Refractory concentrate gold leaching: Cyanide vs. bromine ...

Gold extraction, recovery and economics for two refractory concentrates were investigated using cyanide and bromine reagents. Gold extractions for cyanide leaching (24–48 hours) and bromine leaching (six hours) were the same and ranged from 94 to 96%.

Gold extraction - Wikipedia

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 ...

Improving the gold leaching process of refractory ores ...

To improve the leaching kinetics of refractory ores and gold recovery, a number of pre-treatment techniques are employed prior to cyanidation. These include roasting, biological and pressure oxidation and Albion and Leachox processes. Roasting is the first process employed to increase the leachability of refractory gold ores.

Gold mineral processing - Hatch Ltd

To complicate matters further, these ore bodies are often refractory, where the gold is locked within sulphide minerals; or double refractory, in which gold is locked within sulphide minerals and preg-robbing due to the presence of organic carbon. These must be pretreated ahead of leaching.

ECONOMICS OF REFRACTORY GOLD ORE PROCESSES

Refractory gold ores present a number of problems to the gold producer. Much has been written about the suitability of particular pretreatment processes for specific gold ores. We at Hazen Research have had the opportunity to participate in the development and application of a number of gold ore processes and to review others'

Gold Extraction and Recovery Processes - Semantic Scholar

common method used in the leaching of gold from the ore. This process involves the dissolution of gold containing ores in dilute cyanide solution in the presence of lime and oxygen. For refractory ores such as sulfide ores and carbonaceous ores which are not susceptible to direct cyanide leaching, various

Refractory Gold | Mining | SGS

The problems that result from refractory gold are caused by: Physical encapsulation of disseminated gold particles (usually less than a few micrometers in size) within a mineral that is unreactive and impervious to leaching ; Chemical interference by one or more of the ore constituents in the cyanide leaching process; Physical encapsulation

The process design of gold leaching and carbon-in-pulp ...

refractory gold is readily accessible for cyanide leaching. There are several variations of comminution circuits used in the gold industry, such as: Multi-stage crushing and pebble and/or ball milling circuits, typical of older installations. The process design of gold leaching and carbon-in-pulp …

The reasons of gold refractory, Gold ore classification ...

Nov 28, 2016· The reason of the gold mineral refractory There are so many types of reasons that caused the difficulty of gold ore processing, including physical element, chemical element, and mineralogical element.

The Metallurgy of Cyanide Gold Leaching – An Introduction ...

Oct 20, 2014· Nature of Gold: The surface of a gold particle will typically be dissolved at a rate of around 0.2-0.5 µm of surface depth per hour in a cyanide leach. For large gold particles and nuggets, this is too slow to be fully dissolved in a typical processing plant. Much simpler and less expensive gravity methods are available to recover this gold.

Improvement of Gold Leaching from a Refractory Gold ...

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%) > …

Chloride-hypochlorite oxidation and leaching of refractory ...

In this paper, gold leaching of a refractory sulfide concentrate by chloride–hypochlorite solution was investigated and effects of stirring speed, temperature and particle size on the leaching ...

Pressure Oxidation | Mining | SGS

The process is particularly well suited for treating refractory gold ores, which give low recovery when directly leached with cyanide. SGS is a world leader in batch and pilot plant testing and flowsheet development for pressure oxidation processing.

Extraction of gold from refractory gold ore using bromate ...

Direct leaching of high-sulfur and high-arsenic carbonaceous refractory gold ore and the corresponding leaching rates have not been reported. To recover gold from refractory gold ore more effectively, it is important to accelerate the exposure rate of gold in sulfidic minerals.

Processing Refractory Gold - Hydrometallurgy: Leaching in ...

Refractory ores are normally have either a high sulfide content that masks the gold preventing cyanide leaching of the gold, or high organic content that also block gold leaching (reabsorbs the gold), or it can have a high clay content that also soaks up the cyanide.

Diagnostic Leaching for Refractory Gold Ores - kz.srk.com

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, producing a qualitative assessment of the gold ...

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

The use of Aachen Assisted Leach and Leachox has expanded further into other operations world-wide and recently into the high tonnage tailings retreatment plants in South Africa operated by Evander Gold Mines and AngloGold Ashanti, where the application of the Aachen Reactors is in pre-oxidation before cyanide leaching to accelerate the leach ...

Technology - Direct Gold Leaching from Sulfidic Refractory ...

Title: Direct Gold Leaching from Sulfidic Refractory Ores or Concentrates . Invention: This solution is a less expensive and more environmentally friendly method for. extracting gold from ores or concentrates. The industry standard is leaching using cyanide, but. initial tests have shown that this method is more efficient at gold extraction ...

GOLD RECOVERY OF REFRACTORY SULFIDE CONCENTRATES …

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. Cyanide leaching of the concentrate was performed at 20%-w/w of solid (500 gram of refractory sulfide gold ore concentrate) in a ...

Leaching refractory gold ores – Gold Metallurgy

Apr 02, 2016· These ores, in which the gold is locked into pyrite or arsenopyrite, or present as tellurides, are becoming more important. The Kalgoorlie ores in particular, contain a significant amount of gold tellurides. Thus current studies at Murdoch University on the reactivity of gold tellurides are very pertinent [10]. Gold tellurides prove to be unreactive to…

Gold Mining Process Development – Denver Mineral Engineers

leaching. One major category of refractory ores are gold values contained within the crystalline structure of sulfide minerals such as pyrite and arsenopyrite. For cyanide to leach gold, the cyanide solution must come into direct contact with gold molecules. With many sulfide ores, the …

Gold cyanidation - Wikipedia

Gold cyanidation (also known as the cyanide process or the MacArthur-Forrest process) is a hydrometallurgical technique for extracting gold from low-grade ore by converting the gold to a water-soluble coordination complex.It is the most commonly used leaching process for gold extraction.. Production of reagents for mineral processing to recover gold, copper, zinc and silver represents ...

Cyanide Leaching Of Gold - Mine Engineer.Com

Carbonaceous gold ores can have the carbon adsorb the gold onto its surface, and as a result will not be recovered from the pregnant solution. Leaching gold from sulfide ores is difficult, at best. Generally, the recovery for cyanide leaching of sulfide or refractory ores is no better than 30%, which is not a worthwhile venture.

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, producing a qualitative assessment of the gold ...

Gold Leaching from a Refractory Gold Concentrate by the ...

In this research, effect of mechanical activation on the chloride-hypochlorite leaching of gold from a refractory pyritic concentrate containing ca. 27 g/t gold was investigated for the first time.

CHLORIDE HYPOCHLORITE OXIDATION AND LEACHING …

Chloride–hypochlorite oxidation and leaching of refractory sulfide gold concentrate 63 Fig. 1. The Pourbaix diagram of Fe–S at [Fe] –= 10 4 M, [S] = 10– M and 25 C (the chlorine species regions are also marked) (Marsden and House, 2005) Fig. 2.

Improvement of Gold Leaching from a Refractory Gold ...

systematically. On this basis, the enhancement of gold leaching from the calcine was studied by purposefully pretreating each size fraction with sulfuric acid curing-water leaching or alkali washing. Finally, an efficient process from improving gold extraction from refractory As-, S- and C-bearing gold

Gold Leaching from a Refractory Gold Concentrate by the ...

In this research, NaCl — NaClO solution is used to leaching gold from a refractory gold concentrate, and the influence of NaCl and NaClO concentration, reaction time to the leaching rate were investigated in this experiment. The raw materials and the leaching residue were characterized by a series of analysis methods such as XRD, XRF, SEM and ...