Download or read book The Leaching of Base Metals from the Calcines Produced by the Roasting of Pyrite Concentrates written by and published by . This book was released on 1985 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A number of gold and uranium plants in South Africa concentrate the pyrite in the ore or residue by flotation, and roast the concentrate for the production of sulphuric acid. The calcine produced, which is predominantly hematite, is generally subjected to cyanidation for the recovery of gold and silver that would normally not have been recovered in high yield from the primary concentrate. The calcines often contain economically significant quantities of copper, nickel, cobalt, and uranium. Prior treatment of the calcine for the recovery of these metals would be desirable in terms of the value of the products and also in terms of the possible increased gold recovery in the subsequent cyanidation of the leach residue. Several processes for the leaching of the base metals from plant calcines have been investigated, and an important general conclusion is that an adequate recovery of the base metals requires that a large proportion of the iron should also be extracted. This observation led to a more extensive investigation of the kinetics of the leaching of various iron oxides. The application of electrochemical theory and techniques resulted in a fuller understanding of the various factors that govern the rate of leaching of iron oxides. As a result of this fundamental work, alternative treatment schemes that should yield more efficient extraction from calcines were suggested. Several of these possibilities were investigated, and the most promising were found to require reducing conditions during the leach, or prior partial reduction of the calcine to magnetite or wustite. The effects of various process variables such as the type and concentration of the acid, the temperature, the residual sulphur in the calcine, and the source of the calcine were investigated. The effect of prior treatment of the calcine on subsequent gold recovery by cyanidation was also investigated for a number of the calcines.
Download or read book Drying Roasting and Calcining of Minerals written by Thomas Battle and published by Springer. This book was released on 2016-12-01 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt: The papers in this volume give the reader focused information on the important extractive metallurgy unit operations of drying, roasting, and calcining
Download or read book Unrestricted Mintek Publications written by and published by . This book was released on 1966 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Flotation of Pyrite from Coal written by Kenneth J. Miller and published by . This book was released on 1972 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book INIS Atomindex written by and published by . This book was released on 1986 with total page 1352 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Metals Abstracts written by and published by . This book was released on 1990 with total page 1342 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Journal of the South African Institute of Mining and Metallurgy written by South African Institute of Mining and Metallurgy and published by . This book was released on 1982 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book EPA 600 7 written by and published by . This book was released on 1976 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Annual Report written by Council for Mineral Technology (South Africa) and published by . This book was released on 1981 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Environmental considerations of selected energy conserving manufacturing process options written by United States. Environmental Protection Agency. Office of Research and Development and published by . This book was released on 1976 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Extractive Metallurgy of Gold written by John C. Yannopoulos and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 285 pages. Available in PDF, EPUB and Kindle. Book excerpt: The history of gold begins in antiquity. Bits of gold were found in Spanish caves that were used by Paleolithic people around 40,000 B.C. Gold is the "child of Zeus," wrote the Greek poet Pindar. The Romans called the yellow metal aurum ("shining dawn"). Gold is the first element and first metal mentioned in the Bible, where it appears in more than 400 references. This book provides the most thorough and up-to-date information available on the extraction of gold from its ores, starting with the miner alogy of gold ores and ending with details of refining. Each chapter con cludes with a list of references including full publication information for all works cited. Sources preceded by an asterisk (*) are especially recom mended for more in-depth study. Nine appendices, helpful to both students and operators, complement the text. I have made every attempt to keep abreast of recent technical literature on the extraction of gold. Original publications through the spring of 1989 have been reviewed and cited where appropriate. This book is intended as a reference for operators, managers, and designers of gold mills and for professional prospectors. It is also designed as a textbook for extractive metallurgy courses. I am indebted to the Library of Engineering Societies in New York, which was the main source of the references in the book. The assistance of my son, Panos, in typing the manuscript is gratefully acknowledged.
Download or read book Environmental Considerations of Selected Energy Conserving Manufacturing Process Options Sulfur oxides summary report written by United States. Environmental Protection Agency. Office of Research and Development and published by . This book was released on 1976 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Environmental Considerations of Selected Energy Conserving Manufacturing Process Options Primary copper industry written by and published by . This book was released on 1976 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Leaching Properties and Chemical Compositions of Calcines Produced at the Idaho Chemical Processing Plant written by and published by . This book was released on 1980 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: No significant chemical differences were determined between retrieved and fresh calcine based on chemical and spectrochemical analyses. Little can be derived from the amounts of the radioisotopes present in the retrieved calcine samples other than the ratios of strontium-90 to cesium-137 are typical of aged fission product. The variations in concentrations of radionuclides within the composite samples of each bin also reflect the differences in compositions of waste solutions calcined. In general the leaching characteristics of both calcines by distilled water are similar. In both materials the radionuclides of cesium and strontium were selectively leached at significant rates, although cesium leached much more completely from the alumina calcine than from the zirconia calcine. Cesium and strontium are probably contained in both calcines as nitrate salts and also as fluoride salts in zirconia calcine, all of which are at least slightly soluble in water. Radionuclides of cerium, ruthenium, and plutonium in both calcines were highly resistant to leaching and leached at rates similar to or less than those of the matrix elements. These elements exist as polyvalent metal ions in the waste solutions before calcination and they probably form insoluble oxides and fluorides in the calcine. The relatively slow leaching of nitrate ion from zirconia calcine and radiocesium from both calcines suggests that the calcine matrix in some manner prevents complete or immediate contact of the soluble ions with water. Whether radiostrontium forms slightly fluoride salts or forms nitrate salts which are protected in the same manner as radiocesium is unknown. Nevertheless, selective leaching of cesium and strontim is retarded in some manner by the calcine matrix.
Download or read book Mintech written by and published by . This book was released on 1989 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hydrochloric Acid Leaching and Low temperature Roasting of Tin tungsten Concentrates from Van Roois Vley written by and published by . This book was released on 1983 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Metals Division of Shell SA (Pty) Limited carried our exploratory work on a fairly large deposit in the north-western Cape referred to as the Van Roois Vley deposit, and the Council for Mineral Technology (Mintek) produced high-grade concentrates of the tin-tungsten minerals from this area. These concentrates were treated for the separation of tin and tungsten and for the production of synthetic scheelite of a purity acceptable to industry for further processing in the manufacture of rock-drill bits. The process steps were as follows: direct leaching in 10 M hydrochloric acid at 95 degress C for 3 to 4 hours, dissolution in caustic soda of the tungstic acid formed, and precipitation of the tungsten as synthetic scheelite by the addition of calcium chloride. This process yielded 99,5 per cent recovery of tungsten into a synthetic scheelite with a tungsten content of at least 61 per cent compared with the end-user's specification of 60 per cent as a minimum. The cassiterite residue had a tin content of 60 per cent or better. Concentrates from different zones of the deposit did not all respond well to the process. A patented process (no SA 78/6478) using a low-temperature roast with sodium carbonate as the reactant was tested. This process was partially optimized and yielded over 9 per cent extraction of tungsten from the most refractory concentrates produced from various zones of the deposit. However, precipitation of the tungsten from the carbonate mother liquor presented some problems. The recovery of tungsten from carbonate liquor requires detailed investigation.
Download or read book Report written by Commonwealth Scientific and Industrial Research Organization (Australia) and published by . This book was released on 1956 with total page 542 pages. Available in PDF, EPUB and Kindle. Book excerpt:
