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By Joe H. Skidmore

This paper, describing mining and milling methods and costs at the Gold Hill mine, is one of a series being published by the Bureau of Mines. Boise Basin, in which the geld Hill mine is located, is in the central part of Boise County, Idaho, about 30 miles by air line northeast of Boise. The mine, owned and operated by Talache Mines, Inc., is at the southern end of the town of Quartzburg. About 115 to 125 tons daily is mind by square-setting and is treated in an amalgamation plant.

Jan 1, 1938

By H. H. Heady

This Bureau of Mines report provides specific information regarding the analysis of ores, concentrates, and bullion. It describes analytical services provided by some Federal agencies, and discusses analytical techniques applicable to the precious metals. The appendixes list Bureau of Mines State Liaison Offices and commercial assay laboratories.

Jan 1, 1976

By K. Webb

At both the international and country level, the issue of how the mining sector and indigenous populations should engage on issues of mutual interest or concern has emerged as one of central importance and controversy; involving the mining industry, Aboriginal communities, governments, the courts, and other stakeholders. At its heart, stakeholder engagement is an ethical issue, although it manifests itself in international instruments, domestic laws, industry guidance and agreements. At the international level, the concept of ?free, prior and informed consent? (FPIC), while not subject to widespread agreement on the finer details of evolving definitions, seems to be emerging as an increasingly recognized engagement norm. Within Canada, through a series of decisions, the Supreme Court of Canada (SCC) has articulated a fiduciary obligation of the Crown to consult with and accommodate impacted Aboriginal groups on resource management issues. Provincial governments have been variously attempting to adjust their resource management regimes to stay in alignment with SCC and lower court decisions. Mining sector organizations, working with First Nations partners, have developed agreements to work together for mutual benefit. At the individual mine and community level, there have been instances of constructive engagement, as well situations of physical resistance and legal challenges. The purpose of this paper is to examine the potential impact of new rules under the Ontario Mining Act introduced in 2012 and taking full effect in 2013, which amongst other procedural specifications, addresses the issue of mining industry-Aboriginal consultation in exploration and development activities. Leading up to the passage of the regulations, representatives from some junior mineral exploration companies have been highly critical of the new rules. Similarly, there have been a range of responses to the new rules from some in the First Nations community. The paper will review the regulation in terms of its apparent alignment with SCC decisions and the international norm, compare the regulations with existing mining sector organization guidance documents, and it will draw on the stated perspectives and commentaries of First Nations communities, mining firms, governments, nongovernmental organizations, and others. Building on the foregoing, the paper will provide a preliminary analysis of the perspectives and potential impacts of the new regulation on various stakeholders, and on that basis, possible avenues for further consideration will be suggested.

Aug 1, 2013

By Arthur W. T. Grimley

Hydraulic coal mining is being successfully practiced in China, U.S.S.R., Japan and Canada and in each country, excepting Japan where suitable sites are not available, the system is being expanded to either existing conventional mines or new mines. Productivity levels and economics at these mines are in all cases better than the productivities achieved in conventional mines in the same general localities. In the U.S.S.R. face productivities approaching 50 tons per man shift have been reported while in Canada the latest statistics show average face area productivity levels are in the region of 200 tons per man shift production monitor. In the United States hydraulic mining has not been actively pursued to the same degree and consequently there are no full scale hydraulic coal mines in operation or construction. Because many of the coal measures in the Western U.S.A. are generally somewhat similar to those being successfully hydraulic mined in Western Canada and parts of Siberia it is realistic to believe that successful hydraulic mines can be designed and developed in the Western U.S.A. Particularly if the vast technological base that already exists is used to improve on other people's ideas, systems, methods and equipment.

Jan 1, 1983

By E. C. de Beer

"SynopsisA number of important areas in nuclear fuel cycle, at both the front end and back end, offer ideal opportunities for the application of non-destructive evaluation techniques. These techniques do not only provide opportunities for non-invasive testing of e.g. irradiated materials, but also play an important role in the development of new materials in the nuclear sector. The advantage of penetrating radiation used as probe in the investigation and testing of nuclear materials makes X-ray and neutron radiography (2D) and tomography (3D) suitable for various applications in the total nuclear fuel cycle. The unique and different interaction modes of the two radiation probes with materials provide several opportunities. Their complementary nature and non-destructive character makes them most suitable for nuclear material analyses, analytical method development, and the evaluation of the performance of existing nuclear material compositions. This article gives an overview of the X-ray and neutron radiography/tomography applications in the field of nuclear material testing, and highlights a few of the success stories. Several selected areas of application in the nuclear fuel cycle are discussed to illustrate the complementary nature of these techniques as applied to nuclear materials.IntroductionDuring the development of new materials for the nuclear industry, materials testing and characterization are of the outmost importance to maintain safety standards and reliability. No compromise on safety in the workplace in any area within the total nuclear fuel cycle can be tolerated, and therefore most in-situ material characterization and testing is conducted by certified and qualified personnel schooled in destructive and non-destructive testing (DT and NDT) methods. Certification and qualification in NDT can be obtained through many training centres in South Africa in accordance with European, American, and other international standards (SGS, n.d.; SAIW, n.d.; African NTD Centre, n.d.)."

Jan 1, 2015

By B. J. Scheiner

The Bureau of Mines has developed a system for dewatering waste slurries by flocculating mineral particles with polyethylene oxide (PEO) and dewatering the resulting flocs on static and/or rotary screens. This paper discusses data obtained from dewatering, rheology, and ion-exchange experiments. A possible mechanism is postulated for the attachment of PEO to claylike particles through a water bridge with the intershell waters of the exchanged ion and the polymer.

Jan 1, 1986

By W. C. Hirt

Deposits of ferromanganese crust containing cobalt and nickel occur on the seafloor in the Pacific Ocean near the Hawaiian Islands and Johnston Atoll. This paper describes developmental flotation metallurgy to separate crust from its associated substrate gangue. Important variables in ferromanganese crust flotation include reagent type, aeration rate, conditioning time and agitation intensity, pH, temperature, water type, and feed size distribution. Flotation in seawater of minus 600 ~m (-28 mesh) material assaying 6.2% Mn, 0.2% Co, and 0.13% Ni with diesel fuel-crude tall oil-sulfonate collectors produces concentrates assaying 15% Mn, 0.6% Co, and 0.3% Ni with recoveries of 89-95% while removing 62% of the feed weight.

Jan 1, 1990

By F. S. Wartman

The presence of magnetite, either dissolved or suspended as solid crystals, in slags from the copper reverberatory furnace is a frequently mentioned cause of an abnormally high copper content in those slags. The presence of this oxide in the slag is to be expected, since it is present in appreciable amounts in both converter slag and roaster calcine which comprise a considerable proportion of the furnace feed. Magnetite is also a product of some of the furnace reactions. These abnormal losses result in several ways. Magnetite is supposed to favor the formation and retention of copper ferrite, in the slag. Crystals of solid magnetite suspended in the slag are objectionable-because they make the slag less fluid and often entrap globules of matte. Frequently these crystals settle into a layer at the slab-matte interface which may have such mechanical strength as to create a false bottom and interfere with furnace operation by preventing separation of matte from slag. Magnetite may, by crystallizing on the furnace bottom, build the bottom to such a level that the furnace can no longer be operated.

Jan 1, 1928

By Miroslav Raudensky, Kallol Bera, Jaroslav Horsky, Jee G. Chang, Ampere A. Tseng

"A combined experimental and finite element approach to study the local heat transfer coefficient is presented in this paper. The heat transfer coefficients at different cooling regimes in a roll are quantified by an inverse heat conduction technique; the heat transfer phenomena involved are then discussed. A discussion of the application of the heat transfer information found in the present study for better design of a roll cooling system is also included. Finally, an identification of areas where further work is needed is presented.IntroductionIn metal rolling processes, the roll is used as a tool to deform the workpiece at very high speeds. As shown in Fig. 1, the heat transfer phenomena involved in the process are complicated by the interaction between the roll and the strip, mainly including 1) the heat transferred from the workpiece to rolls in the contact regions, 2) the heat created in the interface due to the deformation of the workpiece and the friction between the workpiece and roll, and 3) the heat removed by watercooling as well as the ambient air. All of these transport phenomena occur at extremely high pressure, high speed, and high heat flux; these make the control of the roll temperatures an extremely challenging problem.In hot rolling, proper cooling of rolls can lead not only to improve the roll shape quality by controlling the thermal crown of the roll, but also to extend the roll life by minimizing the thermally induced stresses [1,2]. Also, knowledge of roll temperatures can contribute to insights about the roll/workpiece interfacellubricant behavior, and lead to the desired surface condition of the workpiece. Therefore, adequate roll cooling or control of roll temperatures is of critical concern to mill designers and process engineers. In order to have proper operation of the process, a good understanding of the influence of cooling practices on the roll is essential [3]."

Jan 1, 1994

By D. B. Stewart

In the past few years, much effort has been spent in elucidating the impact of diesel engines on the mine environment. This paper summarizes diesel fundamentals , exhaust emissions and typical tailpipe concentrations. Mine sampling results and an evaluation of exhaust treatment systems are discussed. A review of changes in pollutant concentrations between the tailpipe and the mine exit is made and suggestions are given to reduce operator exposure to diesel contaminants.

Jan 1, 1978

By R. W. Utley

The purpose of this study was to seek and evaluate possible relationships between the composition of coal refuse, as expressed by washability data, and factors affecting the product ion of a lightweight aggregate from refuse by bloating. The study was related to an intense program in the Department of Mineral Preparation at the Pennsylvania State University to study the possible elimination of air pollution from coal refuse fires by producing a low- carbon secondary refuse. Another phase of this program is considering possible uses of such a secondary refuse. Thus one study was to determine if a lightweight aggregate could be produced from this new refuse material and what effect the nature of refuse beneficiation would have upon the characteristics of a commercial aggregate product.

Jan 1, 1965

By M. de Beer

The conversion of carbon-containing feedstock into liquid fuels can proceed via the Fischer-Tropsch synthesis, which is catalysed using supported cobalt catalysts. These catalysts contain noble metals to facilitate the reduction of oxidic cobalt species in the catalyst precursor to metallic cobalt, which is the catalytically active species for the Fischer-Tropsch synthesis. This is thought to occur via hydrogen spillover, i.e. the diffusion of atomic hydrogen over the support from the noble metal to the oxidic cobalt moieties. Noble metals may also affectthe dispersion of cobalt in the active Fischer-Tropsch catalyst. The economic aspect of the addition of noble metals to the Fischer-Tropsch catalyst is discussed.

Jan 1, 2014

By R. W. Nash, A. E. Schwaneke, V. R. Miller

The Bureau of Mines developed a detector for controlling sorting devices to separate the copper-bearing fragments from the barren portion of Michigan native copper and western prophyry copper ores. A successful sorter could be used to preconcentrate the ore and eliminate costly hoisting or hauling of waste. An induction balance unit was developed and used in sorting tests on crushed sized - 2.5 + 1. 3-cm (- 1 + 1/2- in.) ores from the Kingston (0.9% Cu) and Centennial (1.6% Cu) mines of Upper Michigan. Concentrates of 4.0% and 7.5% Cu, respectively, were obtained at recoveries of 85 and 80% of

Jan 8, 1978

By E Widzyk-Capehart, P Vallejos, R Asenjo, J Ruiz-del-Solar

Throughout the minerals industry, it is evident that a new wave of technological innovation is needed as the mining sector looks for ways to achieve higher security and safety as well as higher production rates with less investment. Innovation has always been one of the key factors in achieving success within the mining industry. However, its importance will be especially relevant in the coming years if negative trends in commodity prices and new challenges facing the industry (lower grades, deeper mines and economy of scales) are to be overcome and the future sustainability and profitability of the sector ensured.The drive towards fully autonomous operations has begun, with the implementation of automated systems in both surface and underground operations. However, these automated systems are currently planned and realised with well-defined automated tasks within structured environments and isolated spaces. Currently, there is no interaction between automated systems, manned systems or humans, which creates physically isolated environments.For fully autonomous and continuous operations, the automated systems need to operate in environments that enable flexible interactions between automated machines, tele- and manually operated machines and humans.In this paper, we address the automation paradigm considering the synergistic collaboration between humans and automated systems. In this paradigm, humans and machines would interact in a flexible, collaborative and synergistic way without the need for isolation. The implementation of this concept within mining operations will have to be underpinned by science and technological developments and will require adaptation from many fields, including robotics, automation, distributed systems, communication, human factors, pattern recognition and mine design.The paper also presents the research and development work being undertaken at the University of Chile’s Advanced Mining Technology Center, in collaboration with the Chilean mining industry. This will provide the basis for flexible interactions between humans and technology-based systems towards a future of autonomous and continuous mining systems.CITATION:Ruiz-del-Solar, J, Widzyk-Capehart, E, Vallejos, P and Asenjo, R, 2015. Synergistic collaboration of humans and automated systems – innovative steps towards fully autonomous and continuous mining systems, in Proceedings Third International Future Mining Conference, pp 83–94 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

By G. Haesebroek

In L969 Metallurgie Hoboken-Overpelt started an industrial plant for the separation of iron and zinc from a concentrated CoCL2 solution. Iron and zinc are extracted in column contactors by a solvent containing 12 vol % of tertiary amines in xylene. The extracted metals are stripped from the pregnant organic phase by precipitation with a NaOH solution at pH LL. In this paper an overview is given of the industrial process. In order to overcome some drawbacks of this process (low flash point of the diluent, reagent consumption, batchwise stripping) an alternative solvent extraction process has been examined. In this alternative process, iron and zinc are extracted with an or¬ganic phase containing 50 vol % of TBP in Escaid 110. The pregnant solvent is stripped with water in conventional mixer settlers. Despite the ability of this process to overcome most of the inconveniences due to the use of tertiary amines, it suffers from the poor stability of TBP in concentrated chloride solutions, resulting in unavoidable and inacceptable precipitation phenomena in the stripping section.

Jan 1, 1988

By W Akpan

The Royal Bafokeng community in South AfricaÆs North West Province represents a unique case in Sub-Saharan Africa in terms of its positioning in the natural resource economy. It receives royalties directly from mining firms for the extraction of Platinum Group Metals, which include platinum, ferrochrome, rhodium and palladium. In 2007, royalty income of about R290 million (approximately US$32.2 million) was reported. Such direct revenues have enabled the community to invest in educational, medical and other social infrastructure, thus complementing governmentÆs social provisioning efforts. Indeed, the Bafokeng community owes its present-day modernisation efforts to mineral rights, and in particular, the legal-institutional arrangement that has enabled it to play an active role in South AfricaÆs lucrative extractive economy. However, the distribution of platinum wealth in this community is not only uneven, but also appears to have had little impact on the broader socio-economic conditions in the community. Despite claims by community leaders of heavy investment in education and skills development, the community continues to be faced with very high levels of unemployment, illiteracy, sprawling informal settlements, poor access to medical facilities and malnutrition. This paper examines the sociological paradoxes and contradictions thrown up by the approach adopted to involve community members in the mobilisation of mining royalties for developmental ends. The central argument is that the current æmodelÆ contradicts the communityÆs stated goals of using platinum wealth to drive up broad-based development and modernisation. This is mainly because it leaves out the vast majority of community members, who are uneducated and unskilled. The core analysis is based on pilot data from an ongoing study in the Royal Bafokeng community.

Jan 1, 2009

By E. C. Harder

BRITISH Guiana, Great Britain's only South American colony, may be reached by very comfortable steamers, both from North America and Europe. The trip from North American Atlantic ports requires about 12 to 14 days; that from Europe about 18 to 20 days. A number of steamship lines, including Canadian, American, and Dutch, have regular sailings between North America and British Guiana, with calls en route at various interesting ports in the West Indies and northern South America. Moreover, several lines, including British, German, and French, have steamships operating regularly between Europe and the West Indies. Indeed, so popular have the West Indian voyages become in recent years that, during the winter months, special cruises in considerable number are organized for many vessels that ply in the trans-Atlantic service in the summer. A trip to British Guiana, therefore, has become a delightful experience. After visits at the various attractive Leeward and Windward islands and Trinidad, the approach to the low, flat, British Guiana coast, with its muddy coastal waters extending for many miles offshore, is somewhat of a contrast. Arrival in Guiana waters is signalled by the appearance of the modern high-power Demerara Light, located "on a shoal about twelve miles from the mouth of Demerara river. From this point, if the tide is right, a pilot takes the steamer across the bar, eight to ten miles offshore, and into Georgetown harbour. At high tide, the water above the bar ranges from 15 to 18 feet in depth, depending on whether it is neap tide or spring tide; at low tide, the corresponding depths are 9 to 11 feet. As the bar is of soft mud, however, it is usually possible for vessels to pass over it with a draught of about two feet in excess of that indicated by the tide tables. Upon nearing the shore, one sees first the Georgetown wireless towers, then the light-house and the tall chimneys of sugar mills and of various factories in Georgetown, and finally the palms and other tropical trees and the houses of Georgetown itself along the sea shore and the east bank of Demerara river. Extensive wharves operated by various exporting and importing companies stretch along the river bank and activity prevails in Georgetown harbour. The principal exports are sugar, rice, gold, diamonds, bauxite, balata, lumber, fruit and other tropical products. The imports are food-stuffs, wearing apparel, and manufactured materials of many kinds.

Jan 1, 1936

By E. J. Lintner

This paper is one of a series being prepared by the United States Bureau of Mines describing clay mining, crushing and grinding methods, and costs, at various operations throughout the United States. These papers are designed to disseminate technical information regarding methods used. The, cost tabulations represent local operating expenditures only and not total production costs. It is recognized that publication of total production costs may in many instances cause embarrassment to the individual operator as well as to the industry as a whole. On the other hand, operating costs are essential to the technical discussion and study of the methods employed. The attention of the reader is specifically called to this differentiation in order that no misunderstanding of the scope of the cost tabulation shall ensue. The following report deals specifically with the methods employed by the Evans Pipe Co., Uhrichsville, Tuscarawas County, Ohio. The author wishes to acknowledge the assistance of the following company officials: T. J. Evans, II, president; T. J. Evans III, vice president and general manager; and L. P. Young, general superintendent.

Jan 1, 1936

By C. Dorfling

Experimental work was performed using a bench scale autoclave to evaluate the effects that leaching temperature, pressure, initial acid concentration, and the solid to liquid ratio have on the behaviour of base metals and platinum group metals in a high-pressure sulphuric acid oxygen leaching system. The concentrations of metals in the leach solution were measured over time at different leaching conditions. At the conditions investigated, the initial acid concentration had the largest influence on the copper leaching kinetics, while the leaching rates of the other precious metals (OPMs: rhodium, ruthenium, and iridium) were highly dependent on the leaching temperature. A set of chemical reactions that can be used to describe the leaching chemistry was proposed, and the associated reaction kinetics were quantified. As a first estimation, the rate expressions were considered first order, and the rate constants were determined using the method of least squares, considering the experimental and predicted concentrations obtained for the different leaching conditions. Of the OPM compounds, the sulphides showed the fastest dissolution rate, followed by OPM alloys, and finally the OPM oxides. During the initial leaching stages, base metals and OPMs competed for the available dissolved oxygen, with oxygen being preferentially used for copper leaching. Precipitation of OPMs during the initial leaching stages can be ascribed to copper and nickel dissolution according to exchange reactions between dissolved OPMs and copper present as digenite or nickel present as polydymite. Control of the autoclave residence time is of particular importance to enhance the selectivity of this leaching step, given the dependence of the PGM leaching rates on the extent of copper dissolution.

Sep 1, 2012

By J. D. Dixon

This Bureau of Mines report describes the results of an investigation for developing and applying procedures for stabilizing excavations openings in highly yielding ground. The approach developed in this report involves nonlinear modeling of the progressive relaxation of the zones of rock mass around the excavations opening where Coulomb criterion of failure is exceeded. Stresses are calculated by using a computer code; Coulomb-failure condition is examined for both intact rock and joints (using strength parameters [~] and c). The rock mass in the failed zones is relaxed by reducing the Young's modulus of the rock based on an empirical formulation that is a function of the shape of the opening and the extent of the failed zone. In addition, the material in the failed zone is assigned reduced strength paramters 0' and c'. The limiting (or convergent) relaxed zone is obtained through an iterative process by manually changing the rock modulus and the strength parameters between iterations. Support pressures are computed by applying forces normal to the excavation surface. The approach is applied to the analysis of stability and support requirements for an entry in a longwall coal mine.

Jan 1, 1985