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By J. E. Dutrizac, J. B. O'Reilly

"Zinc is a relatively abundant element which occurs as both high-grade sulphide ores {sphalerite ZnS) and oxide ores which the ancients collectively termed ""calamine"" (smithsonite ZnC03 and/ or hemimorphite Zn4Si201(0H)2 - H20 and/ or hydrozincite Zn5(C03) 2(0H)6). Although oxidic zinc is readily reduced by carbon, the process becomes thermodynamically viable only at - 1000°C, and at this temperature the zinc is released as a vapour (B.P. 907°C). Casual cooling of the vapour results in its re-oxidation by excess combustion air or even the carbon monoxide product of the reduction reaction. ZnO + C = C09,, + Zn vapom Only fairly rapid quenching of the zinc vapour and the isolation of the reduction products from the combustion gases will yield metallic zinc; these conditions were not produced deliberately until the advent of distillation technology. Until quite recently, the principal use of zinc was in brass manufacture; galvanized iron was not discovered until the 19th century and zinc casting alloys are a relatively recent invention. As will be seen, brass could be produced without recourse to a pure zinc intermediary, and the discovery of brass preceded that of zinc by many centuries. The purpose of this paper is to outline the discovery and early development of both zinc and brass with special reference to the European scene."

Jan 1, 1999

By John J. Deutsch

"1T is a great pleasure for me to be present at the Annual Dinner of the C.I.M.; a pleasure which is combined with a mutual opportunity that I value highly. First of all, this occasion gives me a chance to meet again many Members of your Institute and to become more fully informed of the special problems of the mining industry. This alone is ample reason for me to welcome the invitation to join you tonight. In addition, this occasion provides me with an opportunity to tell you something about the work of the Economic Council which might be of particular interest to your industry.In the mining industry, keen competition and constant change are basic facts of life. The continuing prosperity of the Canadian mining industry depends fundamentally on how successfully it is able to adapt both to the changing conditions within the industry and to major trends which operate throughout the world.First of all, the scale and organization of the industry are evolving to new and different dimensions. As one authority has put it, ""The cream of the small high-grade, easy-to-mine ore deposits of this world have been consumed and mining is becoming more and more an industry of very large scale, complex operations. It has already become in most countries a capital intensive industry and its problems, scientific, technical and economic, are growing in difficulty."""

Jan 1, 1966

By H. E. (Buzz) Neal

"Abstract - The Labrador Trough contains world-class iron deposits which have been mined since 1954. The direct shipping of Knob Lake ores were mined at Schefferville from 1954 to 1982. Concentrate production began in 1961 in the southwest end of the Trough, with three mines currently producing concentrate and pellets at a rate of 35 Mt per year. West and north of Schefferville, several billion tonnes of taconite have been outlined in fine-grained, cherty magnetite iron formation. Several deposits of highly metamorphosed magnetite-specularite iron formation are located west of Ungava Bay. Numerous studies have shown that this medium- to fine-grained iron formation can be beneficated to 66% to 68% iron. In the area from Wabush Lake to Mont-Wright, a medium- to coarse-grained friable specularite-quartz iron formation is repeated by folding to form several large deposits. In this area, three mining operations are located with reserves and resources in the order of 5 billion tonnes.The iron deposits occur within iron formation in sediments in the extensive Proterozoic geosyncline called the Labrador Trough. Several facies of iron formation within the Sokoman Formation reflect variations in chemical composition and depositional conditions. The correlation between the mineralogy and textures is discussed to illustrate the development of different types of iron ores. This band extends for about 1100 km southeast of Ungava Bay through both Quebec and Labrador. Further south, it turns southwest past the Wabush and Mont-Wright areas to within 300 km of the St. Lawrence River. The iron formation is essentially folded and faulted along most of its length. The degree of metamorphism is variable, ranging from intense in the northern and southern portions to greenschist facies in the central portion.The stratigraphy, structure and mineralogy of the producing mines are described along with the history of discoveries. Geological input is required to achieve the strict specifications of the international iron ore market."

Jan 1, 2000

By W. H. Patterson

The history and experience of early companies in the Islands is illustrated by the typical transactions of Trans-Western from 1959 to date. Trans-Western had entered into farmout agreements with companies strong enough to carry out at least the required minimum exploratory work and then such development as might be warranted. The farmee companies were required to make deposits to guarantee work performance during the first period of validity, i.e. the first 3 years of the 12-year life of the permits, and at the rate of 5 cents per acre. At that time, a good deal of geology was available, as a result of extensive exploration that had been carried on by the Geological Survey of Canada and other geological enterprises, with field parties travelling over and camping on all of those Islands. Trans-Western's farmees then selected, from Trans-Western's priority on 13.5 million acres, what they believed were the lands most prospective of producing large oil and gas discoveries, and, having the right to trim off acreage which they considered less prospective, thereby reducing the acreage of Trans-Western and its farmees to in excess of 5.5 million acres. The farmees then commenced a 3-year program carrying out geological exploration to the required minimum of 5 cents per acre, and with some permanent and many mobile camps.

Jan 1, 1969

By S. E. El-Alfy, John Starkey

"The Iron Ore Company of Canada treats up to 125,000 t/d of iron ore at its Carol Concentrator in Labrador City, NF.A complete water balance study in the concentrator was done to show how to reduce the consumption of fresh water, to improve metallurgy in the magnetic separation (mag) plant, and to help reduce maintenance costs for the reclaim water and tailing pumping systems.The study showed that more than 60% of the water used in the mill was internally recycled dirty water from dewatering cyclone overflows, and that water reduction was closely tied to the effective use of these internal reclaim pumping systems. In addition, new operating parameters were set for the 4 -15,000 USGPM reclaim water pumps which should save over $100,000 per year in maintenance costs.IntroductionThe study described in this paper was set up for the purpose of lowering water usage in the concentrator, and to reduce tailing and process water pumping costs (operating and maintenance). Another benefit was also expected, namely, to improve magnetic separation efficiency through better water and density management of magnetic separator feed streams.The procedures selected to perform this work were: ( 1) to prepare accurate, as built flowsheets of the entire iron recovery process, including fresh and process water systems, (2) to calculate normal material balances in all circuits at full production, (3) to use the computer spreadsheet model so generated, to evaluate specific ways to reduce water consumption and (4) to re-evaluate metallurgical performance and operating parameters in the light of this information.Overall control of the 28 spiral iron recovery lines was found to be excellent because automated start up and shut down of the individual lines had been incorporated in the design from the start. Because production rates can vary due to sales requirements, mine and mill maintenance delays and hardness variance, the mag plant (which treats spiral tailings) must deal with a wide variety of operating conditions. Good water management therefore is a key item in achieving high recovery of the fine free magnetite which is too fine for recovery in the spirals.In order to make the study as accurate as possible, process data for major flows was reviewed by metallurgical staff and then by mill supervisors. The operating picture of the concentrator so generated was judged to be a good estimate of the mill at full production. By changing key inputs, the variance of process water demand and tailing slurry produced for several other operating conditions were studied.The usefulness of this exercise has prompted this present presentation to be made. Older plants by nature have undergone many revisions as operators have worked through ore changes, market changes, labour cost increases and the availability of new equipment, to improve their operation. Sometimes therefore it is necessary to stop and reassess what is happening in a plant in order to continue the never ending work of process optimization. The techniques used here were ideally suited to the gravity/magnetic concentration flowsheets used, but there is no reason why similar studies could not be done in other process plants.The authors of this paper hope that this experience at IOC will be helpful to others who face similar challenges in the pursuit of excellence in their processing plants."

Jan 1, 1995

By A. B. Rossetti

"THE MISSION TO Offshore Scotland was in my opinion a very worthwhile venture, as it indicated the scope of the offshore oil and gas business and how we might exploit it to the fullest here in Nova Scotia - if our offshore fields eventually become producing fields. The writer was able to attend a considerable number of lectures and as a result gained some valuable know-how on the engineering design, financing and operation of the North Sea oil industry. There are many new fields of technology that had to be developed to overcome the North Sea's hostile environment and a great deal of the same technology will have to be developed to win oil and gas from our continental shelf. The visit left me with several impressions, which in the main are:(1) The high order of investment required to develop offshore oil. The investment ranges from 10 to 20 times that required for a similar output on land. Each barrel of oil costs on the average of about $2,- 500 per barrel per day.(2) Because of the high investments required, before the first oil is produced the field must be brought into production at the earliest possible date and initial lead time from decision to production is less than four years. In the British Petroleum field, working at a depth of 450 feet will require an investment of $900,000,000 to develop a production of 400,000 bbl per day. (3) The size and complexity of equipment required is beyond anything ever imagined. Problems which must be overcome are such factors as water depth, wind velocities, wave height, wave period, long periods of darkness, low temperatures, distance from land, and fog."

Jan 1, 1973

By A. O. Dufresne

WITHOUT transportation, mining would be quite impossible. Any person familiar with the operation of a mine knows full well that from the minute ore is blasted, it is kept moving until it reaches the treatment plant. In the mill, by means of conveyors and elevators, the ore is brought from receiving bins to one machine after another until finally its valuable mineral is separated from the gangue. The finished product must then be shipped -either by boat, rail, or motor trucks to industrial centres, where it undergoes further treatment and transformation into finished commercial goods. Everybody appreciates that the winning of an or-e includes, amongst various operations, the moving of large quantities of material of generally low value. Transportation, therefore, must be considered One of the most important factors in the economics of mining. My assignment, this afternoon, is not to treat of that phase of transportation as it directly affects mining operations, but rather to consider some of the aspects of overland transportation and its influence in bringing about the development of mining camps in Canada. I shall take the liberty of rapidly surveying conditions facing prospectors, mine developers and operators from the time a region is still in a pre-pioneering stage until such time as a mine starts shipping its concentrates.

Jan 1, 1956

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 E. A. Roux

As the first mine-to-metal zinc operation utilising atmospheric leaching, solvent extraction and electrowinning, Skorpion Zinc faces unique challenges and opportunities. One of these challenges is found in the solvent extraction circuit, in which di-ethylhexyl phosphoric acid (D2EHPA) is used as the organic extractant. Although D2EHPA is an excellent extractant for zinc, it suffers from the co-extraction of ferric iron, which is produced during leaching and by the corrosion of the grinding media. This situation is partially mitigated by iron precipitation in the neutralisation step prior to solvent extraction. Unfortunately, some ferric iron still reports to the solvent extraction process. This leads to a slow build up of iron in the organic phase. Chemical stripping is used to maintain the Fe concentration at an acceptable level. In this paper, the efficiency of the iron removal process is discussed.

Jan 1, 2006

By D. A. Trotter

"This paper traces the main advances in mine lighting from neolithic times to the 1960s. The earliest lights consisted of reeds or strips of wood soaked in grease. As man's knowledge increased, the oil lamp, the candle, kerosene, acetylene and finally electricity have allowed him to see where no natural light could penetrate. These advances in technology, however, did not come easily. Many false starts were made and great dedication was required by a few lighting pioneers to overcome the many technical difficulties that were encountered. The lighting of coal mines in particular caused unique problems, as there was the ever-present threat of methane explosions. Advances in mine lighting will continue, but these advances are only possible because men like Davy, Wolf, Marsuat and Edison paved the way.IntroductionMan's first efforts at mining consisted of merely picking rock off the surface of the earth. The sun was his only source of light. The early mines of the Neolithic age were simply vertical pits, 5 to 8 m deep. In order to follow an orebody, miners began to dig horizontally from the bottom of these pits, and as work progressed the need for additional light became apparent. With the discovery of the light-giving properties of fire, man was no longer dependent on natural light. Figure 1 gives an impression of the earliest artificial mine lighting used.Early Evidence of Mine LightingCarbonized residue from wood chips which had been inserted into rock cracks can be found in early Neolithic workings. The mines at Krzemionki Opatowski in Poland contain very narrow low tunnels that were lit in this fashion and were worked from 2300 to 1800 B. C. The wood had to burn downward to provide light and because wood burns poorly in this position, the chips were probably soaked in animal fat to make them burn more easily."

Jan 1, 1982

By M. R. Swaan, G. J. Stewart

"ABSTRACTThe application of failsafe techniques to ask the ""What if"" questions about any process has been well established in the chemical industry for many years. The unusual number of fatalities that occurred in Ontario during 1986-87, prompted Inco management to look at the Fail Safe techniques as a method of improving safety performance.INTRODUCTIONOne of the major areas at any time for potentially disastrous accidents is the shaft, where all men and materials must travel. In April 1987, Inco's Thompson Mine's first Fail Safe Team was established to look at its shaft operations. The initial group of eight people was made up of hourly equipment operators, mine foremen, engineering, maintenance and the superintendent. This group took the name of Shaft Risk Analysis Team or SRAT.The many tasks or jobs that are performed in a shaft prompted the team to divide the work under six major headings; slinging, moving men, skipping, dewatering, shaft inspections and moving materials. Each of these areas contained many different tasks which are interrelated. The only way to understand this interrelationship was to flow chart the steps that actually occur in getting any job done.The flow charting is done by the foreman and operators using existing standard manuals and their experience of what actually takes place. In many cases, it soon became apparent that they had been ""working around"" many problems created by their standards. Fine tuning of these flow charts takes place at the weekly meetings, where input from all involved leads to a better understanding of the actual job being analyzed and its potential hazards. Two major points need to be emphasized in getting good flow charting at a mine:I. It must never be blame oriented or you will never discover how the jobs are actually done and hence you won't know what to improve.2 . All team members must have equal voting rights in deciding how to put the charts together so that they have ownership of the finished product. It is far too easy to end up with amanagement view of the way it should be. Many different techniques or methods are being employed to improve the tasks and reduce the risks associated with any job once the basic flow chart is established. The ones found to be the most useful are highlighted."

Jan 1, 1989

By C. W. Drury

It is practically fifteen years since stellite was first introduced into industry, and since then the progress made in its manufacture has been so rapid and the number of successful applications so varied that it was considered a review of the more important phases would be of general interest. Stellite is a cobalt-chromium-tungsten alloy, containing approximately 2. 75 per cent carbon. The high percentage of carbon is necessary for the requisite hardness and resistance to wear at ordinary temperatures, whereas the tungsten is essential to impart hardness at a red heat. Chromium imparts hardness and strength, and cobalt renders the alloys more resistant to oxidation. The metals cobalt and chromium are completely soluble in all proportions, both in the liquid and solid state, the equilibrium diagram showing a minimum in the solubility curve at approximately 50 per cent cobalt and l,340°C. Cobalt and tungsten are completely soluble up to 40 per cent tungsten, which is beyond the limit of the; tungsten content of stellite alloys. In the presence of carbon, carbides are formed, which are essential in stellite possessing good cutting or wearing properties.

Jan 1, 1930

By J. W. Thomson, H. J. Lloyd, R. J. Taylor

"THE HOLLINGER MINE has been producing gold and by-product silver almost continuously for forty-eight years. The value of current production is $10,000,000 annually from one million tons of ore. Its management •has, particularly over the past decade, increasingly . concerned itself with the problem of profitable operation in a time of steadily rising costs and a fixed price of gold. At one period in the life of the mine, before World War II, production resulted in yearly profit margins that were stable and relatively thick. In winning gold from a series of inconsistent vertical ore lenses, operating management was much better protected than it is today against a general rise in cost or dip in grade of ore. The tissue-like thinness of present-day margins demand more careful handling. A sharp rise in costs, if protracted, could easily rip the tissue to shreds and close down the business. The counter-measure of raising grade and gutting the mine would bring on the end perhaps more rapidly, without having contributed much to the recovery of our national re-sources, nor to community welfare. The alternative is to keep costs under control."

Jan 1, 1960

By R. H. Waddington

Historical The limitations of reverberatory furnace operation have prompted many investigators to consider electric furnaces for melting electrolytically refined cathode copper. In the majority of cases where experimental work was performed, the furnace used was of the granular resistor, induction, or indirect-arc rocking type, and attempts to adapt the three-phase direct-arc furnace to copper melting appear to have been relatively few. In 1935, the International Nickel Company of Canada, Limited, carried to an advanced stage its experimental investigation of continuous melting of copper in the three-phase direct-arc furnace, and demonstrated that this process was technologically and economically practicable. Trial operations were conducted at the Huntington, W.Va. works of the Company, and were followed by the installation at Copper Cliff, Ontario, in 1936, of a full-scale unit for commercial operation. Two years later, a second unit was installed -which raised the electric melting capacity to a point permitting complete replacement of the coal-fired reverberatory furnace operation in the production of refined copper castings.

Jan 1, 1946

Mineral engineering is defined as those engineering activities that relate to the discovery, development and utilization of mineral resources. Using petroleum engineering as an example, it is shown that the breadth of the field to be studied is a major educational problem. Breadth of field is aggravated by the rapidity with which technological demands may change. At present, special short courses serve to update engineering education. Recent experience suggests an increased rate of change for the future. The fact that engineers have typically human needs and goals, and the fact that engineers respond to these in our free society, introduces a third class of problems. One approach to the solution of these problems is the unified engineering curriculum based on a core of subject mat-ter common to all engineering. Experience suggests that the unified curriculum is an effective method to minimize the importance of the first two problem areas presented, and shows a degree of success in handling some problems within the third area. Perhaps, for the good of all segments of society, it is best to have both career-oriented and unified curricula represented by educational institutions of high quality.

Jan 1, 1963

By Mike Rylatt

"The BHP Diamonds Inc. and Blackwater Group (Dia Met Minerals Ltd., Charles Fipke and Stewart Blusson) joint venture began production at Canada=s first diamond mine during the last quarter of 1998.Construction of the processing plant began in mid 1997. During the 1998 winter season, the heavy process plant equipment was delivered to the Ekati site, 300 km NE of Yellowknife, by the ice road. Towards mid 1998 the construction activities were complete and commissioning began. The mine officially opened in October 1998.Initial production of 9000 tpd kimberlite will be from the Panda pipe grading 1.09 ct/t at an average value of US$13O/ct.Processing starts with a gyratory crusher reducing the ROM kimberlite to 90% passing 15Omm before further reduction to minus 75mm in a WaterFlush crusher. The crusher product discharges into a 4m diameter x 7m long primary scrubber. After screening, the minus 75 +1 mm kimberlite is conveyed to a 250 ft feed bin ahead of the 1.7 m diameter x 1.1 m wide high pressure grinding roll. The HPGR produces 50% minus lmm in a single pass, the compacted flake product is dis-agglomerated in a secondary scrubber. The scrubber product is screened into a minus 25 +lmm heavy medium separation plant feed and conveyed to a 375t HMS feed bin ahead of two 150 HMS modules. Milled 270D ferrosilicon at a slurry density of 2.6 g/cc and HMS feed are pumped to three 420mm diameter cyclones. Heavy mineral concentrates, approximately 1 % of the plant headfeed, are pneumatically transported to the Recovery plant for final diamond recovery using wet high intensity magnetic separators and high intensity (attrition) milling prior to three stages of x-ray recovery. At full production, Ekati will produce approximately 2 kg/day of diamonds.This paper details the later commissioning phase and the first three months Oof operational activities during the build up to full production at the Ekati processing plant."

Jan 1, 1999

By G. S. Farnham

Abstract This paper lists the interests of the Physical Metallurgy and Chemical Research laboratories of the Metallgesellschaft, which were visited by the authors, members of a group of Canadian investigators sent to Germany by the Department of Reconstruction in 1945. The Physical Metallurgy Research Laboratory The following information was obtained from Professor E. Schmid, Chief of the laboratories. It is understood that Dr. Schmid is a former Nazi and was to be removed from his post in November (1945). Aluminium Research The laboratories investigated the corrosion resistance of the high-strength aluminium-magnesium-zinc alloys. The same test procedure as used by V.L.W. was followed and Dr. Schmid co-operated closely with Dr. Brenner on this project. Intercrystalline corrosion was combatted by additions of chromium, titanium, or vanadium, and the work in this field parallels that of Dr. Brenner of V.L.W. * Dr. Schmid reports that Bollenrath and Siebert believe that corrosion difficulties with these alloys can be overcome to some extent by heat treatment. He himself was of opinion that the correct answer lay not only in correct alloying but also in correct heat treatment. The heat treatment involved either interrupted quenching or a change in quenching rate from a solution temperature of 500°C. The procedure is either a slower cooling from solution temperature or an interrupted cooling with a holding period at l50°C. Work had been done on piston alloys, the 11-13% Si, 1% Ni, 1% Cu, and 1% Mg being the favoured material. This is called Lo-Ex and is similar to Mahle 124 or KS1275.

Jan 1, 1946

By B. R. Schneiders

"Atikokan is 200 km west of Thunder Bay and earned its mining fame from the discovery of the Steep Rock Iron Range in the late 1930s. Gold, however, was discovered in the Atikokan and Mine Centre areas in the late 1800s and eventually led to one of Ontario's first gold camps, and a total production of approximately 52,000 oz of gold and 174,000 oz of silver from 218,000 tons milled.The general geology of the area consists of Early Precambrian rocks of the Wabigoon and Quetico subprovinces, separated by the east-trending Quetico Fault. The Wabigoon Subprovince, to the north, consists of metavolcanics, minor metasediments and granitic batholiths. The Quetico Subprovince consists of metasediments and granitoids. Small ultramafic plutons occur throughout the metasediments.Within a 50-km radius of Atikokan, more than 50 gold occurrences, prospects and past producers have been discovered since the 18oos. The Atikokan Gold Study performed by the Ontario Geological Sur vey (Wilkinson, 1980, 1982) defined three types of gold mineralization in which gold is concentrated in quartz and quartz-carbonate veins:I) Metavolcanic-Hosted, Stratabound Type-associated with altered felsic fragmental units and chemical sedimentary rocks; possible gold mineralization source rocks. The mineralization is due to metamorphogenic (epigenetic) enrichment. Associated with dynamic metamorphism events and/or felsic intrusive events.2) Marmion Lake Batholith Type-occurs within the gneissic core of the batholith associated with north east-trending lineaments, representing faults or shear zones. Mineralized veins are related to several periods of deformation and shearing, suggesting that metamorphogenic veins were produced during dynamic metamorphism.3) Contact Zone Type -occurs in the contact zone rocks between gneissic batholiths and meta volcanic belts. Hydrothermal solutions produced during several deformational periods acted to leach and concentrate gold mineralization. Localized, discontinuous shear zones host the epigenetic (metamorphogenic) veins.Twenty-one properties in the area were mapped and sampled, and researched petrographically and geochemically. Geological data from the Atikokan Economic Geologist Program of the Ontario Geological Survey are used in discussing the types of mineralization, genetic models, and exploration targets and techiques."

Jan 1, 1983

By L. A. Kaufman

"AbstractThe Bureau of Mines, Ottawa, in conjunction with Eldorado Mining and Refining (1944), Limited, has developed an automatic concentrator for uranium ores.A brief review of radioactivity is given which shows the present limitations for obtaining •good results by electronic concentration. The ores after being mined, or at any other stage of a concentrating process, can be analysed for the uranium dissemination and from these results the possibility of an economical concentration can be estimated.The electronic and mechanical parts of the equipment are described. Difficulties in the operation's, and means by which they have •been and are •being overcome, are discussed. The capacity of the units, the results obtained, the man-power required, and other pertinent data are presented. Simple control analysis on the percent U3O8 has been developed.Research is continuing along lines to develop a more completely automatic unit using a scintillation detector, and applying a few new ideas and some devices that have been developed in colour sorting.IntroductionIt is well known how important the Geiger counter is in the field of exploration for uranium. It was in late 1946 that Dr. C. Lapointe, of the Bureau of Mines, Ottawa, first started work on an automatic picking unit to concentrate uranium ores. He used the principle that if a number of pieces of unknown ore, some of which contained uranium, were individually brought up close to a Geiger-Müller tube, then the pieces containing uranium could •be easily picked out due to their activity. Since then a good deal of work has been done by the Bureau of Mines in conjunction with Eldorado Mining and • Refining (1944), Limited, to develop an electronic concentrator."

Jan 1, 1950

By G. A. Gross

"The Soviet Union has enormous reserves of iron ore in many different kinds of deposits that are widely distributed in this vast land area. The present iron ore industry is based mainly on deposits in Precambrian cherty iron-formation at Krivoy Rog, Kursk and Murmansk. Extensive reserves of both naturally enriched hematite ore and magnetite iron-formation in these areas alone could sup-ply all the domestic ore required for several hundred years.Many contact metasomatic magnetite deposits discovery in recent years in the eastern Ural Mountain belt and east of the Kusnetsov basin in Siberia are being developed, with ore reserves measured in billions of tons. Oolitic limonite-chamosite-siderite ores of Cretaceous and younger age at Kerch on the Black Sea and around the east and southern perimeter of the West Siberian basin constitute some of the largest concentrations of iron in the world. These sedimentary ores are low grade, of poor quality and difficult to beneficiate. Banded jasper magnetite and hematite iron-formation in volcanic rocks of Devonian age in Kazakhstan and along the Mongolian border are of special geoloica1 significance.Iron deposits in the Krivoy Rog and Kursk areas were examined and a large number of geologists discussed their work on deposits in many other parts of the Soviet Union during the writer's seven-week study tour of mines and research institutes in Moscow, Leningrad, Novosibirsk in Siberia and Kiev in the Ukraine. The descriptive geology of iron deposits of useable ore and of marginal material has been well documented in the course of systematic work and a large number of scientists are studying fundamental problems on the origin and treatment of iron ore."

Jan 1, 1967