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By K McLeod

{Figure 1} The Placer Dome-Western Areas Joint Venture?s South Deep Twin Shaft Complex, has been planned and dreamt of for nearly 20 years. [ ] The gold reserve at the bottom of these shafts is one of the largest single intact gold deposits remaining in the world today, containing an estimated 57 million ounces. This is about the size of the fictitious reserve created by inventive prospectors for the infamous BREEX scam in Kalimantan about ten years ago and about the size of the reserve Harmony claims as its own in it?s current hostile takeover bid for Gold Fields. So it is certainly of the magnitude that dreams are made of. [ ] {Figure 2} The unique orebody lies in a continuous, highly concentrated, thick deposit, an estimated twelve kilometres along dip and a two kilometre wide strike. Due to the thickness of some sections of the reef, up to 60 metres in places, bulk mining methods will be required for it?s extraction. [ ] {Figure 3} The twin shaft system comprises a main shaft which had an initial design depth of 2765m and a ventilation shaft of 2760m, making them the world?s deepest to be sunk in a single lift. The shafts were

Jan 1, 2005

[Aamot, Olav Crone, (M'29) Chem. Engr., Elektrokemisk, Raadhusgt. 23, Oslo, Norway. Abadilla, Quirico A., (M'38) Min. Engr., Dir. Bureau of Mines, Manila, P. 1. Abbott, Agatin, (J'40) Asst. Geol., Trench Mine, Patagonia, Ariz. Abbott, Clarence E., (M'04) Civil Engr., V.P., Tennessee Coal Iron & R.R. Co., 1642 Brown Marx Bldg., Birmingham, Ala. Abel, Raymond L., (M'28) Prof., Chem. Engrg., Univ. of Pittsburgh, Pittsburgh, Pa. Abel. Walter D., (M'32) Min. Engr., Div. of Corporations, State of Calif., 403 California State Bldg., Los Angeles, Calif. Abele, Louis T., (M'31) 4800 Patterson Ave.. Richmond, Va. Abell, Leo M., (M'31) Research Met., Mount Morgan Ltd., Mount Morgan, Queens., Australia. Abenius, Hakan V., (M'37) c/o Falu Gruva, Falun, Sweden.]

Jan 1, 1940

By Richard Keyon

El presente texto describe la geología, depósito, litología y fisuras de la mina de Toquepala. El depósito está situado en un terreno compuesto de volcanitas Mesozoicas y Terciarias, intrusionadas por apófisis dioríticas del batolito andino. La alteración hidrotermal se generaliza en la zona de mineralización. Los minerales de arcilla se presentan en abundancia en algunos sitios, pero su porcentaje está indeterminado. El cuarzo y la sericita constituyen los principales productos de alteración, y en muchos casos las texturas de la roca original han desaparecido.

Jul 1, 1958

Table 1.-Salient statistics of carbon black produced from natural gas and liquid hydrocarbons in the United States [ ]

Jan 1, 1967

Jan 1, 1968

By W. N. Hamilton

"Evaporites abound in the Western Canada sedimentary basin, recurring throughout the stratigraphic column and widely scattered over the basin region. Alberta, situated centrally over the basin, includes many of the evaporites within its borders, but only a few have the right geological conditions to form potential economic deposits of salt or gypsum. These include the Middle Devonian Elk Point Group and related evaporites, Upper Devonian Wabamun Group-Palliser Formation evaporites, and evaporites of the 'Triassic Charlie Lake and Whitehorse formations.Salt deposits underlie almost half of Alberta. The major deposits belong to the Elk Point Group, which includes thick salt units in the Lotsberg, Cold Lake and Prairie Evaporite formations. Another, younger salt deposit in the Wabamun Group has only local distribution. Elk Point salts have a maximum aggregate thickness of 430 m in east-central Alberta. The deposits deepen southwestward across the province, from minimum depths of210 m at Fort McMurray to 1820 m at Edmonton.The thickest, most extensive salt deposits are the upper Lotsberg and Prairie Evaporite salts. Both have excellent development potential. The upper Lotsberg is up to 150 m thick, consists of clear, very coarse crystalline halite with only minor impurities, and has a notable lack of non-salt strata in its succession. Analytical data for the Lotsberg Salt show extraordinary chemical purity. Prairie Evaporite Salt differs lithologically from the Lotsberg in having a significant non-salt component. The deposit is up to 200 m thick and consists of medium crystalline halite, brownish coloured and cloudy as a result of finely dispersed impurities. The main impurities-shale, anhydrite and dolomite-are most prevalent as interbeds in the salt succession, ranging from very thin laminae to beds several metres thick. Although of lesser purity, the Prairie Evaporite Salt is shallower, thicker and more extensive than the Lotsberg and the salt quality is quite acceptable for most industrial uses."

Jan 1, 1982

[I-Institute of Metals Division PAUL D. MERICA, Chairman ZAY JEFFRIES, Vice-chairman W. M. CORSE, Secretary General Committee ROBERT J. ANDERSON H. C. JENNISON L. W. SPRING WILLIAN K. FRANK DAVID LEVINGER R. L. SUHL J. R. FREEMAN, JR. PAUL McKINNEY R. F. WOOD]

Jan 1, 1928

By Shun Myung Shin, Kang Jeong, Kyoungkeun Yoo, Jin Koo, Dong Hyo Yang, Soo Sohn

"The optimum discharging condition to dismantle the batteries without explosion was investigated to recycle the lithium primary batteries, which could be exploded by heating too much or crushing. The 3 waste lithium primary battery cells were discharged with 500 cm3 of 0.5 kmol·m-3 sulfuric acid. Fe concentration and pH increased rapidly after 3 days at 35? and after 1 day at 50?. Chromium concentration increased by 4 days at 35? and 2 day at 50?and then decreased, and nickel concentration was very low. Because Li concentration increased gradually, Li became dissolved after the dissolution of cover material. When the discharged batteries were shredded, the batteries discharged at 50°C were not exploded and those discharged during 3 days at 35°C were exploded. This result shows that the waste batteries could be stabilized within 1 day at 50°C and 4 days at 35°C. Introduction Lithium has some advantages for battery e.g. it is the lightest metals and also has the highest electrochemical potential at 3.04V[1]. For over thirty years lithium primary batteries became famous for their performance in various applications such as IT, medical, and military[2,3]. They gained a reputation for their long shelf life, constant voltage, wide operating temperature range, and low self-discharge characteristics[3-5]. World primary lithium battery market was expected to grow from $820.6 million in 2003 to $1,1355.3 million in 2010 (http://www.frost.com, Frost & Sullivan)[2-4]. The lithium primary batteries have very various sizes and components. Lithium batteries are made with lithium metal as anode active material and non-aqueous solvent as electrolyte. As cathode active material, various kinds of materials were used such as manganese dioxide (nominal voltage, 3.5V), thionyl chloride (3.6V), and carbon monofluoride (3.0V). In Korea, 50 % of the spent lithium primary batteries must be recycled because spent lithium primary batteries have been listed in EPR (Extended Producer Responsibility) of the enforcement degree of the act on the promotion of saving and recycling of resources. However, the batteries have been landfilled since there is no economic method to recycle the batteries in Korea[2,3]. When the batteries were heated too much, charged, pierced, over discharged, or short-circuited, the batteries explode because lithium reacts violently with water or air and because contents such as lithium, electrolyte, and sulfur become flammable by high temperature[4]. Therefore, it is so difficult to recycle safely the spent lithium primary batteries."

Jan 1, 2008

By Luiza Esteves

Corrosion testing was performed in white liquor from a Brazilian Kraft mill. Specimens of duplex stainless steel (DSS) and lean duplex (LDSS) were exposed at 170 °C for 30 days to simulate conditions of the digester. Corrosion rates were determined from weight loss measurements. After this exposure, the corrosion products formed on the steel surface was characterized by using scanning electron microscope (SEM) equipped with EDS, X-Ray Diffraction (XRD), and X-ray photoelectron spectrometer (XPS). EBSD can be used to quantify of basis balance phases in DSS and LDSS. General corrosion rates for UNS S32304 LDSS were higher than the UNS 31803 DSS in industrial white liquor at 170 °C for 30 days. XPS and XRD analyses indicated that the film formed after the immersion test may be consisted by Fe and Cr oxides and sulphides.

Oct 30, 2017

This three-part report provides the results of an industrial engineering study that assessed the safety and efficiency of underground ore handling in U.S. metal mines. One of the primary findings of the study was the improvement needed in controlling muck size in the are handling stream. Oversize ore is causing much additional labor, creating work stoppages, and is a principal cause of accidents in metal mines. The specific objectives of the Present Systems Study were to determine and evaluate the productivity of existing ore handling systems in a representative group of underground metal mines, to relate the available historical accident record statistics of these selected mines to the specific operations in the overall ore handling operations, and to highlight the potential areas of improvement for each mine on the basis of productivity and associated hazardous index for each operation.

Jan 1, 1974

By A. Shemi

Tungsten carbide scrap (WC–Co) is material generated from the tungsten carbide manufacturing process and worn out or used carbide parts from industry. Tungsten (W) ores contain about 3 wt% WO3 and their W concentrates about 10– 75 wt% WO3. Tungsten carbide scrap typically contains 40–95 wt% W. The high intrinsic value of W and the fact that the least valuable scrap contains more W than the average tungsten ore makes tungsten carbide scrap a worthy material for re-use. This study has investigated the selective dissolution of the cobalt (Co) binder phase, and recovery of tungsten monocarbide (WC) and Co using an acid leach process. The Co component was selectively leached leaving the WC solid particles intact. Further investigation using a complexing agent-aided acid leach process that takes advantage of organic chelating agents that form a soluble tungsten complex in place of the passive insoluble tungsten oxide is envisaged. The optimal dissolution of the Co binder phase using an inorganic acid in conjunction with an organic complexing agent is a novel approach with the potential of reduced leaching times and possibility of regenerating the unreacted organic acid.

In 2005, 14,666 mining operations reported employment statistics to the Mine Safety and Health Administration (MSHA).1 Almost half (48.5%) were sand and gravel mines, followed by stone mines (30.6%), coal mines (14.1%), nonmetal mines (5.0%), and metal mines (1.8%).

Jan 1, 2008

By John Petty, John Loviza

As a blaster, have you ever had that uneasy feeing in the pit of your stomach as a codes enforcement official drives onto your jobsite? Have you ever needed an ally in a court of law against an unjust damage claim? Have you ever wished for a better and more open relationship with the guys who wear the badges?

Jan 1, 1996

By W. H. Young

THE DOMEST[C bituminous coal and lignite industry remained fairly steady in 1959 compared with 1958. Although mechanization continued to expand and production increased slightly, consumption, average value, exports, and employment decreased. The percentage of underground production mechanically loaded, the percentage of total production mined by stripping, and tonnage per man per day were at their highest levels. Production.-The output of bituminous coal and lignite in 1959-412 million tons-was 0.4 percent greater than the 410.4 million tons produced in 1958. Production was retarded in 1959, largely owing to the steel strike and reduced exports.

Jan 1, 1960

By Aline Silva Magalhães

As elevadas taxas de encruamento nos estágios iniciais de deformação plástica observadas para os aços bifásicos constituem uma das principais características que os habilita para aplicação em componentes estruturais na indústria de automóveis. Neste trabalho foi analisada influência de tratamentos intercríticos com aquecimento em temperaturas diversas, seguido de resfriamento brusco, no comportamento em termos de encruamento de um aço bifásico, por meio de dois métodos distintos de determinação do expoente de encruamento. Observou-se que a elevação da temperatura intercrítica influenciou de modo a reduzir o valor do expoente de encruamento, dado que o aumento da temperatura reflete a elevação do percentual de martensita na microestrutura do aço. Além disso, para as diferentes abordagens aplicadas para o cálculo dos valores de n, verificou-se que por meio da técnica de linearização da curva tensão versus deformação foram obtidos valores superiores do expoente de encruamento quando comparada à abordagem utilizando o critério da estricção.

Aug 17, 2017

By Rafael de Araujo Silva

As ligas ß-Ti têm sido consideradas materiais com potencial para armazenagem de hidrogênio no estado sólido. A adição de elementos de liga estabilizadores da fase ß, tal como o Nb, retém esta fase metaestável em temperatura ambiente. Neste trabalho a liga Ti-40Nb (at.%) foi produzida via fusão a arco e suas características microestruturais foram caracterizadas visando avaliar os efeitos da aplicação da deformação plástica severa (SPD, severe plastic deformation) e da hidrogenação. A laminação a frio sob atmosfera de Argônio foi a técnica de SPD escolhida. Os resultados principais mostraram que é possível hidrogenar a liga fundida Ti-40Nb em temperatura ambiente após laminação a frio. Os efeitos da deformação plástica severa na microestrutura da liga, como a introdução de discordâncias, foram importantes para o aperfeiçoamento da cinética de absorção em temperatura ambiente (25 °C). Após a dessorção da fase hidreto (CFC) a microestrutura volta a ser constituída pelas fases ? (CCC) e ?” (ortorrômbica).

Aug 17, 2017

By John W. Langley

In the summer of 1888 it was the fortune of the writer to present the subject of the desirability of establishing a set of samples of steel, which should be analyzed with extreme care, in order that they might become standards to which scientific and commercial analyses of iron and steel could be subsequently referred; also, that greater uniformity in the results of analyses might be brought about, since these standards would bear towards analytical methods somewhat the position which the original units of weight and length, the gramme and meter, or the pound and yard, preserved in Paris, London, and Washington, do to the mechanical arts. The plan met with hearty co-operation, with the result that com mittees were appointed in Sweden, Germany, France, England, and America, to receive the material and to see that the necessary au alyses were executed. In England, the British Association for the Advancement of Science appointed a committee, which subsequently published a plan

Jan 1, 1891

By L. J. Prosser

The Bureau of Mines has completed an underground degasification project in which an underground piping system was used to transport methane from the coalbed to the surface. In a la-month period four horizontal holes were drilled to an average depth of 1,450 feet. All four holes were surveyed vertically and azimuthally. In 991 days of degasification, 255 MMcf of gas was drained from the coalbed. The underground piping system proved to be a safe and effective means of transporting methane from the coalbed to the surface.

Jan 1, 1981

By F. G. Schwartz

The Bureau of Mines developed a rapid and precise method for predicting storage stability of motor gasolines. This method resulted from the investigation of many analytical techniques as well as a study of fuel composition and fuel component gum-forming mechanisms. The first section of this bulletin discusses the development of the prediction test through its several phases, including revision of the standard 110° F storage test; attempts to develop a modification of the ASTM D525 induction bomb test; and the ultimate abandonment of this procedure with the adoption of the 16-hour oven test that was both precise and rapid. The second section comprises a discussion of further studies of fuel com- position, including the reactivity of certain sulfur compounds and hydrocarbons to form gum. The compositions of various gums and inorganic deposits are reported in terms of elemental analysis and spectroscopic examinations. The reactions of tetraethyllead with selected hydrocarbons are also reported.

Jan 1, 1972

By Rodrigo Cesar de Miranda

A importância de descrever o processo de beneficiamento por um modelo matemático tem sido apresentada por vários pesquisadores. O principal benefício é o controle e a otimização do processo dentro de uma situação industrial. O modelo seria capaz de prever determinada variável de controle do processo a partir de dados conhecidos. Assim, a simulação dinâmica representa um marco no campo da otimização de processos minerais. Essa tecnologia de simulação tem uma ampla aplicação no estudo de processos, o que permite a obtenção do seu conhecimento e domínio operacional. Além disso, possibilita melhores definições nas etapas de projeto, além de realizar uma análise de confiabilidade mais realista. O presente trabalho consiste em realizar uma análise de confiabilidade, através da simulação dinâmica, para entender como as paradas não-programadas influenciam a produção de uma planta de beneficiamento de ferro. Ainda, visa entender o desempenho fenomenológico dos equipamentos de acordo com a entrada de diferentes tipos de minérios e também como são suscetíveis a condições climáticas.

Aug 17, 2017