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By Xuanxue Mo, Kaihui Yang, Steven D. Scott

Abstract -The Changning-Menglian metallogenic belt in western Yunnan, China, is characterized by the occurrences of both Pb-Zn-Cu and Cu massive sulfides in Permo-Carboniferous mafic volcanic sequences. These deposits were formed in a back-arc basin at a rifted continental margin in the Paleozoic Tethys Ocean. Pb-Zn-Cu deposits are associated with alkalic basalt, andesite, and lesser felsic volcanic rocks intercalated with limestone, which probably formed along an immature rifting segment on a continental basement. These volcanic rocks are enriched in K, Ti, LREE, and other incompatible elements, and have the attributes of alkalic within-plate basalt. An extensive unit of sulfide- carbonate-silica shale in proximity to massive sulfides contains high values of Mn, As, Mo, W, Sn, Sb, and Hg, and has REE patterns that are similar to the volcanic rocks. This, together with the graded bedding in the footwall volcanic rocks, suggests that the sulfides precipitated in a shallow, unstable, and carbonate-saturated volcanic basin. A stringer zone is traced downward for 500 m below the massive sulfide orebodies. It is characterized by an upper sericite-quartz zone and an extensive lower skarn alteration with enhanced W, Sn, and Bi. Lead isotope data show both continental basement and magmatic sources may have supplied the ore metals. Cu deposit and occurrences are hosted by tholeiitic units that represent the mature spreading segments in the back-arc basin. The tholeiitic lavas have LREE-depleted or flat REE patterns similar to MORB or back-arc mafic lavas. The cupriferous massive sulfides are overlain by an extensive unit of chlorite-magnetite or ochre, suggesting a relatively oxygenated oceanic basin. Ni and less Co mineralization is found in dolomite veins of the stringer zone. Enhanced concentrations of Ni, Co, Au, and As are found in the massive sulfides and in sulfide-rich tuffites. The geological setting and mineralization of the Changning-Menglian belt has similarities with modern back-arc basins such as the Manus Basin in the western Pacific.

Jan 1, 1999

By Xuehui Xia

Abstract -There are a number of sedimentary exhalative massive sulfide (SEDEX) deposits in the Proterozoic Langshan-Zhaertai rift at the western segment of the northern margin of the North China platform in China, including more than ten large, medium and small deposits located in a belt of 300 km EW by 50 km to 100 km NS, with large Cu, Pb, Zn, Ag, and S reserves. In several representative SEDEX deposits in the rift, the mineralizing elements are prominently zoned, horizontally or vertically, with Cu decreasing but Pb increasing from west to east, Cu decreasing but Zn increasing from bottom to top, and Zn restricted to the bottom half. The ore-hosting rocks, characterized by a clear manganese halo, have developed a polymetallic mineralization in positive relation with their carbon contents. Their isotopic aspects are: ?34S has relatively large positive values, fluctuating between +5‰ and +35‰, compared with Pb isotopic compositions which are less variable, with a model age of 1600 Ma to 1800 Ma, showing that they are mantle-derived. The mineralizing materials were associated undoubtedly with the contemporaneously faulting events in the rift. The deposits owe their origin to seafloor exhalation, with sedimentary rocks as their hosts.

Jan 1, 1999

By Jian Deng, Haitian Sun, Zengqian Hou, Shuhe Song

"Abstract - Volcanogenic massive sulfide (VMS) deposits, an important base-metal deposit type in China, occur widely in submarine volcanic districts of variable magmatic affinities. These VMS deposits range in age from Archean to Mesozoic, but most are in Proterozoic and Paleozoic sequences. More than 60% of VMS deposits formed in the Paleozoic, the most important metallogenic eon. Three important Paleozoic VMS-metallogenic provinces include Northern Qilian, Sanjiang and Altai provinces. The Proterozoic constitutes the next important era, but with no VMS deposits in the middle Proterozoic. VMS deposits associated with the Proterozoic volcanic rocks occur around the Yangtze Platform and in the western Kunlun-Qinling. The Triassic is third in importance, with VMS deposits concentrated in the Sanjiang Tethys. The Archean has only one VMS deposit, on the northern margin of the Sino-Korea Platform.Five distinct compositional classes of Chinese VMS deposits have been distinguished: Cu, Cu- Zn (or Zn-Cu), Cu-Fe, Zn-Pb-Cu, and Pb-Zn (-Cu). The Cu, Cu-Co, and Cu-Zn types of deposits occur sporadically from the Archean to Paleozoic, and are closely associated with mafic and ultramafic volcanic sequences. The Zn-Pb-Cu and some Cu-Zn type deposits are restricted to the Paleozoic and Triassic, and are hosted by calc-alkaline felsic rocks in bimodal basalt-rhyolite sequences, whereas Cu-Fe and Pb-Zn type (except for the Laochang deposit) deposits are restricted to the Proterozoic and occur in calc-alkaline volcanic sequences. As large quantities of marine mafic volcanic rocks were deposited in western China, Cu and Cu-Zn deposits are major types of Chinese VMS deposits.Chinese VMS deposits formed in a wide range of paleo-tectonic settings and depositional environments, such as island-arcs, rifts, aulacogens, and ocean ridge hot spots. Among these, the rift and back-arc environments are the most important, containing about 60% of Chinese VMS deposits. Aulacogens are a subordinate environment where most of the Proterozoic VMS deposits formed. The oceanic ridge and hot-spot systems are common in the tectono-magmatic domains in China, but contain only a few small Cu and Cu-Zn type VMS deposits.The Chinese VMS deposits have usually been influenced by both deformation and metamorphism to various degrees, resulting in changes in the shape and metal distribution. Seven representative deposit styles have been recognized: sheets, sheet plus strata-bound stringer, cyclically zoned deposits, mounds, mound-like deposits, strata-bound stringer-disseminated, and stockwork-disseminated deposits. The formation of these various styles of deposits is controlled by several key factors, such as lithology and permeability of the host rocks, focused or unfocused discharge, temperature and chemical composition (e.g., salinity) of hydrothermal fluids, as well as depth of seawater."

Jan 1, 1999

By H. M. Thurgood, F. A. Godfrey, F. W. Gilbert

This is a detailed presentation of the ancillary facilities, including power production, water supply, shiploading facilities, fire-fighting equipment, housing and community services. Additional subjects discussed include construction problems, townsite philosophy and staff organization.

Jan 1, 1968

By R. P. Plasket, D. A. Ireland

Ancillary smelter operations and sulphuric acid manufacture at Impala Platinum Limited by R. P. PLASKET. Pr. Eng.. M.Sc. (Chem. Tech.). Natal (Fellow) and D. A. IRELAND. Pr. Eng.. B.Sc. (Chem. Tech.). Natal (Member) The de-watering, spray drying, and converter operations at Impala are described, aspects that may be new to the minerals industry in South Africa being elaborated. Air-pollution control necessitated the installation of a sulphuric acid plant to limit the emission of sulphur dioxide to the atmosphere. Closer control of the smelting and converting operations was required for successful operation of the acid plant on the inherently Iow and varied concentration of feed gas from converter blowing. Approximately 82 per cent of the sulphur entering the smelter is converted to sulphur dioxide, of which 67 per cent is fed into the sulphuric acid plant.

Jan 8, 1976

By Friedrich Brandstetter

Dentro del desarrollo técnico es importante desplazar las construcciones de infraestructura de forma frecuente hacia el subsuelo. Esto requiere el empleo de equipos especiales, métodos, así como de nuevos materiales de construcción con características especiales que faciliten la ejecución de estos proyectos. Así el acero fue reemplazado por resina sintética, generando resultados muy alentadores en la construcción segura en la naturaleza. En ese sentido, el presente texto señala el empleo de estas resinas y su optimización en la economía.

Mar 1, 1979

This paper reviews recent positive developments in Europe on the regulation of gold mining. However, it also examines the problem that while gold projects may be bankable and technically and environmental defensible, the odds tend to be stacked against granting of an environmental permit. The historic background to this situation is examined and current developments and initiatives are critically analysed. Standards and benchmarks for the industry have been established across the community and these have a strong influence in European Union accession (and aspiring) states as well. While this is welcome in regard to improving environmental performance, it also represents a significant milestone with mining (and particularly gold mining) now æon the mapÆ as a legitimate enterprise, a situation that was patently not the case prior to 2003. At the project level, very frequently, the difficult biophysical problems are addressed and satisfactorily dealt with according to the new regulations, but still there are problems regards trust and acceptance that underpin a æsocial licenceÆ. What goes wrong and how can companies deal with the social/environmental issues that lead to entrenched views and concerns, irrespective of any amount of demonstration of good practice and corporate social responsibility? What is the role of the non-governmental organisation (NGO) and are they as accountable and responsible as they should be? The findings presented draw upon recent experience with the environmental permitting of projects in Spain, Greece, Romania, Bulgaria and Serbia on behalf of Australian, Canadian and British companies as well as international funding institutions.

Jan 1, 2007

By J. A. Finch

In this paper, the author offers a personal view of what the next 30 years holds for mineral processing. Restating that mineral processing will remain a vibrant industry in raw material production, growth opportunities in waste management are identified. The processing sequence familiar now (mining ?mineral processing ?extraction) will become more interwoven. In situ processing (i.e., milling underground) will evolve from concept to demonstration. Opportunities to exploit physical properties altered in chemical (pyro- and hydro-) processing will present themselves. In primary grinding, the path to AG/SAG milling will progress with little deviation but opportunities in regrinding are wide open. Flotation will see the trend to designing bubble/particle reactors accelerate simultaneously with a vigorous response from mechanical cell suppliers. Gravity separation remains a bastion of the lone inventor but this author anticipates that the new lines will come from the waste management business. The paper concludes with the examination of the “research cycle” and identification of growth in small “high tech” companies and university research centres

Jan 1, 1998

By G. Mike Bernard

The Andacollo gold mine is located near the town of Andacollo (population 14,000 people) in Chile’s region four. It is about 56km (35 miles) by paved road from the coastal city of La Serena. Santiago is about480 km (300 miles) south. Site elevation varies between 1,000 and 1,280 m(3,300 and 4,200 ft). The climate at the Andacollo site is moderate but arid. Average annual rainfall is only 130mm (5 in.). Because there is little rain and the temperature varies only a few degrees (14 to 24 C or 57 to 75F), there are no problems with freezing, solution dilution or pad saturation. The climatic conditions are ideal for heap leaching.

Jan 1, 1996

By G. M. Bernard

The Andacollo gold mine is located near the small town of Andacollo, Chile (population 14,000) in the fourth region. It is approximately 35 miles by paved road from the coastal city of La Serena, and Santiago lies about 300 miles to the south (see map.) Site elevation varies between 3300 feet and 4200 feet. The climate at the site is moderate but arid, with an average annual rainfall of only five inches. Because there is little rain, and the temperature varies only a few degrees (57"F to 75°F); there are no freezing, solution dilution, or pad saturation problems. The climatic conditions are ideal for heap leaching.

Jan 1, 1996

By Tim Watson

Andacollo Hypogene Project ?Overview Project description: Sulphide copper concentrator Throughput:55,000 tpd Location: Approximately 50 km from La Serena Elevation: Approximately 1,000 m ASL Start feasibility study: July 2005 Start of construction: May 2007 Construction completion: December 2009 Final cost(1,2,3):435 Million US $ (1) Excludes third party costs, 220 kV power line (2) Cost is based on a Chilean Peso to US Dollar foreign exchange rate of 535 to 1 (3) Does not include US$40.3 million for the Elqui River Pipeline Project or US$8.0 million for the stock pile cover

May 1, 2010

By P. W. Ocerbeek

The occurrence, properties, and uses of andalusite, and its advantages over other refractory minerals and materials, are discussed. Ore reserves are given for the five producing areas, and statistics on production, export sales, and prices are included to illustrate the growth of the industry since the early 1960s. The mining and beneficiation procedures are described, with special reference to new techniques in concentration and magnetic separation. As fines dumps represent a considerable source of andalusite, possible methods of recovery are discussed. . The outlook for the future appears favourable, and possible competition from other sources and substitute refractory minerals are mentioned. It is concluded that the industry is in a sound position to maintain South Africa's status as the world's foremost producer and supplier of andalusite.

Jan 1, 1989

By P. E. Davidson

The management of solid waste is known to be a large and increasing problem in high-population areas throughout the world. It is not necessary here to add further definition to the nature and magnitude of the problem. Instead, it is the purpose of this paper to describe a new process, called the Andco-Torrax System, which will be of use in converting municipal solid waste into useful energy forms and a granulated slag by-product. The paper includes a description of the first commercial plant for the process.

Jan 1, 1977

ANDES, lying south of Chuquicamata and north of Braden on the western slope of Chile's cordillera, can best be described as a big well-managed copper-mining enterprise without any peculiarly outstanding features. In point of copper produced, since output started in 1927, it ranks fifth among the Porphyries, being exceeded only by its two Chilean contemporaries and by Utah Copper and Morenci in the United States. Even so, there is little to distinguish it from other properties. It does not have the phenomenally rich ore (better than 2 per cent copper) that characterizes Braden; and it is not in the same class as Chuquicamata whose ore has the excellent tenor of around 1.7 per cent, nor has it Chuqui's immense tonnage of proven ore reserves and potential ore resources. One might say the operations are standard in that there are no basic or radical departures from established practice. A letter from New York supplying me with sundry pertinent facts for which I had asked, makes this comment regarding the answer to one inquiry: "omitted because it is the ordinary equipment found in any well-run mine." The substance of that remark applies generally to the other operations, plants, and facilities. One interesting fact that helps explain this situation should not be overlooked. Until the "new" Morenci in 1942, Andes was the last of the Porphyry copper mines to come into production. It did not do much pioneering because other companies had, of necessity, charted the way in many particulars. The company was organized by the Anaconda Copper interests in 1916 to take over a, group of claims held under option by William Braden who, a few years earlier, had interested

Jan 1, 1957

ASIDE from being the youngest of the Porphyries-from a producing, not a geologic standpoint-Andes probably presents the most finished piece of engineering, considering the enterprise as a whole: The various units of the mining and reduction works are well designed and efficiently operated, but that is true also at most of the other properties. Some mills or smelters may be superior to those at Andes; but as a complete mechanism for the exploitation of a big copper orebody, the Andes plant stands in a class by itself in many respects. Chuquicamata and Braden, as well as the properties in the United States, grew piecemeal. Capacities were increased and new plants were built as expansion progressed. Andes, on the other hand, existed on paper essentially as it is today before a start was made on actual construction of the reduction plant. More than $35,000,000 had been spent in developing and equipping the mine, and in building the concentrator and smelter, before the first ton of blister copper was produced on January 14, 1927. And another $12,500,000 was spent during the next two years in building the leaching plant and completing other construction. The orebody had been fairly well developed and tentative plans for the erection of reduction works had been made when the post-war depression descended on the copper industry and dictated deferment of the construction of a plant. This delay, however, gave the engineers opportunity to study the problems thoroughly in preparation for the design of the reduction works. The task was performed at Anaconda, Montana, under the direction of Frederick Laist, metallurgical manager, and Wilbur Jurden, chief designing engineer, of the Anaconda Copper Mining Company's staff. More than $1,150,000 was spent on

Jan 1, 1933

Andesites are a major source of aggregate for much of the North Island of New Zealand. There are regional differences with respect to some important properties of the andesites. Some are reactive with cement and are designated as potentially deleterious or deleterious by the concrete industry. Other andesites, particularly those that are slightly altered or weathered, have rather high Plasticity or Clay Indices and perform poorly in road construction.   The performance of the andesites has been investigated and can be shown to be determined by: +        the chemistry of the rock which in turn determines the chemistry of the glass in the rock; +        the presence of large amounts of groundmass glass in the rock; and +        the nature of the superimposed alteration processes. Environment of extrusion and how rapidly the rock has been cooled or chilled are also important as they determine the fabric of the rock and how much glass will be present in the rock.   There are three main types of alteration that affect the quality of the aggregate: 1.   hydrothermal alteration, 2.   late magmatic alteration associated with the devitrification of glass, and 3.   weathering.   Each of these alteration types produces different alteration minerals. In fresh andesites the devitrification of glass has an important affect on the rockÆs properties. The Taranaki andesites are shown to have unusually (in comparison with other North Island andesites) high Na2O contents, held in the groundmass glass, which is the fundamental reason for the high alkali û silica reactivity of these andesites.

Jan 1, 2005

By A. H. G. Mitchell

Gold-poor and gold-rich porphyry and epithermal gold-silver deposits of Caenozoic and Cretaceous age in the western Pacific and central and eastern Europe are confined to predominantly andesitic continental margins and island arcs. The arc volcanic rocks overlie a complex non-oceanic basement of stacked nappes, the uppermost of which is often ophiolitic. The emplacement of ophiolite triggered a reversal of tectonic polarity, subduction and arc magmatism. Andesitic volcanism and the formation of a strato-volcano were followed by the ascent of magma and porphyry copper mineralisation. Regional propylitic alteration came from convecting, predominantly meteoric fluids. Magmatic degassing caused advanced argillic alteration. This is commonly unmineralised in perched water tables, but may sometimes host high sulphidation gold or enargite gold at deeper levels within the propylitic zone. The onset of extensional stress after the andesitic volcanism allowed meteoric water to circulate to depths of 5 km or more, with consequent cooling of an ascending magma body at depth and the development of low sulphidation epithermal gold mineralisation near and immediately above the sub-volcanic basement surface. All andesitic arcs are mineralised. Regional controls on their ore potential include the level of erosion and geological features in the basement that focus the ascent of fluids. Differences between the mineralisation of the European and the western Pacific arcs may reflect the presence of older, more granitic basements in many of the European arcs.

Jan 12, 1992

Andrew Carnegie, America's best-known ironmaster and philanthropist, died at his home at Lenox, Mass., Monday, Aug. 11, after a three days' illness. A pioneer in the steel industry, he introduced into this .country the Bessemer process And formed the plans that have resulted in this country's supremacy in the steel markets of the world. Known throughout the world for his, gifts, he is also known to engineers as the donor of the home of their National Societies and as the founder of the Carnegie Institute of Technology, of Pittsburgh. For many years, also, he was an honorary member of the American Institute of Mining and Metallurgical Engineers, the American Society of Mechanical Engineers, and of the Engineers Club of New York. What he considered the secret, of his success is shown by the epitaph he wrote for himself, "Here lies a man who knew how to enlist in his service better men than himself." He was buried Thursday, Aug. 14, in Sleepy Hollow Cemetery, Tarry-town, N. Y., the funeral services being private, in accordance with his wish.

Jan 9, 1919

By AIME AIME

ANDREW FLETCHER, newly elected Treasurer and Director, has spent his entire mining career in the employ of the St. Joseph Lead Co. and brings to the Institute Board a career rich in financial experience and varied in interest and accomplishment. "Drew" Fletcher was born in New York City on Feb. 6, 1895. After graduating from the Sheffield Scientific School of Yale in 1916 as a mechanical engineer, he became a shipyard mechanic in Wilmington, Del. The next thirteen years saw. him gradually enlarging his responsibilities until he ultimately became the head of the W. & A. Fletcher Co., in Hoboken, N. J., ship repairers. In 1929 his program for merging the Fletcher plant with five other New York shipyards was finally consummated in the formation of the United Dry Docks, Inc., which subsequently was purchased by Bethlehem Steel, with the result that today the old Fletcher yard and organization has been expanded into one of the finest ship repair units in the United States.

Jan 1, 1944

By S. K. Mitterecker, T. Hofbauer, F. Baerhold

"Acid regeneration is a very important process step in each acid leach circuit. It is required to recover dissolved metals and HCl from spent leaching acid. Andritz Metals presents its recently commissioned spray roast pilot plant. The facility is now available for testing and demonstrating acid recovery or metal oxide production which is a requirement in several flow sheets under development for the mining and specialized oxides industries. Results from pilot test campaigns are reported here. We are currently focusing on a nickel ore leaching process, which requires both a feasible iron control and acid regeneration step. In addition, we disclose the results of a magnesium ore and aluminium recycling test campaign conducted in our pilot plant facility.INTRODUCTION Hydrochloric acid regeneration is widely used in the steel industry to regenerate spent pickle liquors into hydrochloric acid at a typical concentration of 18 wt.%. Andritz Metals (formerly known as Ruthner) has built more than 200 acid regeneration plants worldwide (Andritz Metals brochure). As technology leaders Andritz also has vast experience with specialty metal oxide plants, producing metal oxides such as aluminium oxide (Al2O3), magnesium oxide (MgO), nickel oxide (NiO), cobalt oxide (Co3O4) and mixed oxides from metal chloride solutions (Baerhold F., Lebl A., Starcevic J., 2006), (Jedlicka, H., n.d.), (Ruthner M.J., Krischner H., 1973), (Ruthner Ind. Planungs AG, 1967). Hydrochloric acid leach circuits have been developed and proven in the industry for many years. Examples of industrial applications are: synthetic rutile production (TiO2) (Walpole E.A., Winter J.D., 2002), Quebec Iron and Titanium’s UGS process (Patoine M.-C., De Mori A., Borowiec K., Coscia C., 2002), magnesium and potassium production (Priemer H., 1973) and Goro Nickel (Vahed A., Colton D.F., Duterque J.P., Karner W., Baerhold F., 2004), (Taylor A., 2013). One of the critical process steps in developing a hydrometallurgical process is acid regeneration, as it is an economic requirement to recover both the dissolved metals and acid (commonly HCl) from the spent leaching solution."

Jan 1, 2016