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AT the meeting of January 28 which was held too late to be reported in the February MINING AND METAL-LURGY, Messrs. Taylor, Barron, Bassett, DeGolyer, Hutchinson, Norris, Rand, Reynders, Smith, Sweetser and Callow were present. Aside from routine matters, relating to finances and membership,, the Board author-ized establishment of a payroll account and payment by check. It also approved plans for a regional meeting to be, held at Cleveland on April 19 and 20 under the auspices of the Ohio Section and the Iron and Steel Committee. Following a report from the Committee on increase of Membership, Messrs. Barron, Bassett, and Sweetser were appointed as a special committee to con-sider the feasibility of increasing the dues. Mr. Read was made secretary of this Committee. A pleasant feature of the meeting was the presence of past-presi-dent Olcott and the presentation by him to the Institute of an elaborate scrap book, covering the excursion through Mexico made by the Institute in 1901. The meeting was preceded by a dinner at which Scott Turner spoke of the problems of the Bureau of Mines and the large volume of service work for the govern-ment it was now called on to perform. M. L. Requa discussed the need of more exact data covering our national reserve of minerals. E. N. Cooper gave a vivid picture of conditions in Mexico. W. H. Bassett told of the problems before the Institute of Metals, and Zay Jeffries told of the plans for that Division now being formulated. Max W. Ball reinforced what Mr. Requa had said relative to the importance and value of conservation studies as relates to minerals.

Jan 3, 1927

By H. Rozovsky

"AbstractThis paper discusses the methods of handling air in a large asbestos mill presently being completed at the Jeffrey mine of the Canadian Johns-Manville Company in Asbestos, Quebec.The mill, being the largest single asbestos producer in the world and capable of handling over 14,000 tons of ore per day, requires vast quantities of air. A minimum of 2,500.000 c.f.m. is required or about 10 tons of air for each ton of ore milled.Short descriptions of the process and systems requiring this air are given, followed by details of the fans and filters which make up the heart of the mill.This 'draw through' system, located on the top or 12th floor, is an automatically .controlled volume-pressure system creating the required suction to draw .air throughout the mill building and its numerous air systems.The dry mechanical method of milling develops enormous quantities of airborne dust and fibre. A section of this paper is devoted to a description of the multiplicity of dust systems within a system to control, filter, and remove this dust.Finally, the paper describes the method of returning the filtered air to the• working floors or to the outside, with some notes on heat, humidity and dust counts.IntroductionGeneralTHE discussions in this paper deal only with operations where air movement is involved. No attempt is made to delve into production methods.The Jeffrey mine of the Canadian Johns-Manville Company, located about 100 miles east of Montreal, is the largest single asbestos producer in the world, being responsible for over half of Canadian asbestos fibre production."

Jan 1, 1955

By Óscar Cantorín

El presente texto describe las ventajas del sistema de relleno utilizado en la compañía minera Ares de Arequipa. La metodología del relleno se inicia en el tajo de una chimenea, la cual contiene las tuberías bicapa. Luego se conecta mediante un niple las tuberías de una sola chapa, y se instalan hacia el tope del ala del tajo que entrará en relleno. Entonces, se prepara una barrera con tablas y puntales en el límite señalado para rellenar, y la parte interior se forra con tela prolipropileno. Al estar preparado el tajo, se comunica al personal de Planta de Relleno el inicio de la operación, donde se hace una mezcla de agua y cemento para lubricar la tubería. Luego se procede a bombear la mezcla con las proporciones de diseño y un slump promedio de 8 pulgadas. El tajo de 60 m de longitud, se rellena hasta en 3 etapas, ya que las tuberías son recuperadas en su totalidad y finalmente el relleno queda a 0.5 m del techo de la labor. Entre los principales beneficios de este tipo de relleno tenemos que: no tiene excedente de agua, no necesita sistema de drenaje, permite la continuidad del minado ya que no es necesario esperar más de un día para reiniciar las operaciones, recuce el costo del relleno con la disminución de cemento y prolonga la vida de la cancha de relaves.

Sep 13, 2001

By Ryan CG, Both RA, Mernagh TP, Large RR, Hunns SR, Gemmell JB

The Hellyer and Mt. Chalmers deposits are mound-style volcanic-hosted massive sulphide (VHMS) deposits in Australia. Textural, petrographic and microthermometric investigations of fluid inclusions in the Hellyer stringer system indicate that Type I, primary, liquid-vapour inclusions are 10-15 pm in size, and yield homogenisation temperatures of 170-220¦C in early 2A veins, 165-322¦C in main-stage 2B veins and 190-256¦C in late-stage 2C veins. These data suggest a waxing and waning thermal history. However, the average salinity remained between 8-11 NaCl equiv. wt % in all Stage 2 veins. At Mt. Chalmers, Type I inclusions up to 20 ¦m are found in quartz from the mineralised zone, and these inclusions yielded homogenisation temperatures of 160-268¦C and salinities of 5-8 NaCl equiv. wt %. Laser Raman spectroscopic (LRS) analysis indicates the presence of CO2 (

Jan 1, 1995

By M. E. Wadsworth

"For his creative efforts in explaining the electrochemistry of sulfide mineral leaching systems." Leaching reactions that occur during the dissolution of selected base metal sulfides and metals are considered in terms of surface reactions and the influence of intermediate or final products formed. These products may be solid layers, requiring solid phase diffusion for the reaction to proceed, or ions in solution that can influence the kinetics by controlling the mixed potential of the solid. Three general types of reactions are proposed to explain observed rates of reaction. Examples are presented for non-oxidative and oxidative leaching of galena (PbS), anodic dissolution and oxidative leaching of molybdenite (MoS2) and cyanidation of silver and gold.

Jan 1, 1986

[Council for 1993/94 President Dr H. Scott-Russell President Elect J. A. Cruise Vice Presidents Senior D. A. J. Ross-Watt Junior P. D. K. Robinson]

Jan 1, 1994

By Jeffrey Oke D.S.H. Oke, Craig J. Archibald, Anna P. Perry

Underground mining at the Diavik Diamond Mine (Northwest Territories, Canada) commenced in 2003 and has targeted four kimberlite pipe orebodies. The A154 North (A154N) pipe was mined using longhole open stoping with cemented and uncemented rock fill. During the later stages of mining, unique geotechnical challenges developed in the upper portion of the orebody, resulting in difficult ground conditions during secondary stoping. The two uppermost stoping horizons in A154N (A- and B-blocks) were located within the widest portion of the kimberlite pipe and were mined using a multi-panel retreat, overhand primary–secondary extraction sequence. Primary stopes were commonly advanced to near the top of each block prior to the initiation of secondary stoping. Ore development was excavated to full stope width, and secondary development initiated at the base of the block adjacent to mined-out primary stopes resulted in the formation of tall, slender hanging pendant pillars—locally up to 100 m high—laterally supported by frictional contact with adjacent cemented rockfill pillars. Beginning in 2015, differential vertical movements across the ore-waste contact of A154N pendant stope pillars were identified, and the extent and rates of movements increased significantly as secondary stoping progressed through to 2025. These conditions created significant challenges for the safe extraction of remaining stopes and raised concerns for deeper mining blocks if similar methods were maintained. This case study describes the factors contributing to the observed ground behaviour and outlines the strategic mine design modifications and tactical risk mitigation measures implemented to manage geotechnical risk in the remaining A- and B-blocks and to prevent recurrence in lower A154N mining horizons.

May 2, 2026

By Louis J. Cabri

The ion microprobe (dynamic SIMS technique) is a very sensitive instrument for the quantitative determination of trace concentrations of precious metals (often at the ppb level) occurring in common sulfide minerals, either chemically-bound or as discrete particles too small for resolution by SEM. The technique involves sputtering a 250 x 250 Jim area of the grains to a depth of about one ILm and analysing the secondary ions emitted from a circular central region in the sputter crater with a 62.5 I'm diameter. The combination of quantitative mineral-specific sub-ppm analyses together with depth-profiling and the ability to produce secondary ion maps of trace precious metals makes this a very powerful technique in quantifying the precious metal distribution in refractory and other sulfide ores and process products. The technique is particularly well-established for analysis of gold-and platinum-bearing ores and process products.

Jan 1, 1996

A. R. Ledoux,New York City: The so-called combination method " is generally used in assaying bar copper for silver. It has been modified from time to time. Briefly outlined

Jan 1, 1901

By Walter Fuchs

IT is now generally conceded that coal is the product of deposition and transformation of debris of forests and swamps.29 Ample data are available to illustrate the metamorphosis of biochemical substances through biological action; other data show the progressive regional metamorphism existing in coal beds;25 and numerous examples of change effected by intrusion of igneous dikes into coal deposits have been established.23 However, often the relative importance of the biological and the geological factor in determining the character of the various natural coals is a debatable question. Since both biological and geological factors are ever present in nature, the problem, at first glance, would appear to resemble certain probability problems: specifically the simultaneous toss of two coins, with the biological factor as heads and the geological as tails. The probability is 2:I for the combined effect of both factors, as compared to the exclusive effect of either one. if the a priori probability is the same for each factor. This condition can be analyzed by a thermodynamic treatment of data, which may be obtained from a consideration of pertinent biological, chemical, geophysical and geological facts. SYNOPSIS OF BIOLOGICAL AND CHEMICAL FACTS The biosphere is not sterile; i.e., microorganisms are always present. Microorganisms have been established in the ocean deep, under the ice of the polar regions, in the sand of the deserts, and in swamps far below the surface. The various biological media may be acid, neutral, or alkaline, and they may or may not be readily accessible to air. Microorganisms are encountered almost everywhere, except where the temperature is not within the range tolerable by microbial life. Of course, with changing conditions, the type of microorganisms will change. All chemical products of life-proteins, fats, carbohydrates, lignins, waxes, resins may serve as a habitat of microorganisms. In the decomposition of a medium, some microorganisms macerate organic matter mechanically and remove certain constituents for their own nutrition; others decompose a large part of the organic matter but may leave certain constituents undecomposed. Some attack only certain specific ingredients of the organic matter. All of them build up cell substance. The nitrogen content of the medium largely determines the degree of decomposition. Below 1.7 per cent nitrogen, growth of microorganisms and hence decomposition of organic material is retarded; consequently organic material will accumulate. l7,32 Such accumulations of organic material may give coal eventually. Coals differ in type and rank. The nature of the original vegetation and the conditions attending the transformation of the accumulated debris determine the type of coal such as bright, splint, cannel, and algal or boghead coals. Chemical analysis of representative samples of a given type of

Jan 1, 1941

By F. Paredes, W. R. Holman, R. W. Crawford

The diffusion coefficient for hydrogen in the ß titanium alloy containing 13 pct V, 11 pct CY, and 3 pct A1 was measured over the temperature range 20° to 500°C. Results fit the expression: D= 1.58 x lgs exp-------==-----) cm2,sec THE diffusion coefficient for hydrogen in the metastable ß-phase titanium alloy containing 13 pct V, 11 pct Cr, and 3 pct A1 was measured as part of an investigation of the effects of hydrogen on the mechanical properties of titanium alloys. Several theories on the mechanisms of hydrogen embrittle-ment include diffusion of hydrogen at ambient temperature as an important step in the embrittling process.'-5 In hydrogen-contaminated a-ß titanium alloys, it has been postulated that the rate-controlling step may be the rate at which hydrogen diffuses from the ß phase to stress- or strain-nucleated brittle hydride platelets at the a-ß interface.' However, embrittlement of the all-ß alloy investigated in this work may proceed by a different mechanism, since this alloy can be embrittled without the formation of detectable hydride platelets.6 Troiano has suggested that in this case the mechanism of delayed failure or embrittlement is similar to that proposed for high-strength steel, i.e., repeated crack initiation caused by a decrease in bonding energy as hydrogen diffuses to points of high tri-axial stress at the root of a notch. In both types of alloy the rate of embrittlement is believed to be controlled by diffusion of hydrogen in the ß phase. Accurate hydrogen-diffusion data in the vicinity of room temperature should therefore be of some assistance in understanding the mechanisms of embrittlement in these two classes of titanium alloys. Diffusion of hydrogen in pure titanium has been studied by Wasilewski and Kehl7 at temperatures above 500°C. Their measurements on diffusion in the ß phase were extended below the ß-a transformation temperature (882°C) to approximately 600°C. This was possible because of the 8 stabilizing effect of hydrogen. No results at lower temperatures have been published and there are no data in the literature on hydrogen diffusion in the ß -phase alloy used in this program. Hydrogen diffusion in metals is generally investigated by measuring the rate of transport of hydrogen past a solid-gas interface, i.e., by absorption, permeation, or degassing-rate measurements. These methods produce accurate diffusion data when bulk diffusion is the rate-determining step in the over-all process. However, at the lower temperatures of interest in hydrogen-embrittlement studies or under conditions where surface films are present, the measured rates may be surface-controlled and the calculated diffusion coefficients will be in error. Surface effects were eliminated in the present work by using a modification of the common welded-couple technique m which two bars with uniform but different compositions are joined before the diffusion anneal." The same type of step change in the initial concentration vs distance curve was produced by electrolytically hydrogenating thin-strip specimens which had been electrically insulated over half of their length. Concentration vs distance curves were determined, after appropriate diffusion-annealing treatments, by vacuum-extraction analyses of transverse samples sheared from the strips. Diffusion coefficients were calculated by the methods of Grube.M This technique was feasible because of the large concentrations of hydrogen which can be charged into p -phase alloys without the formation of hydrides15'16 and because of the extremely low degassing rates observed when hydrogenated titanium alloys are heated in air. EXPERIMENTAL WORK The diffusion couples were cut from a 0.022-in.-thick mi ll-annealed sheet.* Strips 8 in. long by 1/2

Jan 1, 1965

By J Harris, P Kirsch, R LaBouchardiere

æMining + Health in DevelopmentÆ is a project funded by the International Mining for Development Centre (IM4DC, 2012) to develop a centralised database of corporate sustainability initiatives for managing and improving occupational and public health, based on information extracted from social and environmental reports of major mining, oil and gas (MOG) companies. This register of materials has the potential to increase stakeholder awareness of the unique health risks impacting the minerals industry, employees, their families and surrounding communities, as well as to inform stakeholders on global industry approaches to health management.Data and preliminary outcomes from analysis of different MOG corporate sustainability reports on public health and disease management are presented for six African countries (Democratic Republic of Congo, Ghana, Mozambique, Sudan, Tanzania and Zimbabwe) and six Asia-Pacific countries (Indonesia, Mongolia, Pakistan, Papua New Guinea, Philippines and Vietnam).With the minerals industry facing ongoing rapid growth worldwide, including continuous expansion into developing regions, the æMining+Health in DevelopmentÆ project will inform industry, civil society and regulators of current health management practices and programming among the different sectors of the minerals, oil and gas industries and across various regional operations. This baseline information will serve as a resource for minerals industry managers, providing a forum for sharing best practice health management approaches amongst MOG companies.CITATION:LaBouchardiere, R, Harris, J and Kirsch, P, 2012. Mining and health in development - An inventory of global resource industry health initiatives in developing countries, in Proceedings International Mine Management 2012, pp 75-90 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 20, 2012

By A. Rahmanab, A. Torpy, M. I. Pownceby, M. N. Zaman, N. Haque, W. Bruckard, J. Tardio

Ilmenite is the principal feedstock for producing TiO2 - used in paints, plastics and paper and the production of Ti metal. The Brahmaputra River system in Bangladesh represents a potentially new source of ilmenite concentrated within sandbar placer deposits and the current study presents results from beneficiation and characterisation studies conducted on Brahmaputra River Fe-Ti oxides. Characteristic of fluvial systems, the ilmenite concentration is low (~0.5 wt-%), however extensive annual dredging for waterway navigation provides the economic impetus to recover saleable ilmenite. The Fe-Ti oxide suite derived from magnetic fractionation comprises homogeneous ilmenite, titanohematite and hematite, although many grains exhibit complex exsolution within the (Ilm-Hem)ss series. The textural variability results in difficulty generating a pure ilmenite feedstock with the bulk concentrate typically being low in TiO2, containing 31.0 wt-%TiO2 and 62.7 wt-% (Fe2O3). Results are interpreted via an analysis of the implications for producing a commercial-grade ilmenite concentrate suitable for TiO2 production. Keywords: Ilmenite, titanohematite, Fe-Ti oxide exsolution, TiO2 production

Jan 1, 2020

By Michael J. Nicol

Growing environmental and occupational safety concerns about the use of cyanide in gold processing has increased the interest in more acceptable alternatives. The most likely of these is thiosulfate. However, the thiosulfate process lacks a proven in-pulp method of recovering the dissolved gold, because activated carbon is not effective for the absorption of the gold thiosulfate complex .. Anion exchange resins do offer a possible route for in-pulp recovery. This paper describes work aimed at the evaluation of the effectiveness of commercially available anion exchange resins for the recovery of gold from thiosulfate leach liquors? and pulps. It has been found that strong-base resins are superior to weak-base resins in that they have a larger capacity, which assists in reducing the competition from other anions within a leach solution. Further studies with a selected commercial strong-base resin have shown that competing polythionateanions (particularly tri-and tetrathionate). Lower the maximum possible gold loading but that gold is selectively recovered over other base metal anions in solution. Kinetic experiments found that while? competilig anibns did not affect the initial rate? of gold loading it was important to minimise the contact time of the resin in solution so to prevent displacement of loaded gold by competing anions over longer times. A small-scale resin-in-pulp plant investigation showed gold can be recovered from a leach pulp by a strong-base resin to yield gold loadings of 3000 mg/L, barren pulp containing less than 0.05 mg/L of dissolved gold and. copper loadings of 500 mg/L. Loaded copper was displaced gold and at a loading of 2000 mg/L gold the copper loading was minimal «500 mg/L). The resin was found to recover gold adsorbed on the solids that would, otherwise have. reported to tails if a solid/liquid separation method were used. A patented two-step elution process in which copper and then gold are separately eluted from the resin is also discussed.

Jan 1, 1998

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 William Fink

THE investigation of aluminum alloy systems prior to 1923 was severely handicapped by the low purity of the best aluminum available. However, by that time, the electrolytic purification of aluminum had been developed by the Aluminum Company of America,(1)? and in May, 1923, there was initiated, under the direction of E. H. Dix, Jr.,(2) a program for the investigation of the aluminum-alloy systems using the purest electrolytically refined aluminum. Up to the present time 15 papers (a) have been published, most of which are on the binary aluminum systems. Work is now in progress on the ternary systems, and it seems probable that most of the future work will be on ternary systems. Therefore this survey of the binary aluminum systems investigated up to the present time (the sixteenth paper of the series) concludes the first phase of this program. Certain qualitative relations between corresponding portions of the various binary diagrams as well as between different parts of the same diagram were noted some time ago by R. S. Archer.(4) In the present . paper these relations and others are considered quantitatively by the application of well-known thermodynamic equations or by newly discovered empirical relations No attempt will be made here to present the history of the develop-ment of the thermodynamic equations defining equilibrium or their application to metallic systems, although a list of references is given at the end of this paper for those who are interested in this phase of the

Jan 1, 1934

By J. J. Antony

The Cactus Gold Mine is a joint venture comprised of Middle Buttes Partners Ltd. (CoCa Mines, Inc.--operator, T. Congdon and W. Carey) and Compass Mining, Inc. The project includes 2.4 sq. miles of contiguous mining claims and leases in the Mojave Mining District, Kern County, California, approximately B5 miles northeast of Los Angeles. The property is readily accessible year round by all-weather roads and is within 6 miles of the main line of the Southern Pacific Railway.

Jan 1, 1988

By John Griffen

DURING the past year, purchases of coal-preparation equipment and the discussions and plant-scale tests conducted indicate that much attention is being given to better recoveries of coal by preparation plants and improved quality of the finer sizes to widen their market. In the anthracite regions the new equipment was predominantly for the cleaning of the steam sizes, much of it for treating No. 4 and No. 5 buckwheat. The units installed were largely coal-washing tables, Hydrotators, and Menzies cone separators.

Jan 1, 1944

By W. F. Marshall

The Bureau of Mines conducted a series of experiments to determine the influence of exhaust rebreathing on emissions from various gasoline and diesel engines. Tests were conducted that simulated operation of engines in nonventilated spaces as well as in spaces with partially restricted ventilation. Results of these tests showed that exhaust rebreathing can have a marked effect on exhaust emissions and thus on the composition of the air in the working space. For the case of restricted ventilation, unacceptably high (greater than 50 ppm) levels of CO in the air of the working space resulted from exhaust rebreathing rates as low as 8 pct exhaust in the engine's intake. Operation in a nonventilated space resulted in highly critical CO levels (fatal in a few minutes) at times corresponding to 1 to 3 pounds of fuel consumed per 1,000 cu ft of space. Tests involving spaces of various sizes showed that volume of the air space [per se] is not important--the primary variable is fuel consumed per unit volume of air space.

Jan 1, 1973

By Will H. Coghill

[The supply of gravel spar and of acid spar is not well balanced. Gravel spar -- 85 per cent flourspar, 5 per cent silica -- gluts the market, whereas acid spar -- 98 per cent fluorspar, 1 per cent silica -- is somewhat scarce. Hence it is desirable to convert some of the gravel spar into acid spar. Knowledge of this condition prompted the Franklin. Fluorsrar Co. at Paducah. Ky., to enter into cooperation with the U. S. Bureau of Mines and the Missouri School of Mines and Metallurgy to improve the methods of fluorspar, milling so that morn acid spar would be available. The fluorspar company detailed Mr. Omar Greeman for the work. During the course of the investigation, while Mr. Greeman was also doing work for a master's degree in the School of Mines? an extensive study was made of gravity concentration of fluorspar ores. Decrepitation by heat treatment was also given a laboratory try-out. A part of tie time was spent on flotation; these notes relate only to the flotation. The results of one of the flotation runs is appended. The test was made in a 500-gram mechanical-agitation machine. The sample was ground to 100-mesh in a pebble mill.]

Jan 1, 1928