pretreatment of refractory ores in gold leaching process congo

pretreatment of refractory gold ore

Sequential pretreatment of double refractory gold ore. Double refractory gold ore was sequentially pretreated to oxidize sulfides by thermophilic archaeon Acidianus brierleyi and then to decompose carbonaceous matters using the cell-free spent medium (CFSM) from white-rot fungus Phanerochaete chrysosporium.The pretreatment by A. brierleyi significantly improved the gold recovery from 25% to …

The problems caused by iron ... - International Mining

A section of the article on gold recovery techniques in the May issue of the magazine had to be cut due to space constraints. It covered the paper Basic iron sulphate – a potential killer for pressure oxidation processing of refractory gold concentrates if not handled properly presented at this year's SME annual meeting by Chris Fleming of SGS. . He suggests investigating the use of a ...

Pressure Oxidation Pretreatment of Refractory Gold ...

Pressure oxidation of gold containing concentrates and ores is an effective pretreatment for liberating refractory gold. This is particularly true when an appreciable portion of the gold is associated with sulfides and is not amenable to conventional cyanidation. A brief review of the literature on pressure oxidation of refractory gold materials is presented.

Pretreatment Process on Refractory Gold Ores with As

1. Introduction. 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.

Refractory Ore Gold Process Description

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. Sulfide minerals are impermeable minerals that occlude gold particles, making it difficult for the leach s

Gold extraction - Wikipedia

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. Sulfide minerals are impermeable minerals that occlude gold particles, making it difficult for the leach solution to form a complex with the gold.

Alkaline sulfide pretreatment of an antimonial refractory ...

This paper presents the alkaline sulfide pretreatment of an antimonial refractory gold and silver ore. In the ore, gold occurs mainly as gold-silver alloys and as associated with quartz and framboidal pyrite grains, and, to a small extent, as the inclusions within antimonial sulfides. Silver is present extensively as antimonial sulfides such as andorite.

Characterization of refractory behaviour of complex gold ...

leaching tests were also performed to shed light on the refractory characteristics of ore. The leaching tests show that the extraction of gold and silver is consistently low, i.e. ≤47% and ≤19.2%, respectively, over a leaching period of 24 h.

Application Note Refractory Gold Pretreatment - pH

Application Note Refractory Gold Pretreatment - pH Mining: Gold Processing Refractory gold ores are defi ned as containing minerals or carbon compounds that trap encapsulated gold and make leaching extraction diffi cult. These types of ores require pretreatment prior to cyanidation. Options for pretreatment include the following processes:

(PDF) Treatment of a Copper-Rich Gold Ore by Ammonia ...

treatment of a copper- rich gold ore by ammonia assisted cyanide leaching Figure 7. Effect of ammonia pretreatm ent (1 M NH 3 ) and the addition of ammonia (0.5-1 M NH 3 ) on the

Pressure Oxidation of a Refractory Sulfide Concentrate and ...

Significant advances have taken place in the treatment of refractory gold ores and concentrates during the past decade. In sulfide ores, pyrite is the most common host mineral for gold. Studies by Gasparrini (1983) showed that gold occurs in pyrite as native gold or electrum in all sizes and forms. Arsenopyrite is probably the second most common host for gold and forms similar associations ...

GOLD RECOVERY OF REFRACTORY SULFIDE CONCENTRATES …

The problem of refractory sulfide gold ore that has a gold recovery less than 50% when direct cyanidation applied, still exists until now. It needs oxidative pretreatment for cyanidation to be effective in gold recovery the objective of this study is figuring out the effect of sodium nitrite as an oxidizing reagent on cyanidation of refractory gold ore.

Gold mineral processing - Hatch Ltd

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 ...

:: Maelgwyn Minerals' Leachox Refractory Gold Process hits ...

It's now over 10 years since the European Patent Office advised its decision to grant Maelgwyn Mineral Services Ltd (MMS) a European Patent for its Leachox process for the treatment of refractory gold ores. Since that time the process route has become the industry leader in the low-cost recovery of gold from refractory and sulphide orebodies.

PRETREATMENT PROCESSES IN GOLD RECOVERY BY …

highly refractory ores, the processed gold ore should be pretreated before leaching. Without pretreatment process the gold recovery degree can remain under 50 % or for moderately refractory ores in the range of 50-80 %. In these cases, to increase the recovery degree to acceptable levels (over 80 %), pretreatment

Diagnostic Leaching For Refractory Gold Ores | SRK Consulting

Diagnostic Leaching For Refractory Gold Ores 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, producing a qualitative assessment of the gold deportment within the sample.

Pretreatment of a refractory arsenopyritic gold ore using ...

A sodium hydroxide pretreatment at ambient temperature was evaluated to increase gold extraction from a high-grade arsenopyrite mineral. A 2 k factorial experimental design was established, with the following variables: NaOH concentration (0.1–3 M), solid concentration (40–200 g/L) and treatment time (6–48 h). After applying the pretreatment, standard leaching tests with thiosulfate ...

ALTA Gold 2012 E-Doc - Albion Process

leaching circuits, even when the ore is finely ground. The cause of low gold recoveries can be either through the presence of naturally occurring 'preg robbing' carbonaceous materials or gold physically 'locked' in sulphide minerals. The majority of gold ores are classified refractory because the gold mineralogy is contained in sulphides.

Microbial Pretreatment of Refractory Gold Ore - Xinhai

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 gold ores due to coarse size or thin and gangue minerals symbiosis relations complex factors through the above process unable to ...

REFRACTORY GOLD - PanTerra 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 extraction - QueensMineDesignWiki

Figure 4 - CIL/ CIP Process Flow Schematic. Both CIP and CIL are continuous processes, where activated carbon is added to the ore/ water pulp. The first step in gold extraction is leaching the gold which turns gold in solid form to liquid with cyanide in the presence of oxygen.

[PDF] Bottle Roll Testing for Cyanidation of Gold Ores ...

This paper evaluates the influence of some of the critical parameters of bottle roll testing procedure on gold extraction results and leaching behaviour. The conventional testing procedure with special emphasis to the testing duration, feed particle size, and NaCN concentration in the starting leach-solution, was assessed critically and compared with alternative approaches regarding these ...

pretreatment of refractory ores in gold leaching process congo

Pretreatment Process on Refractory Gold Ores with As. BACTERIAL LEACHING AS A PRE-TREATMENT STEP FOR GOLD RECOVERY FROM REFRACTORY ORES In this article, pre-treatment such as bio-leaching before cyanidation is discussed as an alternative technique to treat refractory gold ores containing pyrite and arsenopyrite. There are two methods of

Developments in the pretreatment of refractory gold ...

submicroscopic gold inclusions within sulphide minerals such as arsenopyrite and pyrite. Such ores require a pre-treatment process to alter or destroy the sulphide matrix and render the gold accessible to cyanide and oxygen (Gudyanga et al., 1999). The gold in high-sulphur and high-arsenic refractory gold concentrate (HGC) is encapsulated

Review of gold extraction from ores - ScienceDirect

Australia is now an important gold producer in the world. The nature of Australian gold production is briefly reviewed and the hydrometallurgy of gold extraction is considered. The choice of processing routes for free milling, complex and refractory ores is discussed.

Gold Leaching from Refractory Ores—Literature Survey ...

Apr 27, 2007· 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.

refractory gold ore crushing equipment

Pretreatment of Refractory Ores in Gold Leaching Process ... - . 2013219 ... Pretreatment of Refractory Ores in Gold Leaching Process Congo quarry mining equipment for sale in kenya quarry processing plant in guinea... Get Price; Where to find ore crushers, grinders, impact mills, hammer mills and ...

Microwave pretreatment of a double refractory gold ore ...

Abstract 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. One possible remedy is to roast the ore and thus oxidize the pyrite and remove the organic carbon. In this research, microwave roasting of a double refractory gold ore was investigated as an ...

Refractory Gold Ore Treatment Methods

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 is associated with arsenic, antimony, tellurium, and …

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.