Pressure Oxidation Pretreatment of Refractory Gold

1984 ◽  
Vol 1 (1) ◽  
pp. 1-4 ◽  
Author(s):  
R. M. G. S. Berezowsky ◽  
D. R. Weir
Keyword(s):  
Pressure Oxidation ◽  
Refractory Gold

Processing of gold-antimony concentrates

2021 ◽  
pp. 59-65
Author(s):  
A. V. Markelov ◽  
K. M. Falin ◽  
V. A. Puchkina ◽  
A. N. Titova
Keyword(s):  
Selective Extraction ◽  
Leaching Rate ◽  
Pressure Oxidation ◽  
Selective Precipitation ◽  
Refractory Gold ◽  
Atmospheric Leaching ◽  
The Common ◽  
Two Stages ◽  
Special Process

This paper describes the results of a study that looked at processing of goldantimony concentrates with selective extraction of antimony and gold as commodities. The common global practice of processing antimony sulphide concentrates (20–30% Sb) is based on alkaline sulphide leaching followed by precipitation of metallic antimony by electrowinning. However, application of this technique to process sulphide concentrates that, apart from antimony, also contain gold, can be difficult as, together with antimony, up to 10–15% of gold can leach to the solution. It takes a special process during final refining of cathode antimony to recover that gold. This paper describes a process that involves two stages of atmospheric leaching of antimony. The gold that leached to the solution is precipitated with zinc after the first stage of antimony leaching. Together with atmospheric leach tailings, it then goes to the pressure oxidation unit. This process helps oxidize the rest of the sulphides and release refractory gold. The resultant cake is processed following a standard sorption cyanidation technique. The paper looks at the antimony leaching rate and the rate at which gold leaches to the solution during this process. The paper describes the results of selective precipitation of gold from gold-antimony solutions and highlights certain features of this process. A series of tests was conducted to test the techniques of pressure oxidation of atmospheric leach tailings and cyanidation of the residue. The paper also describes a process that was developed for processing of goldantimony concentrates and precipitation of antimony and gold. An antimony recovery exceeding 90–95% can be achieved when using this process. At the same time, the percent of dissolved gold can be reduced from 10–15 tо 1–3%.

scholarly journals Process simulation and gate-to-gate life cycle assessment of hydrometallurgical refractory gold concentrate processing

2019 ◽  
Vol 25 (3) ◽  
pp. 456-477 ◽  
Author(s):  
Heini Elomaa ◽  
Pia Sinisalo ◽  
Lotta Rintala ◽  
Jari Aromaa ◽  
Mari Lundström
Keyword(s):  
Global Warming ◽  
Life Cycle Assessment ◽  
Life Cycle ◽  
Environmental Impacts ◽  
Process Simulation ◽  
Development Stage ◽  
Environmental Indicators ◽  
Gold Recovery ◽  
Pressure Oxidation ◽  
Refractory Gold

Abstract Purpose Currently, almost all cyanide-free gold leaching processes are still in the development stage. Proactively investigating their environmental impacts prior to commercialization is of utmost importance. In this study, a detailed refractory gold concentrate process simulation with mass and energy balance was built for state-of-the-art technology with (i) pressure oxidation followed by cyanidation and, compared to alternative cyanide-free technology, with (ii) pressure oxidation followed by halogen leaching. Subsequently, the simulated mass balance was used as life cycle inventory data in order to evaluate the environmental impacts of the predominant cyanidation process and a cyanide-free alternative. Methods The environmental indicators for each scenario are based on the mass balance produced with HSC Sim steady-state simulation. The simulated mass balances were evaluated to identify the challenges in used technologies. The HSC Sim software is compatible with the GaBi LCA software, where LCI data from HSC-Sim is directly exported to. The simulation produces a consistent life cycle inventory (LCI). In GaBi LCA software, the environmental indicators of global warming potential (GWP), acidification potential (AP), terrestrial eutrophication potential (EP), and water depletion (Water) are estimated. Results and discussion The life cycle assessment revealed that the GWP for cyanidation was 10.1 t CO2-e/kg Au, whereas the halogen process indicated a slightly higher GWP of 12.6 t CO2-e/kg Au. The difference is partially explained by the fact that the footprint is calculated against produced units of Au; total recovery by the halogen leaching route for gold was only 87.3%, whereas the cyanidation route could extract as much as 98.5% of gold. The addition of a second gold recovery unit to extract gold also from the washing water in the halogen process increased gold recovery up to 98.5%, decreasing the GWP of the halogen process to 11.5 t CO2-e/kg Au. However, both evaluated halogen processing scenarios indicated a slightly higher global warming potential when compared to the dominating cyanidation technology. Conclusions The estimated environmental impacts predict that the development-stage cyanide-free process still has some challenges compared to cyanidation; as in the investigated scenarios, the environmental impacts were generally higher for halogen leaching. Further process improvements, for example in the form of decreased moisture in the feed for halide leaching, and the adaptation of in situ gold recovery practices in chloride leaching may give the cyanide-free processing options a competitive edge.

An acidic pressure oxidation pre-treatment of refractory gold concentrates from the KweKwe roasting plant, Zimbabwe

1999 ◽  
Vol 12 (8) ◽  
pp. 863-875 ◽  
Author(s):  
F.P. Gudyanga ◽  
T. Mahlangu ◽  
R.J. Roman ◽  
J. Mungoshi ◽  
K. Mbeve
Keyword(s):  
Pressure Oxidation ◽  
Refractory Gold ◽  
Pre Treatment

Pre concentration and pressure oxidation of Porgera refractory gold ore

1986 ◽  
Vol 3 (4) ◽  
pp. 201-208 ◽  
Author(s):  
D. R. Weir ◽  
J. A. King ◽  
P. C. Robinson
Keyword(s):  
Pressure Oxidation ◽  
Gold Ore ◽  
Refractory Gold

Pressure oxidation of double refractory gold bearing sulphide Concentrates

2019 ◽  
pp. 55-66
Author(s):  
Ya. M. Shneerson ◽  
◽  
L. V. Chugaev ◽  
Keyword(s):  
Pressure Oxidation ◽  
Refractory Gold ◽  
Gold Bearing

scholarly journals Flotation of Carbonaceous Matter from a Double Refractory Gold Ore: The Effect of MIBC on Flotation Performance and Kinetics

Minerals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1021
Author(s):  
Sugyeong Lee ◽  
Charlotte E. Gibson ◽  
Ahmad Ghahreman
Keyword(s):  
Bubble Size ◽  
Gold Recovery ◽  
Carbonaceous Matter ◽  
Flotation Kinetics ◽  
Pressure Oxidation ◽  
Gold Ore ◽  
Refractory Gold ◽  
Flotation Performance ◽  
Thiosulfate Leaching

The use of alkaline pressure oxidation to pretreat refractory gold ore often results in insufficient gold recovery (<60%) in downstream thiosulfate leaching. To improve gold recovery, flotation was considered for the separation of carbonaceous matter (C-matter). In this study, the effect of MIBC on C-matter flotation was investigated to understand the role of the frother in bubble and froth formation and on flotation kinetics. MIBC dosages between 30 and 150 g/t were used in combination with 500 g/t of kerosene as a collector. The results showed that the recovery and selectivity of C-matter were improved with increasing MIBC dosages. Improved selectivity at higher MIBC dosages was attributed to faster C-matter recovery as bubble size decreased to the critical coalescence concentration (CCC) and to changes to the foam structure. Analysis of flotation kinetics showed that the flotation rate increased as the MIBC dosage increased due to the decreasing bubble size and the reduced induction time caused by the interaction between the collector and the frother. The results of this study explain the role of MIBC in C-matter flotation and can be used as a design basis for scavenger-cleaner flotation testing. Overall, the results show the potential for flotation as a means to improve gold recovery in thiosulfate leaching through the removal of C-matter.

Acid leaching decarbonization and following pressure oxidation of carbonic refractory gold ore

2016 ◽  
Vol 23 (7) ◽  
pp. 1584-1590 ◽  
Author(s):  
Du-chao Zhang ◽  
Qing-kai Xiao ◽  
Wei-feng Liu ◽  
Lin Chen ◽  
Tian-zu Yang ◽  
...  
Keyword(s):  
Acid Leaching ◽  
Pressure Oxidation ◽  
Gold Ore ◽  
Refractory Gold
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