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By C. B. Kenahan

The Bureau of Mines is developing methods for reclaiming the metal and mineral values contained in municipal incinerator residues. This report describes the first phase of the research, in which reliable methods for sampling and analyzing municipal residues were established and the composition and characteristics of the residues were determined. Samples were obtained from a variety of grate-type furnaces and also from a rotary kiln furnace. The samples were processed on a batch basis and separated into their natural categories by a variety of methods including screening, magnetic separation, air separation techniques, and handpicking. The main components of the residues were determined to be metal and metal oxides, glass, and ash.

Jan 1, 1968

By C Hall, J L. Mauk

New 40Ar/39Ar dates of vein and wall rock adularia from seven epithermal deposits and one porphyry copper prospect help constrain the ages of mineralisation in the Hauraki Goldfield. Vein adularia from the Paritu region yielded a single 40Ar/39Ar plateau date of 16.315 ¦ 0.066 Ma. Five 40Ar/39Ar plateau dates of three samples of vein adularia from the Opitonui deposit overlap within error to yield a preferred age of 13.149 ¦ 0.016 Ma. Two samples of vein adularia from the Night Reef at the Broken Hills deposit yield exceptionally flat 40Ar/39Ar plateaus, and all dates overlap within error to provide an age of 7.121 ¦ 0.010 Ma. Two 40Ar/39Ar plateau dates of one sample of vein adularia from the Wharekirauponga deposit overlap within error to provide an age of 6.318 ¦ 0.061 Ma. Four 40Ar/39Ar plateau dates of three samples of vein adularia from the Maratoto deposit overlap within error to provide an age of 6.411 ¦ 0.022 Ma. Two samples of adularia from altered wall rock at the Sovereign deposit yield three 40Ar/39Ar plateau dates that range from 6.547 ¦ 0.021 to 6.806 ¦ 0.028 Ma. This suggests that mineralisation formed around 6.6 Ma, but the results are complicated because the adularia contains minor illite that post-dates adularia formation. Results from the Karangahake deposit are complex. Two samples of vein adularia yield three 40Ar/39Ar plateau dates that range from 6.116 ¦ 0.116 to 6.901 ¦ 0.101 Ma, whereas one sample of wall rock adularia that contains minor late illite yields two 40Ar/39Ar plateau dates that overlap within error to provide a date of 5.734 ¦ 0.041. The range of dates indicates that more work is necessary to understand the history of mineralisation at this deposit. Two samples of vein adularia from the Tui deposit yield four 40Ar/39Ar plateau dates that overlap within error to provide an age of 5.714 ¦ 0.017 Ma. These results confirm previous work that indicates that the ages of epithermal deposits young southward in the Hauraki Goldfield. These results are also consistent with previously postulated different ages for deposits hosted in Kuaotunu Subgroup rocks in the northern goldfield (>10 Ma), and deposits hosted in Waiwawa Subgroup rocks in the southern goldfield (7.1 to 5.7 Ma).

Jan 1, 2005

By Luis Vassallo

El presente trabajo señala los beneficios que pueden obtenerse de la adopción inteligente de una estrategia de colaboración electrónica que responda a las necesidades de este segmento y que proporcione soluciones de verdadero valor agregado. Así, el modelo monolítico que prevaleció por muchos años, donde cada empresa era propietaria de las licencias mineras, operadora, mantenedora, contratista, vendedora, embarcadora y financiera, está desapareciendo. En la cadena de valor del proceso minero intervienen más empresas, contribuyendo valores agregados específicos y especializando funciones. Este cambio demanda mayores flexibilidades de los sistemas de información que deben ser totalmente abiertos, y permitir el intercambio instantáneo de información que facilite reaccionar oportunamente a las diferentes variables de la operación. Por ello, la colaboración electrónica permite a la minería adaptarse a un mundo que está cambiando.

Aug 25, 2002

By Frederick H. Raab

A power-line proximity-warning (PLPW) system must have a high probability of detection (alarm activation at a specific distance), low probability of false alarm, and minimal set-up and maintenance. Tests of electric-field sensors have not demonstrated a dependable alarm distance. Alternative sensing methods such as microwave radar, optical radar, and sonar can meet the requirements by direct measurement of the range from the boom to the power line. Suitable microwave techniques include RF pulse, chirp FM/CW, and baseband pulse. Baseband-pulse radar has adequate range capability and does not require expensive microwave components. The radar cross section of a power-transmission cable is adequate for its detection optical-radar systems based upon LEDs and photodiodes are inexpensive, but can achieve only marginal performance in this application because of their limited modulation bandwidth. Since laser diodes and cryogenically cooled photosensors must be used to achieve the desired range resolution, the cost of an optical-radar system is greater than that of a microwave radar system. Sonar systems are feasible, but are not as precise and cost at least as much as baseband-pulse-radar systems. The performance of both optical-radar and sonar systems is degraded by dirt, necessitating the inclusion of a "windshield wiper.' Baseband radar appears well suited to the PLPW application. The cost of a baseband-pulse radar PLPW system is expected to be comparable to that of an electric-field PLPW system. Development and testing of an experimental model are therefore recommended.

Jan 1, 1982

Lower Miocene Maryville Coal Measures at Waitewhena Coalfield, in the Taranaki coal region, include seams of sub-bituminous coal up to 4 m thick. During coalfield exploration Fletcher Challenge Ltd drilled ten cored holes, all of which encountered at least one seam. Coal quality is variable. Ash ranges from six to 12 per cent and sulphur from 0.5 to three per cent. A basal seam, overlying the Lower Mokau Sandstone, appears to extend throughout the area under investigation. A rider seam, of variable thickness, closely overlies the main seam in most drillholes. The rider converges with the main seam to the north and vertical trends in coal properties suggest that the seams are united in some locations. A less extensive seam sometimes occurs at the top of the coal measures beneath the Upper Mokau Sandstone. The lithostratigraphy of the intervening coal measures is complex, and coexistence of fluviodeltaic, lagoonal/lacustrine, and marine depositional environments is provisionally inferred. Lateral variations in coal properties (clastic derived ash, volatile matter, inertinite, hydrogen), thickness of the sedimentary parting between the basal seam and rider, texture of the coal measure sediments, and distribution of the upper seam all indicate persistence of a relatively low lying northeast-trending zone which may have been structurally controlled. Available data indicate that coal measure accumulation was terminated by marine transgression from north to south.

Jan 1, 1987

By Javier Támara

Para aumentar la productividad de la empresa minera es necesario conocer el sistema de aire -en tanto se prioriza los intereses de los clientes, y así se puede suplir todos los componentes necesarios para garantizar una máxima eficiencia y confiabilidad del sistema completo de aire comprimido que va desde el filtro de admisión hasta el punto de uso. En ese sentido, el presente texto describe las estrategias para realizar Solucionazing en ahorro energético y así aumentar la produtividad de los sistemas de aire.

Aug 25, 2002

By Gary A. Kingston

Low-cost hydroelectric energy in the Pacific Nortnwest has been an important factor in the development of a ferroalloy industry. Eleven companies, employing approximately 1,000 persons, produce about 116,000 tons (1954-58 average) annually of ferrosilicon, ferrochromium, ferromanganese, ferrophosphorus, silicomanganese, and ferronickel. About 7,500 tons (1954-58 average) of these ferroalloys is consumed in the Pacific Northwest States of Washington and Oregon; the rest is used principally in other western and mid-western markets. In 1959, the Bureau of Mines began a study to determine the current status and to evaluate the potential of the ferroalloy industry in the Pacific Northwest. The Bureau gathered information from operating alloy plants in Oregon, Washington, Idaho, and Montana; from published materials; and from consumers of ferroalloys.

Jan 1, 1962

By A. C. Richardson

The mine of the Porter Coal Co. is located at the town of Porter in the northwestern part of Jefferson, County, Ala., about 20 miles west of Birmingham. The operations in this mine are confined to the middle and bottom benches of the Mary Lee bed. The coal from the Porter mine is handpicked and washed before being placed on the market. The handpicked lump coal and the washed egg and nut, coal are sold chiefly as domestic and steam-raising fuel. The coal finer than 1 inch is washed in 2-compartment jigs and utilized in the manufacture of metallurgical coke. The coal company has found that, when coal ranging in size from 1 to 0 inch is washed in jigs, a considerable amount of high-ash material finer than 3/16 inch remains in the washed coal. This paper gives the results of an investigation which was conducted for the purpose of determining the washing characteristics of the through 316-inch raw coal and the extent to which the ash might be reduced by means of coal-washing tables. This investigation has been made in connection with an. extensive study of the coal-washing problems now being conducted by the United States Bureau of Mines and the University of Alabama, with the cooperation of the coal-mining companies of the State.

Jan 1, 1933

By Blaisdell J. L, MacPherson G

The present communication records the results of a research investigation conducted in the Porcupine Gold Mines in Timmins, Onto. Soon after silicosis became a compansable disease in Ontario under the Workmen's Compensation Act in 1926, the attention of mine operators and physicians was drawn sharply to the prevalence and importance of this condition in the mining industry. A number of examining centres were established in Northern Ontario by the Workmen's Compensation Board, and the yearly X-ray examination of miners was made compulsory.Although working conditions were soon improved, the mining industry realized that they were confronted by a problem demanding basic research for its final solution. The late Sir Frederick Banting had, for a number of years, been interested in silicosis, and it was upon his suggestion that an experimental investigation was undertaken at the McIntyre-Porcupine Mines Ltd., Schumacher, Ont., in November, 1932. A preliminary report of this investigation was published in 1937 by Denny, Robson and Irwin and a further report by the same authors in 1939.Accepting the theory that silica exerts its injurious effect upon animal tissue through a slow transformation into silicic acid in the presence of body fluids; these authors assumed that if the solubility of the silicious material retained in the lung could be sufficiently reduced, the usual fibrotic response would be modified or would not occur. A search was therefore undertaken for some non-toxic compound that would fulfil this purpose. After investigating ma:qy substances, Denny and Robson discovered in 1936 that the presence of small amounts of aluminum powder almost completely inhibited the solubility of silicious material in vitro. An intensive study of the mechanism involved later showed that the reduction in solubility was due chiefly to a coating of the silica particle with a thin film of a gelatinous hydrated alumina which on drying formed the crystalline alpha aluminum monohydrate boehmite (AI203.H20). The presence of this absorbed layer on the surface of the quartz was indicated by -staining it with aurin (ammonium salt of aurin tricarboxylic acid) and proved by Germer and Storks by means of electron diffraction patterns.Inhalation experiments with animals were at once begun, using pure quartz dust with and without aluminum powder. (See original communications.) These observers showed that while typical silicosis was produced in about 5 months in the control animals receiving silica dust alone, the...

Jan 1, 1945

During the period 1979 thru 1982, Multi Mineral Corporation conducted a mining research program at the United States Department of the Interior's Bureau of Mines Oil Shale Mining Environmental Research Facility in the Central Piceance Creek Basin, Rio Blanco County, Colorado. The program consisted of mining, environmental and geotechnical research data and, the results are described in this report.

Jan 1, 1983

By K. R. P. Petersen

Paper written on project work carried out in partial fulfilment of M.Sc. Eng.(Metallurgical Engineering) degree The interrelationship between mineral liberation and leaching behaviour of a gold ore is ill defined, mainly due to the complexity of both leaching and mineral liberation. This study presents a neural network approach to modelling the liberation of gold bearing ores. A complete mineralogical analysis of unmilled and milled ores, including gold deportment and gangue content are used as inputs to a self-organizing neural net, which generates order preserving topological maps. The arrangement and shapes of these clusters are coupled to unmilled free gold data to predict gold liberation in milled ores (absolute error: 8.1%). Moreover, the self-organizing maps were diagnostic of the quality of data used, indicating that the relationship between particle size and gangue material content requires further investigation.

Jan 1, 2003

The area (330 sq. miles) shown on the map of the Brocks Creek District (Fig. 1), was mapped by the Northern Territory geological party of the Aerial, Geological and Geophysical Survey of Northern Australia. This work was done in two stages:-(i) In 1935, an area of 30 sq. miles around the Golden Dyke mine was mapped by P. S. Hossfeld, Senior Geologist, and A. H. Voisey, Assistant Geologist. The results were described in a detailed report (10).(ii) In 1939, an area of 300 sq. miles in the Brocks Creek district was mapped by C. J. Sullivan (Senior Assistant Geologist), and V. M. Cottle and S. N. Kiek (Assistant Geologists) under the general supervision of P. S. Hossfeld (Senior Geologist).An outline structural map, together with some geological notes was published (1), but that map does not show the amphibolites, and the relationship between ore occurrence and general geology is not emphasised. The publication of the detailed maps and reportwas postponed indefinitely as a result of war. The original mapping was based on air photographs with a scale of approximately 1 in. to 1,200 ft., and all detail which could be shown at that scale was mapped. Features recorded included rock types, details of structure, mineralisation, and surface workings, creeks and soil boundaries. Underground mapping was also carried out. The present map is much simplified from the original, but it is hoped that it shows sufficient information to reveal close relationship between structure, granite, sills of amphibolite and gold occurrence. About 50 per cent. of the area is covered by deep soil or alluvium, and in these portions the geology of the underlying rocks was not determined with accuracy, though in many places strike trends could be deduced from air photographs.Because the A.G. & G.S.N.A. had published the geological notes and map referred to above, and because the publication of the detailed report and maps is still postponed indefinitely, approval has been given by the Bureau of Mineral Resources, Geology and Geophysics (which took over the affairs of the A.G. & G.S.N.A. at the termination of its operations) to the preparation of the present paper so that information would be available to the public.The views expressed in this report are those of author. The results of the investigation suggest that in areas where granites are predominantly concordant with bedding, ore deposits may be found at approximately the same stratigraphic horizon. It is thus important to correlate beds even though their relationship may have been obscured by faulting and folding.

Jan 1, 1950

By B. Burke, R. Colquhoun, K. Thomas, R. Walton, D. Fentie

The new Roasting Facility at Barrick’s Goldstrike Mine in Nevada, U.S.A. was developed to process 12,000 tons per day of refractory gold ore. The process consists of crushing, dry grinding, roasting, extensive gas purification, calcine quenching and leaching in the presence of activated carbon. The new plant is integrated into the existing Goldstrike facility, treating ore from both open pit and underground sources. The process design, procurement, construction and commissioning of the Roaster facility was performed successfully over a 3½ year period with peaks of 400 engineering personnel and 950 construction personnel supporting the project. The US$330,000,000 project was completed ahead of schedule and under budget. The commissioning was well planned and proceeded smoothly through a rapid start-up to achieve all primary goals within three months of the start of processing of ore.

Jan 1, 2001

By Clements R. J, Davey J. M

Development of the process from the pilot stage to the current operation of the Capel, WA plant is briefly described.The design criteria for a larger sized plant are discussed together with factors that relate suitable feedstocks and coal types to the capital cost, capacity and product grade of future plants at locations other than Capel. The application of the process to the direct reduction of iron ores is briefly discussed including its commercial application at Rockwood, Tennessee.

Jan 1, 1980

By Vincent Joannes, Marine Lasne, Luca Brenelli, Colin Serridge, Inge van Baardwijk, Martin Stanley, Anthony Fisher, Mary Ellen Bruce, Tony Suckling, Pedro Avellanosa

"Abstract The European Federation of Foundation Contractors (EFFC) and Deep Foundations Institute (DFI) developed a sector-specific carbon accounting methodology and associated “carbon calculator” for foundations and geotechnical works. The EFFC-DFI Carbon Calculator is believed to be one of the construction industry’s first collaboratively produced carbon calculator tools for European and international countries based on verifiable and standardized data. It is intended that the tool be adopted internationally and become the open-source industry standard for ground works. A detailed methodological guide is provided with the calculator (Lemaignan and Wilmotte, 2013). This guide explains the background of the standards, accounting methodologies, emission sources and factors that were used as the bases for the tool development and includes detailed guidance on use of the calculator.Drivers for DevelopmentFoundation contractors anticipate project cost and carbon emissions will become inextricably linked in response to the climbing price of fossil fuels and carbon intensive materials as resources become scarce. Low carbon solutions will therefore become more competitive options. Also with high profile construction projects having low carbon/carbon neutrality as requirements, sustainability in the foundations industry also becomes a market issue.This carbon calculator will be used to lead the industry and shape the expectations of commissioning organisations by providing insight into the carbon cost of their projects. Commissioning organizations are encouraged to be aware of the carbon impact of projects and to also facilitate a fair and accurate way of comparing footprints to provide a level playing field for foundation contractors."

Jan 1, 2014

By Xiang Sun

Microwave heating has been used in numerous industrial processes due to its great advantages when compared with conventional heating methods. However, microwave heated products can be affected by non-uniform temperature distribution resulting from the mechanisms of microwave heating. To overcome this problem, a critical step is to have a temperature-time profile. In order to characterize and evaluate microwave heating effects, an accurate temperature measurement is needed. This paper discusses the possibility of applying several temperature measurement techniques in microwave processing. Both contact and non-contact methods are introduced and compared.

Jan 1, 2006

By J. K. Afidenyo, J. Osei-Owusu

"The Obuasi Mine of AngloGold Ashanti Limited has been operating the world’s largest Biooxidation Plant at its Sulfide Treatment Plant (STP) in Ghana, using the Gencor Biox® technology since February 1994. The Biox® technology was preferred to other alternative methods of treating refractory sulfide ores such as roasting, pressure oxidation and nitric acid leaching due to among other reasons, its lower capital and operating costs, reduced technical risk, relatively benign environmental impact and its ease of operation and maintenance in a remote location.STP has since commissioning succeeded in operating this technology successfully but not without some operational problems. The Plant has seen a number of upgrades and modifications in its circuits which were motivated by cost, operational and throughput constraints.The objective of this paper is therefore to highlight the mine’s experience in the treatment of its complex carbonaceous refractory sulfide gold ores with emphasis on plant operations and improvements such as the Biox® reactors expansion, flotation concentrate upgrade project and neutralization circuit modifications. The Biox® Plant operating cost is also discussed.INTRODUCTIONThe Obuasi mine forms part of the AngloGold Ashanti Group of Gold Mines. It is located in the Adansi West District of the Republic of Ghana. The mine is primarily an underground operation, although some surface mining still takes place. Ore is processed by two main treatment plants: the Sulfide Treatment Plant (for underground ore) and the Tailings plant (for tailings reclamation operations). A third plant, the Oxide Plant, is used to batch-treat remnant opencast ore and stockpiles, of which there are adequate tonnages to keep the plant operational until 2008.Though reference is made in this paper to the Tailings and Oxide Treatment Plants, the main focus will be on the Sulfide Treatment Plant."

Jan 1, 2008

By C Bellia, A Maldonado, S Strong, H Baxter

This paper discusses the technical and cost benefits of alternative data collection techniques used to collect lithological information, obtain laboratory testing samples and perform in situ testing. A comparison between diamond coring and sonic coring techniques is made using data from a recent geotechnical investigation for a final pit slope cut-back. The impacts of the coring method on laboratory strength testing results, material character testing and, ultimately, the mass strength parameters and subsequent slope design adopted are compared. The sonic coring method was chosen out of necessity and enabled the collection of tube samples of a clay unit of interest as well as bulk samples for material character and geochemical testing. The sonic coring generated unexpected degradation of clastic units, while cohesive clay-dominated units were recovered well. The likelihood that disturbance due to the coring method would result in lower than expected triaxial strength results was recognised ahead of time, with surplus samples collected and single-stage triaxial strength testing undertaken. This testing compared favourably with historic three-stage testing, where sample degradation occurred during the later stages. Material character testing of fine-grained, clay-dominated units was comparable with historic diamond core testing, while grain size estimates for more clastic units tended to be finer than previous results. The use of sonic coring over non-cored methods enabled the collection of material texture data, geotechnical properties and a full suite of geochemical analyses. This provided a comprehensive understanding of the lithological and geotechnical character of the rock and soil mass. A high-confidence geotechnical model was developed. The end result was the development of a slope design that was more aggressive than was previously designed (5° steeper inter-ramp angle), which has proven to be appropriate to the conditions following excavation. Overall, sonic coring was a cost-effective means of obtaining additional geotechnical data for the site.CITATION:Baxter, H, Bellia, C, Maldonado, A and Strong, S, 2015. Case study assessing alternative data collection techniques and analysis methods to assist with geotechnical slope design, in Proceedings Iron Ore 2015, pp 419–428 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By S. J. Jung

A fundamental study of fragment size distribution and characteristics of fracture pattern is presented for the dynamic penetration of a conical bit into coal block. In this paper, damaged zones during crater formation and fragment size distribution were studied. Bit with a sharper tip angle and a smooth body configuration performed better penetration. Results suggest that in coal cutting the trend should be toward the face cleat direction using a sharper angled tip bits which consumes less energy for an optimum range of penetration depths, thus attaining maximum cutting efficiency and reducing fine fragments.

Jan 1, 1989

By S. Slottee

The technology of making and using ?paste? from mine tailings is increasingly well known by the minerals industry. The primary applications are water recovery and ?stacking? of tailings with minimal use of dams and ponds. This paper highlights some applications, other than water recovery and stacking, that have come to the attention of a paste thickener equipment supplier. As generated by thickeners, paste (also called ?thickened tailings?) is a non-settling, relatively high concentration, suspension of solids that can be pumped. Paste deposits with an angle of repose, allowing minimal use of dams. High solids concentration allows more water recovery at the paste thickener than is achieved in conventional and high rate slurry tailings thickeners. This paper is based on paste as produced in a flow sheet that includes a thickener, underflow pumps that are typically centrifugal, transfer pumps that can be centrifugal or positive displacement, and a distribution system at the deposition site. Examples of paste applications other than water recovery or stacking include: ?mine? an existing tailings pond by removing slurry, recovering coal or iron ore values, and return the new tailings to the pond as a paste that does not res-suspend; use paste to seal an existing tailings pond from leaking to groundwater or to an underground mine; extend the life of an existing tailings pond by thickening the tailings to paste; move an existing dry tailings impoundment to a new location by slurrying, pumping, paste thickening, and redeposit; minimize the size of a filter by paste thickening the feed; operate a paste thickener and filter in parallel on a tailings stream with re-mixing to achieve a high solids concentration. The use of paste tailings technology has been expanding over the last 15 years. The applications, both implemented and under consideration, are increasingly diverse and include all minerals tailings. Tailings handling designers should always consider a paste option to the conventional slurry solution.

Jan 1, 2011