Lecture 4_Leaching of Gold.pdf - The Leaching Process: A...Chlorination Leaching of Refractory Ores - Hydrometallurgy: Leaching …
Leaching Guide of Refractory Gold Ore - cnlitereagent - Diagnostic Leaching For Refractory Gold Ores | SRK Consulting
Gold Leaching from a Refractory Gold Concentrate by the Method of Liquid Chlorination. C. Li, Hongxu Li, X. Yang, Shuai Wang, Lifeng Zhang; Materials Science, Chemistry. 2015; The method of chloride-hypochlorite leaching has the advantages of short process, low pollution and higher in reaction rate compared with the traditional leaching method.The Outotec gold cyanide leaching process enables sustainable and cost-effective gold recovery. ... Free-milling gold materials are cyanide leachable and so are the refractory gold materials after suitable pre-treatment. Possible pre-treatment methods such as pressure oxidation, bio-oxidation, roasting, and ultra-fine grinding are also ...
(PDF) AUTOCLAVE TECHNOLOGY OF REFRACTORY GOLD … - A sustainable approach for gold recovery from refractory source …
Refractory Gold Technology Sherritt's Refractory Gold Technology is used to recover gold from refractory sulphide feedstocks. Many gold ores and concentrates contain fine grained gold locked within sulphide minerals, such as pyrite and/or arsenopyrite, unavailable for recovery by conventional leaching. In Sherritt's goldRefractory gold-bearing ores: a review of treatment methods and recent advances in biotechnological techniques By Francisco Carranza Biohydrometallurgy and Biomineral Processing Technology:A Review on its Past, Present and Future
Leaching and CIL processes in gold recovery from refractory ore … - Leaching Kinetics of Antimony from Refractory Gold Ore in …
Baseline leach experiments have established the refractory nature of the concentrate. Roasting of this concentrate at 450-550°C for one hour prior to leaching has increased gold and silver extraction values to approximately 89% and 70% respectively by thiourea leaching, and 76% and 74% by cyanidation.Gold is generally produced from two major types of deposits mined as free milling ores and refractory ores. Free milling ores are constituted by placer mechanisms and most of the oxide ores (and some sulphide). These ores are relatively easy to process through cyanidation and generally give very high gold recovery, >95% (Ellis & Senanayake, 2004). Refractory ores …
Refractory Gold Technology - US4559209A - Leaching refractory gold ores - Google Patents
Nichromet both has a process that uses chloride and bromide to leach gold from refractory ores high in sulphides. I also suggest you look at papers by Dr. Corby Anderson that use alkaline sulfide leaching to extract gold from refractory ores. The latter can be run at modest temperatures and lower pressures than smelting.Gold recovered during Stage 1 is not considered refractory. A portion of the cyanidation leach residue is advanced to Stage 2. Stage 2: Leach residue is reacted with hydrochloric acid to dissolve labile sulfide minerals such as pyrrhotite and …
Bacterial leaching as a pre-treatment step for gold recovery … - (PDF) Recovery of Gold from the Refractory Gold …
Gold recovered during Stage 1 is not considered refractory. A portion of the cyanidation leach residue is advanced to Stage 2. Stage 2: Leach residue is reacted with hydrochloric acid to dissolve labile sulfide minerals such as pyrrhotite and liberate any gold that may be associated with them.List Gold Refractory Process Methods Where gold is associated with arsenic, antimony, tellurium, and certain other minerals, …
Improving the gold leaching of refractory ores using the … - Improving the gold leaching process of refractory ores using …
which further increases the environmental burdens of gold proces-sing from refractory resources (Norgate and Haque 2012). The ability of acidic chloride solutions to dissolve gold and refractory sulfides simultaneously has been recognized as a potential advantage of gold leaching (Lundström et al. 2015;The Leachox refractory gold process has to date been applied to the selectivetreatment of several refractory gold ores but on a relatively small scale. In this paper the successful ... compared to conventional open tank leaching but particularly for refractory gold ores which can be very slow leaching. This leads to a significant reduction in ...
Simultaneous sulfide oxidation and gold leaching of a refractory gold - The Leachox™ Refractory Gold Process – The Testing, …
et al., have previously used ozone as a means of improving gold recoveries from refractory gold ores subsequent to hypochlorite leaching. Other studies on pre-treating has been done by Rodríguez-Rodríguez, et al. (2018) and the results have shown that ozonation can be a suitable alternative to treat refractory gold ores.With the development of beneficiation technology, the definition of refractory gold ore is changing. Generally speaking, refractory gold ore in leaching field is a kind of ore whose leaching rate of gold is less than …
Refractory Gold Ore Treatment Methods - Mineral … - Experimental testing of technologies for processing refractory gold ...
The sulphide ores tend to be refractory to leaching when employing a normal cyanidation process. Recoveries of gold, when employing a normal cyanidation process in the treatment of sulphide ores, tend to be less than 80%. This is the case despite the ore being finely ground from 53 to 75 µm ( Adams, 2005, Flatman and Muir, 2005 ).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.
Improving the gold leaching process of refractory ores … - The Leachox™ Refractory Gold Process – The Testing, Design ...
The refractory nature of the concentrate requires a pressure oxidation (POX) step to oxidise the sulfide minerals and unlock the value metals. ... the leaching of gold and copper sulfides for many years, it is simple to configure and has relatively easy control features. In this system, cool quench liquor is fed to the autoclave compartments onRefractory gold concentrate and leach residue surface atomic composition with different treatments. The leaching conditions were a reaction temperature of 80 • C reaction time of 15 min, and HNO ...
Improvement of Gold Leaching from a Refractory Gold … - PRESSURE OXIDATION OF REFRACTORY GOLD ORES: THE …
Primary deposits of gold-bearing ores are characterized by a variety of chemical and mineralogical composition. The search for a cost-effective method for processing gold-bearing ores is inextricably linked with a set of preliminary studies aimed at studying the composition of the ore, the forms of finding useful components, as well as assessing the effect of impurity …However, pretreatment processes involving thermal oxidation, such as roasting, chemical oxidation, such as acid leaching, acid or alkaline pressure leaching; or biological oxidation such as bioleaching with T. Ferrooxidans liberates gold from refractory minerals. Gold is then recovered from the oxidized mass by alkaline cyanidation.
Processing Refractory Gold - Hydrometallurgy: Leaching … - Diagnostic Leaching For Refractory Gold Ores | SRK …
A diagnostic leach test can be very useful to qualitatively assess how gold occurs within the ore and the extent to which it may be refractory. Several different permutations of diagnostic leach tests depend on specific objectives, but they generally involve the sequential leaching of a gold ore sample with progressively stronger reagents ...Combining sulfide oxidation and gold leaching using chloride/hypochlorite solution was used for a refractory sulfide concentrate containing 20.45 g/t gold. Leaching tests at different concentrations of Ca(OCl) 2 and NaCl, and also various initial pHs were performed.
Pressure Oxidation of a Refractory Sulfide Concentrate and Thiourea - Direct Cupric Chloride Leaching of Gold from Refractory …
The Albion process is an atmospheric leaching process for processing zinc concentrate, refractory copper and refractory gold (Joe, 2005). This process is an integration of the Ultra-fine grinding (UFG) and oxidative leaching at atmospheric condition (Mike Hourn, 2014). "The Leachox Process is essentially a range of established and new unit ...The total gold leaching ratio of a refractory As-, S- and C-bearing gold concentrate calcine by direct cyanidation was only 70.2%, but there was a significant variation in the gold leaching ratio based on size fraction, in the following order: medium size fraction (82.6%) > coarse size fraction (72.3%) > fine size fraction (59.7%).
(PDF) Recovery of Gold from the Refractory Gold Concentrate … - Gold Cyanide Leaching Process - Outotec
In the refractory gold concentrate leaching experiments, nitric acid leaching at high temperatures could limit the decomposition of sulfide minerals, because of the passive layer in the refractory...However, even after many improvements, the leaching of refractory gold ore remains a process of some duration (24 hours or more to reach acceptable gold recoveries). From recent literature investigations, hydrodynamic cavitation has been found to be a promising new approach which may advantageously enhance the cyanidation process. ...