copper-lead-zinc camp at Manitouwadge, the nickel camp at Sudbury and at numerous isolated base metal properties, both in and out of the Province of Ontario.Without exception, when acid mine drainage type effluents were evident, the specific companies involved worked sulphide or sulphide-associated ores. Without exception, the ore bodies contained quantities of iron sulphide (in various mineralogical forms) and, without exception, the milling circuits serving these operations were such that the iron sulphides were rejected to the tailings areas as waste.Once in a tailings area and after a varying period of time, iron sulphides react to form water soluble salts which, when discharged in the effluents from the tailings area, can affect stream chemistry and stream ecology.It is not unusual that the minerals pyrite, marcasite and pyrrhotite (all iron sulphides) react to form a stable oxide under atmospheric conditions. The law of stability of rocks and minerals, for instance, states that rocks and minerals are stable only in the environment of their formation and, as the environment surrounding them changes, the rocks and minerals tend to change to other species which are relatively more nearly stable under the conditions of the new environment (a). Under atmospheric conditions, iron oxide exhibits a greater stability than iron sulphide."

Jan 1, 1971

By P. M. Dranchuk

"""PLANET EARTH seen from space appears as a fragile and limited life-supporting system in a vast emptiness. That such a view is, in fact, an accurate one is now more widely accepted than it was not long ago, before Earth's problems of over-population, overconsumption, limited resources and environmental degradation attained the limelight. The danger is that a government and public now deluged by doomsday prophecies and bemused by equally confident reiterations that technology will cure all may hesitate in coming to grips with the problem, in the hope that, given time, it will go away."" With these words, Preston Cloud begins a recent editorial, in Science(l), in which he presents a brief resume of some of the findings of the Committee on Resources and Man of the National Academy of Science-National Research Council(20.Their report, which is based on a two-year study by an extremely competent group and consists of some 250 pages of text, is even more far-reaching and sobering than the report on Energy Resources(3). It begins by quoting Sir Macfarlane Burnet as follows:""There are three imperatives: to reduce war to a minimum; to stabilize human population, and to pre-vent the progressive destruction of the earth's irreplaceable resources.(4)"

Jan 1, 1971

By A. F. Laurin, A. L. Dorr

"Because of its wide areal extent, its numerous lithological facies and its high degree of metamorphism, the Quebec portion of the Grenville province has only partly been explored and prospected. Rock types that are economically among the most interesting in the Grenville are those of mafic and ultramafic compositions, because of their great potential for coppernickel and chromium-platinum. The peculiar mode of occurrence and the distribution of these igneous masses in which copper-nickel mineralization is known to occur indicate' two common geological features: (1) aerial photographs and/or topographic maps strongly' suggest close spatial (and possibly temporal and genetic) association of most of these mineralized mafic and ultramafic intrusions with circular structures; (2) when plotted on a large-scale map comprising the Quebec portion of the Grenville, these circular structures fall along two lines which could correspond to major tectonic features. Even though the genetic links among the mineralized mafic-ultramafic masses, the circular structures and the linear features are not yet fully understood, their associations are believed to be empirically valid and should therefore be used as geological tools by those interested in exploring the Grenville for copper-nickel and possibly chromium-platinum deposits. It should be noted that these mafic and ultramafic bodies do not appear to be spatially related to anorthosite complexes."

Jan 1, 1971

By F. D. Forgeron

"ONE OF THE FIRST DOCUMENTED APPLICATIONS of soil geochemistry in the Canadian Shield was that carried out by Chisholm in the Kenora district in 1949. This survey proved successful in outlining sulphide-associated gold veins utilizing cold-extractable metals. Since then, mining companies, government agencies - both provincial and federal - and universities have conducted soil investigations. Some of the results are documented in publications, others are on open file in provincial and federal mines departments and, unfortunately, many other investigations with both successful and unsuccessful results are buried in company files or have been discarded. This paper deals with soils within the scope of chemical studies of overburden in the Canadian Shield. The subject is a broad one and some definition is required. The soil investigations discussed herein are those aimed at the testing of specific targets more or less in the source area. This definition distinguishes soil investigations from other overburden studies which commonly monitor metal accumulations at some substantial distance from the metal source. Naturally this distinction is relative, because in many instances there is overlap."

Jan 1, 1971

By B. Meddings, O. J. I. Evans

"This paper is mainly concerned with the present and probable future role of hydrometallurgy in the production of base metals.The economic and technological bases of the hydro-metallurgical plants built and operative in the mid-fifties are compared to those in production in the mid-sixties. The trends observed are extrapolated and some estimates made concerning the probable size and type of hydrometallurgical plants which will be operative in the mid-seventies.The impact of emerging socio-economic factors such as pollution control and the market demand for specialized metal products which favour hydrometallurgical recovery processes are also discussed."

Jan 1, 1971

By G. V. Sirianni, G. E. Viens, R. A. Campbell, G. N. Banks

A combination shaft-electric furnace for the smelting of ores and the melting of metallized feed is being developed at the Mines Branch. When iron oxide pellets are smelted in this unit, they are preheated and partially reduced in the shaft before being transferred to the electric furnace where smelting is completed. Also, limestone flux added with the pellets is-preheated and calcined in the shaft. It has been demonstrated that, in smelting iron oxide in this unit, the throughput of the 250-kva electric furnace can be approximately doubled and the amount of electrical energy required can be very significantly reduced when the shaft furnace is operated in conjunction with the electric furnace. These benefits are achieved mainly by utilizing the sensible heat and latent energy contained in the arc furnace off-gases.

Jan 1, 1971

By J. R. Jutras, C. Brissette, J. Champagne

"Pure cadmium sulphide was leached by the action of the bacterium Thiobacillus thiooxidans in the presence of finely divided sulphur. The influence of time, temperature, pH and concentration of inoculum on the extent of the cadmium extraction was studied. Under optimum conditions, up to 72 per cent of the cadmium could be dissolved over a six-week period. A cursory study of the role played by elemental sulphur seems to indicate that its presence is essential but that the sul1>huric acid produced through its oxidation is a minor factor in the cadmium extraction."

Jan 1, 1971

By H. Link

"The extremely low permeability of the water-carrying beds in the nevonian formation of the potash district of Saskatchewan does not permit the injection of cement or chemicals to seal off sufficient water from the shafts to guarantee the safety of the mine. Based on many years of experience with wet shafts in the German and French potash mining industry, Alwinsal Potash of Canada Ltd. decided to have their potash mine shaft near Lanigan, Sask., which was completed in September of 1967, lined by means of an absolutely watertight lining of combined concrete and steel-plate construction.This shaft lining, consisting of two steel shells of welded construction with concrete filled in between, has proved itself before in the German coal mining industry. It guarantees a permanently dry shaft. With this type of lining, time-robbing and very often abortive injections are superfluous and the regular repair and adjusting work as well as the corrosion of conveyances and ropes can be avoided. Above all, however, the danger of a water inrush into the shaft is abolished completely."

Jan 1, 1971

By G. M. Behrend

"The mining and processing of mineral ores is a very old industry which is steeped in tradition. Rising demand for metals has recently forced the exploitation of lower-grade orebodies which require extensive beneficiation. The high capital expenditures involved, together with market pressures for high-quality concentrates and pellets, have forced the development of new process technologies which are heavily dependent on automatic process control. Development of suitable instrumentation has been rapid and it is being applied to mining processes today with a high degree of sophistication. The drive for higher efficiency and profitability goes on and has reached a level at which modern digital computers appear to be the only answer. However, the efficient application of a digital process computer is extremely complicated and is therefore approached by the mining industry with considerable hesitation.Some of the benefits promised by the digital computer can be obtained today by other means, which are more manageable and can provide immediate payoff. The result would be a building-block system which would utilize the digital process computer as its final component, to perform true plant optimization, free from routine chores."

Jan 1, 1971

By M. Gyenge, O. F. Coates, K. Barron

"It is suggested that artificial supports might be used to increase, with safety, the angle of hardrock open-pit slopes. Guidelines for designing such a support system, based on a simplified analysis, are given. The installation, construction and instrumentation of a trial support system is described and a breakdown of the construction costs is given. On the basis of this cost analysis, the economic benefits derived from reduced waste-rock excavation are compared with the support costs for a typical mine. In an example, it is shown that the slope angle in an open-pit mine 500 ft deep, with benches 50 ft high by 30 ft wide, could be safely increased from 37Yz degrees without support to an optimum of 53 degrees with support. In this case, the support costs would be approximately $900 per linear foot of pit wall and the savings due to decreased excavation of waste rock (at $0.34/ton) would be approximately $1,900 per linear foot, yielding an increased margin of profit of approximately $1,000 per linear foot of pit wall. This figure could be increased to $6,000 per linear foot if the steeper slope were used to extract more ore.More than 50 per cent of the support costs are accounted for by diamond-drilling the holes for the deep cable anchors. The use of percussion drills for this purpose would seem to offer a means of significantly reducing the support . costs and thus further increasing the profit margin available."

Jan 1, 1971

By R. R. Montigny

A brief description is given of the history, location and geology of the Granisle Copper Limited operation on Copper I land in Babine Lake. Detailed information is given with regard to pit design, planning, drilling, blasting, excavation and haulage. Equipment maintenance and mining costs are also presented.

Jan 1, 1971

By A. Sobering, G. N. Carlson

"This paper describes the conversion of the grinding section of the W a bush Mines pelletizing plant from conventional wet, open-circuit trunnion overflow ball milling, with filtering, and bentonite mixing on a common conveyor belt, to dry, open-circuit, grate discharge grinding, with pug mill mixing of bentonite and water at individual mills.The test work and data on operating economies to justify the cost of conversion are given. It is too early, at the time of writing, to have complete operating confirmation, but data are available. A brief description of the original plant is included."

Jan 1, 1971

By Hulbert A. Lee

"A REVIEW OF MINERAL DISCOVERIES IN CANADA, and in particular the Canadian Shield, using the physical aspects of overburden reveals a trend in the art of exploration. At an early time of exploration (1847-1954), float and heavy clasts were used successfully to find ore deposits with little knowledge of Quaternary environments. At a later time (1955 to present) , use of Quaternary rock-units for sampling have made possible tracing indicator trains of float, heavy clasts and other ore-type clasts to the source bedrock. The basal till of retreat ice is now recognized as a1l favourable sampling environment and as such has been used to successfully discover hidden orebodies. The esker massive gravel is beginning to be recognized as a favourable environment and use of it has met with technical success. An understanding of those changes that have taken place during the transportation of the material and after its deposition is essential to proper sampling and treatment of the samples from the basal till and the esker massive gravel. Use of float and heavy clasts in search of orebodies is continuing in present-day exploration on the Shield. Lessons learned from it are being incorporated into exploration using favourable Quaternary rock-units for sampling. Hence, both subjects have a need for review and are discussed in this paper."

Jan 1, 1971