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Jan 1, 2009

The paper outlines the history and current status of the VALMIN Code and sets out the background, methodology, results and recommendations of the Independent Review of the VALMIN Code undertaken during 2001 under the Chairmanship of Ian Goddard. The paper is based on the final report of the Taskforce, which was submitted to the Board of The AusIMM for consideration.

Jan 1, 2002

By W. M. Shaver, W. R. Dengler, F. A. Edwards

INTRODUCTION The Macassa Division of Lac Minerals Ltd. is a high grade gold mine that has been operating in Kirkland Lake, Ontario for the past 51 years. It produces approximately 120,000 tonnes of ore per year, averaging approximately 18.7 grams per tonne (0.45 ounzes per ton) of gold. Over the years, the ore body has been developed to a point where mining takes place below the 1,220 m (4,000 feet) elevation and 1,830 m (6,000 feet) west of the original shaft. The mine is currently serviced by two surface and two winze shafts. (Figure 1). The ore body extends below the 1,930 m (6,400 feet) Level which is the bottom of the existing mining operation. An ambitious underground exploration program has substantially increased these reserves. Concurrent with the discovery of greater reserves, has been rapidly escalating mining costs, particularly labour which constituted 66% of the total cost in 1981. These costs continued to escalate as the major proportion of mining was carried out to the west, far away from the existing hoisting systems. This required three lift hoisting for men, materials and ore. I n addition to the increased travel time and ore handling expense, increased humidity and temperature and ventilation and compressed air losses have added to the inefficiency of the operations. As a result, studies were initiated in 1980 to assess the future of the Macassa operation.

Jan 1, 1985

By Zwaan J, Kepa J

Ok Tedi mine has become one of the major copper producers in the world. In the process of becoming of age, it overcame the challenges of operating in a locality which is young in geological terms, experiences very high rainfall and has a topography which gives rise to frequent landslides. This paper discusses some of the geological, mine and geotechnical engin- eering aspects of the Mt Fubilan ore deposit.

Jan 1, 1991

By BUREAU OF MINES

This report is submitted in accordance with the provisions of the Synthetic Liquid Fuels Act of April 5, 1944 (30 U.S.C. 321-325, as amended), which require that: "The Secretary of the Interior shall render to Congress on or before the first day of January of each year a report on all operations under this Act." Owing to the broad scope of the content and the diversity of interests represented, the Annual Report for 1953 has been divided into two separate publications. Each has been published by the Bureau of Mines as a Report of Investigations, and the respective titles follow: R. I. 5043, Part I - Oil From Coal. R. I. 5044, Part II - Oil From Oil Shale. Identical in each report, the introduction summarizes research progress made in 1953 under the entire Synthetic Liquid Fuels program. A free copy of each of these publications may be obtained by a written request to the Bureau of Mines, Publications Distribution Section, 4800 Forbes Street, Pittsburgh 13, Pa. The R. I. number and title of the publication desired should be indicated.

Apr 1, 1954

Thickener Modelling - Incorporating Shear Effects

Sep 13, 2010

By George L. Gates

[When clays e.re mixe~ "Jith "~later to nake mud fluids f'ol' use in :irilling ','Iells "for oil and gar: h;:r vue :;'0 tary me thee. t 18 liquid mij~ tUl"es have certair.. phypicr..l characteri.",t.ics that vary ",dth t e Qlldlltit.y find]

Jan 1, 1941

By G. H. Damon

Since 1963, Bureau of Mines Information Circular 8179 has served the mining industry as a fundamental safety guide in the field of blasting agents. In the intervening 14 years, many changes have occurred, and this report presents revised and new recommendations which recognize these changes. For example, AN-FO is now supplied mostly premixed, whereas in 1963 much of it was mixed by the blaster; aluminum metal (A1) and other fuels are now often added to AN-FO to increase strength, and flake aluminum powder is used as a sensitizer in water gels; and water gels or slurries that are now extensively used were just coming into practical use in 1963. To provide the widest possible margin of safety, some of the Bureau's recommendations are more stringent than existing regulations,

Jan 1, 1977

By H. M. Chikashi

Keywords: Pyrometallurgy, furnace, bath agitation, regression analysis, entrainment This paper presents the results of linear regression analysis of the influence that each component of slag has on the losses of copper in slag-cleaning-furnace slag. Data used for the analysis are actual plant data collected over the past two years of operation. Facts obtained from the study will be helpful for smelter management to control these components in the flash smelting furnace feed and slag, to levels which will enable better control of copper in slag, and smoother operation of the KCM slag-cleaning furnace.

Jan 1, 2011

A genesis based on new developments in the physical chemistry and flow properties of colloidal substances is proposed for the pipe-like Peko orebody. The rheological behaviour of sediments is governed by the contained colloids. Remobilization of thick pasty sediment during diagenesis is regarded as an essential step in the concentration of metal dispersed in sediments. At a high concentration the sediment pore fluid is a dense gelloid such that van der Waals attractive forces between the colloidal particles exceeds the coulombic repulsion. This permits accretion of the colloids into globular clots and their fracture fragments. These have a uniform size distribution dependent upon the rate of shear, and the sediment lithifies to clotted, porphyry-like, "gritty", dolomitic or igneous-looking intrusions and flows. The physical chemical properties of natural sediment colloids appear adequate to account for ore formation.Adsorption accounts for the dispersion and retention of metal in sediments. Accretion accounts for the segregation of the colloidal materials to give the various types of clotted igneous-looking intrusive source rocks. Syneresis enables the colloids to spontaneously draw together and to dehydrate. Formation of an ordered lattice achieves a lower energy state and desorbs metals and insoluble metal compounds "particle by particle" into the escaping water of hydration and pore water. Peptization enables migration of the metal hydrosols as stable dispersions until they merge for outflow through seepage zones or water extrusion channels. Nucleation and concretion precipitate the metal dispersoids from pore waters seeping through hydrous parts of the source rock, porous beds, faults, and zones of weakness by which the connate waters leave the lithifying sediments. Gelatinous precipitated mineral matter in the ore channels is capable of thixotropic reliquefaction when disturbed by shock or movement. Local reintrusion, flowage, interveinings,brecciation, and intermixing of the materials is the result.The principles of the suggested genesis are applicable to both syngenetic and epigenetic mineral accumulations.

Jan 1, 1966

By Fernanda da Silva Machado

Em um mundo de recursos naturais decrescentes, com a intensificação das indústrias automatizadas de todos os tipos (I4) e contínuo aumento da população, é necessário desenvolver melhores caminhos para a geração e distribuição de riquezas. Uma das alternativas para este objetivo é o conceito da Economia Circular. Este artigo apresenta um exemplo focado na intensificação do uso de resíduos de biomassa na produção integrada de aço exclusivamente baseada na combinação de reatores industriais existentes em um layout que favorece o conceito da economia circular. O ferro também é obtido do processamento tradicional de sucata, reprocessamento de resíduos de ferro e óxidos de ferro, como a escória, pequenos óxidos de ferro, reversos metálicos, resíduos da indústria siderúrgica integrada tradicional. Os resíduos de biomassa são provenientes da demolição de casas de madeira, e outros resíduos de biomassa, como limpeza florestal para evitar-se incêndios, resíduos de moinhos, paletes usados e qualquer outra fonte de biomassa. As combinações dos reatores tornaram-se possíveis devido à nova versão do processo de Carbonização Contínua, Carboval, um reator especialmente projetado da tecnologia Lambiotte tradicional, para produzir, de preferência, o carvão vegetal que possui as mesmas características necessárias para alimentar o Mini Alto Forno tradicional a base de carvão.

Oct 30, 2017

This report covers the work performed by the Advanced Products Division of FMC Corporation under Bureau of Hines Contract J0155166, Design Evaluation for Development of an Advanced Bolter Module. FMC has evaluated the existing ISMS bolter designs, and the corrections and improvements in progress, including the effect of the three-chain magazine presently being fabricated, and recommends that a complete bolter module featuring a new magazine, safety post and lower stabilizer or similar device be designed, fabricated, and tested, A 29 week program is proposed which includes a four week demonstration. This module would eliminate those reliability problems not presently being solved and would provide a reliable bolter module for a production oriented miner/ bolter.

Jan 1, 1975

By Joseph F. Davies

Along with the humanitarian need for preventing accidents the cost of injuries must be considered. As a means of bringing the facts concerning the prevalence of accidents in mining and their direct cost before the operating officials and others interested in accident prevention in the mining industry, the United. States Bureau of Mines ha as recently made studies and published reports dealing with these subjects in several States 4. This report gives available data on the causes and direct costs of accidents in Virginia coal mines for the 4-year period 1929 to 1932, inclusive. Mounting compensation costs and insurance rates resulting from mine injuries indicate the necessity of measures to decrease the number and severity of accidents. These direct costs, as well as additional losses of an indirect nature, can be eliminated from the cost of production to the extent that accidents are prevented or reduced in severity.

Jan 1, 1934

Plant based on the New Jersey refluxing process was installed at the Cockle Creek Works of Sulphide Corporation Pty. Ltd. to refine portion of the zinc output from the Imperial Smelting furnace.Refining of impure zinc is effected by distillation in two stages in vertical columns comprising a series of superimposed silicon carbide trays designed such that ascending zinc vapours and descending liquid metal are in intimate contact. In the first stage, portion of the zinc and its cadmium content are distilled from impure feed metal, condensed, and while still molten, fed to the second column in which zinc is boiled under controlled refluxing conditions to remove the cadmium content.The resultant zinc has a purity in excess of 99·995 per cent zinc.The availability of refined zinc has made possible the production of a number of zinc alloys for marketing in addition to the basic grades of zinc.

Jan 1, 1970

By V. A. Danielson

The Bureau of Mines examined sources, consumption, and movement of iron and steel scrap in the southeastern States--Alabama, Florida, Georgia, Kentucky, North Carolina, South Carolina, and Tennessee. Officials of the scrap-processing and scrap-consuming industries were interviewed, data was obtained from the published literature, and a canvass was made by the Bureau of scrap consumers. The Southeast generated excess scrap which was shipped to domestic and foreign consumers in about equal proportion. Total 1963 demand in the Southeast was 3,336,000 net tons, of which purchased scrap was 75 percent, foreign exports 13 percent, and domestic exports 12 percent. Alabama, with 47 percent of the purchased scrap consumption in 1963, was the most important scrap-consuming State, and Kentucky, with 34 percent, was the second most important one. Southeast demand was 4.8 per-cent of the total U.S. demand. Projected 1980 consumption is 8,340,000 tons. Scrap prices showed a slight downward trend for the period 1953-63, although gross consumption increased slightly. A significant trend in processing scrap in the Southeast is the preparation of smaller bundles or "briquettes" weighing from 75 to 150 pounds, which are easier for consumers to handle and inspect. Another significant development is the "shredding" of automobile scrap which produces a dense, clean scrap especially desirable for use in electric furnaces.

Jan 1, 1967

By Brad Murray

Evaluating the performance of a shielded tunnel boring machine (TBM) can be difficult because the ground cannot be observed directly and in relation to the TBM attitude within the excavation. It is difficult to determine whether performance problems are caused by ground loading, steering issues, fine muck packing against the shield, or migration of annular grout around the shield. The Arrowhead Tunnels Project in Southern California uses strain gauges on its shielded hard rock TBMs to detect shield strains early and correlate them with tunneling conditions, thereby increasing the chances that problems will be correctly diagnosed and addressed to optimize TBM performance. The frequent automatic measurement of shield strain has also been valuable by confirming whether remedial methods used to free the machine after stoppages are effective. This paper discusses the qualitative interpretation of characteristic strain patterns on the Arrowhead Tunnels TBM shields and discusses installation details and special considerations for setting up a strain measurement system.

Jan 1, 2008

By Kyle Wagner, William Joa, Colter Angell, Catherine Johnson, Marty Langenderfer, David Doucet

The goal of any business is to seek the maximum profitability for the organization through optimization the use of resources, processes and the application of new technologies. An analysis of various case studies demonstrate that blasting can have positive impacts on the crushing and milling processes resulting in increased profitability for the mining industry (Grundstrom, Kanchibotla, Jankovich & Thornton, 2001). This paper describes the case study of two copper mines in Peru producing Cu-Mo and Cu-Au concentrates, which together with their strategic partner, have implemented a project focused on the improvement of rock fragmentation. The project was based on techniques of pattern size reduction, the use of high energy explosives and the technology of electronic initiation. Combined, these techniques were shown to have significantly impacted the efficiency of downstream processes.

Jan 1, 2019

By Jeffrey M. Listak

This report describes a study, conducted jointly by BethEnergy Mines Inc. and the Bureau of Mines, to assess the effects of longwall front abutment loading on various supplemental support materials utilized in a predriven recovery room. The purpose of the predriven recovery room is to reduce longwall equipment transfer time by eliminating the premove preparation associated with conventional recovery methods. In addition, the room provides a large area in which face salvage equipment can maneuver. Results of four recovery-room study areas show the progression and influence of the front abutment on the longwall panel and supports and their subsequent behavior. The best performance (i. e. the support that most facilitated recovery) of support material was achieved through the use of a concrete mixture which had a sand content of 35 percent by volume. The longwall transfer time was reduced by 30 percent which translates to a production advantage of 37,000 raw tons of coal per panel.

Jan 1, 1989

The Barrick Zaldivar mine is an openpit, heap-leach copper mine in Region II of northern Chile at an elevation of 3,300 m (10,826 ft), approximately 1,400 km (870 miles) north of Santiago and 175 km (109 miles) southeast of the port city of Antofagasta. In 2006, Zaldívar produced 307 million lbs of copper, with reserves estimated at 5.7 billion lbs. The mine uses conventional methods of openpit mining: Pure cathode copper is produced by three stages of crushing and stacking the ore, followed by heap leaching and bacterial activity to extract copper from the ore into solution. A solvent extraction and electrowinning process then removes the copper from solution and produces the cathode copper. A flotation plant also recovers copper contained in the fine fraction of the crushed ore. In 2006, an existing A-frame structure that covered copper ore from the mine?s secondary crushing operation was damaged beyond repair. The material delivery configuration of this original structure had the conveyor carrying incoming ore directly over the low roof to drop ore into the building at its peak, and ore trickling from the sides of the conveyor had accumulated on the roof, overloading it. A better solution had to be found, and fast: First, the Chilean Commission does not permit uncovered piles of this type since the extremely fine material leads to serious pollution problems. Second, Barrick Zaldivar is very concerned about worker safety, and the amount of dust created by the uncovered pile was not acceptable. Finally, some amount of copper was lost in the dust generated by the winds of the Andes. The major issues faced by Barrick Zaldivar in designing a new structure included:

Jan 1, 2009

By Jan Krason

Introduction The South African Witwatersrand is the world's largest gold-bearing province and gold producing district. But the production capacity of the very big mines (Vaal Reef, Driefontein Cons., Western Holdings, Western Deep Levels, and others) is not as large as that of the Soviet Union's Muruntau gold mine. The Muruntau gold-bearing ore body was discovered in 1956-57, and has been in operation since that time. In the early 1970s, this mine produced 70 to 80 t/a (2.3 to 2.6 million oz per year) of gold. Within the last few years it has become the world's largest producing gold mine. Russian authors do not publish ore reserve or rate of production data. But it is very likely that the Muruntau mining complex, which involves several ore bodies, is currently producing about 143 t/a (4.6 million oz per year) of gold. The author has confirmed this by personal information from several knowledgeable Russian geologists. This amounts to one-half of

Jan 11, 1984