The pretreatment of an antimonial refractory gold and silver ore was investigated using alkaline sulphide leaching. The ore assayed 20 g/t Au and 220 g/t Ag and contained predominantly quartz/clay and barite, and to a lesser extent, sulphides such as pyrite, stibnite, sphalerite, zinkenite (Pb 9 Sb 22 S 42) and andorite (Sb 3 PbAgS 6).The latter mineral was identified to be the most important ...
In the biooxidation process, bacteria partially oxidize the sulfide coating covering the gold microparticles in ores and concentrates. In this way, gold recovery from refractory minerals can increase from 15-30% to 85-95%. In the last 15 years at least ten large-scale commercial gold processing units have been established in South Africa ...
A "refractory" gold ore is an ore that has ultra fine gold particles disseminated throughout its gold occluded minerals. These ores are naturally resistant to recovery by standard cyanidation and carbon adsorption processes. These refractory ores require pre-treatment in order for cyanidation to be effective in recovery of the gold.
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.
This study was undertaken to evaluate the nitric acid leaching as a potential pre-treatment process prior to cyanidation of refractory gold/silver ores. ... A Preliminary Study on Nitric Acid Pre ...
Abstract: Gold telluride ores are important gold refractory ores due to the presence of sulfides and other gangue materials. ores. For the conventional cyanide leaching process, pretreatment such as oxidation is required to achieve high gold recovery. Roasting is .. process of gold telluride ores from a KCGM flotation con.
Rose and Newman's very comprehensive book, The Metallurgy of Gold, does not even contain the term refractory in its latest, fourth edition (1937). 1 Dorr and Bosqui's Cyanidation and Concentration of Gold and Silver (2d edition, 1950) has a brief chapter (XIII) on "Cyanicides and Refractory Ores," with only four pages devoted to ...
FL is pioneering a mechano-chemical pre-treatment process known as the Rapid Oxidative Leach (ROL) for refractory gold ores. Sally Rocks, senior R&D chemist believes her team has made an extraordinary breakthrough which will have a profound effect on the industry.
refractory ore gold and pretreatment 2012 ... pretreatment of refractory gold ore with microwaves . pretreatment of refractory gold ore, BINQ Mining . Get Price pretreatment of refractory ores prior to gold leaching ...
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.
Recovery of gold increased gradually to its maximum value of 93.05% as the value of cyanide strength increased from 0.8 to 1.2% and the addition of sodium nitrite raise to 1.2 M. No improvement for further addition of nitrites. This introduction of new hydrometallurgical pre-treatment process has given more option for treating refractory ores.
ALKALINE OXIDATIVE LEACHING OF GOLD-BEARING ARSENOPYRITE ORES By P. Bhakta,1 J. W. Langhans, Jr.,1 and K. P. V. Lei2 ABS"rRACT The U.S. Bureau of Mines developed an alkaline oxidative pretreatment leaching procedure to increase the recovery of gold from arsenopyrite (FeAsS) ores. The best solution compositions for
Developments in the pretreatment of refractory gold minerals by nitric acid D.-X. LI College of Environmental Science and Engineering, China The paper covers many literature reports of processes using nitrogenous species as an oxidant for processing refractory gold ores, especially development in the pretreatment of refractory gold
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
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 .
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The reasons of gold refractory, ore classification, and preprocessing methods. I.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.
grades for refractory resources. We believe ROL for gold has this potential." FL is pioneering Rapid Oxidative Leach (ROL), which is a mechano-chemical pre-treatment process for refractory gold ores. Sally Rocks, senior R&D chemist believes her team has made an extraordinary breakthrough which will have a profound effect on the industry. "We
This study was therefore aimed at investigating the ability of the CM-deactivating fungus, P. chrysosporium, to also solubilize/oxidize sulfides found in refractory gold ores so as to assess the potential of a single-stage process for the pretreatment of double refractory gold ores. 2. Experimental investigations 2.1. Materials
As free-milling oxide deposits are depleted on a world-wide scale, the mining companies capable of efficiently mining and processing both low- and high-grade refractory sulfide deposits will become industry leaders. This chapter addresses a new process for the biooxidation of refractory gold ores developed by GeoBiotics, Inc.
and reagent concentration (Na2S and to eliminate penalty elements includ- In this study, the alkaline sulfide pre- NaOH) on the pretreatment process ing As and Sb from ores/concentra- treatment of a highly refractory gold/ and cyanide leaching of gold and silver tates.23,24 In this respect, Ficeriová et silver ore containing antimonial sul ...
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: • Roasting
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.
BACTERIAL LEACHING AS A PRE-TREATMENT STEP FOR GOLD ... FOR GOLD RECOVERY FROM REFRACTORY ORES ... This leaching process decomposes the sulfide matrix, thus exposing the encapsulated precious metals to leaching solution.