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Jan 1, 1994

By P Moynagh

"A plan is critical but on its own it is a bit one dimensional, the three dimensions critical to success over the long-term, through changing economic, geological and management conditions are:the quality of your planning an ability to see and adapt to change a disciplined continual improvement/learning system.This paper will examine how a number of major Australian resource companies have used a commitment management system to connect the ‘theory’ embodied in plans (whether mine, project, maintenance or training plans) and immediate reality ‘practice’ as experienced by supervisors and their crews in the workplace. This paper draws on management theory embodied in management operating systems (MOS), Lean, Theory of Constraints and Six Sigma approaches to continuous improvement and a good dose of real world experience. It is embodied in the statement: ‘successful organisations are driven by a series of commitments that people make to each other and deliver on’.Citation:Moynagh, P, 2016. Everyone Has a Plan Until They Get Punched in the Mouth – Creating Trust, Commitment and Results in Tough Times, in Proceedings Ninth AusIMM Open Pit Operators' Conference 2016, pp 293–299 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 15, 2016

By G. Kleyn

"Sub-standard practices and their adverse impact on safety performance remain a challenge in the South African gold mining industry. The purpose of this study was to investigate the root causes of sub-standard practices and the effect on safety performance in South African gold mines. The focus of the study was on the underground production operations at a gold mine in the Free State. The study consisted of three parts: a personal investigation into the causes of sub-standard practices at the mine, a comparison with the results of a cultural study performed at the West Wits mines, and a behavioural survey.The studies described in this article yielded similar results in terms of the key drivers behind sub-standard practices. It was found that substandard practices had a number of causes, and the origin lies within the habits, attitude, and behaviour of employees. Current methods of addressing sub-standard practices and improving safety performance were found to discourage employees from performing work safely and according to procedure. It was concluded that the lack of critical behavioural habits for the given work environment and job title could possibly be the primary reason for the occurrence of sub-standard practices. IntroductionSince the implementation of the Mine Health and Safety Act, 1996 (Act 29 of 1996) and the Mine Health and Safety Regulations, the South African mining industry has been striving to improve health and safety performance and has placed great emphasis on adherence to mine standards.The Act requires employers in the mining industry to report accidents, incidents, and dangerous situations to the Regional Principal Inspector of Mines in their area. The data provided by employers is captured and analysed by the South African Mines Reportable Accident Statistical System (SAMRASS) and made available for public viewing (Department of Mineral Resources, 2011).A review of the national mine-related accident statistics shows clearly that the South African gold mining industry has improved its safety performance markedly over the past decade, but is still facing major challenges (Figure 1). These include meeting the Mine Health and Safety Milestones (Department of Mineral Resources, 2011)."

Jan 1, 2016

By W. T. Wertman

A research program to aid development of better and more efficient methods for producing petroleum and increasing its ultimate recovery from underground formations is an integral part of the work of the Bureau of Mines on conservation of the Nation's natural resources. Economic, efficient production of recoverable oil and gas from a reservoir depends to a great extent upon the best and most accurate information that can be obtained from a study of the reservoir rock and its fluid contents. Information on oil and water saturation is pertinent and essential in wildcat, extension, and pool wells for good reservoir operations and prediction of performance. This report presents results of an investigation by the Bureau of Mines of core recovery and degree of drilling-fluid contamination occurring during cable-tool coring operations using oil-base mud. Representative core samples were obtained from 6 major oil-producing sands in 8 fields of West Virginia, Pennsylvania, and New York. Field-mixed, oil-base drilling mud was used for the first coring test, and lightweight, premixed oil-base mud, with an organic chloride tracer added, was used in coring eight other wells. Tracer analyses were made to determine contamination of core by drilling-fluid filtrate. Core analyses, including oil and water content and minimum interstitial water-saturation tests, were made on selected core samples to compare and evaluate water saturations determined by the two methods.

Jan 1, 1958

By James S. Grichar

Interest in mergers in the nonfuel mineral industry developed when 5 were listed among the 50 highest valued mergers in the United States in 1981. This report presents a Bureau of Mines study of trends in merger activity from 1960 to 1979 and explores motives for mergers in the nonfuel mining and mineral industry. The objective was to determine precedent for or a trend toward the 1981 acceleration in merger activity and to examine certain financial motives for non fuel mineral mergers. Data indicate that the relative value of non fuel mineral mergers has grown since 1972 although the number of mergers has remained proportionate to historical trends for all mergers. Since 1974, the assets acquired in "large," nonfuel mineral firm mergers, those of $10 million or more, have comprised at least 93 pct of assets acquired. More nonfuel mineral firm mergers involved mineral companies as the acquiring firm than vice versa but mining and minerals firms acquired were of higher value than nonmining firms. A major motivation for mergers involving large mineral firms was the acquisition of assets at less than replacement costs. Univariate statistical testing, a methodology chosen for its applicability to the data, confirms this hypothesis while rejecting other financial motives. The remainder of the work is devoted to a discussion of suggested areas for future study.

Jan 1, 1984

By R. L. Loofbourow

Reasons for reexamining underground mining include: 1. The assurance that more deep deposits of useful minerals will be found. 2. The existence of deeply covered deposits of industrial minerals near large markets where quarries are becoming depleted or are lacking. 3. Surface property values, zoning and other limitations on open pit mining. 4. Expectation that underground space will be increasingly used for transportation, power plants, storage and similar purposes. 5. The improvements which have been made in underground mining. During the last three or four decades many changes and improvements have been made underground. All underground construction and mining has benefitted to some extent but the effect on the productivity of labor employed with some methods- has changed little and the use of these methods has declined. Productivity of labor in other methods has increased substantially. The relative usefulness of mining methods has changed and a vital industry, bituminous coal, has been returned to health. In this paper, consideration is limited to nine methods used with high productivity during the period under review. These methods are not necessarily better than others but they may be considered the prime methods in the sense that, in our economy, many, low grade ores, coal and the principal industrial minerals could hardly be produced by less productive means.2 Although most of the examples cited are from mining as such., the first four methods discussed can be used for the construction of stable excavations of various' shapes in sound rock.

Jan 1, 1967

By J. Armanet

THREE MINING colleges are maintained in France; the École Nationale Supérieure des Mines, of Paris; École Nationale Supérieure des Mines, of Saint Etienne; and the École Supérieure de la Metallurgie et des Mines at Nancy. Besides graduates of these schools, a few graduates of the École Centrale des Arts et MIanufactures and of the École Polytechnique are employed as ]nine managers or engineers; however, most of the latter have taken a graduate course at one of the mining schools.

Jan 1, 1939

By Guillermo Mariaca, Jorge Muñoz Reyer

As far as technology is concerned there has been no development in Bolivia during the year 1936, because the country, just emerging from the war with Paraguay, is only beginning to rebuild its economic foundations. Great steps, however, are being taken in order to secure a rapid and sound development of its oil resources, as follows: 1. The new Petroleum Law, which contemplates the problem of proration and conservation of natural resources, prohibiting the wasteful use of gas, and regulating the number of wells, their spacing and the permissible output per well, for each particular pool according to the conditions prevailing therein. 2. The creation of an official entity with the object of developing and exploiting a large petroliferous area. This entity has been called Yacimientos Petroliferos Fiscales Bolivianos (Y.P.F.B.), and the region assigned to it is all the sub-andean zone, which is approximately one hundred miles wide and borders the eastern part of the Oriental Andean range, from Argentine to Peru. It is said that drilling will be started immediately in various localities. At the present time a wide geological survey of part of the area is being made in order to find out which regions offer the best possibilities of commercial development. Y.P.F.B. has been authorized by the Government to draw up contracts with private companies for the exploitation of limited zones. Production The only company that has been producing in the country in 1936 is the Standard Oil Company of Bolivia, and only from two of its fields: Camiri and Sanandita. New wells were not drilled. During the first nine months of the year 12,762,958 liters (80,275 bbl.) was produced, 34,985 bbl. from the Camiri field and 45,290 bbl. from the Sanandita field. Reports for October, November and December are not yet available. The total for the year 1935 was 25,978,737 liters (163,388 bbl.).

Jan 1, 1937

In the interest of safety in mining, the Bureau of Mines recommends: 1. That cages or skips used for hoisting or lowering men in vertical and steeply inclined shafts shall be provided with safety catches designed to prevent falling of the cage or skip if the hoisting rope or other connections break; and 2. That cars used. for hoisting or lowering men with ropes in slopes shall be provided with arresting devices, other than ordinary brakes, that come into action if the hoisting rope or other connections break. In presenting this decision, it is recognized that the principal requirements for safety in hoisting operations are the use of hoisting ropes of ample size and strength to provide a factor of safety recognized as adequate by the best en engineering practice; their proper care, protection against undue wear and corrosion, and frequent inspection; and immediate removal of ropes from service when inspection or tests cast doubt upon their further safe serviceability.

Jan 1, 1938

By J. Hendry, K. Brady, J. Yorzyk

Drawing from the experience of nickel, copper, aluminum and mineral borates, this paper illustrates the business value that the mining, minerals and metals industry as a whole can gain from applying life cycle assessment (LCA) to products and operations. Through the use of case studies, the paper explores how companies and industry associations have used LCA to their advantage: from evaluating capital investments, meeting customer information needs, supporting new product applications, and developing credible marketing information on the environmental performance of their products. It also explores the dynamics of LCA adoption and integration within companies, and provides recommendations to further strengthen institutionalization of LCA.

Jan 1, 2010

CHAIRMAN LITTLEJOHN: Some of the members will want to question Mr. Farnham on some of the things he has brought tip, so we will throw the meeting open for discussion. I am quite sure Mr. Farnham will be willing and glad to answer any questions that may be put to him. MR. HOLMAN: I would like to ask Mr. Farnham a question in regard to the Duckbill: How wide a face will it operate without moving the bill? MR. FARNHAM: The Duckbill is a device that was developed in the Union Pacific Mine at Rock Springs, within the last few months, and it is shaped something like, a dustpan, with discharge throat in the rear. They made one seven feet wide and found it was too wide, and the one they are using now is between three and four feet in width. The front section of the conveyor, which attaches to the duckbill, meshes into it to form a sliding section, and the front end of the Duckbill is pushed by the upper segments. I saw one used in a room twenty-four feet wide, and they drew it back after they cleaned out one room and pushed it forward again. MR. HOLMAN: You have no arrangement other than ratchet work? MR. FARNHAM: The ratchet is for forward working and back; the sections are made 12 or 13 feet long, and the stroke of the conveyor automatically works the ratchet; they can ratchet it back; it is a hand device. MR. HOLMAN: They just swing the end of the conveyor across the face to pick up the loose coal? MR. FARNHAM: Yes; they are also planning to use it endwise along the panel face, that and the room work both are quite new in their application, and I do not think the Union Pacific is giving out any results as yet, because the system has not been in use long. MR. HOLMAN: We are planning on putting one in very shortly. MR. HALL: I understand they can swing it over 30 degrees one way or the other, and it goes the same way easily because of the continual jar of the back and forward motion on a 60-degree swing. SECRETARY SHUBART: Take on a comparatively long conveyor, you can get quite a sweep, a large part of the circle. The Duckbill could command quite a large range. For a 12-foot entry, take a four-foot wide advance through the middle of the shot coal, with a 12-foot advance, ratchet back, swing the Duckbill to the rib and repeat; but I do not think they could get as much as 60 degree. on the end of the Duckbill without curving further back. The conveyor is light and not normally set on any permanent foundation. I saw one of Mr. McCarty's first machines, a rather rudimentary one, clean tip a 12-trot entry, 21 tons of coal, in 16 minutes, three men at the face and one at the loading end. MR. FARNHAM: The average time to clean the entries is about an hour-to clean up good-it wouldn't take but a short time; that is why they get this record of several cuts a shift. CHAIRMAN LITTLEJOHN: Are there any other questions you would like to ask Mr. Farnham? MR. HOLMAN: We were discussing this entry driving in regard to the entry loader; an entry loader in advance work, just what you have to do to place the jackbars with the sheave-blocks? Do you dig along the ribs after the coal is shot or do you have any other scheme that could be worked out to a good advantage? MR. FARNHAM: This record is a report I have just received from our Chicago office, without the full details, which I have written for. I am sorry I cannot give you the details. This was an Indiana or Pennsylvania mine, near Pocahontas, not the one where they had an accident. I assume they set the jacks ahead and swung and dumped the coal partly out with a scoop and partly by hand, but the application for that for entry driving is entirely new. The reports stated that they anticipated using that as a standard method of entry driving in the future. I will be glad to see that you get a copy of it when I get the report completed. MR. MONAY: Mr. Shubart, did you say they loaded 12 tons in 16 minutes? SECRETARY SHUBART: Twenty-one tons. MR. MONAY: How long did it take to change the machinery out of there

Jan 1, 1926

By D. H. Davidson

The basic principal in the ISL process involves the recovery of metal values by moving fluids through rock instead of moving rock. The process combines surface and sub-surface operations, with the economic performance controlled by four major factors; rates of fluid injection and production from wells; the rate of mineral solubilization; the volume of rock swept by the fluid; and the volume of solution processed through the system. This paper discusses various technical and economic parameters affecting these four factors and how they impact project costs.

Jan 1, 1985

By D. E. FOCG, A. E. Wells

When the United States entered the World War governmental agencies found little definite knowledge available as to the exact capacity of each sulphuric acid plant in the United States to manufacture acid under the stress of a great emergency. It is true that on account of the demand for acid for the manufacture of munitions for the Allies, prior to the entrance of this country into the war, most of the acid plants near industrial centers in the Eastern and Northern States were running at or nearly their maximum capacity, but, . for various reasons, many plants in these States and plants in other districts were not. For a number of years statistics as to the production of acid by the plants of the country were compiled by the United States Geological Survey, but obviously such figures did not give information as to the maximum capacities that might be available for meeting the he.a vy war ·requirements, or as to the steps that would have to be taken to bt-ing these capacities into use. During the summer and early fall of 1917 various attempts were made to obtain the desired information, but no satisfactory or complete data were obtained. Late in 1917, under the authority granted to the Bureau of Mines by the explosives act, the Director of the Bureau of Mines directed A. E. Wells, metallurgist of the bureau, to uiake a complete survey of the situation. Mr. Wells personally conferred with officials of the acid companies and visited most of the acid plants in the North that are east of the Mississippi River. The information obtained through this personal survey, together with that obtained through the ready cooperation of the subcommittee on ncids, and the subcommittee on fertilizers of the Committee on Chemicals of the Council of National Defense, enabled the preparation of a report containing the desired data concerning the sulphuric acid industry. This report was made immediately available to the War Industries Board and to those offices in the War and Navy Depart- ments that were most directly concerned in planning the explosives program and in obtaining the necessary supplies to produce the explosives. Beginning with this survey and report, the sulphuric acid section of the war minerals investigations of the Bureau of Mines took an active part in all matters pertaining to the sulphuric acid industry during the remainder of the war. Mr. Wells, the chief of the section, was appointed an associate chief of the sulphur, pyrite, and sulphuric acid sections of the War Industries Board. .Also, by this direct contact with the War Industries Board, the data obtained by Messrs. R. R. Hornor, H. A. Buehler, a.nd 0. Lindstrom, who were in charge, for the bureau, of the investigations concerning the supplies of pyrite and sulphur, were constantly made available to all interested Government agencies. D. E. Fogg, of New York City, was appointed chemical engineer to the sulphuric acid section to make special investigations relating to the acid industry, especially the possible utilization, in an emergency, of those sources of raw material.not then being used. Mr. E. E. Corbett, of Brooklyn, N. Y., was appointed chemical engineer to make investigations concerned primarily ,vith the conservation of acid. Direct and intimate contact with the industry was had through the close cooperation with the committee on acids of the Chemical Alliance, this committee during the greater part of 1918 occupying rooms with the acid section of the bureau. With the ending of the war and the close o:f the active work of the acid section of the bureau, the suggestion was made by many interested parties that a bulletin be prepared giving some qf the fun. damental and most important facts regarding the sulphuric acid industry, including a discussion of the technical :features of the manufacture of acid. During the war the bureau received -a vast number of inquiries in regard to various phases of the industry, a.nd this fact also made such a bulletin seem desirable. Therefore, the present bulletin was prepared to cover the main facts in regard to the industry in this country, including a discussion of the supplies of sulphur-bearing raw materials, the situation of the acid plants, the principal points in regard to manufacturing processes, and the uses of the acid. No attempt has been ma.de to discuss at length the manufacturing processes, as details differ more or less at the different plants and in general are carefully guarded by the acid ·companies. A great deal of the data given in this bulletin may be found in various pub]ications, but this is the first publication in which such data have been assembled and made readily available. Most of the data were obtained directly from observation and from cooperating acid companies or from individuals who had been or are now engaged in acid manufacturing and were liberal and generous in making their information available for publication. Care has been exercised to publish no data that were obtained as confidential by the bureau's representatives. The average acid manufacturer may be already more or less acquainted with most of the information presented in this bulletin, yet it is believed that the bulletin will be of value to those who wish to obtain a. general review of the present condition, both the economic and technical, of the sulphuric acid industry in the United States.

Jan 1, 1920

By C. B. Catanach

The development and in place leaching of a chalcocite ore body at Mountain City, Nevada is described. Block caving was used to induce permeability while ore removed during development was leached in heaps on the surface. Copper was recovered by precipitation on iron. Excess ground water which seeped into the mine was pumped into a deep disposal well. A parallel system was used to purify water by lime neutralization. Copper extraction was at an annualized rate of 11% during the first six full months of underground leaching and totalled approximately 30% during six months of heap leaching. Leach solution flow and distribution had a major effect on extraction rate. Enrichment of leach solutions with ferric sulfate did not produce conclusive results until analyzed with the aid of a leaching model.

Jan 1, 1976

By Andreas Brandner

"At the beginning of 2007 the Austrian contractor PORR was awarded with remediation works for a 48-km long part of the railway line from Campina to Predeal – part of the Trans European main Corridors TEN-T priority line 22 Bucurest – Brasov, connecting the southeast European countries with the heart of Europe.Due to partly new realignment and change of regular sections as well as protection against rockfall and slope slide a huge bunch of slope stabilization works became necessary, which were awarded to the contractor PORR and their designer IB-Brandner.Following the studies of the tender documents for the planned protection measures responsible managers of PORR decided to propose an alternative protection design by IB- Brandner. Changing the original design a more flexible and environmentally compatible solution consisting of high performance net, soil nailing and rockfall protection systems (fences) was elaborated and adapted to local needs. During design process, several critical areas were identified and additionally taken into account.In the paper examples of the design and erection process show how difficulties in implementation starting with the presentation of the idea continuing to the realization on site were managed and a technically more sophisticated and commercially competitive solution could be delivered to the customer Romanian Railway – case study.The European Commission awarded – following an election process in which all citizens of the EU could join - the remediation project Railway line Campina – Predeal in Romania as the environmentally best EU co-financed infrastructure project. GENERAL PROJECT EVALUATIONDue to original design slope stabilization should be done by concrete slabs fixed with prestressed anchors and shotcrete cover.The area to be secured was limited to a 12-meter strip left and right from the railway track without reference to nature and local needs. Discussions with the client and his designer and rising awareness for the hazards to address took several months. Site visits in Austria to provide insight in the problems of dealing with natural hazards helped to convince the client of the needs and our alternative design."

Jan 1, 2017

By Norman Weiss, H. W. Kaanta

CUSTOM ores reach across the New Mexican mesa to American Smelting & Refining Co.'s new lead-zinc mill at Deming. The influx of ores justified increasing mill capacity from 12,000 tons per month to 20,000 tons per month with the installation of a second milling section. Deming mill has met a complex material handling problem with the successful instrumentation of modern machinery and knowledge. A tight, compact plant does a big job with the aid of the latest ore moving equipment. Location and Layout The mill is located three miles northwest of Deming in the tumbleweed covered valley of the Mimbres River, 30 miles north of the Mexican border. Deming has a population of 4000 and is about halfway between Lordsburg and Las Cruces and 54 miles southeast of Silver City. The AT&SF and the SP railroads and U.S. Highways 70, 80, and 260, cut across the mesa to the town. Asarco mill station is east of the AT&SF single track, and north of Deming. The nearly level terrain is covered with fine sand supporting only yucca and tumbleweed. Compacted gravel at depth affords excellent foundation bearing. The climate is semi-arid, but the district is underlain by water-bearing strata. Tailing disposal space is plentiful. The Deming site appeared favorable because of easy rail and highway access, central location in a mining district, excellent climate, plentiful water supply, space for all present and future requirements, and proximity to a town. The milling plant is a 250-ft square. The rail spur forms the west side; sampling plant, fine-ore conveyor and bins are on the east; track hopper, primary conveyor, and crushing plant lie on the south; and the mill building completes the north side of the square. Construction The mill site was chosen and the land purchased in 1,946 and 1947. Design began in 1948, and Stearns-Roger Mfg. Co. of Denver started construction in June 1949 completing work in April 1950. Construction is steel and concrete throughout, with main concrete floors supported on cellular steel beams. The building is covered by galvanized corrugated iron, attached to the frame by welded Nelson studs, and made dust tight at the joints with roofing paper and asphalt sealing compound. Crushing and Sampling Custom ores, delivered to the mill by railroad cars or trucks, are weighed on arrival. A Robbins car shaker dumps the ore into a 100-ton capacity steel hopper. Adjacent is a 40-ton truck hopper. Three 36-in. Pioneer apron feeders supply ore from the receiving hoppers to a 36-in. conveyor which runs to the crushing plant. A tramp-iron detector protects the primary crusher except when handling magnetite containing ores. A 2 ½ -in. spaced grizzly precedes the primary Traylor 24x36 in. jaw crusher set at 4 in. A Symons 4-ft cone crusher in closed circuit with 48x78 in. Robbins Gyrex screen completes crushing to 5/8 in. The discharges of both crushers drop upon a common conveyor, which, after gaining sufficient elevation, transfers ore to a return conveyor. This return conveyor passes under a suspended magnet and over a magnetic head pulley to the Gyrex screen. Screen undersize is conveyed by a 20-in. belt to the sampling plant. Crushing rate varies from 60 to 90 tons per hour. Ores containing magnetite and pyrrhotite nullify the magnetic detector and overload the magnets

Jan 1, 1952

By Harvey N. Davis

MUCH has been written and said during the last twenty years about the place of the engineer in modern life, about the fundamental role that he plays both in developing and in maintaining the material foundations of modern civilization, about the advantages, and also the dangers, of the machine age that he has inaugurated, about the Frankenstein problems that he has unconcernedly foisted upon a generation utterly unable to cope with them, and about the obligation that rests upon him to stop inventing machines and turn his almost legendary energy and skill to inventing institutions that will constitute a solution of the problems he has raised, and contrariwise about his utter inability to offer wise or useful counsel in fields outside the narrow boundaries of his technical training.

Jan 1, 1938

The presence of gold or tin in a particular place in payable quantities may be suspected from geological and prospE;cting reports. It behoves the engineer by judiciously spaced boreholes or pits to establish whether the place is exploitable with profit, and it is the purpose of this paper to set out the ways in which this is done. The various types of deposit to be considered occur in Malaya, Thafland and Borneo, in which countries the writer spent four years in estimating alluvials.The methods described were used in actual practice both by the writer and previous engineers for the same company. The subsequent exploitation of the alluvials evaluated by the methods given below shows that the recovery was as good as, and sometimes higher than, expected. No claims are made to the originality of the methods, but it is 'felt that they may be new to some engineers and< interesting to others contemplating alluvial testing.

Jan 1, 1942

Major changes occurred in the management of loss prevention and risk management at operations in North and South America due to increased insurance premiums following the Olympic Dam fire in Australia in 2001. There are many different scenarios on how fires can develop and the estimated maximum losses (EML) those fires can incur. The EML is utilised by insurance companies to determine the cost of insurance premiums. The cost of insurance can be controlled at existing and newly designed solvent extraction (SX) plants by using risk reduction methods and design criteria to limit the fire exposure. A review of data collected during several loss prevention risk assessments can show how a budget can be protected from dramatically increased premiums and see which design of SX plant and fire protection standards best apply to your operations. The paper will investigate the pitfalls of existing materials of construction, capacity, geography, management practices, fire risk minimisation, and fire suppression systems. Intelligent engineering and managerial improvements implemented by the operations in the Americas in the past two years have further minimised the fire potential and benefited companies in insurance renewal negotiations.

Jan 1, 2003

By Charles "Chick" Rodgers

"The Key Lake uranium mine is the largest single uranium producer in the world. It is owned 2/3 by Cameco Corporation and 1/3 by Uranerz Exploration and Mining. Cameco is the operator. Current production is fourteen million pounds per year of uranium oxide (U308).The mine's location is 570 kilometres north of Saskatoon on the southern edge of the Athabasca Basin approximately at latitude 57° 11 'north and longitude 105° 34' west. Access to the mine is by an all-weather road and a private airstrip.The mill was commissioned in 1983. A molybdenum plant was constructed in 1989 in response to increasing molybdenum content in the yellowcake or final product. Early test work had showed that the first ore body to be mined, the Gaertner deposit, would present few problems with regards to molybdenum in the product. However, the test work also showed that the higher molybdenum content of the Deilmann ore, the second Key Lake orebody to be mined, would result in increased molybdenum concentrations. Without the molybdenum plant, penalties would become excessive and some product might not accepted by the refineries.This paper will describe the current Key Lake mill process with emphasis on the molybdenum solvent extraction process. It will cover the chemistry of the process, process development in the mid 1980's, and current operating practices.The Key Lake milling process consists of five individual plants, crushing and grinding, leaching -counter current decantation (CCD), solvent extraction, yellowcake/crystallization and bulk neutralization (Figure 1. Simplified Mill Flowsheet). A detailed mill flowsheet can be found in the appendix."

Jan 1, 1996