Us5536297a gold recovery from refractory carbonaceous ,process for recovering gold in which an ore slurry of refractory sulfidic and refractory carbonaceous ore having preg-robbing characteristics due to the presence of organic carbon is subjected to pressure oxidation in an autoclave. the oxidized ore slurry is mixed with a thiosulfate salt lixiviant, which mixture is maintained at a pH between and 8.7 while the slurry is agitated in aChatear en línea
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process for recovering gold in which an ore slurry of refractory sulfidic and refractory carbonaceous ore having preg-robbing characteristics due to the presence of organic carbon is subjected to pressure oxidation in an autoclave. the oxidized ore slurry is mixed with a thiosulfate salt lixiviant, which mixture is maintained at a pH between and 8.7 while the slurry is agitated in a the gold deportment data show that 37.5% of the gold losses in the cil residue are related to sub-microscopic gold contained in the unoxidized pyrite mineral phase the carbonaceous matter present in the ore exhibits strong preg-robbing capacity and contributes to 44.5% of the gold losses in the form of surface goldautoclave pressure oxidation followed by carbon-in-leach cyanidation was the process of choice, even though the twin creeks ores contain preg-robbing organic carbon. laboratory tests showed that optimum operating conditions were as follows: a fine grind size of 80% passing to microns, a temperature of 100 psig oxygen over-pressure, and 120 minutes of batch autoclave characterization, diagnostic leach tests, and preg-robbing tests. material and methods mineralogical characterization, dlt, and adsorption tests were performed to study the gold distribution and preg-robbing, using four samples taken from the mill carbon in leach tailings at the kittil mine in finland
apr 19, 2013 deportment of gold in an autoclave pressure oxidation (acpox the gold recovery is low and a gold deportment study of the cil residue was the need for optimization of the oxidation process in the autoclave facility. more detailed. get price september.preg-robbing is an important phenomenon that inhibits gold recovery due to the presence of naturally occurring carbonaceous matter. autoclave oxidation, and bacterial oxidation polymetal to expand pressure oxidation gold treatment in russia. adding that the new facility would use a titanium-lined steel autoclave operating at 240 and a pressure of bar. high carbon content drives high sorption activity and dictates the use of high-temperature pressure oxidation compared with tag archives: preg-robbing. polymetal to expand pressure oxidation gold treatment in russia. february 2019 metallurgy, mine operation news, mineral processing, adding that the new facility would use a titanium-lined steel autoclave operating at 240 and a pressure of bar.
ways: pressure oxidation for sulphide oxidation and CM passivation; recommended grain sizes should be smaller than microns and autoclave operated at the temperatures of or greater. the approach is primarily limited to processing double refractory ores with low preg-rob capacity due to limited oxidation effect on cmsslurry from the grinding circuit, at approximately 35% solids and 8085% passing 135 mm is pumped to three thickeners. thickener underflow, at approximately 54% ww solids, is pumped to a train of four acidulation tanks. sulfuric acid is added to the slurry to destroy sufficient carbonate prior to entering the autoclave circuit. process air is also injected into the acidulation tanks to aid pressure oxidation allows to carry out the efficient processing of goldbearing sulfide materials. however, application of this method for processing of double refractory raw materials leads to irreversible gold losses due to autoclave preg-robbing of gold by organic carbon. thermodynamic and experimental data indicate that almost complete sulfide decomposition leads to a high value of the processing of gold is becoming more complicated due to the increasingly complex nature of the remaining gold-bearing ore bodies. this worldwide phenomenon is the driving force for the development of alternative technologies for the leaching and recovery of gold from so-called double refractory ores. barrick gold recently commercialized a unique calcium thiosulfate leaching plant to treat
jan 19, 2011 gold recovery can be adversely affected by pregrobbing on inherent carbonaceous material during autoclave pressure oxidation of sulphide ores. the time of flight sims technique has been applied for direct determination of gold species on individual carbonaceous particulates from AC pox stream samples.mar 19, 2009 the percent sulfide oxidation was typically 97% and the residue discharged from the autoclave contained less than 0.06% sulfide. the autoclave discharge also contained 0.49% total carbonaceous material or tcm, a portion of which contributes to the phenomenon of preg robbing.the present invention is directed to a precious metal recovery process in which carbonaceous material, such as preg robbing carbon, is floated after sulfide oxidation to separate the carbonaceous material from the precious metal.carbonaceous materials in rob for highre preg-level of preg-rob ores, special treatments such as roasting, chlorination, nitric acid wash, biooxidation and pressure oxidation are require. pretreatment of preg-robbing gold ore can also be performed by using
carbonaceous gold ores have the ability to adsorb gold cyanide from leach solutions during processing. this phenomenon, known as preg-robbing, is responsible for poor recoveries as the carbonaceous materials of the ore compete with activated carbon used during the leaching and adsorption phase of processing. chemical oxidation of carbonaceous materials by different reagents the tendency of preg-robbing was demonstrated by adding carbon in a non-preg-robbing ore. It was shown that the preg-robbing tendency in the chloride-bromide media was very strong. addition of 0.01% ww of carbon powder into the non-preg-robbing ore decreased gold recovery from to 70% and addition ww of carbon decreased gold recovery todouble refractory gold ore contains gold particles locked in sulphides, solid-solution in arsenopyrite, and preg-robbing material such as carbonaceous matter, and so on. the diagnostic leach test and preg-robbing approaches are widely used to investigate the occurrence and the distribution of refractory gold. dlt serves to qualitatively evaluate the gold occurrences within the ore.disseminated gold particles can be trapped within the mineral matrix, even at fine grind sizes. the ore can contain highly reactive minerals that consume free cyanide or oxygen. In addition, the ore can contain preg-robbing elements such as organic carbon that will re-adsorb the dissolved gold as it is leached.
carbon is a preg-robbing mineral and can be managed in a few different ways. It can be burned off, treated with pre-flotation, or deactivated with other chemicals. In recent years gravity concentration has been used as an effective treatment for dealing with carbonaceous ores. for optimal gold recovery, it is vital to know the type of ore you be used to effect the oxidation of sulfide minerals. the arseno process involves the use of a catalyst. pressure oxidation procedure that has gained com mercial status for treating gold-bearing arsenopyrite or pyrite employs sulfuric acid and oxygen as autoclave pressure oxidation is an effective pre-treatment option when extracting gold from refractory ore bodies, such as pyrite and arsenopyrite. while gold processing plants are the most common utilizers of pox technology, the process can also be solutions. every autoclave and preleach circuit is a custom design, based on the experience and expertise of the design team. with the right innovative and proprietary equipment designs, your pressure-oxidation needs can be effectively met.
application of the process to preg-robbing gold ores, and to silver ores, is also briefly discussed. methods of recovering the gold from the platsol liquors are examined. development OF the platsol process fundamentals pressure oxidation has been used commercially since 1985 to pretreat refractory gold ores prior to cyanidation 10.variety of feed materials may be subjected to pressure oxidation of their sulfide content to liberate gold contained therein for later recovery by cyanidation. energy is required to pump the feed slurry into the pressurized reaction vessel, to heat the slurry to the reaction temperature, to supply oxygen, and to agitate the slurry and disperse the oxygen.abstract. carbonaceous gold ores have the ability to adsorb gold cyanide from leach solutions during processing. this phenomenon, known as preg-robbing, is responsible for poor recoveries as the carbonaceous materials of the ore compete with activated carbon used during the leaching and adsorption phase of processing.aug 11, 2016 ore consisting of graphitic sheared schist is preg-robbing, and gold recovery was also low. introduction of pressure oxidation processing before cyanidation has increased gold recovery. pressure oxidation residues include ferric iron oxyhydroxide, jarosite, and iron arsenate, and associated waters have very high dissolved as. dissolved As
5.3 preg-robbing behaviour by the ores at low cyanide concentrations 118 5.4 the effect of activated carbon and cyanide on the reversibility of preg-robbing 122 5.5 the role of 4-in preg-robbing 127 5.6 comparison of preg-robbing between the concentrates and gold-free mineral samples 131provided is a method for treating refractory gold-bearing ores that have both sulfide material with which the gold is associated and from which the gold is difficult to separate and having organic carbonaceous material having an affinity for at least one of gold and a gold complex. the mineral material is pressure oxidized in the presence of a halogen-containing material in a manner to reduce the evermore increasing complexity of gold ores is forcing operations to seek alternative gold leaching reagents to the traditional use of cyanidation. At the barrick goldstrike mine, the implementation of a non-toxic thiosulfate leaching process is about to become an industrial reality. with modification to the existing infrastructure and leaching circuit, this new process allows for the its capacity to preg-rob gold. from this, a simple and robust method has been developed based on the raman spectra of the sample and carbonaceous material content to predict the preg-robbing capacity of an ore. the potential exists to develop a predictive tool using raman spectroscopy for characterising the preg-robbing capacity of an ore.
kolkata autoclave pressure oxidation gold au high frequency screen compared with the commonly screening and grading equipments, the high frequency screen adopts higher frequency. mgp au produced cells, fine grinding with isa mill and preg robbing management pressure oxidation autoclave (30 bar and. get price.autoclave treatment of refractory sulfide gold ores oxidizes minerals, such as pyrite, containing gold that cannot be recovered through conventional cyanidation. oxidation liberates the gold by putting iron into solution. At high temperature and pressure, the dissolved iron tends to precipitate.the suggested concept was used to diminish the loss of gold via partial oxidation of metallic gold in autoclave processing of pyrite- and concentrates. possibility of using strongly basic anion exchange resin of minix brand and weakly basic anion exchange resin purogold brand in the high-temperature-adsorption of dissolved gold from the leach solution by the activated carbon added. the preg-robbing tests revealed that the gold ores exhibited a varying degree of preg-robbing behaviour. In this regard, the pyritic ore had the highest preg-robbing potential while the free milling ore showed minimal preg-robbing activity.
jan 01, 2005 preg-robbing is an important phenomenon that inhibits gold recovery due to the presence of naturally occurring carbonaceous matter. In case of certain ores, gold recovery by cyanidation is limited by the presence of naturally occurring carbonaceous material that adsorbs gold from alkaline cyanide solution unless steps are taken to prevent this adsorption reaction from occurring.preg robbing gold in autoclave oxidation. process for recovering gold in which an ore slurry of refractory sulfidic and refractory carbonaceous ore having pregrobbing characteristics due to the presence of organic carbon is subjected to pressure oxidation in an autoclave. the oxidized ore slurry is mixed with a thiosulfate salt lixiviant preg-robbing gold ores. j.d. miller, daz, in gold ore processing 2016. 3.5 pressure oxidation. this technique uses autoclave leaching with pure airoxygen, high pressure, and temperature for the treatment of refractory carbonaceous ore treatment (sibrell, An economic assessment for the processing of preg-robbing gold ores, from mild preg-robbing ores to very high pregrobbing ores, has been provided in 2007 with consideration of different options autoclave oxidation of refractory gold-sulfide different methods allowing to decrease gold wastes in preg robbing are considered.
jan 01, 2013 autoclave preg-robbing of gold, on the other hand, manifests itself to a full extent at malomir materials. gold losses can be dramatically high in autoclave pressure oxidation of refractory sulphide ores and subsequent cyanidation is or preg-rob gold from the cyanide leach solution. carbonaceous matter present in the carlin type carbonaceous sulphide ores has shown varying degree of preg-robbing activity In that regard it is important to develop technology and yakov shneersons research works with citations and 1,191 reads, including: the use of mercury to inhibit autoclave preg-robbing of gold: pilot plant trialsIf the gold can not be concentrated for smelting, then it is leached by an aqueous solution: the cyanide process is the industry standard.; thiosulfate leaching has been proven to be effective on ores with high soluble copper values or ores which experience preg-robbing: the absorption by carbonaceous components which preferentially absorbs gold and gold-cyanide complexes.
refractory gold ores are those that do not yield high gold recoveries in conventional cyanide-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.