Download or read book Investigations on the Treatment of Refractory Gold Ores from the Giant Reefs Mine written by and published by . This book was released on 1966 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: Additional samples of ore from the Giant Reefs Mine were investigated in the light of previously reported results. Fine grinding and dilute leaching in the presence, and in the absence, of mill waters was carried out. It was found that the refractoriness of these ores is due to the chemical interference during cyanidation and that satisfactory results could be obtained by leaching at 5:1 liquid/solid ratio in the presence of mill water. As the mine was not in operation when samples were taken, no sample representing a 'mill head' could be obtained. Therefore each of the samples investigated was composed of rock chippings from one particular site. These samples differed from each other considerably in grade and composition. It was found impossible to assign a constant head value and behaviour to any of the samples because significant variations in gold content and chemical activity were observed in duplicate portions of each of the samples. This variability of properties made it impossible to determine exact conditions for maximum gold extraction for any of the samples. However, the above-mentioned leaching technique was found to give consistently high extractions on duplicate portions of each of the samples.

Download or read book Investigations on Refractory Gold Ores written by H. W. Mcculloch and published by . This book was released on 1963 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Treatment of Ore from the Giants Reef Gold Mine Preliminary Tests on an Ore Sample from the Sulphide Zone written by and published by . This book was released on 1963 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Exploratory tests on the treatment of an ore sample from the sulphide zone of the Giant Reefs Mine were carried out. The sample contained 3.3 dwts gold per ton and about 25 per cent of sulphide minerals which comprised arsenopyrite, lollingite, pyrrhotite and pyrite. A table concentration test indicated the possibility of recovering about 35 per cent of the gold in the form of a concentrate assaying 34 dwts gold per ton. The inclusion of a gravity concentration step in the treatment process therefore appears worthwhile. A series of flotation tests investigated the effect of varying the degree of grinding. Recoveries of gold increased as finer grinding was employed and the maximum recovery of 87 per cent of the gold was obtained at a grind of 97 per cent minus 200 mesh. The results of cyanidation tests indicated that direct cyanidation of the ore is the most promising method of treatment. Gold extractions of 85 per cent were obtained in several tests in which the ore had been ground to 80 per cent minus 200 mesh. There is a possibility that the extraction indicated can be increased by finer grinding and/or modification of the cyanidation procedure employed. The cyanidation tests were inadequate in number to indicate the conditions that enable maximum extraction of the gold to be obtained, but the following operations appear to favour a high extraction: aeration of the pulp prior to cyanidation; filtration and washing of the ground ore prior to cyanidation; stage addition of reagents to maintain the optimum reagent concentration and to avoid excess reagents. The use of calcium carbonate or magnesia instead of lime gave promising results and merits further testing as a means of avoiding instantaneously high pH values. The report contains suggestions for further testwork which should include more detailed flotation and cyanidation tests; in carrying out the cyanidation tests special attention should be given to procedures that are likely to reduce the consumption of cyanide.

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 Investigation of Refractory Gold Ores Laboratory scale Tests on the Roasting of Ore from the Mount Morgan Mine written by and published by . This book was released on 1965 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The construction and the operation of the kiln is described. The effect of the temperature and the residence time in the kiln on the subsequent gold recovery, and on the arsenic, sulphur, and carbon contents of the product, have been investigated. Activation of the carbon, by roasting, yields low gold-extraction figures, owing to the precipitation of the gold onto the carbon. At high temperatures (ie, 730 degrees C), where the carbon is substantially burnt off, the gold extraction increases to a value of 74.5 per cent. The alloying or coating of the gold by lead compounds or other constituents in the ore during roasting is thought to be the cause of the limit to the maximum gold extraction figures obtained. Arsenic does not appear to have any effect on the extraction of gold from the ore. The pyrite surrounding the gold particles is decomposed and cracked during roasting, thus allowing penetration by the cyanide solution.

Download or read book Investigation of Refractory Gold Ores Suggestions for Future Work on Refractory Gold Ores of the Barberton Goldfield written by and published by . This book was released on 1966 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: As a result of both the writer's visit to the Kalgoorlie goldfield in Western Australia and the testwork conducted in the Government Metallurgical Laboratory on refractory gold ores, several recommendations have been made in this report for future work on the refractory gold ores from the Barberton goldfield. The conclusion has been drawn that it is unlikely that a treatment method, for oxidation of auriferous sulphide concentrates, economically superior to roasting will be developed. Consequently, eight recommendations, oriented towards the possibility of increasing the income of the Barberton mines, have been made. These recommendations, which aim at reducing the gold content of all waste material discarded from the reduction works and developing the recovery of saleable material other than gold, are as follows: 1. That cyanidation of the flotation concentrate be investigated with special reference to reducing the gold value of the calcine cyanidation residue and to the recovery of silver. 2. That the method of roasting be assessed with a view to improving, if warranted, control over the chemical reactions involved during roasting. 3. That testwork be continued on the recovery of gold from the calcine cyanidation residue. 4. That methods for reducing the gold content of the flotation tailings be investigated. 5. That the recovery of arsenic and gold from the flue gases be investigated. 6. That the recovery of elemental sulphur, or alternatively, the manufacture of sulphuric acid be investigated. 7. That the recovery of gold from the carbonaceous scum from the Sheba mine be investigated. 8. That the pressure oxidation of the auriferous sulphide concentrate be investigated.

Download or read book Investigation of Refractory Gold Ores Examination of the Ore from the New Consort Mine Barberton District written by and published by . This book was released on 1965 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Ore from the New Consort Mine was submitted to the Laboratory as one of a number of refractory gold ores from the Barberton district. The results of conventional cyanidation tests and roasting tests carried out in the laboratory led to the conclusion that the sample of ore received is not in fact refractory, because extractions of approximately 96 per cent of the gold have consistently been obtained by conventional cyanidation techniques. This result is in agreement with the predictions of a mineralogical examination carried out in the Laboratory. The results obtained indicate further that roasting before cyanidation, which is the treatment at present given to the ore at New Consort, is, in fact, detrimental to gold extraction.

Download or read book List of Unrestricted Mintek Publications Issued from 1966 to 1982 written by Helena Wilhelmina Glen and published by . This book was released on 1983 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: This publication lists the 834 unrestricted reports, 449 papers, 41 patents, and 4 other technical publications that were issued as publications of the National Institute for Metallurgy (NIM) and the Council for Mineral Technology (Mintek) from 1966 (the year of NIM's inception) to 31st December, 1982. For ease of reference, these publications are also classified under research topics. Also included are details of the periodical issued by Mintek and a list of its current miscellaneous publications, which include the annual report, and brochures and leaflets of various kinds.

Download or read book Treatment of Refractory Gold Ores written by T.G. Carnahan and published by . This book was released on 1977 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Memoranda on the Treatment of Refractory Gold Ores by the Macarthur forrest Process written by and published by . This book was released on 1890 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Colloquium on Refractory written by Western Australian School of Mines and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Papers from speakers at a conference.

Download or read book A Mineralogical Investigation of Refractory Gold Ores and Their Beneficiation written by and published by . This book was released on 1986 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: A mineralogical investigation of the main causes of refractoriness of metallurgically complex gold ores in South Africa is reported. It is suggested that this refractoriness is related to the presence of submicroscopic gold, carbonaceous material, pyrrhotite, and base-metal sulphides. Means by which problems in the beneficiation of these ores can be overcome were also investigated, and some possible solutions to these problems are offered. A study of beneficiation products from the Fairview Mine showed that submicroscopic gold is associated mainly with arsenopyrite, the gold content of which can be up to 2700 g/t. During miling of the ore, the grains of arsenopyrite, which are smaller than 150 um and have a low resistance to attrition, are selectively broken down. The response of the ultrafine sulphide particles to flotation is relatively poor, and they are preferentially lost to the final tailings together with the gold they contain. It is suggested that the overgrinding of auriferous sulphides can be minimized by the removal of the coarse sulphides from the comminution circuit by flotation or gravity separation. At high rates of aeration in the scavenger and cleaner flotation cells, ultrafine gangue and pyrrhotite are selectively recovered. This material may be recirculated and build up in the flotation circuit, where it may have a detrimental effect on the flotation of the sulphides. Hence, if the amounts of these components can be minimized, the recovery of the gold and the sulphides in these refractory ores can be improved. Means by which this might be accomplished are suggested.

Download or read book Memoranda on the Treatment of Refractory Gold Ores by the Macarthur Forrest Process written by G. S. Fowler and published by . This book was released on 1891 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Pyrometallurgical Treatment of Refractory Gold Ores written by Mark G. Aylmore and published by . This book was released on 1987 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Metallurgical Problems Involved in the Treatment of a Refractory Gold silver Ore from the Demming Mine at Demming Owyhee Co Idaho written by Arthur Maine Piper and published by . This book was released on 1920 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Treatment of Gold Ore from the Great Western Gold Mine Great Western Vic written by John G. Hart and published by . This book was released on 1938 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Microbial Pre treatment of Double Refractory Gold Ores written by James Kofi Afidenyo and published by . This book was released on 2008 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of microorganisms notably bacteria in mineral processing industry is presently one of the leading emerging pre-treatment techniques being employed for the processing of double refractory gold ores and concentrates. Currently numerous studies are in progress to further improve upon the efficiency of the bacterial process and to investigate the potential of other microorganisms. In this study, microbial pre-treatment of double refractory gold ore (sample A) and concentrate (sample B) was investigated using a white-rot fungus, Tramestes versicolor (ATTC 20869). Pulp density, temperature, pH and retention times were the process variables considered. Preliminary studies investigated the amenability of selected pure sulfide sulfur minerals, various types of coal and ore sample A to fungal degradation. Various pre-treatment scenarios were also studied to optimize gold extraction. These were single stage, a two-step and two stage processes involving the well known chemolithotrophic bacteria Acidithiobacillus thiooxidans (ATTC 15494), Acidithiobacillus ferrooxidans (ATTC 19859) and Leptospirillum ferrooxidans (ATTC 53992), the bacterium, Streptomyces setonii (ATTC 39116) and the white-rot fungus, Tramestes versicolor. Preliminary results for sample A indicated that T. versicolor did not degrade sulfides significantly at its optimum growth conditions (pH range of 4.5 - 5.0) and carbonaceous matter was not degraded but rather passivated as preg-robbing decreased significantly. Lignite was inert to passivation by T. versicolor unlike bituminous coal and to lower extent anthracite. Stimulated alkaline conditions (pH range of 9.5 - 10.5) recorded the overall best sulfur oxidation. Results of both the single stage and two-step processes confirmed that carbonaceous matter was passivated by T. versicolor; as preg-robbing decreased significantly from 18.1% to [Less than or equal to] 1.0%. Gold extraction by cyanidation of the pre-treated sample A was 82.5% for the two-step as against 80.5 % for the single stage and 15.0% for the untreated sample. Application of the two-step and single stage process conditions to sample B resulted in 93.3% and 89.9% gold extraction respectively as against untreated concentrate of 30.5%. For the various two stage pre-treatment processes investigated, the abiotic - S. setonii process recorded the best gold extraction of 81.5% for sample A.S. Setonii degraded carbonaceous matter unlike T. versicolor which passivated it. However, it takes only 3 - 7 days for T. versicolor to effect passivation and eliminate preg-robbing while 14 - 56 days is required for S. setonii to degrade carbonaceous matter significantly. The result of the novel microbial pre-treatment process indicated that sulfide sulfur was degraded under alkaline conditions and carbonaceous matter passivated by T. versicolor at its optimum growth conditions. This led to a significant improvement in gold extraction from the double refractory gold ore and concentrate investigated.