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By AIME AIME

UNDER the auspices of the Institute's Committee on Industrial Preparedness, a symposium was arranged for the Annual Meeting on the subject "Ores, Metals, and the War," with many well-known Government men and industrialists participating. Wilfred Sykes, president of the Inland Steel Co., of Chicago, presided, with C. K. Leith and Clyde Williams as vice-chairmen, Mr. Williams presiding over the latter part of the meeting. On the Auditorium stage in the Engineering Societies Building was a formidable corps of "experts," with an audience of several hundred to hear what they had to say and to ask questions.

Jan 1, 1942

By Bedrand L. Johnson

THE phosphate-rock industry is built upon natural deposits of rocks and minerals in which the element phosphorus is present as a phoshate. The term ?phosphate rock? is a general one, applied to certain rocks of different degrees of consolidation and of diverese origin, charater and occurrence, composed of intimate mixtures of several phosphate minerals, largely submicrocrystalline, usually calcium phosphates, in commerical quantities, with various impurities. This term includes phosphatized limestones, sandstone, shales, and igneous rocks; nodular phosphates ; residual weathered phosphatic limestones ; vein phosphates ; and phosphatic sediments, both consolidated and unconsolidated.

Jan 1, 1944

By Rolando Patiño Patroni P

El presente estudio revisa la fisiografía, geología, tipos de metamorfismo, efectos de intemperismo y trabajos de exploración en las minas de Marcona. La zona minera de Marcona está ubicada a 800 m.s.n.m del sur de Lima, Ica, cuyo terreno está comprendido por una plataforma costera, donde la erosión no solo ha producido afloramientos de rocas resistentes, sino también de cuerpos de mineral. Su geología está compuesta de rocas que se subdividen en sedimentarias, volcánicas, ígneas y metamórficas. Asimismo está el granito de San Nicolás, andesita porfirítica, granodiorita y los intrusivos básicos. Su estratigrafía se desarrolla por el aluvión, la formación Pisco, Copara, los volcánicos Nazca, formación Cerritos, Marcona, Complejo Lomas. Entre los efectos del intemperismo está la zona de lixiviación, zona superior de sulfatos, zona inferior de sulfatos y la zona de sulfatos primarios. Finalmente, los trabajos de exploración se realizan a través de los levantamientos magnetométricos (prospección), perforaciones a percusión seca, sondajes diamantinos y las labores subterráneas.

Jul 20, 1959

By Paul M. Tyler

According to Lindgren , the economic importance of pegmatites stems from the fact that they represent the principal natural storehouse of two classes of mineral products : (1 ) common minerals in exceptional size and purity and ( 2 ) several of the rarest minerals , which are not commercially available from other types of deposits . Most pegmatites can be described simply as coarse- to very coarsegrained granites . Pegmatite includes coarse -textured igneous rocks of any composition , such as syenitic , alkali syenitic , dioritic , or gabbroitic ; but basic pegmatites are far less common than those that are associated with acid rocks and correspond approximately to the mineral composition of ordinary granite . Moreover , only a very few basic pegmatites can be considered as economic sources of useful minerals . Whereas , in ordinary granitic rocks the individual minerals usually measure 1/8 to 1/4 inch across , in pegmatites they are characteristically over 1 inch and often more than 12 inches in diameter . Although some of the constituents of the pegmatite may be only a fraction of an inch in length , single crystals more than 10 feet long are by no means unusual , and some crystals are enormous . A whole quarry was operated in the Urals within a single crystal of feldspar . Huge quartz crystals are quite common although usually imperfect . Muscovite plates 10 feet in diameter have been mined in India , and the Purdy mica mine in Canada contained a mica crystal measuring 6.5 by 9.5 feet and weighing nearly 7 tons , which supplied more than $20,000 worth of trimmed mica sheet . A loglike crystal of spodumene in the Etta mine in the Black Hills of South Dakota was 42 feet long . Giant crystals of beryl weighing several tons apiece have been mined from several properties . Because so many rare minerals are found in substantial concentration only in pegmatites , it is a common fallacy to suppose that pegmatites are always enriched in rare elements . Traces of most of these elements , of course , are found in almost all igneous rocks , and they reappear in the sediments derived from igneous rocks . It does not follow , however , that all or even most pegmatites contain higher percentages of rare elements than other granitic rocks . Geological evidence points to the probability that notable concentrations of rarer minerals or elements in pegmatites are more or less fortuituous , such additions often being ascribed to events subsequent to the original emplacement of the main body of the pegmatite . Most pegmatites consist principally of potash , feldspar , and quartz . Even mica , although commonly present , is not an essential constituent . Probably

Feb 1, 1950

By Wm Petruk

"The tungsten-bismuth-molybdenum deposit in southwestern New Brunswick occurs in greisenized and silicified tuffite * and feldspar porphyry in and adjacent to volcanic necks. The ore minerals occur as veins and veinlets and as disseminated grains in gangue. These minerals can be grouped into three assemblages. Assemblage 1 consists of oxides and phosphates of W, Ti, Fe, Nb, Sn, Ta and rare-earth elements, with the main minerals being deposited in the sequence wolframite, rutile, cassiterite. Assemblage 2 consists of arsenopyrite, molybdenite and bismuth, and assemblage 3 of sulphides with minor cassiterite and arsenopyrite. Sphalerite is the main sulphide mineral, but it contains minute inclusions of copper-tin- and indium-bearing minerals. Textural relations suggest that most of the elements can be recovered from this ore by conventional mineral beneficiation and extraction methods, but a variety of techniques must be employed. It is expected that the wolframite and molybdenite can be recovered satisfactorily, but poor recoveries are expected for bismuth and cassiterite. A sphalerite concentrate can be readily obtained by flotation, but it would contain a wide variety of elements. It is suggested that leaching be used to recover the bismuth and the elements in the sphalerite concentrate."

Jan 1, 1973

By S. H. Ash

The paramount responsibility of Government is to protect the general welfare. One of the chief functions of the Bureau of Mines is to investigate and publicize methods of increasing safety and efficiency in mining operations. In an industrial civilization, energy resources constitute the foundation of a sound economic structure (14).4/ Coal is only one source of energy, but it provides more than half the energy consumed in the United States.

Jan 1, 1946

By R. H. Sprute

The Federal Bureau of Mines conducted full-scale field tests in electro-kinetic dewatering and consolidation of slimes in cooperation with the Hecla Mining Co. at two of the firm's underground mines in north Idaho. To test the technique on new deposits, 4,000 ft3 of slimes from a collection sump, pumped into a watertight stope equipped with electrodes, were treated in two steps. Immediately after placement, direct current was applied using a floating electrode to hasten settlement of suspended fine particles. After removal of clarified water, the residue was further dewatered and hardened with electrokinetic treatment. In 25 hours, the material had become firm and dense with a surface capable of supporting workmen. In testing old deposits, 10,000 ft3 of slimes, placed in an unused tail drift 10 to 12 months previously, were treated. This material was sufficiently consolidated by electrokinetics to allow its removal from the mine with standard ore-handling equipment. In both tests, electrokinetic treatment densified slimes in a relatively short time with moderate power consumption.

Jan 1, 1976

By N Guresin, R Dunne, S Blanco

This paper presents the results of research work conducted to assess if aqueous solutions of sulfur dioxide (SO2) can be used to treat roaster calcine leach residues such that recovery of gold in this material can be achieved with subsequent application of the thiocyanate (SCN-) leaching system. The project is mainly aimed at assessing an alternative use for sulfur dioxide gas generated during flotation concentrate roasting. The calcine leach residue sample used in the study contained 2.56 g/t gold. The reason for this high level of residual gold is thought to be due to gold surface passivation by thin iron oxide films, presence of gold in solid solution with refractory iron oxides and encapsulation of gold in the structure of these iron oxides.The study was conducted in three stages. The first stage was the characterisation of a sample from a roaster calcine leach residue. The second stage in the project was a set of leaching tests to assess the feasibility of using aqueous solutions of sulfur dioxide to reductively dissolve refractory iron oxide mineral phases contained in the calcine. The final objective was to assess the efficiency of thiocyanate, a gold complexing ligand stable under acidic and oxidative conditions, to extract gold liberated during sulfur dioxide leaching.The study showed that the reductive sulfur dioxide treatment of the calcine leach residues followed by oxidative thiocyanate leaching to extract gold was not a particularly efficient process as only around 20 per cent gold could be extracted. Leaching the calcine residues by any of these systems separately also extracted the same amount of gold (12 - 14 per cent) implying that irrespective of the solution potential, the acidity helps dissolution of gold encapsulating minerals, mostly hematite, but at a very slow rate. The findings on the topic in the literature and during this study show the requirement for further technical investigations and economical analyses on two cases. The first case is to roast gold concentrates to produce magnetite rather than hematite followed by sulfur dioxide and thiocyanate leaching of magnetite containing calcines. The second case is to apply a magnetic concentration process to conventional roast-cyanidation calcine residues to produce a gold-rich magnetite concentrate that can be further treated with sulfur dioxide followed by thiocyanate leaching.For both cases, the best evaluation of the sulfur dioxide leach system in extracting residual gold from calcine leach residues will require a detailed economic analysis to find out the balance between the value of the gold recovered and the loss of revenue from acid production. There are a number of roasters that do not produce acid. In these cases, a portion of the unwanted sulfur dioxide gas can be used to recover gold in magnetite containing calcines as an economic incentive.CITATION:Guresin, N, Blanco, S and Dunne, R, 2013. Leaching roaster calcine leach residues with aqueous solutions of sulfur dioxide and thiocyanate, in Proceedings World Gold 2013 , pp 129-136 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By Ernesto Diez-Canseco Yañez

El siguiente trabajo señala los modos de aprovechamiento del mineral de carbón denominado "andracita", en tanto materia combustible de producción de las briquetas. Es decir, se busca crear un producto biocombustible que mantenga su calidad ecológica y que a su vez genere mayores posiblidades de venta en el mercado internacional, Para ello es necesario, evaluar el nivel de los aglutinantes en su composición y tratar de conservar sus características primigenias de dicho producto.

Jun 20, 1954

By T. S. Fuller

THE work of D. J. McAdam1,2 at the U. S. Naval Engineering Experiment Station, Annapolis, Md., on what has been called by him "corrosion fatigue" has focussed the attention of the engineering profession in general, and of those interested especially in the study of corrosion in particular, on the importance of making tests which will indicate as nearly as possible what can be expected from a given material in service. Pitting is unquestionably the chief agent operating so tremendously to reduce fatigue limits, but in the light of previous work3, 4, 5, 6, 7, 8 it is fair to assume that absorbed hydrogen resulting from the action of the corroding medium upon steel may, under certain conditions, have a perceptible influence. The experiments described in this paper deal more precisely with stressless corrosion, or "prior-corrosion fatigue, "9 and have been carried out to test such an assumption, to segregate, if possible, the effect of pitting from that of absorbed hydrogen, and although very preliminary in nature they indicate results which are striking.

Jan 1, 1929

By T. S. Fuller

The work of D. J. McAdam, Jr.1,2 at the U. S. Naval Engineering Experiment Station, Annapolis, Md., on what has been called by him "corrosion-fatigue" has focussed the attention of the engineering profession in general, and of those interested especially in the study of corrosion in particular, on the importance of making tests which will indicate as nearly as possible what can be expected from a given material in service. Pitting is unquestionably the chief agent operating so tremendously to reduce fatigue limits, but in the light of previous work3, 4, 5, 6, 7, 8 it is fair to assume that absorbed hydrogen resulting from the action of the corroding medium upon steel may, under certain conditions, have a perceptible influence. The experiments described in this paper deal more precisely with stressless corrosion, or "prior-corrosion fatigue,"9 and have been carried out to test such an assumption, to segregate, if possible, the effect of pitting from that of absorbed hydrogen, and although very preliminary in nature they indicate results which are striking.

Jan 1, 1929

By T. S. Fuller

The work of D. J. McAdam, Jr.1,2 at the U. S. Naval Engineering Experiment Station, Annapolis, Md., on what has been called by him "corrosion-fatigue" has focussed the attention of the engineering profession in general, and of those interested especially in the study of corrosion in particular, on the importance of making tests which will indicate as nearly as possible what can be expected from a given material in service. Pitting is unquestionably the chief agent operating so tremendously to reduce fatigue limits, but in the light of previous work3, 4, 5, 6, 7, 8 it is fair to assume that absorbed hydrogen resulting from the action of the corroding medium upon steel may, under certain conditions, have a perceptible influence. The experiments described in this paper deal more precisely with stressless corrosion, or "prior-corrosion fatigue,"9 and have been carried out to test such an assumption, to segregate, if possible, the effect of pitting from that of absorbed hydrogen, and although very preliminary in nature they indicate results which are striking.

Jan 1, 1929

By A. C. Bigley

Before going into this subject, I would very much like to call to your attention some past history on patents granted by the United States Patent office that involved ammonium nitrate. On February 10, 1885, a patent was granted to Russell S. Penniman. "The object of this invention is to securely protect ammonium nitrate against deliquescent and to maintain it in substantially its normal disintegrated condition, so as to afford a new product suited for ready use in the manufacture of high explosives, and enable the immediate admixture thereof with any of the well known explosive substances or compounds heretofore employed. 'Whether the nitrate be thus granulated or otherwise reduced to a granular or divided condition, it is then thoroughly mixed with about twelve (12) percent of the fluid or semi-fluid carbonaceous protecting medium, which forms a readily applied jacket or coating for the granules of nitrate and also serves as a carbonaceous element in such explosive compounds as it may thereafter be employed in."

Jan 1, 1958

By R. L. King, J. Cervik, A. A. Campoli

The Bureau of Mines performed laboratory experiments to evaluate the triboelectric effect of particulate-laden gas streams on polyethylene pipe at various velocity, humidity, dust-size, and dust-load conditions. Charges in excess of 10 kV were produced on the outside and inside surfaces of laboratory pipe samples, when exposed to 40 pct relative humidity (RH) gas stream containing coal dust. However, no charges were produced in laboratory tests that duplicated the over 75 pct RH and dust-free gas streams found in working underground pipelines. Bare cop- per wire, which is wound around the polyethylene pipe in a 1-ft (31-cm) spacing and grounded, eliminated the charge on the outside surface of the pipe, but not on the inside of the pipe surface,

Jan 1, 1986

By Stephan Stecura

One of the principal objectives of the Bureau of Mines program for development of superrefractory ceramic materials is to obtain fundamental data on the physical properties of refractory oxides. Elements of particular interest to research workers in the Bureau include groups III and IV of the Periodic Table and the rare-earth group. This report contains thermal expansion and phase inversion measurements on oxides of scandium, yttrium, lanthanum and 12 lanthanide series elements (promethium and terbium omitted) up to 1,350°C, made by high-temperature X-ray diffractometer techniques. Thermal expansion values were calculated from unit cell dimensions measured at selected temperatures; with anisotropic oxides expansion was determined parallel to each major crystallographic axis. The combined random and systematic errors in the thermal expansion values are considered to be less than 3 percent of the total expansion at 500° C, and approximately 2 percent at 1,000° C, No difference in expansion coefficients was observed between heating and cooling cycles for oxides that did not undergo phase inversion. Tabular data of linear expansion, in percent, linear expansion coefficients, and graphical presentation of linear expansion as a function of temperature are presented.

Jan 1, 1961

By David B. Brooks

I gratefully acknowledge the help of a number of American and Canadian geologists, in both federal surveys and in private firms, who took the time to discuss this problem with me. Hans Landsberg and Bruce Netschert also followed the study with interest and encouragement. In their 1961 monograph, THE FUTURE SUPPLY OF THE MAJOR METALS, Bruce Netschert and Hans Landsberg noted that identified potential resources (that is, known but submarginal resources) of lead and zinc were much lower relative to reserves (that is, known and supermarginal resources) than was the same ratio for other metals.1/ Put another way, it seemed that for such metals as iron, manganese, copper, and aluminum, slightly more favorable economic conditions or modest advances in technology would greatly increase reserves by permitting the exploitation of vest quantities of leaner or deeper or otherwise less valuable mineral deposits. But for lead and zinc, Netschert and Landsberg concluded that either: "(1) there is relatively little material below present cutoff grades; [or] (2) such material exists, but for some reason there are no data.? 2/ This situation, which they called "the lead-zinc anomaly" has been subsequently discussed by other authors. The purpose of this paper is to carry the discussion further by examining the evidence in favor of (1) and (2) and by advancing a third alternative.

Jan 1, 1967

By LESTER W. STRAUSS

OUR early knowledge of history and geography attracted most of us to the mineral resources of South America. The romantic tales of the Spanish activities, which were curiously alluring, and Prescott's exceptional bi-Conquest histories-Mexico and Peru-no doubt fired our minds with the .then metallic wealth of the Spanish colonies. Later developments, intensified within the past eighty years, have, however, changed its fame which now rests on such metallics as copper and tin, and among the non-metallics on nitrate of soda and petroleum. South America proper, excluding Panama, is made up of thirteen countries, a coincident parity with our original thirteen States. Its area is given as 7,231,300 square miles, or slightly less than North America (8,037,000 square miles), is made up as follows:

Jan 1, 1930

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 Leslie D. Marrus

This project and final report represent an effort to collect, analyze, and verify reliability and performance data on currently available medium -to-high seam models of continuous miners being used in underground coal mining. The analysis determined availability, mean time and tons between failures, amounts of down time associated with various failures, labor and part costs required to correct failures, and various indices of maintainability. Machine performance and reliability are discussed relative to cumulative tons (machine age) produced and production rates (machine loading). It was determined that performance can be significantly improved given preventive maintenance programs that will increase machine availability.

Jan 1, 1976

By John C. Machisak

THIS INFORMATION CIRCULAR covers the calendar year 1055 and contains statistical data on employment and injuries pertinent to metal and nonmetal mining and to their mills and processing plants that are voluntarily reported annually to the Federal Bureau of Mmes. This report, unlike previous publications, lists not only production and development workers but also office employees associated with mining and milling or processing. The last publication m the series, Information Circular 7798, Injury Experience in the Metal and Nonmetal Industries, 1954, also contains unpublished injury and employment statistics for 1943 through 1953. The Bureau is authorized to request data on injuries and employment from operators in the metal- and nonmetal-mining industries. The information voluntarily submitted by these operators contributes immeasurably to the promotion of safety in the mineral mining industries as it discloses the hazards to which metal and nonmetal workers are continually exposed during mineral extractive operations.

Jan 1, 1959