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By H. M. Smith

Data from the Bureau of Mines routine method for the analysis of crude petroleum are used to characterize crude oils. Some data are used directly while other data are used to calculate the aromatic) naphthene) and paraffin contents of the distillation fractions and the correlation index of the paraffin-naphthene portion of the fractions. The calculated properties show significant differences in composition between crude oils. The methods of calculation and interpretation of data are explained and illustrated.

Jan 1, 1966

By C. Hudson, D. Tremblay, A. Frey

"A discussion of the design, challenges and successes associated with the commissioning of the gravity recovery circuit at Canada’s newest open pit gold mine - Atlantic Gold’s Moose River Consolidated Project in Nova Scotia, Canada is presented. An overview of the project, its historical significance and overall flowsheet is provided with special focus given to the design and selection of the gravity circuit equipment including the scalping screen, gravity concentrators and the novel intensive leaching technology selected for the project. The performance of the gravity circuit is benchmarked against the feasibility study process design specifications and the outcomes are discussed. Challenges encountered during commissioning are also presented, including the use of third-party automation and the effects of screen sizing on overall gravity circuit performance. Mechanical modifications made to the Sepro Leach Reactor for the Moose River project are also discussed. A detailed technical review of the mechanical and operational aspects of the Sepro Leach Reactor is provided with key operational data on leach times, recoveries, reagent usage, solid-liquid separation, pregnant solution quality and its influence on bullion purity.INTRODUCTION Atlantic Gold Corporation’s Moose River Touquoy Mill in Nova Scotia, Canada was commissioned in the fourth quarter of 2017 with commercial production declared in March of 2018. The 2 Mtpa process plant uses a conventional, gravity-CIL process. This site was previously mined in the 1870s. Interest waned in the early 1900s but resumed in the 1930s and the mine was brought back into production in 1935 until an underground mine collapse in 1936. This mining district became famous after CRBC radio commenced a ground breaking, around the clock, broadcast of the rescue operations. Over 100 million people listened to the broadcast from Canada, the United States and the United Kingdom. These broadcasts changed radio, transforming it from a medium for music to on the spot, breaking news reporting. The mill was constructed by Ausenco on a fixed price EPC contract in the historic Moose River gold mining district, 95 km north-east of Halifax by road. The mill will process ore from the adjacent Touquoy pit for the first 5+ years of operation; after the Touquoy reserves are exhausted, the mill will process ore trucked 37 km from the Beaver Dam deposit for an additional 5 years."

Jan 1, 2019

By Radmuller H

The proposed underground mine at Porgera forms an integral part of the Porgera Joint Venture project in Enga Province in the remote Highlands of Papua New Guinea. The total in-situ reserves are approaching 400 tonnes of gold making the Porgera deposit one of the largest in the world. The remote, rugged and inhospitable terrain, recent unstable geological environment and primitive yet socially complex nature of the densely populated local community, combine to make the Porgera project very different to developing mines in Australia. The Porgera project is a challenging and exciting mining exploration venture in the final stages of feasibility study submission and negotiations with the National Government of Papua New Guinea. A 1476 m exploration adit was driven in the footwall of the high grade mineralisation for diamond drilling purposes as part of the evaluations necessary for the feasibility study. Ground conditions encountered have ranged from weak mudstones with high water content, requiring immediate steel set support, to competent intrusives.

Jan 1, 1988

By Z. Naziemiec

Since several years in Poland a huge demands on mineral aggregates occur, for the reason of intensive development of housing and road industry, as well as industrial building. Limitations in re-sources of broken aggregates in Central and Northern parts of Poland cause, that both the non-waste production of aggregates with high quality and the production of alternative aggregates from recycling gain greater importance, nowadays. It entails increase in demands for crushing devices, which are easy and reliable in operating as well as inexpensive and enabling to obtain a good quality products. Jaw crusher, regarded as the most spread in Polish industry, meet these requirements, however, their crucial disadvantage is a large content of irregular grains in crushing products. Numerous investigations show, that the shape of grains is a significant feature of aggregates, which influences on durability and quality of produced concretes. The advantage of jaw crushers is their easy operation, low price as well as low amount of dusts (wastes) generated in comminution products in comparison to other types of crushers (i.e. hammer crushers).

Jan 1, 2014

By Sylvain J. Pirson

A fluid mining process has been developed by the writer whereby phosphate deposits are leached in place through the injection of a weak and recoverable acid solution much in the same manner as in the recovery of oil by water-flooding. The phosphate mineralization is dissolved In place, selectively treated in a surface plant and a high grade diacalcium phosphate substatially free of fluorine (hence of feed grade quality) is recovered. Because of its finely divided and powdery state, the plant product is highly desirable as stock material for the manufacture of triple-superphosphate and of high grade phosphatic chemicals. Details of well completion, fluid injection, areal sweep and solution efficiency, plant design and economics are presented The rate of return on investment is particularly attractive under conditions of shallow occurrence of the phosphate mineralization such as in the Bone Valley formation of Florida. The process may also be applied economically to the Phosphoria formation of wide- spread occurrence in the Northwest United States through the application of selective formation fracturing (or Hydrofrac) previous to fluid mining operations.

Jan 1, 1959

By Z. C. Shen

As core part of flotation column, aerator has been always priority research. A new type of porous aerator made of stainless sintered microcellular material is designed , which diameter is between 20µm to 40µm. High bubble surface area flux is obtained at low air pressure 20kPa by this type of aerator in water. In order to extend its applied range ,experiments were carried out in alkali slurry (pH=12) , resulting with porous aerator clogged after working 20 days . Sampling the cross-section of aerator detected by microscope and X-ray diffraction ,the reason clogging was found. Then plugging aerator was reactivated after putting it in acidic liquor treated by ultrasonic for about ten minutes. On-line aerator maintenance can be done in no down time , and it can be repetitive-used after recovered ,so reduced capital costs.

Jan 1, 2014

By Zhi Yang, Ahmad Ghahreman, Farzaneh Sadri

Impurity removal is a very important stage of the hydrometallurgical treatment of rare earth elements (REE) processing circuit, which is performed after water leaching of the acid baked REE concentrate. Lime neutralization has a high efficiency in removal of impurities and is the preferred process due to its economic advantage; however, the process has its own problems, such as the production of large volumes of gypsum and co-precipitation of REE with gypsum, i.e. REE loss. This work deals with the effect of several additives (cetryltrimethylammonium bromide (CTAB), polyvinylsulfonic acid (PVS) and polyacrylic acid (PAA)) on the uptake of REE by gypsum from synthesized acidic solutions. The main purpose of this study is to investigate the changes in the crystalline morphology of gypsum precipitated by the addition of crystal habit modifiers and to determine the crystal changes’ effects on the uptake of REE by gypsum. In this regard, different concentrations (0.2, 2 and 5 g L−1) of above-mentioned additives were studied at room temperature.

Mar 1, 2018

By William H. King

The Nevada Massachusetts tungsten deposits (fig. 1) are in the Mill City Mining District in north-central Pershing County, Nev., about 37 miles southwest of Winnemucca. Contact metamorphism of thin limestone beds within a series of metamorphosed sedimentaries formed scheelite-bearing ore bodies. These deposits are distributed over a wide area. A Bureau of Mines development program was started January 11 d was completed on July 25, 1941. This work was centered on the outer and less explored beds in the district and comprised trenching, sampling, and diamond drilling. Exploratory work was done in cooperation with the U.S. Geological Survey. Project work substantially increased the reserve tonnage of marginal ore in three of the areas explored and proved the nonexistence of tungsten in a fourth area. The following pages summarize the history of the district, outline property ownership, and describe physical features and ore deposits. The plan and results of the work performed by the Bureau of Mines are presented along with geologic and topographic maps, assay maps, and diamond drill-hole logs.

Jan 1, 1950

By T. C. Campbell

Copper is extracted from the Chuquicamata oxide ore by a hydro-metallurgical process. The ore is crushed to 3/8-in. sizing, and leached with a sulfuric acid electrolyte. Chlorine is precipitated. and the ferric iron reduced in the enriched electrolyte, after which the copper is recovered by electrolysis with insoluble Chilex and lead-antimony anodes, the spent electrolyte being returned to leaching. Cathodes are melted and refined in market furnaces and cast into commercial wire-bar and cake shapes. Sulfuric acid for the process is supplied by the brochantite in the ore. Water for washing the ore is advanced through the solution system and finally after cutting by electrolysis to from 6 to 16.0 grams per liter is completely stripped by the cuprous chloride method and run to waste. The cuprous chloride so obtained plus that resulting from precipitation of chlorine from strong solution is dissolved in ferrous chloride brine and the copper cemented on scrap iron. The cement so obtained is in part used to reduce ferric iron in electrolyte, and as it is of exceptional purity is also furnace refined and cast into an exceptional quality of fire-refined copper. Fig. 1 is flow sheet of the operation. The reduction plant is composed of seven divisions as follows: (1) crushing, (2) leaching, (3) tailings disposal, (4) dechloridizing, (5) sulfur dioxide treatment, (6) electrolytic tank house, (7) smelting and melting. A brief description of each of these divisions will be given. Crushing Ore that is frequently blocky and up to 5 ft. in section is crushed in four stages to 3/8-in. mesh. The first stage of crushing is called primary and the next three stages are known as secondary crushing. The first stage is accomplished with two 60-in. Superior McCully gyratory breakers by which the ore is broken to 9 in. The second coarse gyratory breakers crush the ore to 3-in. sizing. There are seven No. 10 McCully gyratories in this service, for one of which recently has been substituted a No. 7 cone crusher. The third and fourth stages of crushing are accomplished by fifty 48-in. disk crushers. In the third stage 14 disk crushers break the ore to 1 in., and in the last stage 36 disk crushers turn out the final product of 0.371-in. sizing. Reference to the flow sheets of Figs. 2 and 3

Jan 1, 1934

By Liming Yuan, Isaac Zlochower, RICHARD THOMAS, Thomas H. Dubaniewicz, Teresa Barone

Mining vehicle manufacturers are developing lithium-ion (Li-ion) battery electric vehicles as an alternative to diesel-powered vehicles. In gassy underground mines, explosion-proof (XP) enclosures are commonly used to enclose electrical ignition sources to prevent propagation of an internal methane (CH4) air explosion to a surrounding explosive atmosphere. Li-ion batteries can create pressurized explosions within sealed enclosures due to thermal runaway (TR). Researchers at the National Institute for Occupational Safety and Health (NIOSH) measured TR pressures of lithiumiron phosphate (LFP) cells as a function of free space within sealed enclosures and observed an inverse power relationship. A well-confined cell produced 294 bar (4260 psia) of pressure during a TR, far exceeding minimum pressure containment specifications for conventional XP enclosures. Results indicate that adding enough free space surrounding LFP cells can reduce TR pressures to levels below that expected for CH4-air ignitions. Measured TR temperatures were below the minimum autoignition temperature of CH4-air.

Nov 6, 2020

By Sakir Selcuk, Brian Hamilton, Paul Zick

The 1.8 mi (2.9 km) Minneapolis-St. Paul International Airport Light Rail Transit Tunnels and Station project is comprised of the underground segments of the 11.8 mi(18.8 km) Hiawatha Light Rail Transit route in Minneapolis, Minnesota. The 21 ft 2 in(6.5 m) diameter twin tunnels were mined 65 ft beneath one of the busiest airports in the United States using an earth pressure balanced tunnel-boring machine. This paper will provide a project overview, review the major equipment selected, tunnel segment casting, and describe excavation and lining operations for the tunnels and station.

Jan 1, 2003

By Johne Jesus Mol Peixoto

No reator RH, a otimização do fluxo recirculatório de aço entre a câmara de vácuo e a panela é a chave para promover as reações de refino. Neste trabalho, foram utilizados água e solução de cloreto de zinco (ZnCl2) como fluido similar ao aço para investigar a taxa de circulação no modelo a frio de um reator RH em escala 1:7,5. A taxa de circulação foi determinada utilizando o método de pontes de Strain Gages. A técnica PIV foi utilizada de modo a calibrar e validar os resultados. O aumento da vazão de gás de 30l/min para 120l/min resultou na elevação da taxa de circulação para ambos os fluidos. Cálculos preliminares demonstraram que há grande diferença nas condições de arraste de escória entre os sistemas água/óleo e ZnCl2/óleo.

Aug 17, 2017

By T Hill, J Everingham, P Clark

Currently, social impact assessment (SIA) is used to determine social impacts across the life-of-mine (LOM) to closure. This paper draws on recently completed SIA reports from the Martha gold mine in Waihi and qualitative interviews in the community that explored post-closure options, to review the challenges mining companies face when engaging with iwi4 through the SIA process and what that may mean for closure planning. The Maori of New Zealand consistently lobby to have a distinct voice in resource management issues. This is in line with the evolution of indigenous participation in SIA globally and with New Zealand policies, not least of which, the Treaty of Waitangi (the founding document of New Zealand) makes provision for Maori self-determination with regard to natural resources. Land use for mining has been a source of conflict for Maori and mining can have profound cultural and social impacts on the Maori community, yet despite Treaty intentions their representation in SIA has been comparatively limited. With this in mind, the Waitangi Tribunal has released the Ko Aotearoa Tenei (Wai 262) report, which recommends far reaching reforms to laws and policies affecting Maori culture and identity including natural resource management. This landmark report seeks to move the Maori-Government relationship beyond grievance to partnership. Given suggested policy changes in Wai 262 and the risks of poorly conceived closure planning, it is timely to review where Maori currently fit into the SIA process. The findings of this research suggest that improvements to the outcomes of this process will require companies to act beyond compliance. However, these improvements may also ensure mining companies maintain their social license to operate and to ensure continued influence across the life of a project to closure.CITATION:Hill, H, Clark, P and Everingham, J, 2012. æThere is an emptiness for Maori here in WaihiÆ - Understanding indigenous perspectives on post-mine land uses in closure planning, in Proceedings Life-of-Mine 2012 , pp 153-160 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 10, 2012

By L. S. Darken

THE manufacture and treatment of metals comprises operations whose effectiveness depends in large measure upon diffusion phenomena. The significance of such phenomena has, for a few simple cases, long been understood, but in more complex cases it has not been adequately recognized. This paper presents a mathematical analysis of some of the cases in which diffusion leads to the formation of a new phase within the metal, and this analysis provides a basis for interpreting quantitatively many apparently diverse experimental observations recorded in the literature, some of which are outlined in the following pages. OBSERVATIONS RECORDED IN LITERATURE An outstanding instance is the general type of phenomenon in which diffusion of an element into an alloy is followed by a phase change, which most frequently is a reaction (precipitation) of the diffusing element with one or more components of the alloy to form a compound. Thus in certain alloys heated in contact with oxygen not only the usual oxide scale appears but, in addition, beneath the surface, a well-defined zone in which free oxide particles are dispersed with notable uniformity. This zone, commonly referred to as the subscale or zone of internal oxidation, is remarkable in that the visible boundary between it and the unaltered metal is usually sharp. Such a subscale, which appears to have been recognized first in oxidized copper alloys, has been described and studied by C. S. Smith,1 by Rhines,2 and by Rhines, Johnson and Anderson;3 but it appears also in other alloys when they are exposed to conditions that bring about the precipitation of some compound, not necessarily an oxide. Another clear case of this same kind is the diffusion of carbon into a steel containing an element such as molybdenum, chromium, vanadium or tungsten, whose carbide is less soluble in iron than iron carbide, the result being that some part of that element is precipitated as a dispersed carbide. A similar phenomenon may occur on the welding of two alloys each of which contains one of a pair of elements that react to form a compound or a new phase of any sort. But in addition to the precipitation of a compound formed from the diffusing element, other effects may result merely from the presence of the diffusing element. For instance, if homogeneous austenite, nearly saturated with respect to carbon, is heated in contact with silicon in the absence of oxygen, one would expect to find, behind the several iron-silicon phases analogous to a scale, a zone of austenite containing dispersed carbide, because of the fact that silicon decreases the solubility of carbon in iron. As still another example, oxidation of an alloy may result in diffusion toward the surface of one or more of the constituents; for instance, during oxidation of a steel containing an element such as copper, which is less prone to oxidation than iron, there is a notable enrichment of copper just beneath the scale-metal interface. As an example of a yet more

Jan 1, 1942

By P. S. Arthur

The ISASMELT? process is a submerged lance smelting technology operating in smelters in Australia, the USA, Belgium, India, Germany, Malaysia and China. Further plants are under construction in Peru and Zambia. Following the invention of the Sirosmelt lance technology Mount Isa Mines recognised the commercial potential in the novel top blown bath smelting process and embarked on a development program that has lasted more than 25 years. After successful operation of pilot plants and demonstration plants producing copper and lead, Mount Isa Mines decided to license the technology to external companies. Since the purchase of Mount Isa Mines by Xstrata in 2003, Xstrata Technology has assumed responsibility for transferring the technology to ISASMELT? licensees. In the 15 years since the first commercial furnaces started operation plants have been constructed (or are under construction) with a combined annual smelting capacity of more than six million tonnes of concentrates or secondary raw materials. Process development continues on the commercial scale plants at Mount Isa and elsewhere. Many of the improvements implemented by plant operators have been passed on to, and adopted by, other licensees. Exchange of ideas and technical improvements occurs through ad hoc visits to fellow licensee sites and through regular licensee workshops arranged by Xstrata Technology. This paper updates the reader on the status of various ISASMELT? plants either operating or under construction. It highlights the important role that the technology provider?s operational experience plays in ensuring that new smelting plants ramp up quickly to nameplate capacity.

Jan 1, 2006

The global mining industry is perceived to be a world leader in sustainability reporting û with a 2008 Ernst & Young survey placing four mining companies in their top five performers in sustainability reporting in South Africa. There is certainly good evidence to support this finding, but there remain many ongoing issues with respect to sustainability reporting and some important areas for improvement by mining companies globally. This paper begins with a broad (but brief) review of sustainability and the technical basis for reporting against a wide range of typical indicators or measures on the environmental aspects of mining. The various protocols, frameworks or systems are then reviewed, with a particular focus on the Global Reporting Initiative (GRI) and its associated mining sector supplement (including the evolution from environmental to sustainability reporting). A wide-ranging survey of reporting by mining companies is presented, including detailed analysis of 2007 and some commodity sectors over time. Examples of reported data are synthesised and analysed, focusing on their accuracy, consistency and utility for accurate assessment of the life cycle impacts for minerals and metals. A number of areas are identified for improved reporting by all mining companies, including water resources and consumption, energy consumption, process inputs (eg acids, solvents, etc), pollutant emissions, including greenhouse emissions, mine site data (not aggregate company totals) and finally rehabilitation and land status. Given the nature of mining, and considering parallels between æpeak oilÆ and the mining sector, it is critical that the state of sustainability reporting continue to evolve and improve û both in the number of companies using the GRI but also in the level and consistency of data being reported. Overall, the paper presents an important review of the present state of the art in sustainability reporting for mining, and provides a range of insights into ways to help improve reporting in the future for all mining companies.

Jan 1, 2009

By I Sherrell, R Jain

Worldwide iron ore feed grades are trending downwards and will continue to do so with the increasing difficulties of upgrading ores. This has led to operations looking for ways to capture current tailings that still contain valuable material. In the past, these were acceptable to dispose of, but this practice is no longer economically feasible. With the increasing trend of re-mining previous tailings deposits that could be decades old, new equipment designs have been introduced to upgrade current or historic beneficiation plants. These designs can effectively upgrade these tailings to saleable products.Outotec conducted test programs for upgrading iron ore tailings from flotation rejects, thickener underflow or tailings dumps on samples provided by customers around the globe. The studies utilised Outotec’s SLon vertically pulsating high-gradient magnetic separator in combination with preprocessing equipment such as low-intensity magnetic separation, screen or scrubber and flotation for downstream processing of the magnetic concentrate. A review of the equipment required to economically process these tailings is provided, along with testing data and industrial implementation examples. The effect of different operational and design parameters on Fe grade and recovery from processing each tailings sample has been highlighted.CITATION:Jain, R and Sherrell, I, 2015. Iron ore tailings reprocessing to maximise ore production, in Proceedings Iron Ore 2015, pp 149–158 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By Thomas A. Phillips

An economic evaluation of the Bureau of Mines process for the separation of raw urban refuse into its metal, mineral, and energy components is presented. The process recovers ferrous metal, mixed nonferrous metals, aluminum, mixed-color glass cullet, and refuse-derived fuel products from raw refuse. Data for this evaluation were obtained from selected runs at the Bureau's pilot plant in Edmonston, Md. A cost estimate was prepared for a plant capable of processing 1,000 tons per day of raw urban refuse operating two shifts, 6 days per week. The fixed capital cost, based on second quarter 1976 equipment costs, is approximately $14.5 million excluding land and shipping containers. The estimated operating cost is approximately $8 per ton of refuse processed. This does not include credit for the products, transportation of the products, a tipping fee, or a dumping fee for wastes produced. No finance charges or taxes are included in the operating costs.

Jan 1, 1977

By Robert C. Dyni

This U.S. Bureau of Mines (USBM) report summarizes a field demonstration of pneumatic backfilling technologies conducted at the abandoned Hillside Coal and Iron Slope in Vandling, P A. Researchers demonstrated two pneumatic backfilling technologies recently developed under the USBM's Abandoned Mine Reclamation Research Program, the Pneumatic Pipefeeder and the High-Efficiency Ejector. Both systems had previously been evaluated at the USBM's subsidence abatement investigation laboratory near Fairchance, P A. The objective of the demonstration was to fill 100% of the abandoned tunnel with backfill stone to prevent further subsidence. The Pneumatic Pipefeeder was used for 21 days, at a rate of 63 to 124 t/ d (69 to 136 st/d), to fill 88% of the tunnel. The High-Efficiency Ejector was used for 2 days, at a rate of 125 to 132 t/d (138 to 146 st/d) to fill the remaining 12% of the tunnel. The backfill placed by both systems was tightly compacted. The major problem encountered was wear on the polyethylene pipeline from the abrasion of the high-velocity backfill. The use of heavier steel pipe minimized the problem. A cost analysis for the entire project is given.

Jan 1, 2010

By P. Fecko

The objective of the paper was application of bacterial leaching on two brown coal samples from locality Mine Druzba, seams Antonin and Josef (Sokolov brown coal basin, Czech republic). Based on the results of bacterial leaching and petrologic analyses of the given samples, it is possible to say that application of bacterial leaching gived good results. Applying bacterial leaching it is possible to remove from 34% to 47% of total sulphur and from 45% to 64% of pyritic sulphur from the coal.

Jan 1, 2014