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By H. Vincent Wallace

ALTHOUGH it is universally accepted that free oxygen is A necessary in a cyanide solution for the dissolution of gold and silver-in accordance with Elsner's equation that 2Au + 4KCN + 0 + H20 = 2KAu (CN), + 2KOH- little has been written and insufficient attention paid to the drop in extraction due apparently to loss of dissolved oxygen in mill solutions. Aeration or oxygenation of cyanide solutions has been more or less successfully accomplished by various types of agitators such as the Dorr (with or without air lifts), Pachuca tanks and more recently "Turbo-mixers" and Denver "Super- agitators"; also by the introduction of chemical oxidizing agents such as Solozone (Na,O,) . At the Wright-Hargreaves and other mines in the Kirkland Lake camp, the introduction of this reagent at the rate of about 1.25 oz. per ton of ore applied to the feed of the ball mills has certainly been beneficial.

Jan 1, 1932

By B. D. Shah, H. S. Soto

Lack of selectivity in mixed mineral flocculation can be attributed to one or more of the following factors: dissolved ion interference, hetero- coagulation, mechanical entrapment in flocs, and entrainment of fines between flocs. In a study of the apatite-dolomite system, it was determined that dissolved ions do not have a significant effect on selectivity. Heterocoagulation was minimized by choosing proper process conditions and addition of a dispersant. Mechanical entrapment was proved to be insignificant and efforts were made to reduce entrainment by choosing an appropriate method of separation of flocs from fines. A new factor termed "polymer induced entrapment," which occurs due to limited affinity of the polymer to the mineral that is not flocculated, is postulated to be the cause for the loss of selectivity.

Jan 1, 1988

Lack of selectivity in mixed mineral flocculation can be attributed to one or more of the following factors: dissolved ion interference, heterocoagulation, mechanical entrapment in flocs and entrainment of fines between flocs. In a study of apatite- dolomite system, it was determined that dissolved ions do not have a significant effect on selectivity. Heterocoagulation was minimized by choosing proper process conditions and addition of a dispersant. Mechanical entrapment was proved to be insignificant and efforts were made to reduce entrainment by choosing an appropriate method of separation of flocs from fines. A new factor termed "polymer induced entrapment" which occurs due to limited affinity of the polymer to the mineral which is not flocculated is postulated to be the cause for the loss of selectivity.

Jan 1, 1986

By A. G. Taylor

High value materials, such as gold, platinum and other precious metals are subject to loss through unauthorized removal from mines, smelters, refiners, and other places where such materials are processed. A study published in 20011 determined that between 1994 and 1998 an average of 603 kilograms of gold per year was stolen from South African miners and subsequently recovered. This does not include the gold that was stolen but not recovered. At 2011 prices, 603 kilograms of gold would be worth approximately $33 million. Mine security personnel believe that the unrecovered stolen gold far exceeds what is recovered2. Traditionally, metal detectors have been used to screen personnel leaving secure areas to discourage such unauthorized removal. However, with the current near-record prices of gold, platinum, and other precious metals, it has become worthwhile for people exiting a facility to walk out with quantities of product that are too small for ordinary metal detectors to register, resulting in substantial financial losses.

Jan 1, 2012

By Allen G. Taylor

High-value materials, such as gold, platinum and other precious metals, are subject to loss through unauthorized removal from mines, smelters, refiners and other places where such materials are processed. A study by Gastrow (2001) determined that between 1994 and 1998 an average of 603 kg/a (1,330 lb/year) of gold was stolen from South African mines and subsequently recovered. This does not include the gold that was stolen but not recovered. At 2011 prices, 603 kg/a (1,330 lb/year) of gold would be worth approximately $33 million. Mine security personnel believe that the unrecovered stolen gold far exceeds what is recovered (Gastrow 2001). Traditionally, metal detectors have been used to screen personnel leaving secure areas to discourage such unauthorized removal. However, with the current near-record prices of gold, platinum and other precious metals, it has become worthwhile for people exiting a facility to walk out with quantities of product that are too small for ordinary metal detectors to register, resulting in substantial financial losses.

Jan 1, 2012

By O. U. Bradley

THE extent of losses, due to evaporation, sediment, and water, in crude oil stored in steel tanks, is a very interesting question, and particularly so at this time, when every reasonable measure should be employed to eliminate all possible losses of this important natural product. Available information on this subject is incomplete; e.g., during the development of the Cushing Field, considerable surplus oil was stored in steel tanks, but from time to time, owing to changes in weather, somelosses by evaporation and short storage room on the leases, these tanks were topped out, thus rendering inaccurate any system designed to determine the average rate of evaporation or other losses of the oil over a given period. , Furthermore, the losses, as shown by the records at the time, as a result of hasty gages, failed to take into account the temperature and gravity of the oil. Losses may be classified roughly as occurring from evaporation, presence of sediment and water, and leakage. The coefficient of expansion and contraction of crude oil, in relation to temperature conditions, is of material importance; also, the rate of evaporation is dependent upon the gravity of the oil, as the escape of the lighter hydrocarbons in fresh Cushing oil, of from 40 to 42 gravity, on a warm day is considerable, and from available records of temporary storage, it is safe to assume that a loss of 1 to 13 per cent. in volume will easily occur in light crude oil of Cushing grade over a period of. 6 months, including the summer season. The presence of sediment, water, and other impurities, in the oil will also cause, more or less deterioration in quality, particularly when the fresh production is run direct from the. gage tanks, or from the wells on the lease to steel storage, as is often the case when an oil field is being rapidly developed. The bad oil will settle to the bottom of the tanks and may be determined by thiefing and running a centrifuge test on the sample. The amount of water in the oil depends entirely on the conditions under which it is produced. Sometimes in large producing wells, with heavy gas pressure, some water may come in with the oil, particularly if the well has been drilled to the top of a water sand. Under these conditions, cut oil is often produced, which, if not settled out, is carried over into the steel tanks.

Jan 7, 1918

By C. Hanson

Two modes of potential loss of oxime extractants in liquid extraction processes for the extraction of copper have been studied. In loss "by chemical degradation, two mechanisms of acid hydrolysis are possible, some reagents degrade primarily in the organic bulk phase, Others at the interface between the organic phase-- phase protects the oxime but salts added to the aqueous acid phase can promote the rate of degradation. The reagents reported on are the LIX series (Henkel Cpn), SME529 (Shell Chem.Co.) and P5100 (Acorga) Loss by organic entrainment in the aqueous phase leaving mixer-settlers has also been studied, parameters investigated including impeller/tank geometry and the phase inlet arrangements. The consequences of extractant loss by the above mechanisms...are commented upon. They include the direct economic cost, the possible environmental problems and the implications for downstream operations such, as electrowinning.

Jan 1, 1980

By A. Dorsey Lyon

INTRODUCTION A GREAT DEAL of attention has recently been given to the metallurgy of zinc, and much of that which has been said and written on this subject has been in the nature of a criticism. For instance, we are quite accustomed to hearing it said that the metallurgy of zinc has stood still, that it is antiquated, out of date, etc. We are, however, inclined to agree With George C. Stone1 When he says that, although there have been no such spectacular and radical changes as Were worked in the metallurgy of copper and iron by the introduction of converters, there has nevertheless been a decided and marked progress in the metallurgy of zinc, and especially during recent years. However, it must be admitted that, due to the fact that the chemistry of zinc is so different from that of the other metals, the retort process is the only process by which zinc is produced commercially; and, moreover, that losses which occur in the zinc industry-that is, in the mining, milling, and smelting of zinc ore-are very great, for it is stated' that probably less than 50 per cent. of the zinc mined, even

Jan 7, 1914

By Jonathan Peck, Doug Pollitt, Malcolm Scoble

Over the past 5 years the Department of Mining and Metallurgical Engineering, McGill University, has been involved in the performance monitoring of both percussive and rotary drills. Studies conducted in open pit coal and iron ore mines using microprocessor-based research and commercially available instrumentation resulted in the monitoring of at least 6 performance parameters while drilling vertical production blastholes.

Jan 1, 1991

The following record of the important responsibilities already shouldered by Dr. Ricketts will give some indication of the trust and confidence reposed in him by his colleagues. The Institute is to be congratulated that a man who is already so much engaged should be willing to assume the further responsibility of guiding the Institute's Ship of state during the ensuing year. Louis Davidson Ricketts, who is brother of Professor Palmer or Chamberlaine Ricketts, President of Rensselaer Polytechnic Institute, was born at Elkton, Md., Dec. 19. 1859, was graduated from Princeton University in 1881 with the degree, Bachelor of Science, chosen a Fellow in Chemistry and W. S. Ward Fellow in Economic Geology, and after two years' study given the degree Doctor of Science. Following the completion of Iris work at Princeton, Dr. Ricketts went to Colorado and started to work as a mine surveyor. For the 15 years following, his time was chiefly occupied in reconnaissance work, geological work and mine examination. From 1887 to 1890 Dr. Ricketts was Geologist for Wyoming, and at, the end of that period transferred his operations to the Southwest. where he has since been steadily engaged in large mining projects. He was identified with the acquisition of the property now owned by the Moctezuma Copper Co., a , subsidiary of Phelps, Dodge & Co., at Nacozari, Sonora, Mex. From 1899 to 1901 he was General Manager of the property and during his administration the concentrator and reduction works were completed and the mines put on a dividend-paying basis

Jan 3, 1916

By Robert Glass Cleland

DURING the closing month of 1929, Walter Douglas found his health impaired by the strain of many difficult years of alternating prosperity and depression, and in April 1930 resigned the presidency of Phelps Dodge. Douglas was succeeded by Louis S. Cates. The choice broke a tradition that had been held inviolate for almost a hundred years. For the first time in its long history, the direction of the company's policies and operations was entrusted to a stranger without previous Phelps Dodge background, training, experience, or tradition. But the choice was wisely made. For a time at least, the path of Phelps Dodge was to run through rough and dubious ground, and no man in the United States was better qualified to blaze that trail than Louis Cates. After graduating from the Massachusetts Institute of Technology, Cates had served a rough and financially un- profitable apprenticeship at one of the century-old mining camps of Chihuahua, Mexico. Following his return to the United States and a brief interlude as assistant to the president of the National Steel and Wire Company, he had resumed his mining career, first as timekeeper, then as

Jan 1, 1952

Louis S. Cates was born in Boston, Massachusetts, on December 20, 1881. When Cates was in his teens, the family lived at Chestnut Hill, Mass., and he went to the public high school. Then he entered M.I.T., at first in the Department of Electrical Engineering. Next door to the Cates family lived a Mr. & Mrs. Armstrong, who were especially fond of Louis Cates. The latter always called Mr. Armstrong "Uncle." Mr. Armstrong was connected with Kidder Peabody investment firm in Boston. That firm had an office in London and Mr. Armstrong persuaded Cates, before he graduated from M.I.T., to go to work in the London office.

Jan 3, 1964

By AIME

PERHAPS, back in the early eighties, the fates were advised that the world had need of a determined man, yet one who could always inspire teamwork; at any rate on Dec. 20, 1881, Louis Shattuck Cates was born to Edwin Wallace and Emily Allen (Johnson) Cates, in Boston. To his friends he has always seemed a little more determined than anyone else they knew-yet his capacity for organization and enlisting friendly co-operation from all with whom he became associated has perhaps been his greatest asset. His will and imagination set the goal, but his friendliness and qualities of leadership brought results. He was born just nine years after the great Morenci mine was opened by Robert Metcalf and his associates. Educated in the public schools of Boston, Mr. Cates was graduated from Boston High School, and since at that time Boston was headquarters for many of the great mining enterprises and promotions in the country, he chose Massachusetts Institute of Technology as the college which would best prepare him to succeed in the mining industry. He was granted a Degree of S.B. from "Tech" in 1902, but already his getting-along-with-people talent had won him honors. He was class president in his junior year, and "First Marshal" at graduation.

Jan 1, 1946

By AIME

WELL known as an outstanding practical metallurgist, the Chairman of the Institute of Metals Division also possesses a rare combination of research and administrative abilities. Louis W. Kempf was born in Muskegon, Mich., on March 22, 1898. Following his graduation from high school, he obtained considerable experience in the automobile industry while employed by Continental Motors, the Studebaker Corp., and Dodge Brothers. He enlisted in the U. S. Army Signal Corps in 1917, and served overseas with an aviation unit. In 1919, Mr. Kempf entered the University of Michigan and earned both B.S. and M.S. degrees. While there he was elected to Tau Beta Pi, Phi Lambda Upsilon, Alpha Chi Sigma, and Gamma Alpha. In 1924, the Aluminum Co. of America secured his services as a research metallurgist. With a steady job he married Elizabeth Skelley in Cleveland in 1926. They have one son now seventeen. After six years Mr. Kempf was made manager of the Cleveland research division of the Aluminum Research Laboratories which position he held until last year. In 1945 he was promoted to assistant director of the Laboratories. He will direct research involving process metallurgy in Cleveland and New Kensington.

Jan 1, 1946

State of Louisiana, Department of Conservation, Division of Minerals, 126 New Orleans Court bldg , New Orleans, La. Dr. J. A Shaw, Director The Bureau of Scientific Research of the Minerals Division has recently issued the first of a proposed series of Geological Bulletins on the geology of Louisiana, by parishes The bulletin may be had for 25 cents postage by writing to the above address: Geological Bulletin 1, Geology of Iberia Parish (1931) Other bulletins of a more general nature have been published in the past. Bulletin 13, A brief survey of the natural resources of Louisiana (1930) (revised 1931), 14, The clays of the Shreveport area (1927), 16, The clays of Monroe area (1928), 19, The clays of Alexandria area (1929). The latest (Tenth) Biennial Report of the Department of Conservation for 1930-1931, containing a review of the natural resources of the state in the report of the Division of Minerals, may be obtained on payment of 25 cents for postage

Jan 1, 1933

THREE-QUARTERS of the amount needed to defray the cost of the Louvain memorial clock and carillon has been subscribed by one-thirtieth of the total number of mem- bers of the engineering societies that are indorsing this memorial to the engineers who gave their lives in the Great War. Gifts of materials and services have been made, but about $20,000 is still needed to meet the total expense involved. Small contributions from the twenty-nine-thir- tieths of the total membership who have not yet subscribed should promptly provide this sum. The accompanying illus-tration shows the 48 gold stars made by the American Brass Co. for the four faces of the clock, being boxed for shipment at the works of the Dwight & Lloyd Co. at Netcong, N. J. The actual material of the stars is, of course, an aluminum bronze, which retains its gold color without tarnishing.

Jan 5, 1928

By R. L. Shaw, D. W. Alexander

Consolidation Coal Company's Loveridge Mine operates the only coarse coal hoisting and overland slurry transport system in North America. The system has been in operation since April 1980 and according to current haulage levels will have handled over two million tons by this conference date. Original performance goals have been exceeded. The systems will be described and their application to rapid excavation and tunneling haulage needs will be discussed. Manuscript not received in time for publication.

Jan 1, 1983

By H. L. Washburn, W. A. McConnell

There is not a coal preparation engineer alive who would equip his newest and most modern preparation plant with all new and untried pieces of equipment. He may install a few such pieces in which he has great confidence, but he will also spend much time assuring himself that everything else in the plant has been subjected to the test of time. He may arrange these units in a unique manner, but in general, they must have proven themselves elsewhere before he will approve them for his plant. A modern coal preparation plant contains only a few items of processing equipment, the remaining items being devices for materials handling. Consequently, pure automation is almost impossible. Although the main aim of automation is conservation of manpower, it generally results in uniformity of product, lower maintenance costs, and the many intangibles that make a better plant.

Jan 8, 1961

By N. Kanari

Chalcopyrite concentrates and their pure constituents were chlorinated by C12+N2 between 25 °C and 750 °C. The reaction products were analyzed by SEM, XRD and chemical analysis. The effect of gas flow rate and chlorine content of the gas mixture on the reaction rate were investigated. At room temperature, these solids start to react with chlorine giving metal and sulfur chlorides. Complete reaction is achieved at about 300 °C and the iron and sulfur chlorides were fully volatilized. The chlorination residue is composed of valuable metals' chlorides. A simplified flow - sheet for the treatment of chalcopyrite concentrates by chlorine was suggested.

Jan 1, 1998

By H. W. Parsons

Several low-temperature, dry chlorination processes for the treatment of sulphide minerals are reviewed, in a chronological order. These processes include the following: the Swinburne-Ashcroft, Baker-Burwell, Maim, Comstock-Wescott (Aldermac) and the Mitterburg Mining Process. Dry chlorination investigations at the Canadian Mines Branch (now CANMET) and the U.S. Bureau of Mines are discussed, as is a proposed process by the South Africa National Institute for Metallurgy. The techniques used in the process are discussed, as are the shortcomings, problems and failures of the methods.

Jan 1, 1978