Search Documents

By W. D. Hausel

The Wyoming Province is an Archean craton which underlies portions of Idaho, Montana, Nevada, Utah, and much of Wyoming. The cratonic block consists of Archean age granite-gneiss with interspersed greenstone belts and related supracrustal terranes exposed in the cores of several Laramide uplifts. Resources found in the Province and in the adjacent accreted Proterozoic terrane include banded iron formation, Au, Pt, Pd, W, Sn, Cr, Ni, Zn, Cu, and diamonds. The Province shows many similarities to the mineral-rich cratons of the Canadian shield, the Rhodesian and Transvaal cratons of southern Africa, and the Pilbara and Yilgarn blocks of Western Australia, where much of the world's precious and strategic metal and gemstone resources are located.

Jan 1, 1991

By Mary S. Esfandiary

This is a revision of a directory of coal research organizations throughout the world that was first published in 1961 as Bureau of Mines Information Circular 8008. Because of the wide acceptance of the first edition, a revision which would supply up-to-date information on coal research and which would facilitate communication among organizations of similar interest seemed important. This compilation includes the names and activities of organizations of various types-government, university, private, and industry. The areas of investigation that each organization is engaged in are indicated in broad terms: Analysis and constitution, mining and geology, preparation, briquetting, combustion, high-and low-temperature carbonization, gasification, conversion to solid and liquid fuels, and health and safety. Publications issued by and describing the work of each organization are cited; almost all of the organizations also publish results of their investigations in the technical press. Selected technical and trade publications that publish information on the science and technology of coal and are not published directly by any of the organizations listed are cited in the pages following the list of organizations in each country. Information that would improve coverage and accuracy of the next revision of the publication will be welcomed by the Bureau of Mines.

Jan 1, 1966

By M. B. Boyer, C. H. Herty, F. A. Hartgen, G. L. Frear

"DEFINITION OF VISCOSITYViscosity has been defined as the resistance experienced by one portion of a liquid moving over another portion, such as one molecular plane moving over an adjacent plane. A measure of viscosity is the force required to keep one plane in motion at Unit velocity, the other plane being considered stationary. Figure 1 illustrates the general idea that the surface friction between two adjacent areas will be greater the larger the molecules. Therefore it may be assumed that viscosity will be increased by molecular association or agglomeration, and likewise dissociation rill decrease viscosity. According to Maxwell (1)6 the unit of viscosity, the poise, is the tangential force per square centimeter of area of either of two horizontal planes 1 centimeter apart, one of which is fixed while the other moves with unit velocity, the space between being filled with viscous liquid of unit viscosity.The need for a satisfactory apparatus and experimental procedure for the determination of viscosity of high-melting materials at temperatures corresponding to those in pig-iron and steel making has been recognized during the past few decades. The condition of the slag during the smelting and refining periods in the iron- and steel-making processes exerts an important influence on the metal product obtained, this slag condition really meaning the state of viscosity or, vice versa, fluidity, which the slag attains under certain conditions."

Jun 1, 1934

By D J. Brake

Most mine ventilation engineers are involved in ventilation planning and design in some capacity. Ventilation modelling software used by a competent experienced ventilation engineer is extremely useful in developing good ventilation designs by allowing assessment of a wide range of potential options. Unfortunately, ventilation modelling undertaken by persons who do not have sufficient experience or knowledge usually results in a façade that covers up a fundamentally unsatisfactory design. Ventilation models are produced for a wide variety of purposes including: fault-finding of a problem area in a mine and options analysis for resolution of such problems; a complete review or optimisation exercise of an entire mine’s ventilation system; or a much longer life-of-mine type of study. Models can be intended as the basis for studies with diverse purposes such as primary shaft or airway sizing, primary fan specification, examining re-entry times after blasting, resolving leakage or recirculation, or investigating the impact of fires or underground climate or cooling requirements. The concepts of ‘materiality’ and ‘fitness for purpose’ are essential to developing or using a ventilation model and serious mistakes have been made in wrongly using a ventilation model for purposes for which it was never intended, often because it is simply the most recent model on the mine site. Mistakes at this level often translate into faulty ventilation strategies and inefficient or ineffective use of scarce capital for ventilation projects. Validating a ventilation model is a time-consuming and expensive process and not every model must (or even should) be fully validated to meet the objectives at that time. This paper discusses the application of quality assurance in ventilation planning with particular respect to the ‘basis of design’ (BOD) as well as the standards for validating a ventilation model. It also provides a recommended way of dealing with non-conformances in measured versus modelled values of critical parameters in the model.CITATION:Brake, D J, 2015. Quality assurance standards for mine ventilation models and ventilation planning, in Proceedings The Australian Mine Ventilation Conference, pp 221–228 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 31, 2015

By F. Baldini, M. S. Borges

"The proposed method emphasizes the optimization of waste management with regard to the exploitation of raw materials incorporated in the remains of industry, as well as the economics of natural resources as an environmental impact assessment. This system [tool] allows: (a) the conversion of an environmental liability into an asset by finding a line of appropriate research for each type of waste and the development of new materials applicable to other industries, (b) the performance of internal control of the waste generated (production, storage, final destination) as well as legal conformity.Objectives:1.1 General objective:To design a collaborative system for socio-environmental management of industrial waste.1.2 Specific objective:Develop evidence of concepts;Evaluate the deployment of the inventory of waste in an industry;Enable the conversion of an environmental liability into an asset by finding a line of research appropriate to the waste: a case study;Evaluate the environmental legislation in the legal mechanisms that influence company decisions.IntroductionThe global economy is undergoing major changes, among these changes; it should be highlighted those related to technological progress and environmental quality.While the industrialized countries and higher levels of economic growth dominate modem technology, developing countries are identified by a different growth pattern, using the annual growth rate of Gross Domestic Product per capita [3, 18].Growth is when the GDP grows, in percent, over the previous year. Development, on the other hand, is when the countries change their technologies and improve their internal structure. Thus, the growth considers the accumulation of wealth, while the development is concerned with the distribution of wealth, improvement of the quality oflife and environmental quality [3, 18].As the UNESCO report shows (1999), the biggest problem is between consumption and development, what is produced and the end that is given to the product. Therefore, product and by-product have equal importance in the quantity produced [29].On one hand there is a positive relationship between indicators of economic growth and technological progress, however, on the other hand, these transformations are a paradox, confirmed by the dramatic use of environmental resources and the lack of technologies for recycling of industrial scrap."

Jan 1, 2011

By M I. Pownceby, M A. Rhamdhani, S Palanisamy, D Fellicia, B Satritama, G A. Brooks, A Ang

Metal production have long been using carbon sources as both reducing agents and energy sources. Consequently, the global extractive metal sector contributes significantly to greenhouse gas emissions, accounting for approximately 9.5 per cent. Hydrogen gas offers as a promising ecofriendly alternative to carbon in metallurgical processes, serving as both a reductant and energy supplier with a by-product being only water vapour. However, the implementation of molecular hydrogen faces certain challenges related to the thermodynamics and kinetics of metal oxide reduction. In addressing these challenges, researchers have explored the application of hydrogen plasma, generated by subjecting molecular hydrogen to high energy to produce atomic, ionic and excited hydrogen species. Hydrogen plasma offers thermodynamic and kinetic advantages over molecular hydrogen and carbon-based reductants, exhibiting lower standard Gibbs free energy of reaction and activation energy. Therefore, hydrogen plasma can produce metal in fewer steps, process any oxide feed and feed size and even be used to refine metals. Despite these advantages, challenges exist in utilising hydrogen plasma in extractive metallurgy, including electricity costs, potential reverse reactions and industrial-scale implementation. This study provides a mini review of prior research on hydrogen plasma for metal oxides reduction, particularly iron oxide, as well as state-of-the-art techniques for its use in extractive metallurgy applications by mentioning several reactor types. Future prospects and scale-up possibilities of the hydrogen plasma in extractive metallurgy will also be presented.

Aug 21, 2024

By S. A. Shuey

The present industrial practice used to separate aqueous cobalt from nickel is multistage solvent extraction processing. This paper describes a different but simpler treatment technology. The proposed technology has been applied to cobalt/nickel hydroxide intermediate solids produced from the treatment of Electrochemical Machining (ECM) waste sludge, The process consists of dissolving the cobalt/nickel hydroxides in basic cyanide solutions. Cobalt and nickel form aqueous .solution metal cyanide complexes. Nickel can be selectively precipitated from the solution as a nickellic hydroxide solid. Cobalt can be recovered from the leach solution by precipitation of a cobaltous/cobaltic cyanide double salt. The double salt product can then be subsequently treated to produce an appropriate cobalt product. The process chemistry, proposed fiowsheet and preliminary reagent costs are presented and discussed.

Jan 1, 1998

By Rob Boom, Yasuyuki Tozaki, Greg Traquair

The objectives of the business case are to examine a proposed metallurgical project and answer fundamental questions about project feasibility, risks, opportunities, and value. A business case fulfills these basic functions: estimates economic value; helps to understand competitiveness; serves as a risk management tool; and serves as a communication tool. A business case evolves with the project life cycle, and supports the gate reviews at the end of each phase of engineering, through to project construction and operations. A business case must be holistic, including all elements of scope that can impinge on project risk and value.

Jan 1, 2015

By S. G. McDowell

This paper discusses the utilization of automation to increase productivity of continuous miners. Automation techniques are used during the design stage to decrease the time required and ensure the accuracy of the design. This is followed by automated manufacturing processes to reduce manufacturing time and improve the quality and consistency of parts. Combined, the result is a more reliable machine which can provide ongoing production capability. With the use of automation to enhance operator effectiveness and monitoring machine condition the productivity of machines is also improved.

Jan 1, 1991

Jan 1, 2003

By Shiwei Wang, Ziwen Li, Chenhu Zhang, Peng Chen, Chengyong Wang

Accurate prediction of the partition coefficients in coal gravity separation is key to improving the preparation efficiency of coal and promoting its clean utilization. In China, the approximate formula method (AFM) has been applied to the calculation of coal gravity separation partition coefficients for decades, but its accuracy is limited. To improve the accuracy of the predicted partition coefficients, and thus the product yield of coal preparation plants, the present study proposes a modified hyperbolic tangent model to derive direct calculation formulas for the heavy medium and water medium separation partition coefficients. Four groups of coal samples were used to verify the accuracy of the direct formulas, and their predictions were compared with those of the AFM. The results showed that the partition coefficients and partition curves predicted by the direct formulas were closer to the actual values than those predicted by the AFM. Further, when the cleaned coal ash content was basically the same, the cleaned coal yield predicted by the direct formula was lower than that predicted by the AFM, and was also closer to the actual value. These results demonstrate that the direct formula produces more accurate results compared to the conventional AFM. As this formula has a reasonable theoretical basis, is simple to apply, and produces accurate results, it is expected to help improve the design and management level of coal preparation plants.

Oct 15, 2022

By K. G. Davis, P. Fryzuk

A study has been made of the effect of undercooling on the grain structure and solute distribution in small ingots of pure bismuth and of a 100 ppm Ag in bismuth alloy. Autoradiographic evidence shows that in undercooled melts a network of dendrites is formed throughout the melt immediately after nu-cleation. At large undercoolings the dendrites are very thin and closely spaced. The origin of the observed grain morphology can be explained on the basis of information about the mode of solidification revealed by the impurity substructure. WHILE a great number of studies of nucleation in undercooled molten metals have been made, comparatively little attention has been given to the mode of solidification from melts with large undercool- ings. Colligan and Bayles1 and Walker2 have measured the rate of advance of the solid-liquid interface in undercooled nickel melts, but the morphology of the solidifying material remained a matter of speculation. Fehling and Scheil3 have described the grain structure in ingots formed from undercooled melts of nickel, palladium, and copper, and a series of Ni-Cu and Ni-Pd alloys. At small undercoolings, equiaxed structures are observed, the grain diameter tending to increase as the temperature of nucleation is lowered. At greater undercoolings, a columnar structure is developed, while with still further undercooling there is a smaller grain size incorporating rather coarse subgrains. All-bright and Colligan4 examined the grain structure shown by ingots solidified from melts of nickel and of Ni-Ag alloy at an undercooling of 105°C, and concluded that considerable grain growth had taken place after solidification. The object of the present work is to correlate the mode of solidification from undercooled melts with both the grain structure and impurity segregation, using tracers to examine the latter.

Jan 1, 1965

Sailing westward from the Society Islands in the fall of 1774, England's noted explorer Captain James Cook discovered New Caledonia-that long, linear island that has played such an important and varied role in the history of nickel. Upon his return to England the following year, Cook's announcement of this uncharted island generated governmental interest, but its distance from the Island Empire, the troubles in the colonies, and the difficulties with France combined to keep English interest indirect and in the background of the then-current events.

Jan 10, 1968

What is your personal view and assessment of the overall health of the industry in the current global economy? The economic outlook remains soft for the near future and, although the global economy is showing signs of recovery, uncertainty has tempered the pace of recovery. In addition to uncertainty, we are still facing significant economic challenges in many parts of the world, including Europe and the United States. The rapid expansion of China?s economy has recently slowed, further contributing to the sense of uncertainty in the overall health of the global economy. This situation is both a blessing and a curse, depending on which sector of the mining industry we are considering. For example, coal, industrial minerals, aggregates, base metal and precious metals markets are impacted by different forces and drivers and will experience different outcomes within the same economic environment. Let me give a few concrete examples to illustrate this concept. The prevailing economic uncertainty that I have just described tends to drive investors toward safe havens. Gold has historically been viewed as a safe haven and as long as investors shy away from traditional investments, gold prices will remain high and gold mining companies will continue to expand and invest capital in their operations. The same sluggish economy that drives gold prices higher has the opposite effect on other segments of the minerals industry. A great example of this is industrial minerals and aggregates used in construction. The markets that consume these minerals have contracted significantly over the past five years. The outlook for this segment is poor, as the glut of available housing continues to inhibit demand for new construction and, thus, many industrial minerals. In addition to this, the federal government?s lack of political will to enact long-term legislation funding transportation and infrastructure projects continues to be a drag on the U.S. aggregates industry.

Jan 1, 2013

By Matheus Fortes Stiborski

O emprego de materiais sinterizados para conformação massiva permite a utilização de forças menores permitindo que resultados similares sejam alcançados com maquinas de potência menor, outra vantagem é que o blank utilizado para esse processo não contém tensões residuais advindas do processo anterior. Para o processo foi necessário o levantamento das curvas de compressibilidade do material a ser estudado (pó de ferro puro), análise das propriedades do material sinterizado e posteriormente extrusão do material e caracterização do mesmo.

Aug 17, 2017

By Gordon B. Brox, Joseph F. Mcaleer, Charles C. Goddard, Edward P. Shea, Robert G. Ingersoll, Lester G. Zeihen, George J. Burns, John M. Guilbert, Richard N. Miller, Charles Meyer

The Boulder batholith is a composite intrusive in which the Butte quartz monzonite is the dominant rock type. Quartz porphyry dikes intruded the quartz monzonite in directions which were subsequently followed by the eastwest- striking Anaconda system of veins, the earliest major veins in the district. Anaconda veins are faulted by northwest-striking veins of the Blue system, which are most prominent in the central third of the district. Anaconda veins are the major producers in the western third of the district and also in the eastern third, where the "horsetail" zones break off from them. Individual oreshoots are thousands of feet long as well as deep on both systems of veins, but they are generally more persistent and thicker on the Anaconda veins. Viewed broadly, the mineralization in the big veins is arranged in crudely concentric zones of zinc and manganese around a central zone of copper. Only slightly offset from these zones, but earlier structurally, is a zone in which quartz-molybdenite veinlets are prominent. This zone tops at about the 2800 level and widens downward. The pattern of distribution of Cu-Fe-S series minerals in the large veins of the copper zone is not symmetrical with respect to the metal zones. There is a fringe of chalcopyrite-bornite all around the copper front. However, within the copper zone, pyrite-chalcocite-enargitecovellite- digenite assemblages are prevalent near its eastern edge from the 3800 level to the surface, whereas deep on the large Anaconda veins in the western part of the copper zone, chalcopyrite is dominant. Here the chalcopyrite grades upward into bornite-chalcocite ores and eastward into the high-sulfur assemblages of the Leonard mine. Sericite-biotite-K-feldspar alteration envelopes, containing up to about 2 per cent copper as chalcopyrite, are present on some of the quartz-molybdenite veinlets at deep mine levels in the molybdenite zone. These envelopes contrast sharply mineralogically and chemically with the later sericitic and argillic alteration envelopes around Main Stage veins. K'0-Ar'0 ratios indicate that they may be older by about 4 m.y. Secondarily enriched copper ores are mined in the Berkeley pit in the southeastern part of the district. At the present time they account for about half of Butte's production of copper.

Jan 1, 1968

By Armine F. Banfield

The Purpose of the Paper It is fitting that the first paper of a session on the Financial Aspects of Mining should be on the basic data upon which any financial discussion of a mining project must be based. The history of a mining project starts with exploration in an area considered geologically favorable for mineralization and culminates in the discovery of a body of valuable mineral material commonly known as a mineral deposit. Subsequently more detailed exploration establishes the approximate size, shape, tonnage and average grade of the deposit by surface and/or underground drilling, -surface trenching and/or underground workings. Some preliminary metallurgical testing and other studies, as required, are made at this time. Development work is then carried out to provide representative samples for determining flowsheet and metallurgical balances, preparing the deposit for production and establishing more firmly the grade and mining characteristics of the deposit. A feasibility study is then made of the engineering aspects of the project including the estimation of operating coats, the capital required to place the deposit into production, profit and return on investment. A valuation of the deposit

Jan 1, 1972

By Evan Evans

WITH the expiration on April 30, 1941, of the agreement between the anthracite operators and the United Mine Workers of America, a new agreement was entered into, providing for a general wage increase of 7 1/2 per cent effective May 1, to be brought to a total of 10 per cent on Oct. 1. Contract rates were increased from the rates established under the agreement of September 1923, and hourly rates were raised above the agreement of May 1936 as modified from the eight-to seven-hour day in May 1937. The new rates are to be in force for the duration of the agreement, ending April 30, 1943.

Jan 1, 1942

By Rodrigo Monzon Figueredo

Neste trabalho foi estudada a corrosão dos aços API 5L B e X52MS em soluções ácidas descritas nas normas NACE TM0284 e TM0177. A susceptibilidade ao trincamento induzido pelo hidrogênio (HIC) foi determinada em cada meio, os produtos de corrosão foram caracterizados por microscopia eletrônica de varredura e espectrometria de energia dispersiva de raios-X e, posteriormente identificados por difratometria de raios-X. Conclui-se que o pH afeta diretamente a solubilidade dos produtos de corrosão e a permeação de hidrogênio. Na solução 177-A, ambos os aços sofreram corrosão generalizada, enquanto que na solução 177-B foi evidenciada a presença de um filme fino descontinuo. Somente o API 5L B não passou no teste de HIC. Na solução 284-B de maior pH, os aços apresentaram filmes espessos e o trincamento pelo hidrogênio não foi observado.

Oct 30, 2017

Central to any business is its Asset Management Plan which encapsulates the business context and key organisational objectives such as profitability, safety and environmental standards. Life Cycle Planning (LCP) is a key component of an overall Asset Management Plan. A comprehensive approach to Life Cycle Planning forecasts the financial expenditure required to support the performance of the asset over the business life. It incorporates capital, maintenance and operational expenditure along with an estimation of economic life. Within its body the LCP provides the detail of the maintenance plan and method of its execution. Once optimised the LCP becomes the overarching plan executed through the application of several elements of the Asset Management Plan to ensure the return on investment from the assets is optimal. Each of the elements of the LCP is bound by a set of loops that provide information based on the analysis of outcomes. These loops drive the continuous improvement of performance and cost over the life of the asset. In this way we ensure that the LCP is a dynamic plan responsive to the changing business environment. The paper being presented today will describe the process undertaken and the outcomes derived when this approach was applied to a $600 M+ coal handling and preparation plant in QueenslandÆs Bowen Basin. It will also delve into the difficulties encountered from both technical and cultural aspects; the latter proving to be the most difficult to manage. It will describe the hurdles and barriers that hampered progress including the human influences and the natural desire to revert to what has been done in the past when things became a bit difficult. In the end the results are there to show that the upfront expenditure and investment in time was time and money well spent and the outcome has the operation well placed to manage the assets in a manner designed to deliver the optimal business outcome.

Jan 1, 2007