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By D. J. MacKinnon

Zinc metal was first produced in India around 1100 A.O. and a zinc industry based on retorting gradually developed in both India and China(1) . The vertical retort method for smelting zinc ores was developed in England in the 1730s; this was followed by the more fuel efficient horizontal retort process developed by the Belgians in the 19th century(2) . The horizontal retort process was the standard method of zinc manufacture until the 1950s when it became obvious that it could not compete with electrolytic zinc technology(2). The present day extractive metallurgy of zinc is dominated by the electrolytic process which now accounts for almost 80% of the world's primary zinc production. In recent years the electrolytic zinc process has seen significant improvements: the fluid-bed roasting of zinc concentrates, improved leaching and residue treatment techniques such as the jarosite and goethite processes, improved solution purification procedures, mechanization of the zinc electrolysis step and of the zinc melting and casting operation. In addition, new leaching processes have been implemented for the treatment of oxidized ores, particularly silicates, and the pressure leaching of zinc sulphide concentrates is now a commercial reality. Although the electrolytic zinc process was first used on a commercial scale in 1916, its history can be traced back to the 1860s. The purpose of the present paper is to outline the early history of the electrolytic zinc process and to trace the significant developments which led to the first successful commercial electrolytic zinc plants.

Jan 1, 1999

By Robert Sisselman

Dramatic changes have been effected since 1955 in the mode of iron ore shipments within the U.S. In 1955, less than one percent of ore consumed in domestic blast furnaces-approximately 125 million long tons-consisted of pellets. Five years later, in 1960, some 94.8 million tons of ore were consumed, 14% in the form of pellets. Projections for 1980 reinforce confidence in this most economic of blast furnace feeds, and set U.S. pellet consumption at 151.2 million tons. In the last decade, pellets caught fire in other countries. By 1969, world production reached 96 million tons. This compares strikingly with present world output of 154 million tons.

Jan 9, 1973

By M. R. Smith

Barrick Goldstrike Inc.'s Betze/Post Open Pit is located at the north end of the Carlin Trend, in Eureka County, Nevada, U.S.A. (see location Map, Figure 1). About ten open pit gold mines exist on the trend, which strikes northwesterly, through the north end of Eureka County and into Elko County. The final Betze/Post Pit configuration is shown in Figure 2, Pit Configuration. The final pit will be about 2450m long by 1550m wide, elongate in a west-northwesterly direction. The pit straddles the Barrick/Newmont property boundary. The highest elevation of the pit perimeter is 1800m at the south wall, with the east end pit bottom elevation at 1200m.

Jan 1, 1993

By D. D. Harbuck

Previous studies at the U.S. Bureau of Hines have shown that only 70 to 80% of the germanium in domestic zinc process residues can be extracted during H2S04 leaching. To increase germanium extraction, the Bureau developed and researched the hypothesis that minor amounts of germanium and zinc silicate, both present in zinc calcine, dissolve during the leaching stages of zinc processing, forming soluble germanium and silica gel. This silica gel then selectively adsorbs germanium from solution, rendering the germanium insoluble. Testing showed that as the amount of silica gel formed increased, the amount of insoluble germanium in the zinc residue increased. Several processing alternatives are presented for overcoming this problem.

Jan 1, 1991

By R. P. Aikman, F. G. Miller, J. M. Podgursky

As part of a larger study of the mechanism of froth flotation of coal, the rates at which coal particles of various size and specific gravity react to froth flotation were investigated. Results of this study show that in flotation: I) recovery rate increases, but selectivity decreases with a decrease in particle size down to 100 mesh, and 2) recovery rate is constant for all sizes between 100M and 325M. n response to the growing demand for low-sulfur coking coal for iron making, the coal industry is continually striving to perfect methods for cleaning coal to acceptable ash and sulfur levels while maintaining maximum product yield. By present standards the industry has adequate processes for cleaning coarse coal, i.e., + 28 mesh, at almost any desired specific gravity. However, in the case of fine coal, i.e., —28 mesh, neither of the two existing processes - froth flotation or hydrocycloning — in its present state of development yields products that are comparable in ash and/or sulfur content to products normally obtained from coarse coal processes. The work outlined in this paper is part of a larger study directed toward maximum exploitation of froth flotation for fine coal processing. The concepts and data presented are now serving as a basis for designing fine-coal circuits in which improved efficiency is obtained by optimum use of froth flotation with other fine-coal processing methods. The paper includes: 1) A discussion of the value of a detailed wash-ability study as a method of assessing the problems associated with fine coal processing, 2) A general discussion of hydrocyclone principles, included to serve as a basis for understanding the mechanism of coal flotation, and 3) A detailed discussion of the mechanism of coal flotation, as well as the research leading to the optimum use of froth flotation in combination with other fine-coal cleaning methods to provide efficient fine-coal processing. Our study of the rates at which coal particles of various size and specific gravity react to flotation shows that in flotation: 1) recovery rate increases but selectivity decreases with a decrease in particle size down to 100 mesh, 2) recovery rate is constant for all sizes between 100 mesh and 325 mesh, and 3) the flotation process effectively rejects only those extremely fine particles which do not contain surface carbon. (Because of this feature, froth flotation is an excellent method for rejecting clays - the only extreme fines in - 325-mesh coal that are always carbon free.) Washability studies of flotation products are used to assess flotation efficiency. These studies show that: 1) the increase in percent sulfur in flotation products above the theoretical sulfur content as defined by the washability study is due almost entirely to flotation of fine high-specific-gravity particles that are part coal and part pyrite, and 2) in a given size range particle floatability decreases with an increase in particle specific gravity. Error curves are explained and are used to compare the mechanisms of coal flotation and hydrocycloning. These comparisons show that hydrocyclone performance is affected primarily by particle mass, i.e., particle specific gravity and size, whereas coal flotation performance is dependent on both the particle mass and the coal surface available for bubble attachment. Since the error curve is a basic tool for rating the efficiency of any coal processing system, it will be useful to quickly review the principles of error curve construction. RATING COAL-PROCESSING EFFICIENCY BY THE ERROR CURVE The organic component of coal is of lower specific gravity than its impurities, and the most effective principle for coal concentration is therefore separation on the basis of specific gravity. However, since there is no sharp dividing line between pure coal and pure ash components, specific gravity must be closely controlled if the product is to have acceptable quality at maximum yields. In turn, the basis for close control in any coal processing system is the reference standard provided by precise laboratory washability studies. In these studies, coal is carefully separated into a series of progressively higher specific gravity fractions to establish a relationship

Jan 1, 1968

By Seabed Mineral Authority Runanda Takere Moana

The Cook Islands is a group of 15 islands, being a Polynesian nation in the heart of the South Pacific Ocean and now bears the name of famed English navigator Captain James Cook, who sailed here in the 1770’s. In the 1800s, it was re-named “the Cook Islands” by illustrious Russian cartographers from the previous English name of “The Hervey Islands”. SEABED MINERALS The Cook Islands has one of the world’s most abundant deep seabed mineral (SBM) resources of Manganese nodules estimated at 10 billion tonnes, within its large Exclusive Economic Zone (EEZ) of almost 2 million square kilometres. This knowledge has been gained through numerous scientific surveys conducted in the Cook Islands waters by many international scientific research entities, starting with a Russian deep seabed marine survey in the 1970’s, from which many physical samples of these abundant Manganese nodules were first recovered. Some of the 1970’s Russian samples are still retained in the Cook Islands more than 40 years later. Then a comprehensive 21 year Pacific wide Seabed Minerals scientific study, between 1985- 2005, undertaken by the Japanese and SOPAC1 based in Fiji, confirmed that the Cook Islands has a vast, unique and valuable deep seabed minerals resource of Cobalt rich Manganese nodules. These Nodules contain many valuable minerals required by the global market including Nickel, Copper, Cobalt and Rare Earth Elements.

Jan 1, 2018

By III Feeley

The U.S. Department of Energy is supporting the engineering development of three advanced physical coal cleaning technologies--selective agglomeration, advanced flotation, and advanced cycloning--capable of significantly reducing the pyritic-sulfur content of U. S. coals. The objective of this activity is to provide the coal production and electric-utility industries with a cost-effective option for addressing the SO2 emission reductions required by the 1990 Clean Air Act Amendments. A secondary objective is to evaluate the potential of advanced coal cleaning for removing trace elements that are precursors to the formation of hazardous air pollutants. This paper will summarize the status of the three advanced physical coal cleaning engineering development projects.

Jan 1, 1993

By Jared Redyke

Thursday, October 14, 1999 marked another important milestone for America’s space program. At exactly 10:05 AM EST on a beautiful, sunny Florida morning, Dykon, Inc. of Tulsa, Oklahoma detonated approximately 300 pounds of explosives to fell the seven million pound Umbilical and Mobile Service Towers at Space Launch Complex 41 (SLC-41) at NASA’s Cape Canaveral Space Station. Completed in 1965 at the height of the Space Race to the moon, the Mobile Service Tower/Umbilical Towers (MST/UT) were part of the Titan rocket launch facilities. The MST was 265 feet high and weighed over five million pounds. The UT was 175 feet high and weighed over 2 million pounds.

Jan 1, 2001

By H. Warren Newcomen, Dennis C. Martin

"This paper describes the investigation of a large, progressive slope failure on the southeast wall of the east pit at Highmont Mine, British Columbia Geotechnical investigation s consisted of geological and structural mapping, assessment of blasthole drilling records, review of rock core information, slope movement monitoring and back analysis of various possible failure modes. Climate records and mining history were also assessed to determine their relationship to slope movement .Analysis of movement monitoring records and geotechnical information indicates that the failure is deep seated. The upper portion of the failure surf ace occurs along clay filled discontinuities. The lower portion of the failure surf ace appears to occur through the highly altered rock mass. High groundwater pressures and mining at the toe of the slope are documented to have had a major influence on stability at various times during the failure. Stability analyses results are presented and possible remedial measures are discussed.IntroductionHighmont Mine is located near Logan Lake in the Highland Valley approximately 50 km southwest of Karnloops, British Columbia (Fig. I). Mining of the porphyry copper and molydenum ore bodies began in 1980. In May, 1983, when mining in the east pit had progressed to a depth of about 60 m (200 feet) , a failure (designated the Southeast Failure) began to develop in the southeast corner of the east pit. Subsequent mining to a depth of 110m (360 feet) was accompanied by frequent and substantial slope movements involving between 500000 and I 000 000 m3 of rock . The slope was monitored extensively to assess short-term movement trends for operational safety. Geological mapping, core logging and rock mechanics testing were used in conjunction with the long-term monitoring information to determine the failure mechanism, conduct stability analyses, assess the effects of instability on pit design and enable design and installation of remedial measures."

Jan 1, 1988

By Thomas C. Ruhe

The Bureau of Mines conducted research to determine the safe operating conditions for using recycled (used) lubricating oil from mining equipment as a partial replacement for diesel fuel to make ANFO-type blasting agents. The use of recycled oil (RO) saves energy, reduces oil imports, and reduces mining costs. Low ambient temperatures may cause these recycled oils to become too viscous for proper absorption by ammonium nitrate (AN) prills and result in poor blast performance, safety hazards, and environmental problems. To help quantify and resolve these issues, viscosity, mixing, and performance tests were conducted at various temperatures. Diesel fuels No. 1 and No. 2 were studied separately and in blends with 25,50, and 75% RO. Good quality ANFO mixes (94-6) were produced with dry absorbent prills and blended fuel (No. 1 diesel plus RO) at temperatures as low as -40° F (-40°C) with 75% No. 1125% RO, and at -20°F (-29°C) with 50/50. Diesel fuel No. 2 also made good mixes as low as -30" F (-34" C) with 75% No. 2/25% RO, and at 0° F(-18° C)with 50/50. Reference detonation velocity tests were conducted in 1.4" (3.6 cm) diameter steel pipe at 70°F (21°C) on No. 1 diesel ANFO (94-6), giving an average value of 9722 ft/s (2964 m/s). Comparison tests showed good ANFO performance at low temperatures. Blended fuel ANFO (75% No. 1/25% RO) mixed, loaded, and tested at -40°F (-40°C), produced an average velocity of 9247 Ws (281 8 m/s). A 50/50 blend gave a velocity of 8083 Ws (2464 ds) at -20°F (-29°C). Based on these results, a practical field method has been developed to help evaluate whether a specific oil blend will mix properly with AN at a low ambient temperature. This method will help to promote the safe and reliable use of RO ANFO at low temperatures, with adequate performance.

Jan 1, 2008

By H. Warren Newcomen, Dennis C. Martin

"This paper describes the investigation of a large, progressive slope failure on the southeast wall of the east pit at Highmont Mine, British Columbia Geotechnical investigation s consisted of geological and structural mapping, assessment of blasthole drilling records, review of rock core information, slope movement monitoring and back analysis of various possible failure modes. Climate records and mining history were also assessed to determine their relationship to slope movement.Analysis of movement monitoring records and geotechnical information indicates that the failure is deep seated. The upper portion of the failure surf ace occurs along clay filled discontinuities. The lower portion of the failure surf ace appears to occur through the highly altered rock mass. High groundwater pressures and mining at the toe of the slope are documented to have had a major influence on stability at various times during the failure. Stability analyses results are presented and possible remedial measures are discussed.IntroductionHighmont Mine is located near Logan Lake in the Highland Valley approximately 50 km southwest of Karnloops, British Columbia (Fig. I). Mining of the porphyry copper and molydenum ore bodies began in 1980. In May, 1983, when mining in the east pit had progressed to a depth of about 60 m (200 feet) , a failure (designated the Southeast Failure) began to develop in the southeast corner of the east pit. Subsequent mining to a depth of 110m (360 feet) was accompanied by frequent and substantial slope movements involving between 500000 and I 000 000 m3 of rock . The slope was monitored extensively to assess short-term movement trends for operational safety. Geological mapping, core logging and rock mechanics testing were used in conjunction with the long-term monitoring information to determine the failure mechanism, conduct stability analyses, assess the effects of instability on pit design and enable design and installation of remedial measures."

Jan 1, 1988

By Andrea R. Gerson, Roger St. C. Smart, Russell Schumann, Joan E. Thomas, Warwick Stewart, Stuart Miller

Sequential Net Acid Generation (NAG) accelerated oxidation testing using peroxide was carried out on single sulfide mineral samples. The calculation of the nett acid production potential (NAPP) assumes that all the sulfide is present as pyrite and that dissolution results in a 2:1 ratio of H+:SO42-. NAPP as kg H2SO4/t is calculated as 30.6 x wt.% S present. To test whether this calculation is valid a NAPP* value was defined in which instead of using the wt.% S present for the calculation the wt.% S dissolved is used. Stoichiometric analysis of the dissolution products of the sulfide minerals as they would occur at pH 7 indicates, that in all cases, the ratio of H+:SO42- of 2:1 is viable. The NAG to pH 7 and NAPP* closely coincided for pyrite, bornite, chalcocite and covellite. For the three Cu-containing minerals, the NAG to pH 4.5 value was 0 as is predicted on the basis of the speciation likely to be present at pH 4.5. Acid generation is due to hydroxylation of the dissolved Cu between pH 4.5 and 7.0. The NAG to pH 7 and NAPP* values for chalcopyrite, arsenopyrite and pyrrhotite were in reasonable agreement but were not for either sphalerite or galena. Zn is not completely hydroxylated at pH 7 as is assumed by the calculation. For galena, surface analysis identified polysulfide formation on of the leach residue polysulfide. The formation of polysulfide is an acid consuming reaction. Therefore under conditions of accelerated oxidation the NAPP value is a reasonable estimate of the possible acid production in all cases except for sphalerite and galena. However, under conditions of less intense oxidation, for instance in columns, waste rock and tailings dumps, the formation of polysulfides is likely to be more widespread thus reducing the correlation between NAPP and the maximum possible acid production.

Jan 1, 2004

By T Nassis, H M. Nel, T du Toit

Assmang Khumani Iron Ore Mine is exploiting the iron ore deposits that can be found in the Bruce-King-Mokaning farm areas in the Northern Cape, South Africa. The Bruce, King and Mokaning (Khumani) deposits are approximately 10 km south of the town Kathu, adjacent to the Sishen Mine. Assmang Limited is jointly owned and controlled by African Rainbow Minerals Limited and Assore Limited.Measurement, calculation and trending of plant throughput and chemical ore properties are critical in maintaining a successful beneficiation operation due to these values forming the basis of decision-making and thus promotion of efficient ore extraction. The Khumani management and engineering information system (MEIS) supplies information on key process parameters to an operational team and is required to do so within an optimal time frame, for maximum impact.Diverse data is put into the MEIS from multiple specialist systems, with interfaces that require manual intervention. Manual intervention is resource and time intensive to the point which limits the effect on the process and decreases the potential for value addition.Automation of interfaces decreases resource and time requirements, standardising plant wide data sources and providing the opportunity to provide specialist system data to decision-makers in a timely fashion, resulting in maximum impact on the process output.Engineering and metallurgical management systems were interfaced at Khumani Iron Mine by means of an automated table which facilitates the transfer of production data validated within the engineering system as input to the metal accounting system. This interface effectively assigns a master to each specialist data set employed for decision-making and delivers accurate process parameters to the production team within an optimal time frame, resulting in increased potential to improve beneficiation efficiency.CITATION:Nel, H M, Nassis, T and du Toit, T, 2013. The role of metallurgical and engineering information systems in the optimisation of iron ore beneficiation processes, in Proceedings Iron Ore 2013 , pp 453-458 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

By J. L. Jernegan

IN a former paper laid before the Institute, entitled Lead and Silver Smelting in Chicago, I endeavored to give a description of the manner in which argentiferous lead ores from the far West were treated in that city, and also described the method employed in the desilverization of the silver-lead produced from the ores. It will perhaps be remembered, that very siliceous ores, principally from the Emma mine, Utah, containing over 40 per cent. of silicic acid, were then being treated at the works of the Chicago Silver Smelting and Refining Company in the reverberatory furnace, with the use of metallic iron, in the form of borings, as a precipitating medium for the lead ; and that the extraction of the silver from the resulting bullion was effected by the Balbach process. The Swansea Works, also the works at Brighton, just outside of this city, and those of S. P. Lunt, were at that time treating ore of a similar character by the same method. The inadequacy of the process for the ores then under treatment was, in a manner, pointed out by me in the paper above referred to. Since the time of its writing, many and important improvements have been made in the metallurgical treatment of Western ores in Chicago. Most ores are now roasted previous to reduction, and the latter operation is conducted in the shaft-furnace instead of the reverberatory. Such is the fact at least at the Swansea Works, the largest in the city, and here it was where the first steps were taken in this direction. In selecting these works as the subject of this paper, I am in hopes that the description given of the various metallurgical operations, as they are there now conducted, will serve to give an idea of the improvements introduced

Jan 1, 1876

MEN AVAILABLE Engineering Manager, many years' experience in design, construction and operation of industrial plants and mining properties, requiring a knowledge of mechanical, electrical, civil and mining engineering. Have directed many men and engineers working on foregoing projects. Domestic and foreign experience. Now available. M-702. Mining Engineer, 36, married. Thirteen years' experience underground mining operations; exploration, development, mine evaluation, cost estimation and job evaluation. Registered Professional Engineer. Employed. Available reasonable notice. M-697. Mining Engineer, B.S. plus 2 years' pre-law. Three years' experience; completed training program all phase open pit and underground. Last 2 years sintering, nodulizing and wash plants. Varied pre-professional job experience. Veteran, 32, married, 2 children. Available immediately. Will consider any location. M-703.

Jan 1, 1952

By Thomas R. Wildeman

Experimental methods for studying vapors over solid minerals are reviewed and an especially developed method using atomic absorption is described. The method is used to study vapor pressures over Te. Ag, Au, Ag2Te, and AuTe2 from 250°C through 10S0oe. Vapor pressures observed and, concurrently. sintering properties are significantly altered by the form of the solid. The vapor pressures of the tellurium compounds reveal complex processes occurring on the surfaces of the solids. The data given also point out a method of recovering precious metals from their telluride minerals w

Jan 1, 1987

By Wei Zhang, Jinhong Zhang

"In froth flotation, the adsorption of collector on mineral surface is critical for a successful flotation process. In present work, an atomic force microscopy (AFM) has been applied to study the adsorption of potassium amyl xanthate (PAX) on copper sulfides, i.e., chalcopyrite, chalcocite and bornite. The in-situ collected AFM images show that PAX adsorbs on chalcopyrite mainly in the form of oily dixanthogen; while it strongly adsorbs on chalcocite and bornite in the form of insoluble metal xanthate, which binds strongly with the mineral surface. The information obtained from the AFM study shed lights on the collectivity and therefore the selection of specific collector for different copper sulfide minerals in industrial practice.INTRODUCTIONFroth flotation, which treats the highest throughput in mining industry and produces the maximum economic outcome of any surface chemistry process, has been widely applied for the concentration of copper sulfide minerals, i.e., chalcopyrite, chalcocite and bornite. In flotation, collectors are added into the pulp (mixture of water and fine-grained minerals) to selectively adsorb onto the target mineral and render its surface with high hydrophobicity, which is generally beneficial for a strong mineral-bubble attachment and thus a high flotation recovery. Therefore, the adsorption of collector on mineral surface is vital for a successful flotation process and it has been studied by applying various surface analysis techniques, such as IR (Infrared Spectroscopy), CV (Cyclic Voltammetry) and XPS (X-ray Photoelectron Spectroscopy). (Poling, 1963; Allison et al., 1972; Mielczarski et al., 1984; Leppinen et al., 1989; Kartio et al., 1996) These studies have revealed a lot of information, such as the reaction, product and mechanism, of the adsorption of chemicals on mineral surface. It is also of great interest to directly get the image of adsorbed collectors on mineral surface changing with pulp chemistry, such as pH, redox potential, ionic strength and chemical’s dosage."

Jan 1, 2018

By G. H. Lind

New South Wales has a successful history of pillar extraction stretching back more than 60 years. Various methods of pillar extraction ranging from the rib pillar methods (such as the Wongawilli system) to the more recent pillar stripping techniques (similar to those used in the USA) are discussed in this paper. These discussions are based on the experiences of the author stemming from a recent research tour of seven underground pillar extraction operations in New South Wales as part of the Coaltech 2020 collaborative research initiative. Some operational issues of each site visited are presented before some general comments pertaining to the overall success of pillar extraction in New South Wales are discussed. Generally pillar extraction in New South Wales is on the decline in favour of longwalling. However, the pillar extraction that is conducted is done so along specific guidelines to ensure their success, and these are also discussed.

Jan 1, 2002

By A Vickerfält, J Huss, J Martinsson

The European Union has listed vanadium (V) as one of the critical raw materials for the transition to a future green society, as stated in the Critical Raw Material Act, written by Grohol and Veeh (2023). In the steelmaking industry based on V-containing iron ore, V is a possible by-product from the slag. A requirement for slags to be suitable for V extraction is a V content preferably above 8 wt per cent as V2O3 and a phosphorus (P) content below 0.1 wt per cent as P2O5. Hence, it is important to keep V in the slag phase while the P is moved to the metal phase during the steelmaking process.

Aug 21, 2024

By Violeta Vigo Vargas

El Centro de Innovación Tecnológica en Joyería “Koriwasi”, CITE Joyería Koriwasi, es el resultado de una alianza estratégica entre Minera Yanacocha (Asociación Los Andes de Cajamarca) y el Estado (MINCETUR). El proyecto se ejecutó hace cinco años y busca mejorar las capacidades técnicas y las condiciones tecnológicas del proceso productivo del artesano joyero mediante la implementación de una institución prestadora de servicios especializados. En ese sentido, el presente texto describe los objetivos estratégicos de dicha empresa para mejorar permanentemente las capacidades técnicas del artesano joyero en función a estándares internacionales y apoyar el proceso de producción individual del artesano joyero, mediante la facilitación de materiales procesados garantizados y la prestación de servicios de maquinado de calidad, así como desarrollar un sistema de información que promueva la articulación entre la red de artesanos joyeros y el mercado nacional e internacional.

Sep 14, 2009