Download or read book The Use of Activated Charcoal in a NIMCIX Column for the Recovery of Gold from Cyanide Solutions written by and published by . This book was released on 1984 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report is a resume of the work undertaken during the CHARGOLD project between January 1976 and July 1980. Investigations were carried out on the recovery of gold by activated charcoal in a continuous ion-exchange (NIMCIX) column from the following solutions: (a) an unclarified filtrate from the dewatering filters of a uranium plant, (b) an unclarified calcine filtrate, (c) a Merrill barren solution from the uranium plant at Vaal Reefs North Gold Mine (West Section), and (d) a clarified pregnant solution from Durban Roodepoort Deep Gold Mine. Barren solutions high in gold were obtained from the unclarified filtrate owing to a rapid build-up of calcium carbonate on the charcoal. This was overcome by regular washing with acid or adjustment of the pH value of the feed. Gold and silver displace the base metals once there is competition for absorption sites. The absorption of gold from Merrill barren solution was poor owing to the high concentrations of calcium on the charcoal. Recoveries of 90 and 99 per cent were obtained from the unclarified calcine filtrate and the clarified pregnant solution respectively. The charcoal was successfully eluted with sodium hydroxide followed by washing with water at 90 degrees C. The concentration of sodium hydroxide has no significant effect on the efficiency of elution, although pretreatment for at least 1 hour is essential. The temperature of the stripping water should be as high as possible, but the hardness of the water is not critical. The charcoal was regenerated in a rotary kiln at a temperature of 800 degrees C. The gold in the resulting eluate was recovered in an electrowinning cell designed at the Anglo American Research Laboratories.

Download or read book The Recovery of Gold by Activated Carbon in a NIMCIX Column written by and published by . This book was released on 1990 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Columns filled with activated carbon have been used in the past to recover gold, often at low concentrations, from solution streams. These streams have included barren solutions after zinc precipitation, return-dam solutions, dewatering-filter filtrates, heap-leaching solutions and a high-tenor solution resulting from the pressure cyanidation of a refractory ore. These columns have been operated by different methods, for instance, as fixed-bed upflow columns, or as single (deep) fluidized beds, with or without a retaining screen on top to prevent carry-over of the carbon, which allows for higher solution flowrates. However, the most successful method of operation has been as a multiple-stage fluidized-bed column in the countercurrent mode, eg, the NIMCIX column. This configuration allows for a stable gold-concentration profile by preventing axial mixing, and thus ensures efficient extraction of the gold from solution, since the most active carbon always 'sees' the least concentrated solution. It also has lower capital and operating costs than other options. Fluidized-bed columns have an added advantage in that they can treat unclarified solutions and slurries. The NIMCIX column has been satisfactorily tested with slurries containing up to 23 per cent solids in the carbon-in-pulp-in-column (CIPIC) process. In the light of its versatility, the NIMCIX column can be incorporated into a variety of possible flow-schemes for the recovery of gold. Some of these are described, and the costs of installing a NIMCIX column to recover gold from both a solution and a slurry are discussed.

Download or read book The Development of a Process for the Recovery of Gold from Gold bearing Solutions by Means of Activated Carbon Or Resin in a NIMCIX Column written by Mintek and published by . This book was released on 1990 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Gold Recovery Using an Activated Carbon Column written by and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The concept of a multistage fluidized-bed column for the treatment of unclarified solutions dates back to the mid-1950s. Mintek, then the National Institute for Metallurgy, started developmental work on a continuous ion-exchange contactor in 1968, which culminated in the installation of a demonstration NIMCIX plant for the recovery of uranium at the Blyvooruitzicht Gold Mine in 1976. A number of NIMCIX plants were subsequently erected, both in South Africa and abroad, for the recovery of uranium from unclarified liquors. This technology has now been successfully applied to the recovery of gold by the use of activated carbon. The work described in the paper was carried out on a pilot plant that incorporated a seven-stage NIMCIX column and a Zadra-type elution-electrowinning circuit. An interesting feature of the operation was the adjustment of the feed solution to a pH value between 7,5 and 7,8 to reduce fouling of the carbon by carbonate and to improve the loading of gold onto the carbon. The use of a NIMCIX column in place of a tank-cascade for the recovery of gold from unclarified solutions promises lower plant capital costs, which could enhance the viability of, for example, a low-grade heap-leaching operation.

Download or read book A Process for the Recovery of Gold from Activated Carbon by Leaching and Electrolysis written by J. B. Zadra and published by . This book was released on 1950 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Recovering Gold from Stripping Waste and Ore by Percolation Cyanide Leaching written by George M. Potter and published by . This book was released on 1969 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Au gold Recovery Using an Activated Carbon Column written by and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The feasibility of a process involving the use of activated carbon in a multi-stage column (NIMCIX contactor) for the recovery of gold from unclarified pregnant solutions was investigated on pilot-plant scale. It was found that satisfactory extractions, corresponding to a recovery of 99,6 per cent, can be achieved with an average gold concentration of 0,0077 p.p.m. in the barren solutions from a feed averaging 1,89 p.p.m. The results show that excessive loading of CaCO3 can be prevented by lowering of the pH of the feed to about 7,6. This obviates the need for the carbon to be treated with hydrochloric acid. The gold was eluted from the carbon by the Zadra procedure. The operating conditions of the elution and electrowinning circuits are reported, and the elution of the gold and other metals is discussed. The reactivation of the carbon, which was carried out in a vibrating-deck kiln, is described, and the effects of this reactivation on the activity of the carbon and its microstructure are also discussed. The consumption of reagents in the adsorption and elution circuits is presented in sufficient detail to allow the potential of the activated-carbon process as an alternative to the Merill-Crowe process for the treatment of high-grade solutions to be evaluated. In addition, the results of parallel small-scale investigations on the effect of pH on the loading of CaCO3, gold, and other metals on activated carbon are presented and discussed briefly.

Download or read book Hydrometallurgy in Extraction Processes written by C. K. Gupta and published by CRC Press. This book was released on 1990-08-15 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: This two-volume set provides a full account of hydrometallurgy. Filled with illustrations and tables, this work covers the flow of source material from the mined or concentrate state to the finished product. It also highlights ion exchange, carbon adsorption and solvent extraction processes for solution purification and concentration. The extensive reference list-over 850-makes this set a valuable resource for extraction and process metallurgists, researchers, and practitioners.

Download or read book Hydrometallurgy in Extraction Processes Volume II written by C. K. Gupta and published by Routledge. This book was released on 2017-11-01 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: This two-volume set provides a full account of hydrometallurgy. Filled with illustrations and tables, this work covers the flow of source material from the mined or concentrate state to the finished product. It also highlights ion exchange, carbon adsorption and solvent extraction processes for solution purification and concentration. The extensive reference list-over 850-makes this set a valuable resource for extraction and process metallurgists, researchers, and practitioners.

Download or read book Process for Recovering Gold and Silver from Activated Carbon by Leaching and Electrolysis written by J. B. Zadra and published by . This book was released on 1952 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Recovery of Gold from Return dam Solutions by Activated Carbon in a Multistage Column written by and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A pilot-plant investigation in a NIMCIX contactor has shown that activated carbon can extract more than 93 per cent of the gold in return-dam solutions. The average gold concentration in the barren solution was less than 0.003 mg/l from a feed averaging 0.048 mg/l. The carbon was eluted by the Zadra procedure. The operating conditions of the elution-electrowinning circuit are reported, and the elution of the gold and other metals is discussed. The reactivation of the carbon by use of the Rintoul kiln is described, together with the results of reactivation. The cost and the consumption of reagents in the process cycle is presented in sufficient detail to allow the economic viability of this technique for the recovery of gold from low-grade solutions to be evaluated.

Download or read book Gold Recovery Using Activated Carbon written by Pia Sinisalo and published by . This book was released on 2016-09-23 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 The Cyanide Process of Gold Extraction written by James Park and published by . This book was released on 1897 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effect of Metal Impurities on the Adsorption of Gold by Activated Carbon in Cyanide Solutions written by S. A. N. Sheya and published by . This book was released on 1989 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Cyanide Process of Gold Extraction written by James Park and published by . This book was released on 1913 with total page 788 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Precious Metals Recovery from Low grade Resources written by and published by . This book was released on 1985 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: This information circular describes research the Bureau of Mines has conducted to improve technology for recovering precious metals from low-grade resources. Many of the reported findings are recent, and some of te work described is ongoing. Topics discussed include cyanidation of carbonaceous gold ores to enhance gold recovery, a new method for precipitating mercury during cyanide leaching of gold ores, a staged heap leaching process to generate suitable solutions for direct electrowinning of gold, the use of anion-exchange resins to recover gold from cyanide solutions, and precious metals recovery from electronic scrap.