CHLORIDE HYPOCHLORITE OXIDATION AND LEACHING …

2012-10-4 · After 24 hours, direct cyanide leaching of the initial ore resulted in only 54.8% gold recovery. However, cyanidation after dissolving the ore sample in hydrochloric acid (HCl), sulfuric acid (H 2 SO 4), ferric chloride (FeCl 3) and nitric acid (HNO 3), re-spectively, increased the gold recovery to 98.1%. This shows that the ore is a sulfide ...

refractory ore gold and pretreatment 2012

Sulphidic refractory gold ore pre-treatment by selective. 2013-3-1 Often, the gold bearing ores are refractory due to the gold grains and concentration by flotation is necessary, either followed by roasting, bacterial leaching, or pressure leaching in a way that the gold is liberated prior to cyanidation .

Evaluation of Refractory Behaviour of Kaletaş (Turkey ...

2009-9-17 · leaching of free milling ores (Rubisov et al, 1996) However, refractory gold ores are often characterized by the low gold extractions (<50 80%) in cyanide leaching The refractoriness of gold ores and concentrates stems primarily from the inherent mmeralogical features with reference to the mode of presence and association of gold, and carbonaceous

Pretreatment Process on Refractory Gold Ores with As

(PDF) A Preliminary Study on Nitric Acid Pre-treatment of ...

How to Improve the Refractory Gold Leaching Process?

2020-8-18 · The gold leaching rate of most refractory gold ores is about 10% ~ 20% when they are directly stirred by sodium cyanide. Generally, the gold leaching rate of refractory gold ore can be greatly improved by pretreating the raw materials, including oxidative …

Potential pre-treatment and processing routes for …

2021-3-11 · 2.1 Microwave pre- treatment of refractory gold ores . Most of refractory gold occurs within sulphide minerals such as FeS 2 and FeAsS and are treated by roasting, pressure leaching or bacterial leaching to render the gold amenable to recovery by subsequent treatment techniques (Haque, 1987).

(PDF) A Preliminary Study on Nitric Acid Pre-treatment of ...

Effect of nitric acid pre-treatment on the extraction of silver from the ground ore (d 80 : 50 µm) in cyanide leaching (Cyanidation conditions: 1.5 g/L NaCN, pH 10.5, 25 3 C, flow …

Aeration pretreatment of low grade refractory gold ores ...

1990-2-1 · Aeration curing, over a long duration in wetted stockpiles, shows promise as an affordable pretreatment method for oxidizing gold encapsulating sulfide minerals, and possibly organic matter, in low grade refractory ores. Following aeration pretreatment, the ore is reclaimed, neutralized, and cyanide leached by conventional practices. Large tonnages of subeconomic material, including mine ...

Base metal citrate pretreatment of complex ores to …

2020-11-1 · 1. Introduction. With time, the availability of gold and silver ores that require only one leaching stage is diminishing. (Aylmore, 2016; Deniz et al., 2017) many cases, the problem originates from the presence of refractory mineral phases containing the precious metals; while in others, the ore matrix itself is a heterogeneous mixture of mineral phases, some of which compete with the gold ...

(PDF) Bacterial leaching as a pre-treatment step for gold ...

Bacterial leaching as a pre-treatment step for gold recovery from refractory ores … /Physicochemical Problems of …, 1998. Alper Ozkan. Salih Aydoğan. Download PDF. ... Bacterial leaching as a pre-treatment step for gold recovery from refractory ores. …

TREATMENT OF A COPPER

2016-8-3 · TREATMENT OF A COPPER- RICH GOLD ORE BY AMMONIA ASSISTED CYANIDE LEACHING Figure 7. Effect of ammonia pretreatment (1 M NH. 3) and the addition of ammonia (0.5-1 M NH. 3) on the consumption of NaCN (NaCN: 1.5 g/L) Ammoniacal Cyanide Leaching . Ammoniacal cyanidation is one of the most promising alternative processes for copper-rich gold ores ...

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.

280 RECENT ADVANCES IN THE TREATMENT OF …

2015-8-6 · oxidation as a pretreatment method for refractory gold ores has been published by Berezowsky and Weir (6). According to them, the first patent on the use of pressure leaching for preoxidation of arsenical gold ores was granted to the Chemical Construction Company (Chemico) in …

Optimizing the alkaline oxidation pretreatment of a ...

2018-9-28 · Ultrafine grinding was proposed as a pretreatment method prior to cyanide leaching of a gold-silver ore. About 91.92% Au and 82.15% Ag were extracted after ultrafine grinding under optimum leaching conditions such as 150 kg t −1 quicklime dosage, 25% pulp density, 85 °C leach temperature, 500 g t −1 cyanide concentration and 90 h leaching ...

The Metallurgy of Cyanide Gold Leaching – An …

2014-10-20 · Refractory Ores/Solid-Solution Gold: In some ores, Au can be locked inside the sulphide mineral matrix of the ore (so called solid solution), and the cost for the energy required to grind and liberate is simply too high to be viable. These are "refractory ores" and require a chemical, not simply physical, process to liberate gold from the ...

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 ...

microwave pretreatment of a refractory gold

microwave assisted pretreatment of refractory gold ores. refractory gold pretreatment Microwave pretreatment of a double refractory gold ore Double refractory gold ores such as Barrick s Goldstrike ore contain both pyrite and carbonaceous matter and the latter results in the loss of gold from solution during cyanide leaching Get More

Assessment of the Possibility of Hydrometallurgical ...

2021-1-14 · Gold leaching of oxidized copper refractory ore (Tarror mineral deposit) demonstrated low gold recovery by direct cyanidation. The reason was the high copper content present because it forms stable copper-cyanic complexes. Application of ammonium compounds to oxidized ores provides high rates of gold recovery and prevents the formation of copper

Pretreatment Process on Refractory Gold Ores with As

Gold ores are considered refractory if gold extractions from a conventional cyanidation process are less than 80% even after fine grinding. 1) Arsenic-bearing refractory gold ore has stones extremely difficult to deal with. In the stones, gold is locked up in arsenic mineral matrix as the form of microscopic or submicroscopic lattice.

Pretreatment/agglomeration as a vehicle for refractory ore ...

Also as noted above the process is also applicable to the refractory ores of other metals wherein a metal such as silver, uranium or copper is recoverable from its ore via agglomerative heap leaching and wherein chemical pretreatment is effective in oxidizing substantial portions of refractory-causing substances, thereby favorably altering the ...

Flotation of Carbonaceous Matter from a Double …

2021-9-19 · Due to insufficient gold recovery by direct cyanidation, refractory gold ores require pretreatment prior to gold extraction. Properties indicative of refractory gold ores are: preg-robbing caused by carbonaceous matter (C-matter) present in the ore, gold locked in sulfide or silicate minerals, and cyanide- and oxygen-consuming matter (e.g ...

Microbial Pretreatment of Refractory Gold Ore

2016-3-28 · Microbial Pretreatment of Refractory Gold Ore. 2016-03-28 17:59:31 XinHai (1952) For coarse grain size of gold after crushing and grinding by flotation, gravity concentration, cyanide leaching process or several process combined treatment will be able to complete the separation of gold and gangue minerals, but there are some curing refractory ...

Effect of Oxidative Pretreatment and Lead Nitrate Addition ...

2019-11-1 · Cyanidation is the main process in gold leaching. There are several parameters that affect gold recovery and cyanide consumption. In this paper, the effect of the oxidative pretreatment and lead nitrate addition on the cyanidation of Zarshuran refractory gold ore containing 3.32 ppm Au, 1.09% As, and 0.5% sulfur were investigated. Au recovery was increased from 79.4% to 89.4% in the presence ...

Potential pre-treatment and processing routes for …

2021-3-11 · et al, 2018). In refractory gold ores, the gold is highly encapsulated in the sulfide matrix and pre-treatment is an important process to recover gold from the sulfide minerals. The sulfide minerals interfere with recovery of gold thus it is imperative to remove the sulfide minerals prior to leaching.

An evaluation of pretreatments to increase gold recovery ...

2000-1-1 · TABLE 5 Leaching rate constants (k,) for treated and untreated ores obtained during the initial stages of cyanidation Ore Blend Untreated ore ~45 pm Untreated ore ~75 pm Untreated ore ~125 urn Pyrox treated ore ~75 pm PAL treated ore <75 urn Leaching rate constant (tg--l) 0.10 0.28 0.21 0.53 0.32 R2 0.98 0.96 0.97 0.90 0.96 It is apparent that ...

Review Pretreatment Process on Refractory Gold Ores …

mainly about the refractory gold leaching easily through arsenic removal to expose gold, changing the composition, physic-chemical and electro-chemical properties of the ore. Currently, there are four main methods of pretreatments of refractory gold ores with As. Pretreatment options for deal-ing with refractory gold ores are illustrated in Fig ...

application of diagnostic leaching technique for ...

Pretreatment Of Refractory Ores Prior To Gold Leaching . Economics of refractory gold ore processes economics of refractory gold ore processes john e litz and r wayne carter 119th tms annual meeting february 1822 1990 hazen research get price chat online establishing the process mineralogy of gold ores 2004 establishing the process mineralogy of gold ores joe zhou bruce jago and chris …

Refractory Gold Ore Treatment Methods

2016-7-14 · Metallurgical ContentGold Leaching & Processing of Arsenic OreMispickel (Arsenopyrite: FeAsS).6Leaching and Recovering Gold from Antimony MineralsStibnite (Antimony Sulphide, Sb2S2)Telluride Gold Ore ProcessingSolubility of TelluridesGold Extraction from Carbonaceous OreList Gold Refractory Process Methods Where gold …

Pretreatment Of Refractory Ores Just before Gold Leaching

reach it in cyanide leaching process. 2) The gold ores with As must be broken or decomposed in the gold particles scales, so that gold is fully exposed, and then extracted with the appropriate gold leaching agent. The process of crushing or decomposition before gold leaching is called pretreatment of refractory gold. Pretreatment of a ...