recovery of gold from refractory ores zimbabwe

recovery of gold from refractory ores zimbabwe

    Comments

  • Gold processing 101

    An ore containing 1% sulphur will produce a mass pull of approximately 5% by weight to a bulk flotation concentrate where recovery is the key driver If this ore also contains 1g/t Au (for GSR =1), and 90% recovery to concentrate is achieved, then 090g will be recovered and with a concentration ratio of 20 (5% to concentrate) this corresponds ....

  • Gold extraction

    Mar 01, 2018· These refractory ores require pre-treatment in order for cyanidation to be effective in recovery of the gold Roasting is the process used to extract gold from the refractory gold ore...

  • Improving the recovery of gold and copper ,

    One detrimental effect of the changes made to improve the gold recovery was a high residual cyanide content in the CIP tails This was overcome by the use of the Inco process at a cost of 20 cents per tonne ore treated (current cost is 35 cents/tonne) (Zimbabwe currency)...

  • recovery of gold from refractory ores zimbabwe

    recovery of gold from refractory ores zimbabwe Process for Recovering Gold - McGill University Autoclave leaching of refractory gold ores on an industrial scale started in the 1980 s because of the high gold price and because pressure oxidation is an environmentally accepted alternative to roasting Since 1985 about five autoclave leaching ....

  • Gold processing

    Gold processing - Gold processing - Mining and concentrating: The nature of the ore deposit determines the mining and mineral processing techniques applied Oxide ore deposits are frequently of such low grade (eg, 3 to 10 parts per million) that extensive mineral processing cannot economically be justified In this case they are merely shattered by explosives and then piled into heaps for ....

  • Recovery Refractory Resources

    refractory gold ore is gold-containing ore that is resistant to recovery by direct cyanidation and carbon adsorption process More specifically, it is an ore that has a gold recovery rate of less than 80% when direct cyanidation is applied to it Dr Chris Fleming, senior metallurgical consultant at ,...

  • REFRACTORY GOLD

    REFRACTORY GOLD By definition, refractory gold ores contain gold that is resistant to extraction by conventional chemical processing and as a result responds poorly to traditional gold cyanidation techniques such as Carbon-in-Leach (CIL), yielding less than 80% of the contained gold...

  • Gold mineral processing

    Refractory gold ore pretreatment Treatment of refractory gold ore (whole ore and flotation concentrates) has become more prominent since the 1980s, with many gold discoveries often including ores that are wholly or partially refractory Refractory pre-treatment processes include pressure oxidation, biological oxidation and various forms of ....

  • Recovery of Gold in Pyritic Sulfide Ores

    Recovery of gold in sulfide ores has fallen into several categori First is froth flotation, and second is cyanidation of the or Using cyanide to recover gold from sulfide ores generally results in 30 to 35% recovery, and the best I have heard of is around 50% recovery...

  • Alkaline Oxidative Leaching of Gold

    ALKALINE OXIDATIVE LEACHING OF GOLD-BEARING ARSENOPYRITE ORES By P Bhakta,1 J W Langhans, Jr,1 and K P V Lei2 ABS"rRACT The US Bureau of Mines developed an alkaline oxidative pretreatment leaching procedure to increase the recovery of gold from arsenopyrite (FeAsS) or The best solution compositions for...

  • Treatment of carbonaceous refractory gold ores

    Minerals Engineering, Vol 4, Nos 7-11, pp 1043-1055, 1991 0892-6875/91 $300 + 000 Printed in Great Britain 1991 Pergamon Press plc TREATMENT OF CARBONACEOUS REFRACTORY GOLD ORES PM AFENYA Dept of Mining Engineering, UniversityofTechnology, Lae, Papua New Guinea ABSTRACT Gold ores can be categorized into two types - free milling and refractory...

  • Kwekwe roasting plant to reawaken

    Sep 16, 2015· The roasting plant was established in 1937 by the then Government of Rhodesia to assist small and medium scale miners around Kwekwe in the processing of dumps or refractory gold ore These dumps have an estimated 350 000 metric tonnes of ore and according to Peacocke and Simpsons Mineral Processors, they contain 97 220 ounces of gold worth $140 ....

  • US5536297A

    A process for recovering gold in which an ore slurry of refractory sulfidic and refractory carbonaceous ore having preg-robbing characteristics due to the presence of organic carbon is subjected to pressure oxidation in an autoclave The oxidized ore slurry is mixed with a thiosulfate salt lixiviant, which mixture is maintained at a pH between 7 and 87 while the slurry is agitated in a ....

  • Gold Ore Processing, Volume 15

    Gold Ore Processing: Project Development and Operations, Second Edition, brings together all the technical aspects relevant to modern gold ore processing, offering a practical perspective that is vital to the successful and responsible development, operation, and closure of any gold ore processing operationThis completely updated edition features coverage of established, newly implemented ....

  • US4559209A

    A method is disclosed for leaching a gold ore which is refractory due to the presence of sulphide minerals of arsenic and antimony The ground ore is leached with cyanide in a pipe reactor at a pressure of between 5 and 8 MPa The terminal pH value of the pulp is controlled to be 10 or less than 10...

  • Ultra Fine Grinding

    Not all refractory gold ores give a large recovery improvement after fine milling Gold locked in arsenopyrite for example does not achieve the same gold recovery as gold disseminated in pyrite due to the smaller gold particle size of the locked gold (Figure 5) Figure 5 Gold Recovery of Arsenopyrite and Pyrite Ores 50 55 60 65 70 75 80 85 90 ....

  • Processing Refractory Gold

    May be increasing gold recovery from refractory gold ore (with grade 2-3 g/t) to 90-95%?Actual data of top refractory gold ore mines show, that gold recovery is 70% and less What is reason? It is a problem in minerals processing or it is a global science problem? So if you work with refractory ore....

  • Gold extraction

    Refractory ores cannot attain sufficient extraction through conventional cyanidation techniques, and thus there are various alternative methods for extraction, depending on the refractoriness of the ore Gold is locked into its host mineral due to any of the following factors from La Brooy et al (1994)...

  • Recovery of gold from a free

    In this project, the development of a suitable process is intended to recovery high silver by thiosulphate leaching as an alternative to cyanidation after ultra-fine grinding from refractory ore ....

  • refractory gold grinding

    These ores are naturally resistant to recovery by standard cyanidation and carbon adsorption process These refractory ores require pre-treatment in order for cyanidation to be effective in recovery of the gold A refractory ore generally contains sulfide minerals, organic carbon, or both...