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By B. S. Terry, C. L. Harris

After measuring the kinetics of Ni reduction from a SiO2-saturated fayalite slag into a Cu-based metallic phase on a laboratory scale, a general model was developed that is capable of simulating mass transfer to and from metal-slag, slag-gas and metal-gas interfaces for multiple species. The model was used to simulate the reactions that occur when Cu and Ni are reduced from fayalite-based slags into a Cu-based metallic phase. Good agreement was achieved between model predictions and experimental data

Aug 1, 1995

By P Knight, P A. Walker, H E. Speight

Pushback 8 South is the final cut back on the south wall of the East Pit at BHPBilliton?s Mt Whaleback iron ore mine in the Pilbara region of Western Australia. Development of the cutback commenced in 1999 and is now nearing completion with ultimate pit walls up to 300m high. This paper describes the geotechnical, structural and hydrogeological setting of PB8S, reconciliation between design and slope performance and the slope engineering techniques used to effectively manage the risks associated with the slope. These techniques include slope buttressing and sequential mining with waste backfilling, as well as a detailed program of displacement and hydrogeological monitoring, structural mapping and slope stability assessment. During the course of slope formation recent developments in remote slope displacement monitoring using radar and remote structural mapping using terrestrial photogrammetry have also been applied. Aspects of the PB8S slope management plan are relevant to many large scale open pit slopes. This paper provides geotechnical practitioners with information which may be helpful in managing geotechnical risk in similar environments.

Jan 1, 2006

By K. K. Kelley

"INTRODUCTION The Bureau of Mines nitrogen peroxide process (2) 3/ for extracting manganese from low-grade ores is essentially a two-stage process involving the reversible reactionMnO2 + 2NO2 + 6H2O = Mn (NO3)2 . 6H2O (1).At lower temperatures this reaction proceeds to the rigth and affords a means of dissolving manganece and separating it from unreacted ore. At higher temperatures the reaction proceeds to the left and manganese dioxide is recovered and nitrogen peroxide regenerated for recycling. Evidently, therefore, the energy required for decomposition of manganous nitrate is a matter of practical importance. Similar information for certain other nitrates also is desirable beceuse the nitration step of the process produces appreciable amounts of nitrates of other metals, such as iron, aluminum, magnesium, calcium, and barium, some of which are not broken down in the evaporation and decomposition steps. Thus, a portion of the nitrogen peroxide is not directly available for recycling. Whether or not it is feasible to recover nitrogen peroxide locked in the more-stable nitrates depends partly on the energy required and the conditions necessary for their decomposition.To supply information bearing directly on these subjects, several researches were undertaken at the Pacific Experiment Station: (a) Heats of formation (24, 25, 26) of nitrates of manganese, magnesium, calcium, barium, and aluminum were measured at 298.2° K:; (b) low-temperature specific heats (23), in the range 51° to 298.2° K,, and entropies of nitrates of magnesium, calcium, barium, and aluminumm were determined; and (c) heat contents (21) above 298.2° K. of the nitrates of manganese, magnesium, calcium., and barium were measured. The results of these studies, when correlated by thermodymamic methods, permit evaluation, at any temperature of interest, of the energies required to decomposethe nitrates and furnish information concerning the equilibrium pressure temperature relationships."

Sep 1, 1944

By Oswaldo Morales

The shift of mining activities to increasingly more diverse locations places the industry in conflict with local residents over land use and water access. In Perú, there have been significant rises in mining community conflicts with few long term resolutions being apparent. This paper examines the role of culture in these conflicts and suggests that progress maybe able to be made should deliberative engagement occur. Also, that mining conflicts are inevitable and that Peru’s cultural heritage, while contributing to the distance between parties is also the basis from which to start of a process of resolution, should both sides wish to gain the appropriate skills for a more deliberative approach.

Sep 21, 2013

By Russell R. McLellan

Under the Heavy Metals Program, investigations were conducted at the old Badger dill placer mini in Nevada County California to collect data and information regarding drilling and sampling methods and deposit characteristics. The studies contributed to a team effort by five Bureau of Mines research groups to develop new or improved placer mining technology in the Tertiary gold-bearing channel gravel of northern California. This report describes the techniques used and the results obtained in the sampling and drilling stage of deposit delineation studies that were conducted by the Denver Mine Systems Engineering Group. Sampling included the collection and processing of 400 tons of largo and small volume samples from drill holes, underground workings, surface pits, and blast hole rounds. A total of 355 samples averaging 2,296 pounds per sample provided reasonably accurate data for analysis of the gold distribution. These studies indicate that the bulk of the gold is within 40 foot of bedrock in stacked, lenticular zones of cemented gravel that are largely confined to the relatively narrow, meandering course of the deepest portion of the bedrock channel. Drilling studies involved the testing of three types of truck-mounted drills including rotary, bucket and vibratory, none of which proved to be a completely versatile tool for sampling quickly and reliably both consolidated and unconsolidated gravel.

Jan 1, 2012

The 103rd Annual General Meeting of The South African Institute of Mining and Metallurgy was held in the Gold Room, Transvaal Automobile Club, 60 5th Street, Lower Houghton, Johannesburg on Wednesday, 16th August, 2000. Welcome The President extended a special welcome to the guests and representatives of our sister institutes and other associations. Also to recipients of awards, senior members of industry, Honorary Life Fellows, Past Presidents, our Members and other guests, among them the following: Reinie Meyer, President, The Geological Society of South Africa Dr Nielen van der Merwe, Chairman, The South African Institute of Rock Engineering Chris Fourie, President, Institute of Mine Surveyors of South Africa

Jan 1, 2001

By Ajoy K. Singh, B Mohanty, P K. Singh

A study was conducted to investigate the damage potential to underground multiseam openings caused due to vibration generated by open-pit coal mine blasting. The objective was to recommend optimal explosives weight per delay to be detonated in open-pit blasts to ensure the safety and stability of underground openings. Sixteen blasts with varying charge weights and initiation sequences were conducted at Samleshawari open-pit mine and eighty four blast vibration data were recorded in the Hingir Rampur underground colliery in India. Analysis of vibration data showed that roof of the underground openings vibrated with much higher amplitudes compared to those in pillars and floors. The amplifications of vibration in the roof at the junction were upto 4.3 times the pillar vibration. It was observed that coal chips detached from roof when the peak particle velocity reached 131 mm/s or higher. The vibration magnitude recorded was higher in upper-seam openings than in belowseam openings. Rapid attenuation of vibration was recorded in below-seam openings at similar locations. Appropriate particle velocity-charge weight-distance equations were established to calculate the safe explosive weight per delay to be detonated in open-pit mine for the safety of multi-seams workings of underground mine. The support for the galleries and junctions were further modified for the working seams to ensure greater safety.

Jan 1, 2011

By T. M. Williams, P. M. Green

Paper presented at Mineralisation in the Caledonides, the Mike Gallagher memorial meeting held in Edinburgh, 27-28 June 1996. The sediment geochemistry of streams draining Southern Uplands and Lake District turbidites was compared with lithogeochemical data for the source greywackes, using stratigraphically defined catchments. Several systematic trends in element abundance variation between source and stream sediment can probably be applied more widely to interpretation of drainage geochemistry. Pb and Zr increase markedly from source rock to sediment, by adsorption on clay and zircon grain concentration. Variation of feldspar-related elements Rb, Sr, K and Ba appears to be controlled by source grain size and compositional maturity. Ni shows surprisingly little change and Fe and Co are only slightly raised. Cr is particularly useful, with variations superimposed in anomalously high regional levels. Abrupt changes in Cr distribution in stream sediment coincide with stratigraphical boundaries, allowing drainage data to be used as a surrogate for whole-rock values

Jun 19, 1905

By K. L. Paciorek

The aim of the present study is to determine on a gram per gram basis the toxic products of the thermal oxidative degradations of selected compositions. Four families of materials were investigated under the subject contract namely polyvinyl chloride and neoprene compositions, rigid urethane foams I and woods. Three methods were employed to conduct the thermal oxidative degradations: a sealed system (quiescent environment) I a stagnation burner arrangement (dynamic environment) I and a flow-through apparatus (dynamic I but less severe than stagnation burner conditions). The majority of tests were conducted using the first two systems; only limited experiments were carried out employing the third decomposition procedure. All decomposition was done at temperatures of 370 -4000C I the higher temperature being used in the stagnation burner. It has to be stressed that the nature of the products and the relative product concentration are temperature dependent. Thermogravimetric and differential thermal analyses were performed to supplement and extend the above delineated studies and to explore the feasibility of using these analyses as a method for material differentiation.

Jan 1, 1973

By T. Johnson

Mining activity in a number of metal ores has been running quite high over the last few years. In particular, those metals that employ acid functional extraction processes such as copper, nickel, cobalt and uranium have been particularly active. The world?s largest nickel mine ? the massive $4.76 billion Ambatovy nickel mine on the African island nation of Madagascar is nearing completion. When it reaches its full production capacity in 2013, the mine will produce 60,000 MT/yr of nickel and 5600 MT/yr of cobalt. Coming on the heels of the Ambatovy project is the Long Harbour Processing Plant in Newfoundland, Canada which will process the ore from Vale?s Voisey Bay mine in Labrador. Voisey?s Bay is expected to generate more than 50,000 MT/yr of nickel ore when it starts up in 2013. Next up will be the Boleo project in Mexico on the Baja peninsula. When commissioned in 2013, the $1.4 Billion Boleo project is expected to produce 60,000 MT/yr copper, 3100 MT/yr cobalt, 36,000 MT/yr zinc and 100,000 ? 250,000 MT/yr manganese carbonate.

Feb 27, 2013

By R. S. Dean

In general, the Division conducts investigations relating to the treatment of ores and metallurgical products from the condition to which they are mined to the refined metal. At the object of conserving natural resources and eliminating waste by furnishing information on current methods of metallurgical practice making fig fundamental studies of metallurgical processes and developing new processes and alloys to the point of demonstrating their or value. Office of the Chief Engineer The functions of the technical units of the Office of the Chief Engineer are indicates

Jan 1, 1941

By D R. Cohen

As one of the four basic sciences, the study of geology is intrinsically worthy as a means of increasing fundamental knowledge of the behaviour and evolution of the universe. Geological knowledge can also be translated into practical outcomes for society such as resource discovery and protection of the environment. Australia has a long tradition of providing very high quality geoscience programs to prepare graduates for a range of occupations. We are, however, reaching a nexus in the way universities should or can deliver engaging programs. This has been triggered by the rapid evolution of the digital world (the Internet of Things), new technologies, unprecedented access to information, better understanding of the processes by which we learn and adapt our thinking, growing complexity in the problems we must face or opportunities to grasp, and university funding models. Designing education programs for the next generation of geologists extends far beyond tinkering with syllabuses. We must develop skills sets that will allow graduates to work in rapidly changing landscapes, but in doing so may have to sacrifice content to build capability in our graduates. Whereas universities must respond to changing demands on graduates by ensuring degree programs contain an appropriate balance of material and high quality of delivery, industry and government must also fulfil their responsibilities to provide additional training programs for graduates to assist their rapid transition into independent professionals. This paper examines various educational issues being considered in developing the new Decadal Plan for the Earth Sciences, and reflects on directions that education is heading in many of our universities.CITATION:Cohen, D R, 2017. Educating the next generation of geologists, in Proceedings Tenth International Mining Geology Conference 2017, pp 3–10 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

By M. Rantapaa

Measurable improvements in throughput have been documented at Barrick Goldstrike due to increased ore fragmentation through efficient drilling and blasting techniques. A decrease in throughput at the autoclave, due to increasingly hard ore, was identified in early 2002. A team of individuals from the open pit and process areas worked closely on the Drill-to-Mill (D2M) Continuous Improvement initiative to ensure that it would address the needs of both groups, with the target of actually improving throughput in future years, despite the projected harder ores. A series of tests were conducted to determine if adjustments to drilling and blasting could positively influence throughput. Better fragmentation and a subsequent increase in mill throughput were achieved through the use of electronic caps for more precision and flexibility, as well as for allowing extremely fast shots; explosives with a higher velocity of detonation (VOD) to provide for improved shock energy; and improved distribution of the explosives by decreasing pattern spacing. Early tests indicated a significant increase in throughput when processing identified harder ore. It is anticipated that the total process throughput (hard and soft ore) will increase by 6 tph in 2003 due to the improved fragmentation of the hard ore. Barrick Goldstrike?s D2M initiative includes roaster hard ore (BWI>17), as well as autoclave hard ore (BWI>15). Approximately 6 million tons of D2M material were shot in 2003, a relatively small amount compared to the 150 million tons to be mined. The benefit of additional ounces produced should far outweigh the additional drilling and blasting costs.

Jan 1, 2005

By R. Mckinstry, M. Rantapaa, T. Bolles

"Measurable improvements in throughput have been documented at Barrick Goldstrike due to increased ore fragmentation through efficient drilling and blasting techniques. A decrease in throughput at the autoclave, due to increasingly hard ore, was identified in early 2002. A team of individuals from the open pit and process areas worked closely on the Drill-to-Mill (D2M) Continuous Improvement initiative to ensure that it would address the needs of both groups, with the target of actually improving throughput in future years, despite the projected harder ores. A series of tests were conducted to determine if adjustments to drilling and blasting could positively influence throughput.Better fragmentation and a subsequent increase in mill throughput were achieved through the use of electronic caps for more precision and flexibility, as well as for allowing extremely fast shots; explosives with a higher velocity of detonation (VOD) to provide for improved shock energy; and improved distribution of the explosives by decreasing pattern spacing. Early tests indicated a significant increase in throughput when processing identified harder ore. It is anticipated that the total process throughput (hard and soft ore) will increase by 6 tph in 2003 due to the improved fragmentation of the hard ore.Barrick Goldstrike’s D2M initiative includes roaster hard ore (BWI>17), as well as autoclave hard ore (BWI>15). Approximately 6 million tons of D2M material were shot in 2003, a relatively small amount compared to the 150 million tons to be mined. The benefit of additional ounces produced should far outweigh the additional drilling and blasting costs."

Jan 1, 2005

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.Low-sulfidation epithermal gold mineralisation at Ridge Mountain occurs within the Oligocene to Miocene volcanic rocks comprising andesite, porphyritic dacite and diatreme breccia. A diatreme breccia complex with a NE–SW elongated orientation covers an area of 3.0 × 1.7 km. Four main stages of mineralisation were identified, comprising: E–W- to NW–SE-trending quartz-chalcedony veins with disseminated pyrite, chalcopyrite and gold. N–S- to NNE–SSW-trending breccia veins with quartz matrix and disseminated pyrite and accessory sphalerite, galena, chalcopyrite and gold. NE–SW-trending quartz and calcite veins with disseminated pyrite and accessory sphalerite, galena, chalcopyrite and gold. ESE–WNW- to ENE–WSW-trending quartz veins with disseminated pyrite. This stage is only mineralisation that is hosted by diatreme breccia and clearly postdates.Quartz veins of the first, third and fourth stage are less than 2 m wide. Only breccia veins of the second stage are up to 10 m wide. Gold is present in all stages as microscopic inclusions in quartz and sporadically in pyrite. Macroscopic gold can be seen in the first and second mineralisation stages. Gold commonly occurs in association with sphalerite, galena and chalcopyrite in the second and third mineralisation stages.CITATION:Kucera, J, 2015. Diatreme breccia-hosted epithermal gold deposit at Ridge Mountain, eastern Mindanao, Philippines, in Proceedings PACRIM 2015 Congress, pp 587–592 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By K. P. Black, G. W. Sevick, D. E. Hockley, K. S. Sexsmith, J. T. Chapman

Mineralogical analyses of carbonates in depyritized tailings and pyrite concentrate (from depyritization of the tailings) were completed as part of the tailings characterization for the Crandon Project, a massive sulfide deposit in northeastern Wisconsin. The mineralogical study was designed to determine the proportion of calcium and magnesium carbonates, and therefore the effective buffering capacity of carbonates in the tailings. The depyritized tailings are net acid consuming and will be stored in a surface tailings management area. The pyrite concentrate is net acid generating and will be used as backfill in the underground mine workings. The majority of carbonates in the depyritized tailings were ferroan dolomite containing 10 to 15% iron (by weight) and lesser amounts of siderite and magnesian siderite. The proportion of calcium and magnesium-rich carbonates corresponds to several independent tests of carbonate neutralization potential (CO3-NP) availability. The pyrite concentrate had less CO3-NP, indicating segregation of the carbonates during pyrite flotation. These carbonates reported higher iron contents, consistent with the relatively lower availability of CO3-NP in the pyrite concentrate.

Jan 1, 2002

By G. Abramov

The 20th Century saw the modern mining industry enriched by one outstanding method of extracting of mineral resources called Borehole Mining (BHM). Mean while, despite its successful track record in wide ranging locales, few specialists are yet aware of this technology. The intent of this article is to introduce borehole mining to a wider spectrum of drilling and mining professionals. The BHM method is based on in-situ water jet cutting of rock mass. On Fig. 1 the schematic of the method is presented. The borehole mining tool 1 is lowered into the borehole 2 and high pressure water 3 is pumped down. At the bottom part of the tool, one portion of that water comes out through the hydromonitor nozzle 4 in a shape of water jet 5 and cuts the material 6 creating slurry 7. The other portion of high pressure water then comes to the hydroelevator 8 (jet pump, eductor) which produces a vacuum. When the slurry reaches this vacuum zone, the eductor sucks the slurry and pumps it up to the surface, where rock parts are separated from water in a tank 9 or a pond and clarified water is pumped down again closing the re-circulating BHM water supply system. The borehole mining tool is suspended on a drill rig tower 10 which allows the tool to rotate and move vertically along the borehole axis. While extracting rock mass, underground caverns (stopes) 11 are created. If necessary, compressed air 12 can be injected to the raising slurry flow to create an airlift effect. Also, a secondary agent 13 (such as oil, foam, etc.) can be added to the stope through the gap between the tool and the casing. As seen from the illustration, BHM is the remote mining method of extracting of mineral resources through boreholes by high pressure water jets.

Jan 1, 2001

By José Raphael Olegário França

Separação eletrostática é o termo usado para todas as tecnologias de processamento que utilizam forças elétricas que atuam sobre partículas carregadas ou polarizadas sob um campo elétrico estático. O comportamento das partículas depende das suas propriedades elétricas, geométricos e tamanho das partículas. Portanto, a separação de espécies é possível se os parâmetros do campo elétrico e as propriedades elétricas diferentes das partículas são apropriados para o processo. No separador eletrostático de rotor as forças elétricas, combinadas com as forças gravitacionais e centrífugas agem sobre as partículas e são responsáveis pela separação mineral. No presente trabalho as forças eletrostáticas que agem no processo serão substituídas por um modelo de contato de coesão Hertz-Mindlin com JKR. O resultado apresentado, embora com limitações, conseguiu-se fazer uma boa estimativa do processo e alguns dos parâmetros do separador. Com a presente simulação é possível descrever o processo de separação além de permitir a redução de despesas de testes práticos, melhorar a compreensão das relações fundamentais, simular as influências dos diferentes parâmetros e por fim, estimar eventuais aumento de desempenho.

Aug 17, 2017

By Howard W. Wainwright

The Bureau of Mines is engaged in a research program on the characterization of tars produced by low-temperature carbonization of coal and their economical upgrading to more valuable materials, Throughout the years, hydrogenation has played an important role in the treatment of these tars, mainly as a means of converting the whole crude tar or selected fractions to motor fuels; diesel oil, lubricating oil, or various solvents. In some instances, production of specialty chemicals has been the objective. The purpose of this report is to summarize, without critical review, the information of the past 25 years on the hydrogenation of low-temperature tars and related substances as presented in the literature or its English translation. Published articles and patents not abstracted in the main body of this report are included in a bibliography at the end. HYDROGENATION REACTIONS The hydrogenation of tar follows three general types of reactions; 1. The removal of oxygen, sulfur, and nitrogen in the tar to form water, hydrogen sulfide, and ammonia, respectively: [ ]

Jan 1, 1961

The purpose of this report is to describe the work accomplished by Mine Safety Appliances Company under Contract No. H0110845. This contract required the design, installation and testing of a permissible mine surveillance and communication system for the USBM Bruceton experimental mine facility. While much of the design and operational detail of this system can be drawn from the instruction manuals delivered with the equipment, some of it will be repeated here in Volume I for the sake of clarity, but the principal objective will be to report on overall system and subsystem performance and to suggest design alternatives for future consideration. Details of the overall system design will be found in Volume II of this report.

Jan 1, 1973