• 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.

  • Bacterial heap leaching of refractory gold/sulphide ores ...

    Low-grade refractory sulphide gold ores exist in which the gold values are too low to economically justify the use of pre-concentration processes. The pre-concentration process (usually flotation) is followed by the oxidation of the sulphidic concentrate to render the gold amenable to a subsequent cyanide leach.

  • Gold extraction - Wikipedia

    204 204 Cyanidation of Refractory Gold Ores: A Review R.K. Asamoah, R. K. Amankwah and J. Addai-Mensah Ian Wark Research Institute, The ARC Special Research Centre for Particle and Material ...

  • Cyanide Leaching Of Gold - mine-engineer.com

    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. The use of alkalies such as calcium oxide, will prevent the decomposition of cyanide in solution to form hydrogen cyanide …

  • Direct Gold Leaching from Sulfidic Refractory Ores or ...

    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 ...

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

    Oct 20, 2014· Liberation: Cyanide leaching will only be effective if the cyanide can come in contact with the gold particle. For this to happen, the ore should either be sufficiently porous for cyanide to reach the gold, or more usually the ore is crushed and ground to a size at which the surface of the gold is exposed – i.e. the gold is liberated.

  • Improvement of Cyanidation of Antimonial Refractory Gold ...

    The cyanidation tests after ultrafine grinding showed that the recoveries of gold and silver were enhanced by 26% and 18%, respectively. Ultrafine grinding process prior to cyanidation could be, therefore, used as a physical pretreatment method to improve the cyanide leaching of gold and silver from the antimonial refractory ore.

  • Cyanide Leaching | Mining | SGS

    Cyanide leaching has been the industry standard for gold processing for more than 100 years. During the cyanide leach process, a cyanide solution, or lixiviant, is percolated through ore contained in vats, columns or heaps. Gold is dissolved by the cyanide and then removed from the heap or columns.

  • Gold Ore Processing, Volume 15 - 2nd Edition - Elsevier

    Gold Ore Processing: Project Development and Operations, Second Edition, brings together all the technical aspects relevant to modern gold ore processing, offering a practical perspective that is vital to the successful and responsible development, operation, and closure of any gold ore processing operation.This completely updated edition features coverage of established, newly implemented ...

  • Cyanide Leaching | Mining | SGS Argentina

    Cyanide leaching has been the industry standard for gold processing for more than 100 years. During the cyanide leach process, a cyanide solution, or lixiviant, is percolated through ore contained in vats, columns or heaps. Gold is dissolved by the cyanide and then removed from the heap or columns.

  • 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 ...

  • Diagnostic Leaching for Refractory Gold Ores - latam.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 ...

  • GOLD RECOVERY OF REFRACTORY SULFIDE CONCENTRATES …

    Cyanide leaching of the concentrate was performed at 20%-w/w of solid (500 gram of refractory sulfide gold ore concentrate) in a 2.5-liter glass reactor with aeration and stirred at 250 rpm. Leach solutions were prepared using deionized-distilled water at the prescribed concentration of reagents.

  • Gold Mining Process Development – Denver Mineral Engineers

    allow the recovery of gold by standard gravity concentration or direct cyanide 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.

  • The mechanism of leaching of gold from refractory ores ...

    Both the FSG and WDL samples were washed with cyanide or dilute nitric acid solutions in a sHrred beaker, filtered and cyanided. This washing step increased the dissolution rate of Leaching of gold from refractory ores 1385 gold by more than 50% after a leaching time of 2 …

  • 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 …

  • 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 ...

  • ALTA 2018 Refractory and Complex Gold Ores Panel Discussion

    Oct 25, 2018· The main topics discussed included the need for new processes for refractory gold ores, alternatives to cyanide, stability of arsenic residues, heap leaching of refractory gold ores…

  • 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 …

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

    Nov 28, 2016· III. Classification of refractory ores. 1. Carbonaceous gold ore. There is organic carbon which can do'Rob gold'in gold and silver ore, and it causes that gold is adsorbed in the cyanide ...

  • (PDF) Cyanidation of Refractory Gold Ores: A Review

    Cyanidation of Refractory Gold Ores: A Review ... Gold leaching with cyanide and non-cyanide lixiviants is well documented and the reader is referred to a number of classic references and reviews ...

  • INFLUENCE OF PRE-AERATION ON CYANIDE LEACHING OF …

    Influence of pre-aeration on cyanide leaching of a non-refractory sulphide gold and silver ore 649 oxidizing reagents such as sodium peroxide, potassium permanganate, bromine, and chlorine are essential for the dissolution of gold under normal conditions. However, these auxiliary oxidants are not used anymore due to their cost and complications

  • 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

  • Treatment of Refractory Gold Ores - XPS

    where the gold is in the ore by systematically destroying key minerals, followed by cyanide leaching of the residue until all of the gold has been recovered. +1 705 699 3400 Fax: +1 705 699 3431 [email protected] XPS Consulting & Testwork Services 6 Edison Road, Falconbridge, Ontario, Canada P0M 1S0 Treatment of Refractory Gold Ores

  • How to Leach Gold Ore With Chlorination | Sciencing

    Apr 25, 2017· Gold can be leached from stone through alkaline or acidic-based products, including halogens, such as chlorine, iodine and bromine. Halogens are reactive, non-metal elements with seven electrons in their outer shell which allow them to easily combine with other elements. The use of chlorine is both the cheapest and ...

  • Rcovery of gold in pyritic ores - mine-engineer.com

    To my knowledge, this has never been attempted. Generally speaking, cyanide leaching of low grade pyritic ores is economically unsatisfactory in today's market. Low grade ores that do not respond well to cyanide or flotation are generally referred to a "refractory" ore. Which usually means that it needs to be roasted to release the gold.

  • 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 Extraction and Recovery Processes - Semantic Scholar

    available for the extraction of gold metal from its ores. Amongst these methods, cyanidation is the most 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 …