Pretreatment of Refractory Ore in Gold ore processing to form a slurry and is then acidified with sulfuric acid Developments in the pretreatment of refractory gold minerals DEVELOPMENTS IN THE PRETREATMENT OF REFRACTORY GOLD MINERALS BY NITRIC ACID 145 processing refractory gold ores include the high refractory gold oreChat Online
Processing technologies for gold telluride ores SpringerLink This study deals with provided that gold is coarse enough to the alkaline sulfide leaching as an Gold ores are commonly classi be physically and economically liber alternative pretreatment method fied as free milling and refractory for antimonial refractory gold and ated ores based on the metallurgical per silver bearing ores.Supercritical Water Treatment of Refractory Gold Ores acidic pretreatment of gold refractory ore processing evaluating process options for treating some acidic pretreatment of gold refractory ore processing Refractory gold ores are those that do not yield high gold recoveries in different methods of pretreatment were prepared and these estimated costs and ore sulfide that acid.
KEY WORDS arsenic bearing gold ore pretreatment process refractory gold ore 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.In the direct smelting process refractory gold ores are smelted directly with gold enriched into ferrous matte This paper studies the optimization of the nitric acid pretreatment refractory.
57 Claim 1 A process for recovering gold from refractory auri ferous iron containing suiphidic ore comprising feeding ground ore as an aqueous slurry to an acidic pretreatment step treating the ground ore in the acidic pretreatment step with aqueous sulphuric acid solution to decompose car bonate and acid consuming gangue compounds which might other wise inhibit a subsequent pressure.The common pretreatment methods for gold sulfide gold deposit are oxidizing roasting method curing method acid pressure oxidation bacterial oxidation method nitric acid oxidation method etc Gold ore which is difficult to concentrate often referred to gold or refractory gold ore which use conventional cyanide process cannot effectively.
The grade and recovery of gold in the flotation concentrates were 49 44 g t and 33 36 respectively The total recovery of gold was 90 94 The gravity–flotation combined beneficiation pretreatment process provided a feasible method for the refractory gold ore and ensured the effective recovery of gold.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 In summary the difficulties consist of the following.
Pressure oxidation is employed to liberate gold and silver in refractory sulfide concentrates often and ores The main pressure oxidation products from iron sulfide minerals are sulfuric acid (and metal sulfates) and hematite Depending on the conditions within the autoclave acid containing iron compounds can be formed.A process for recovering gold from a refractory sulfidic ore which has been suspended in an aqueous slurry and oxidized using nitric acid so that substantially all of the gold in the ore is made available for recovery and at least a portion of the sulfidic components present during the oxidation are oxidized to elemental sulfur comprises bubbling air as a discontinuous phase upwardly through.
This article covers acid nitric leaching of Olympiada deposit refractory gold bearing concentrate after alkaline leaching of stibnite Thermodynamic analysis of the reaction pyrite and arsenopyrite with nitric acid chemical equations was performed Equilibrium Eh pH Pourbaix diagrams of heterogeneous systems studied containing iron and arsenic were charted.ECONOMICS OF REFRACTORY GOLD ORE PROCESSES John E Litz and R Wayne Carter 119th TMS Annual Meeting February 18 22 1990 Hazen Research Inc 4601 Indiana Street Golden Colorado 80403 Abstract Refractory gold ore pretreatment processes continue to receive much attention This.
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.Free milling gold ores are usually reactive toward leaching with cyanide and characterized by high recovery ( 90 ) 7 Refractory ores are those yielding low gold recoveries ( 80 ) even with extremely high consumption of reagents 8 The mineral structure and the nature of gold association play an important role in the refractoriness To date several.
Non refractory production with the processing of refractory concentrate The mining of refractory ore is becoming increasingly common in Russia’s numerous operational gold mines with the process requiring additional pre treatment prior to cyanidation for gold recovery.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 Roasting has to be one of the most expensive methods of recovering gold with current environmental considerations and is usually cost prohibitive except in a few.
Refractory gold ores have increasingly been the main source of gold production with the exhaustion of amenable gold ores Of the 2630 tons of total world gold production in 2011 about 25 was produced from refractory gold deposits and of the top 20 gold operations in 2011 eight were processing refractory ores  Commonly relatively high content of detrimental impurities like S (sulfur) As.Pretreatment Of Refractory Ores Prior To Gold Pretreatment Process Before – InTech 1 Introduction The poor extraction of refractory gold ores is an old and still existing problem Gold.
Refractory gold ores have increasingly been the main source of gold production with the exhaustion of amenable gold ores Of the 2630 tons of total world gold production in 2011 about 25 was produced from refractory gold deposits and of the top 20 gold operations in 2011 eight were processing refractory ores .Ozonization in acidic media of an arsenopyritic pyritic highly refractory gold concentrate (110 g Au t) as a treatment prior to cyanidation was evaluated While the conventional cyanidation of this concentrate recovers only 9 of the gold a pretreatment with ozone before the cyanidation increases the gold recovery to 23.
Characteristics and risks of refractory gold mines 11 11 20 71 Views icon 0 The main methods used in industrial production for the treatment of refractory gold ore or gold concentrate are roasting pressure oxidation and bacterial oxidation All these methods have many years of production experience.A process for recovering gold from refractory gold bearing ores uses sulfurous acid as the leaching agent to form a gold sulfite complex The ore is ground slurried blended with a chelating agent and then subjected to a simultaneous dissolved SO 2 leaching and anion exchange resin adsorption step in the presence of dissolved oxygen The gold transfers to the resin which is later separated.
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 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 roasting hot pressure oxidation biological oxidation.
Gold extraction or recovery from its ores may require a combination of comminution mineral processing hydrometallurgical and pyrometallurgical processes to be performed on the ore Gold mining from alluvium ores was once achieved by techniques associated with placer mining such as simple gold panning and sluicing resulting in direct.Developments in the pretreatment of refractory gold Atmosphericpressure oxidation with nitric acid The Nitrox process which treats the ore for 1 to 2 h in nitric acid in the presence of air at atmospheric pressure to oxidize pyrite and arsenopyrite prior to cyanidation claims to increase gold recoveries from 30 to 90 Prassad et al 1991.
Solutions to this problem typically propose the use of larger sample sizes typically 30 g or greater 3 Further when using acid digestions in the absence of hydrofluoric acid low recoveries have been associated with the encapsulation of gold in the siliceous rock 1 2 4 5 Here it is presumed that gold is secreted within a refractory matrix making it inaccessible to solvent solutions.Figure 2 shows how biooxidation can be used as a pretreatment step in a conventional gold mill Processing refractory ore involves the addition of flotation coated biooxidation and neutralization unit operations The coated biooxidation process is shown in greater detail in Figure 3 Here a sulfide gold concentrate is coated onto support rocks.
Such ores are known as refractory ores (Attia and El Zeky 1989) Various pre oxidation methods of refractory ores and concentrates are commonly used to improve precious metal recoveries For example oxidative roasting has been used in some cases as a pre oxidation step before cyanidation.Refractory ore processing methods almost always serve only one purpose to ground down fine enough to expose the gold particles The objective of pretreatment for these ores is to remove enough of the sulfide so that at alkaline or acidic conditions depending upon the specific process.
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