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Jan 1, 1966

By J. Moyes

The Intec Process is a generic process for the production of pure base metals and precious metals from sulphides concentrates derived from copper, nickel, zinc and lead ores. The development program for the Intec Process initially focussed on the treatment of copper concentrates, (the ?Intec Copper Process?), and more recently of zinc concentrates, (?the Intec Zinc Process?). Developed and proven in Sydney, Australia at a cost of US$15m over the last ten years, the Intec Copper Process is now ready for commercial application. The knowledge gained during the development of the Intec Copper Process has been applied to the Intec Zinc Process, which utilises the same basic chemistry to produce high purity zinc ingot from metallurgically complex zinc sulphide concentrates containing lead, copper, iron, silver and gold. The demonstrated ability of the Intec Zinc Process to treat low grade mixed zinc/lead/copper concentrates, including those with high iron and manganese levels, holds out the real prospect of overcoming major metallurgical hurdles that have long affected the zinc industry. The Intec Zinc Process consists of the three consecutive circuits of leaching, purification and electrowinning. The leach circuit is of single stage configuration with a series of reactors to which concentrate and lixiviant are fed. Purification consists of cementation and precipitation by pH adjustment. Electrowinning employs an electrolytic cell very similar in design to that of the Intec Copper Process, but differs in that a conventional plate cathode is produced. During electrowinning, the same mixed halide species (BrCl2 -, HalexTM) that is integral to the Intec Copper Process is generated in solution at the anode and exhibits powerful leaching characteristics capable of directly leaching the sulphide concentrate feed. The need to roast the concentrate prior to leaching, as is practised in the conventional Roast/Leach/Electrowin (RLE) process, is thus eliminated whilst a range of by-products (notably lead, copper and precious metals) can be extracted in the simple, single-stage leach. This paper describes the Intec Zinc Process; the technology, predicted economics and its environmental aspects.

May 1, 2002

By E. J. Gleim

An important phase in the Bureau of Mines investigation of electrical machines designed for operation in gassy coal mines is testing enclosures of electrical components for explosion-proof qualities. In brief, this testing consists of filling and surrounding the enclosure with an explosive atmosphere of methane and air and then igniting the atmosphere within the enclosure to determine (1) Whether the resulting explosion is confined without discharge of flame; (2) whether the enclosure walls are permanently distorted; and (3) whether excessive pressures are developed within the enclosure. Ordinarily, the pressures encountered in routine testing do not exceed 100 pounds per square inch gage. Hence, the designer of the machine does not have too much difficulty in taking corrective measures to prevent flame discharge and distortion of the enclosure. Occasionally, however, the explosion pressures greatly exceed 100 pounds. Then the goblet of the designer may not be solved so readily, From experience over the year 0, the testing personnel often can predict that certain construction will result in high. Pressures, but, only in a very general way, has it been possible to advise designers what modifications might be made to reduce the explosion pressures to normal values. For example, if high pressures were developed in a motor starter having a partition with an opening through it, some enlargement of the opening may appear to be the logical procedure, but it has not been- possible to give information concerning the exact amount the opening should be enlarged to prevent development of high pressures .

Jan 1, 1952

By J. A. Kost

A survey of 80 coal producers was conducted to determine the extent and scope of respirable dust control research for underground coal mines and the current methods employed to control respirable dust. Results of the survey showed that proper face ventilation and an adequate water spray system are sufficient to comply with mandatory standards in room and pillar mining. Difficulties still exist with longwall equipment, auger miners and buring machines. In these cases, known dust control techniques are not sufficient to obtain compliance. Present state-of-the-art face ventilation and water systems were discussed in addition to the sampling program.

Jan 1, 1980

By Fernanda de Melo Fernandes

A deposição de filmes finos por plasma melhora várias propriedades físicas, químicas e biológicas de superfícies que contribuem para o enobrecimento dos materiais. O objetivo desse trabalho é estudar a cinética de deposição de filmes finos de cobre, utilizando a técnica da gaiola catódica, alterando a espessura da tampa da gaiola, e sua relação com a variação da potência do tratamento. Filmes de cobre caracteriza-se como bom condutor elétrico e térmico, o que justifica seu uso em microeletrônica, segundo a U.S. Environmental Agency (EPA) existem 282 tipos de ligas de cobre bactericidas, habilitando sua utilização em ambientes estéril. Assim, realizou-se deposições de filmes finos de cobre sobre substrato de vidro, variando a corrente do processo e a espessura da tampa da gaiola. Avaliou-se a variação de peso da amostra depositada, definindo o peso resultante das deposições. Realizou-se também a caracterização por difração de raio-X, microscopia eletrônica de varredura e análise tribológica (calotest). Os resultados mostraram que, o tratamento com espessura de tampa de 12 mm promoveu o filme mais espesso e mais contínuo dentre todos os tratamentos, com uma grande quantidade de cobre depositado, o que induz que a razão ideal diâmetro de furo/espessura da tampa é 0,67.

Oct 30, 2017

By R. H. Pemberton

"THE Mattagami district of Quebec has, during the past few years, experienced intense exploration by virtually every mining company operating in Canada. As a result of this activity, a number of well-mineralized zinc-copper bearing bodies have been found, some of which will almost certainly go into production. Much of the area has undergone what is now termed ""Saturation Prospecting"" or intense and detailed geological and geophysical surveying, followed by the drilling of nearly all possible bets. Considering only the airborne geophysical surveying, some blocks of ground have been flown by virtually every geophysical instrument which has to date been installed in an aircraft. A list of these different geophysical instruments would include: l. Fluxgate-type total field magnetometers 2. Vertical field magnetometer ,3. Nuclear-precession magnetometers 4. Single-frequency out-of-phase electromagnetometers 5. Dual-frequency out-of-phase electromagnetometers 6. Horizontal component measuring electromagnetometers 7. In-phase and out-of-phase electromagnetometers8. Dip-angle measuring electromagnetometers."

Jan 1, 1961

This paper aims to increase our understanding about existing capacity-building approaches and their implications for obtaining a social license to operate in the mining industry. The notion of ?capacity building? is gaining increasing currency in the mining sector in developing countries due to a rapid rise in the globalisation of mining operations. Capacity-building is conceived here as a process that lasts after the mine-cycle, intended to provide local mining communities with tangible skills and knowledge to gain meaningful employment in mining or other industries relevant for the local economy. Building community capacity to understand and effectively respond to these transformations is vital for obtaining a social license to operate, as it promotes sustainable and locally relevant development. Accountability mechanisms such as global norms and international standards increasingly highlight the need to build capacity among stakeholders, particularly among local communities adjacent to mining operations. International frameworks and mining companies have embraced the notion of capacity-building as a driver to assist corporate social and operational performance. However, this narrow understanding of capacity-building through the prism of corporate social responsibility and ?best practice? is preventing the industry from meaningfully impacting communities and maintaining a social license to operate. This latter notion is being widely embedded across multiple industry sectors, as a social and economic reward from mining companies to compensate communities for natural resource extraction and gain social acceptance. Although both concepts are widely recognised in the minerals industry, insufficient attention has been paid to the implications of applying a top-down (mining-orientated) or a bottom-up (community-orientated) capacity-building approach for obtaining a social license to operate, or indeed how these two concepts are linked and applied in practice. At times, communities lack the necessary capacities in the form of education and skills to deal with mining-led livelihood transformations. This is preventing both mining companies and communities from forging sustainable livelihoods and responding to mining-led livelihood transformations, a situation that is creating discontent among communities and reducing the possibility of obtaining and renewing a social license to operate for the industry. Based on a review of current scholarly debates, accountability mechanisms in the mining industry and fieldwork findings in Colombia, this paper will contribute to an understanding of the implications of existing capacity-building approaches that support a social license to operate.

Aug 1, 2013

By Hengwei Yan, Zhanwei Liu, Wenhui Ma, Ping Xiong

The sulfur in high-sulfur bauxite not only pollutes the environment but also harms alumina production. This study investigated the removal of sulfur from high-sulfur bauxite by adding Zn or ZnO during the Bayer process. The results showed that the different valence sulfur (S2−, S2O3 2−, SO3 2−, and SO4 2−) in sodium aluminate solution can be effectively removed by adding Zn during the digestion process. Adding ZnO removes the S2− in liquor, but the other sulfur compounds (S2O3 2−, SO3 2−, and SO4 2−) are not affected. The mechanism of sulfur removal has been elucidated, where the S2O3 2−, SO3 2−, and SO4 2− are first reduced to S2−, and after adding Zn, the S2− enters into red mud in the form of ZnS. The ZnO then reacts with S2− to generate the ZnS that enters into red mud. Thus, this is a new and effective method of sulfur removal by adding Zn during the digestion process. The results shed light on the removal of sulfur from high-sulfur bauxite during alumina production.

Jun 24, 2020

By K. R. Van Doren

The polynomial method for estimating virial coefficients from experimental data suffers from three serious defects: (1) There is no known relationship between the polynomial coefficients and the virial coefficients, (2) the values of the estimates depend upon the degree of the polynomial and the particular set of values used for the independent variable, as well as the random errors in the dependent variable, and (3) the variances calculated for the estimates do not represent the mean square errors of estimation. Attempts to overcome these defects have thus far been unsuccessful; these attempts have also failed to account for the fact that none of the virial coefficients are uniquely determined by the values of the dependent variable for a finite set of values of the independent variable. The conclusion is that virial coefficients cannot be reliably estimated from experimental data unless additional information about the virial expansion itself, such as its rate of convergence, is available.

Jan 1, 1969

By Kallioinen Jouko

"Advanced Flotation Technology is the application driven design of Don-Oliver flotation cells to achieve the optimum performance for each type and grind of flotation. Optimum performance is the combination of both recovery and selectivity.Optimized performance is the combined product of optimized mixing and effective froth removal. Optimized mixing is applied to roughers, scavengers, cleaners and specialty cells such as those to float hydrocyclone underflows in both primary and regrind circuits in order to reduce overgrinding. Effective mixing for fine material is easy, but overmixing reduces selectivity in frothbed.Selectivity in flotation is an important target, especially when treating complex ores, and parameters in frothbed have been examined to improve the separation of minerals and eliminate circumstances that reduce separation rate.Advances in process control have been achieved with expert controls and instructive operator information data. This has gained a higher degree of understanding of cell operation and ore type being processed to be used in future process development work. Excellent results of this Advanced Flotation Technology have been achieved and designs through 7000 cu ft (200 m3) are currently available for high capacity concentrators. This paper will detail how flotation cells are more responsive to the exact requirements of the duty specified."

Jan 1, 2000

By Youliang He

Twin-roll casting is an integrated casting and rolling process that involves the continuous solidification of a melt and the plastic deformation of the solidified metal between two rotating rolls. Computer modeling is a valuable tool to help engineers understand the metallurgical process during twin-roll casting. However, commercially available software can only model either the fluid flow/heat transfer of the melt or the plastic deformation of the solid, but not both. In this study, an object-oriented finite element program was developed to simulate the steady-state fluid flow, solidification and plastic deformation of an A7,31 magnesium alloy in a horizontal twin-roll caster. The melt, the mush zone and the solid were treated as a generalized Newtonian flow in an Eulerian reference frame and different constitutive equations were employed to describe the material behaviours. The effect of operational parameters on the solidification process was discussed based on the simulation results.

Jan 1, 2010

By Hendrick A. D. Kirsten, A. Clayr Alexander

Stillwater Mining Company is currently developing a second underground palladium and platinum mine approximately 21 km (13 miles) west of their existing Nye operation in the Bear tooth Mountains of southern Montana. Portals for the two access tunnels required at the new site were excavated in limestone talus to accommodate4.6 m (15 feet) diameter tunnel boring machines. A review of the technical design, field conditions and construction of the portals is presented.

Jan 1, 2001

By E. H. Burroughs

Persons interested in th_e study of petroleum and allied substances have long felt the need of a bibliographic index to the literature. This bibliography, which is intended to be the first elf a yearly series, has been compiled by the petroleum division of the Bureau of Mines with a view to satisfying this need. The references include only the more noteworthy writings that appeared during the year 191.5 in both ·the United States and foreign countries. Only patents plainly applicable to the industries in point have been included, although, of course, a close scrutiny of the great volume of patent literature might reveal many other patents of possible value. The references are arranged according to the subject classification on pages 3 to 11. This classification, which is to be followed in the succeeding bibliographies of this series, is offered as a guide for further study and classification of the pertinent literature.

Jan 1, 1918

By H. B. Sahu, N. M. Mishra, D. C. Panigrahi

The paper presents the development of a spontaneous heating liability index (SHLI) of coal based on a mathematical approach. The parameters for the calculation of this index have been determined by differential scanning calorimetric studies. Thirty-one coal samples representing both fiery and non-fiery coal seams of different ranks have been collected from different Indian coalfields and their SHLI values have been determined. In addition, the susceptibility of these samples to spontaneous combustion has been ascertained by standard crossing-point temperature measurement. The moisture percentage of all the samples has been obtained by proximate analysis. A comparative study between SHLI and crossing-point temperature, along with moisture percentage, indicates that SHLI predicts the proneness of coal to spontaneous heating more accurately.

Jan 1, 2008

By The Honourable George Prudham

"I AM PLEASED indeed to be present with you here today and to be taking part in the proceedings of your convention. You have been greeted and welcomed to the Province by Premier Manning who is also provincial Minister of Mines and Minerals, and to this City by Mayor Hawrelak. As Minister of Mines and Technical Surveys in the federal government and as Member of Parliament for Edmonton West, I have been asked to share the honour of extending greetings and a cordial welcome to all.It is a happy coincidence that this representative national gathering, indicative of the growing strength and significance of a great basic Canadian industry, is taking place in the Macdonald Hotel, the new addition of which marks another important step forward in the progress of this City and district.This happens to be the third national convention of the C.I.M. that I •have had the pleasure of attending and I trust that I am not presumptuous in expressing the hope that I will have the opportunity of attending many more conventions of the Institute in my present capacity.Dr. Kidd has bestowed on me a high honour by asking me to be Co-Chairman of this Inaugural Session of the Convention and thus to share with him the responsibility of presiding over the proceedings of this afternoon."

Jan 1, 1953

By J. Yuan

Ground calcium carbonate (GCC) and chemically precipitated calcium carbonate (PCC) have become important mineral-based commodities in recent years. GCC manufacturing generally requires high purity and high brightness deposits of marble, chalk or limestone as the stone source. PCC usually uses limes made from lesser quality limestone deposits. GCC products have a wide span of particle size, with a d50 size ranging from sub micrometers to as large as several inches such as those used in landscaping. PCC products are typically limited to less than 10 µm (1,250 mesh). Each PCC product has a narrowly distributed size range. GCC and PCC products tend to have higher levels of whiteness com-pared with other traditional filler and extenders, such as kaolin and talc. Published statistics of GCC production volume often vary due to the exclusion of certain size range GCC products. According to Roskill’s latest estimate, world GCC capacity was believed to exceed 56 Mt (62 millionst) during 2004 for all grades.

Jan 1, 2005

By R. K. Singhal, H. Sahay

Introduction In terms of the world's recoverable coal reserves, Canada ranks 10th, providing 0.6% of the world's total. The US is first with 27.8% and the Soviet Union follows with 24.1%. Figure 1 shows the principal coal mines in Canada. Several provinces contain substantial coal deposits, but the largest deposits are found in the western provinces of Alberta, British Columbia, and Saskatchewan. Conservatively, 90% of the lignitic, 80% of high volatile bituminous, and nearly 100% of subbituminous, and low and medium volatile bituminous coals are located in these three provinces. During the past decade, Canadian coal production of all types increased from 18.8 Mt (2 million st) in 1972, to 25 Mt (28 million st) in 1975, to 61 Mt (66 million st) in 1984. About 38 Mt (43 million st) of this output was classified at thermal and 23 Mt (25 million st) as coking and metallurgical coal (Table 1). The three western provinces currently produce 57 Mt (62 million st) of coal - 95% of Canada's total. The remaining 3.6 Mt (4 million st) (5%) is produced in Nova Scotia and New Brunswick on the east coast. The majority of western coal (98%) is produced by surface mining methods. On the east coast, though, mining is predominantly underground and only 15% is produced on the surface. In 1985, Canada exported close to 28 Mt (30 million st) of metallurgical coal and thermal coal. During the same period, 15 Mt (16 million st) of coal were imported, mostly from western US for use in Ontario and Quebec. Almost 60% of the imported coal was used for thermal applications. The remaining 40% was metallurgical coal for the steel industry. It is generally cheaper to import coal into central and eastern Canada from the eastern US to augment local supplies rather than from western Canada. This is mainly because of high transportation costs. Mining methods The suitability of mining methods in a particular area depends largely on the geological setting. Geology, therefore, simplifies or adds complexities to mining operations, directly affecting the economics. It also influences the flexibility required from the min-

Jan 9, 1986

By J J. Batchelor, J B. Metson

Titanium (ilmenite) concentrate was extracted from a New Zealandilmeno-magnetite deposit. Tailings from the existing processing line at the Waikato North Head ironsand concentration plant were used as a raw material feed. The titanium bearing mineral extracted was defined as intergrowths of ilmenite and hematite in the size range below 150 um. The Owen-Honda equation was used to determine the conditions forilmenite/hematite magnetic separation. Three distinct regions of magnetic field strength for the mineral separation have been defined. Theoretical estimates from this calculation have been confirmed experimentally. Ilmenite concentrate was obtained using medium field magnetic andelectrostatic separation. The final material contains 40.6 - 42 per cent TiO2 and 39.1 - 39.8 per cent Fe (total). The actual yield from extraction was about seven per cent of the Zircon, leucoxene and monazite were found as byproducts of thetitanium concentration process. Preliminary experiments have shown the viability of industrial zircon benefication.

Jan 1, 2000

By Eugene H. Skinner

The U.S. Bureau of Mines conducted experiments on the use of lightweight concrete in the density range of 100 Ib/ft3 for liners in underground mines. Three test sections were completed: a monolithic, portal-type structure with integral walls and arch constructed aboveground; an underground test section constructed in a mine drift using plywood forms; and a second section constructed in a drift using an air-supported formwork. The lightweight concrete in the two underground test sections was placed using piston pumps and a slickline. Fiber reinforcement was added to the concrete in the mine sections without any apparent problems with either pumping or placement of the concrete. In another experiment, the Bureau and Hecla Mining Co., Mullan, rD, used lightweight concrete in the density range of 25 Iblfe to replace timber blocking in a raise preparation structure. Other experiments are described in which low-density, lightweight concrete blocks were produced for mine ventilation doors, stoppings, and barricades. Other mine uses reviewed include pillars and collapsing beams. An advantage of low-density concrete is that it will display up to 50% deformation at a constant yield stress. These hlllovative concepts in deformable concrete lining systems will aid mine operators by decreasing capital and maintenance costs, increasing the available space in underground haulageways, and providing productivity gains and improved resource recovery in the soft, caving, squeezing, or bursting grollnu conditions often found in deep mines.

Jan 1, 1989

By Francisco Raunelli

Anglo American Quellaveco S.A. perteneciente a Anglo American PLC, construyó las bases de la aceptación social del proyecto Quellaveco, (Moquegua) después de un largo proceso de relacionamiento social (comunitario, institucional). En ese sentido, el presente texto describe el proceso de la Mesa de Diálogo con participación del sector civil, autoridades y Anglo American, que buscó consensos para el desarrollo de Moquegua. Así el diálogo, la transparencia y la generación de confianza se ven fortalecidos mensualmente con la participación de Anglo American en las reuniones de la Comisión, donde se decide y se informa del trabajo y avances desarrollados para el cumplimento de cada uno de los compromisos asumidos. Así también se adelanta el cumplimiento de algunos de ellos considerados como prioritarios para la población, ya que los compromisos están asignados para diferentes etapas de la mina (preconstrucción, construcción, operación y cierre).

Apr 1, 2015