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By Julia R. Budden, Peter A. Spencer

Bacterial oxidation processes have often been repo1ted as releasing large amounts of energy so that a large scale operation would require cooling to maintain the required operating temperature for the bacterial culture. These reports are based on the chemical heat release which in some eases has been adjusted for the energy required to fonn the mass of bacterial cell matter per unit volume of solution. There are two flaws in this approach for calculating energy release in the fonn of heat. The first flaw is that it only considers the bacteria in solution. The second assumption is that the only bacterial reaction is the fonnation of cell material and others such as energy for respiration and locomotion are not considered.

Jan 1, 1992

By M. S. Hunter, Al Bishop

In 1994, Lone Tree Mine invited Hunter Hawk to participate in a problem-solving arena at their mine located in Valmy, Nevada. Lone Tree was experiencing consistency problems with autoclave valve component quality and delivery. Based upon a prior working relationship at Homestake Mining Company's McLauglin Mine, located in Lake County, California, both customer and vendor enjoyed a measure of rap­po1i and trust - the keys to problem solving communication. This paper is an overview of the problem solving process that has contributed to Lone Tree's excellent record of 95 per cent autoclave availability since 1995.

Jan 1, 1998

NEW YORK SECTION ALLEN H. ROGERS, Chairman, H. C. PARMELEE, vice-chairman, FOREST RUTHERFORD, Vice-chairman, W. S. DICKSON, Secretary, 71 BROADWAY, NEW YORK, N. Y. J. E. JOHNSON, JR. F. T. RUBIDGE, Treasurer, P. G. SPILSBURY A meeting of the New York Section was held at The Machinery Club on Friday evening, Oct. 4, 1918, The Chairman, Allen H. Rogers, presiding. The CHAIRMAN.-MOST of us, I suppose, have been affected more or less by The request of The Fuel Administration that we leave our automobiles standing in The garages on Sundays. We shall all be interested in hearing about The situation that has called forth This, request, and The Oil Administrator, Mr. Requa, has kindly come from Washington to Tell us about it. MARK L. REQUA.-I am very glad To Tell you about the oil problem during This war period. The United States is supplying by far The greater part of all The petroleum products consumed in Great Britain, France and Italy. In addition To This, we have had To supply a marked increase in our domestic consumption, not only of The refined products, but of fuel oil as well. The combination has put a strain on The oil industry, which it is very difficult To meet. The oil companies, being under contract, had no option as To who should get Their oil first, and They were delivering pro rata To everybody; manufacturers of furniture were getting oil with The same regularity as Those who were making aeroplanes or munitions, and The oil companies felt that something should be done. The first order with which I had. anything To do was The priority list for The delivery of fuel oil. That list contained 12 classifications, beginning with bunker fuel and railroads, and you will realize The complexity of The situation when you hear that munitions plants are in class 11. The priority list held during The winter, but transportation became so bad, because of The number of ships that were Taken for trans-Atlantic use, that some of The oil companies were not able To deliver more Than about 60 per cent. into class 5, and nothing beyond that point. To add To the Troubles, the Tank-car mileage fell off. The average for 1917 was about 36 miles per car per day. in January, 1918, it dropped To about 8 miles, and it must have been nearly zero in The early part. of February. Because of The extremely severe winter, furthermore, pipe lines were not delivering anywhere near Their normal capacity. A new priority list has recently been promulgated, introducing a few slight changes. Natural gas has been brought under its provisions, and it has been extended To include The Pacific Coast, which was not considered necessary last winter. The situation in The gas industry is not satisfactory; it is estimated that There will be a decrease of 10 To 20 per cent. in The quantity of natural gas available This winter, as compared with last winter.

Jan 11, 1918

By M. Tsunekawa, T. Takamori, T. Hirajima

In spherical agglomeration in water, the pattern of the growth behaviour of agglomerates is essentially determined by the surface chemical properties of the particles and the oil-water interface. When particles are suitably hydrophobic and oil-water interfacial tension is not too low under an adequate condition for agglomeration, large agglomerates are formed in the initial stage and micro- agglomerates do not appear. When particles are poorly wetted by oil and the interfacial tension is low, initially micro-agglomerates are formed and, after certain aging time, they grow to large agglomerates in a relatively short time without formation of intermediate size agglomerates. Under adequate conditions, the amount of oil and power input do not produce any remarkable effect on the pattern of growth.

Jan 1, 1980

By E. Wusaty

"Fording Coal is a wholly owned subsidiary of Canadian Pacific Limited. The company was founded in 1968 to mine metallurgical coalfor export at the Fording River operations in southeast British Columbia.Today, Fording Coal Limited also operates the Whitewood mine under contract to TransAlta Utilities and the Genesee mine under a joint venture arrangement with Edmonton Power. Both these operations are located just west of Edmonton and produce subbituminous low-sulphur coal which is used for power generation. Fording also owns and operates two industrial mineral mines in the United States and is mining overburden under a lo-year contract with Syncrude Canada at Fort McMurray.As of December 1992, Fording Coal Limited owns and operates the Greenhills mine which was closed due to bankruptcy. This papers deals with the innovations and changes which have been made and those which are currently being implemented to make this operation competitive in the world export coal market. IntroductionOn December 4, 1992, following a tendering process, Fording Coal was awarded 80% controlling interest in the Greenhills mine by Trustee Arthur Andersen Inc. Assets acquired included 100010 of the land and coal leases and 80% of the major joint venture assets including all structures. The remaining 20% is owned by Pohang Steel Canada Ltd., a wholly owned subsidiary of Pohang Iron Steel Co. of Korea. The Greenhills mine had been in continuous operation since 1983 and was finally closed due to bankruptcy of its majority owner on October 31, 1992.A permit to operate the Greenhills mine was issued by the British Columbia government on January 29, 1993, and Fording Coal Limited started mining operations in late February 1993.To return the Greenhills mine to profitability significant changes were required in workforce productivity, mining methods and equipment selection. These mine plan changes are designed to make the Greenhills operation competitive in world markets, provide longterm employment for the company's workforce and ensure that a secure supply of coal is available."

Jan 1, 1994

By Kirsi M. Riihilahti

The oxidation characteristics of solid copper matte particles under simulated Kennecott-Outokumpu Flash Converting conditions are presented. This project is concerned with the determination of the effects of operating variables on the reaction of the particles. Experiments were carried out in a large laboratory-scale flash furnace with 72 wt-% Cu matte by varying initial particle size, temperature, oxygen partial pressure, oxygen-to-matte mass ratio and residence time. Chemical analysis was used to study the oxidation extent and copper volatilization. Particle fragmentation was examined. Fractional conversion and sulfur removal slightly decreased with initial particle size, while a higher oxygen-to-matte mass ratio mainly resulted in higher fractional conversion and more efficient sulfur removal. The fractional conversion values represented the overall extent of oxidation more closely than degree of sulfur removal.

Jan 1, 1997

By John Chipman, Peter J. Koros

The distribution of copper between liquid silver and liquid iron, Fe-C, and Fe-C-Si alloys was studied at 1600°C. From the data and the activity of copper in silver obtained from the phase diagrams, the activity coefficients of copper in iron up to 3 atomic pct are log y, = 0.90 — 2.4 N, and y": = 8.0. The effect of carbon up to saturation is expressed as log y = 1.8 Ni. The effect of silicon up to 11 atomic pct is insignificant. SLOWLY rising copper content of steel being produced is focusing attention on the lack of information on the behavior of copper in liquid steel. Chou' measured the activity coefficient of copper in liquid iron through its distribution between liquid silver and iron. He obtained a value of 9.12 at infinite dilution. Chipman' calculated the activity coefficient of copper in liquid iron at 1600°C from the phase diagram and obtained a value of 12. Ameiln and Pfeiffer- investigated the possibility of removing copper from liquid steel through the use of lead, silver, and bismuth as solvents. They also calculated that the activity coefficient of copper in liquid iron would be increased five or sixfold by addition of 4 pct C. Langenberg and Lindsay' are investigating the effectiveness of lead and sodium sulfide in removing copper from liquid iron. The experimental method was similar to that used by Chou' and Chipman and Floridis." Silver, copper, and iron were melted together, the copper distributing itself between the two layers so that at equilibrium a,.,, (in Ag) - a,.,, (inFe) and N,.,, (in Ag) yc,, (inFe) (in Ag). [21 N,.,, (inFe) Thus, from the concentration of copper in each layer and the activity coefficient of copper in liquid silver, the activity coefficient of copper in liquid iron can be calculated. The effect of an alloying element such as carbon on the activity coefficient of copper can also be determined from its effect on the distribution, provided the new element is essentially insoluble in silver. The one serious limitation of this method is the increasing mutual solubility of silver and iron in the presence of a third component. The mutual solubilities of pure iron and silver are negligible, but increase with increasing copper concentration beyond the range investigated. Ag-Cu System—The activity coefficient of copper in silver at 1600°C had to be estimated, since direct experimental data are not available. Kawakami" measured the heat of mixing of Ag-Cu alloys at 1200°C by a calorimetric technique. Scheil' calculated the heat of mixing in this system by use of the phase diagram, assuming that the solution is random and that the heat of mixing is independent of temperature. The terminal solid solution may be assumed to obey Raoult's law within the requirements

Jan 1, 1957

By Kurzeme M, Willoughby D. R

Current research at the CSIRO, Division of Applied Geomechanics, into the mode of response of fill as a structural component has been based on model tests for prediction of behaviour and field observation of critical parameters. The procedure is summarised in four stages: (a) define the specific fill function (b) postulate the mode of failure (c) use models to quantify the conditions (d) monitor critical parameters to check or update the analysis in (c). The above procedure is used to postulate the failure modes of each of the possible func- tions performed by fill materials. Analytical techniques, or lines of investigation, are described for each of these modes and specific reference is made, where, possible, to an exis- ting mine environment.

Jan 1, 1973

By Harry H. Posey, John Woodling, Miriam L. Renkin

Natural acid drainage is generated from pyritic rock underlying 17 percent of the upper Alamosa River basin. About one-third of these acid producing rocks have nil carbonate buffering capacity; there the streams carry significant acid plus dissolved Al, Cu, Fe, and Zn. In part of the basin, aquatic life is limited by the natural acid drainage. In the four miles where the Alamosa flows through pyritic rock the river grows toxic to trout. Inhospitable conditions continue downstream for at least another four miles. The waters become refreshed, naturally, through metal dilution, metal oxide and hydroxide precipitation, and acid neutralization. Water quality fluctuates in seasonal cycles. Dissolved metals and acid, which are generated year-round by weathering, are stored over winter in the unsaturated zone in the retained water and in soluble metal- sulfate minerals that form by evaporation of acid-metal waters. Seasonal discharge variations cause metal concentrations and pH to shift in the trunk stream; the acid drainage source streams, however, shift only slightly by season. In early spring, metal concentrations and metal loads increase as metals and acid are flushed from the unsaturated zones by melting snow. Peak metal loads occur at this time, and precede peak flow by up to two months. Other metal load peaks occur during peak flow and monsoon flow, even though metal concentrations are diluted at that time by precipitation. In late spring and thereafter, discharge of neutral pH water wanes, so trunk stream pH falls and metal concentrations return to previous high levels. Metal concentrations appear to be low from November through January when dilution from precipitation is lowest, but rise in February to near peak yearly concentrations. In years with high monsoonal flows, metal-laden waters apparently flush from the unsaturated zone and metal concentrations remain low from about October through January. In years with low monsoonal flows, however, metal concentrations in October and November at least are higher.

Jan 1, 2000

By C. L. Lin

A PC image-based on-line coarse particle size analyzer has been developed to measure particle size distributions under plant situations where overlapped particles are being transported on a moving belt conveyor. Although previous testing had shown satisfactory performance of this image-based system for separated particle size measurements (the non-overlapped case), it was necessary to modify original algorithms in order to solve the overlap problem and make the system suitable for plant operations. On-site testing has been conducted at a large copper concentrator in the southwestern U.S. for further investigation of the overlap problem.

Jan 1, 1995

By G. F. Carr

"IntroductionFLUORSPAR has been found at several •localities in Newfoundland, but all the commercial deposits discovered to date are in the vicinity of St. Lawrence, a town on the southeast coast. Most of the veins are within six miles of St. Lawrence harbour, and between sea-level and an altitude of 400 feet. The St. Lawrence Corporation of Newfoundland, Limited, and Newfoundland Fluorspar, Limited, a subsidiary of the Aluminum Company of Canada. Limited. are the two producers.With the arrival of 1953, the St. Lawrence area entered upon its twenty-second •consecutive year as a producer of fluorspar. Production has increased more or less steadily during this period, as is shown by the fact that approximately one-half of the total shipments to date have been made during the past six years. Between four and five hundred men are employed by the industry, and more than $1,250,000 was paid out in wages and salaries during 1952. Shipments during that year reached an all-time high of 81,283 tons valued at $2,484,943, compared with 67,925 tons valued at $1,966,477 in 1951 (1).As a result of an agreement made in July, 1952, with the United States Defence Materials Procurement Agency, production of the St. Lawrence Corporation, Limited, and St. Lawrence Fluorspar, Incorporated, an affiliated company, will •be increased by .approximately 50,000 tons of acid-grade fluorspar per year. The contract extends over a period of four years, or until 150,000 tons of acid-grade concentrates have been produced."

Jan 1, 1954

By Steve T. Laflin

Since the beginning of the nuclear era, there has never been a commercial solution for the large quantities of depleted uranium hexafluoride generated from uranium enrichment. In the United States alone, there is already in excess of 1.6 billion pounds of DUF6 currently stored. INIS is constructing a commercial uranium processing and fluorine extraction facility. The INIS facility will convert depleted uranium hexafluoride and use it as feed material for the patented Fluorine Extraction Process to produce high purity fluoride gases and anhydrous hydrofluoric acid. The project will provide an environmentally friendly and commercially viable solution for DUF6 tails management.

Aug 1, 2010

By Georges Houlachi, Raynald Labrecque, Jean-Noël Cloutier

"Electrodialysis (ED) is an electro-membrane technology based on electrochemical process using electrical energy for the production of chemicals. The process can be used for concentrating, extracting, separating products, modifying molecules, purifying solutions, pH adjustment and regenerating salts into their base and acid. This paper reviews the principle of ED, present some of the different options and discuss applications that are relevant to the hydrometallurgy and mining industries for the treatment of effluents focusing on recovery of chemicals (acid and metals) and recycling of water minimizing the environmental footprint.INTRODUCTIONElectrodialysis (ED) is usually defined as an electrochemical separation process in which electrically charged membranes and an electrical potential difference are used to separate ionic species from an aqueous solution and other uncharged components [1]. ED technology consists of an electro-membrane technology based on an electrochemical process using electrical energy for the production of chemicals. It is a method combining electrolysis and dialysis was proposed for the first time in 1890 by Maigrot and Sabates [2]. In the late 1930s Teorell, Meyer and Sievers discussed membrane phenomena, revealed membrane potential, electric conductivity, transport number [3]. Meyers and Strauss introduced a multi-compartment ED apparatus consisting of two electrodes and a stack of ion-exchange membranes between them [1]. They succeeded to double the concentration of a KCL solution [3- Tarleton]. In general, ED consumes less energy than electrolysis to perform salt splitting. In that regard, one can expect an energy reduction of about 30% [4–5]. ED offers a great versatility in the domain of separation processes. Indeed, it can be used for concentrating, extracting, separating products, purifying by desalination, pH adjustment and regenerating a salt to acid and base components. This paper reviews the principle of ED, presents various options available and discusses potential applications relevant to the mining and metallurgy industries with economics of some successful industrial applications."

Jan 1, 2016

By Murray Malott

The Sheppard Subway extension is currently being constructed in Toronto, Canada for the Toronto Transit Commission (TTC). McNally International Inc., in a joint venture with PCL and the Foundation Company of Canada were awarded the Twin Tunnels contract of the Sheppard extension. The Twin Tunnels project is approximately 4.4 km in length and consists of two separate twin bore drives each 3.3 km and 650 m in length and approximately 400 m of cut and cover construction. This paper presents a case history of the construction of the soft ground tunnels through the complex Toronto glacial deposits using two 5.9 m outside diameter Lovat earth pressure balance (EPB) tunnel boring machines.

Jan 1, 1999

VARYING in thickness and in number from place to place, coal seams in the Canadian Rockies also range in pitch from nearly horizontal to vertical, sometimes with overturns. Over the entire coal-bearing area there are considerable differences of rank in coals of the same geological age, and there are marked differences in ash content and washability characteristics. Correlation of seams at mining operations within a few miles of each other has often proved impossible. These factors influence mining methods, and, of course, production results. The oldest coal formations of western Canada are of Lower Cretaceous age, as the carboniferous sediments are marine and contain no coal. Coal is also present in formations of Upper Cretaceous and Tertiary ages. The rank of coal varies from semianthracite in some operations in the Kootenay and Luscar formations of the Lower Cretaceous in the Rockies to lignite in the Tertiary fields of the Saskatchewan prairies. Fig. 1 shows the general extent of the formations.

Jan 8, 1954

By R. Church

The southern Powder River Basin (PRB) of Wyoming has developed into the largest coal producing region in the United States in the relatively short time span of 22 years. Since the opening of the first non-captive mine in the Basin in October 1972, truck/shovel fleets have played a major part in this rapid growth. In 1994, more than 200 trucks and 50 shovels will be used at 14 mines to help produce more than 190 Mt (210 million st) of coal in the southern PRB. This article presents an overview of the truck/ shovel operations in the Basin. Fleet sizes are reviewed, applications discussed, operating considerations explored, factors looked at that drive high capacity and restrictions listed for future growth. Fleet size Various sizes of trucks and shovels can be found in the southern PRB. However, a clear trend of increasingly larger size units is being established as producers attempt to remain competitive and productive.

Jan 1, 1994

By J. R. Soule

"The fluorspar deposits in the Gallinas Mining District, Lincoln County, New Mexico, were examined early in February and again in April 1943 by the Bureau of Mines because of the possible importance of newly discovered deposits and of old mine workings showing fluorite-bearing material. There &re many of these deposits spread over a considerable area, and it appeared that exploration might indicate sufficient reserves to support a local mill that could contribute to the supply of fluorspar needed for war purposes. Accordingly, the Bureau initiated an exploratory program in June 1943, which was completed in August 1944.H. E. Rothrock, Roy Earhart, R. G. Smalley, and V. C. Kelly, geologists of the Federal Geological Survey, began mapping and studying the district in May 1943 and continued this work throughout the Bureau's exploration.David J. Stauffer, district ranger, U. S. Forest Service, and several claim owners assisted in the examinations and subsequent exploration.The fluorspar deposits in the Gallinas Mountains are reached by an unpaved forest road, which, leaves U. S. Highway 54 half a mile south of Gallinas station. The road runs due west for 3 miles, then turns due north just beyond the first cattleguard. This north branch is followed for 2 miles to a second cattleguard. There a left branch extends northwest up Red Cloud Canyon to the Red Cloud, and. All. American deposits; the right branch continues north for 2.miles past the Wade Porter ranch, to another left branch, which goes almost 2 miles west to the Hoosier Group deposits. The remaining deposits are reached by trail from either the Hoosier Group or, more easily, from the Red Cloud claim (fig. 1).The Hoosier Group is in sec. l9,, T.. 1S.,1 R. 12 E.; all of the other known ore occurrences are in secs. 13, 14, and 23 to 27, inclusive, T. IS., R. 11 E. All of the deposits are in the Lincoln National Forest and within the limits of a State game refuge. The nearest railroad loading point is Gallinas, Station on the Southern Pacific Railroad. Corona, the next station north of Gallinas, is a Mile or two farther from the deposits.Minor supplied, telegraph, telephone, freight, and express service, and limited living accommodations, Are, obtainable at Corona, 10 to 15 miles from the deposits of Carrizozo, N. Mex., 50 miles south."

Apr 1, 1946

By John C. Machisak

THIS CHAPTER of the Minerals Yearbook relates to employment data and injury experience in the metal, nonmetal, and quarrying industries. Combined statistical data on the mineral industries as a whole can be found in volume Ill. Each industry in the chapter is shown separately, and no attempt has been made to combine and show an overall picture. The voluntary reporting of data on injuries and employment by operators of metal and nonmetal mines and quarries has contributed substantially to the promotion of safety in these industries. Data on injury and employment in the clay mining and milling industry are included for the first time. Table 6 contains data for clay mines only for 1955 and for clay mines and mills for 1956. The clay-mill figures are included with other nonmetallic mills in table 5. The information for norunetallic mills was compiled and published for the first time in the 1955 issue of this report.

Jan 1, 1958

By Roma T. Dec

Many industrial wastes may require preliminary processing to change their particle size, density, surface properties or flowability to become more suitable for treatment and recycle. This can be achieved by pressure agglomeration using roll presses. In the following paper an overview of various roll press processing methods like briquetting, compacting, compacting-granulating or densification is presented together with basics of process and equipment design. The emphasis is focused on major factors influencing compaction process and responsible for pressure build up and final product quality. Finally, two examples of roll press application for briquetting of steel plant wastes and compaction of alumina base catalyst tailings are introduced.

Jan 1, 1996

By J. A. Herbst

During the last decade it has been established that conventional mineral-processing control strategies based on classical control theory result in significant increases in plant throughput and operating-cost savings. It has, however, also been recognized that conventional strategies have important limitations for complex multivariable mineral-processing systems. These limitations center around the fact that single-input/single- output control linkings often result in highly undesirable interactions between controllers. During the last few years new and promising approaches to solving this problem have emerged. These approaches are based on the use of on-line dynamic models to make predictions which are useful for control decision-making. This paper presents a brief summary of the state-of-the-art for mineral-processing control in 1984. This summary is followed by a review of recent developments in model-based control strategies including those in optimal control, self- tuning regulators and decoupling control. Expected trends for the future in the control of mineral-processing operations are discussed.

Jan 1, 1984