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硫代硫酸盐提金理论研究:阴极过程及浸金机理 总被引:6,自引:2,他引:4
本文研究了金在硫代硫酸盐溶液中溶解的阴极机理,结果表明,在含铜氨的溶液中,二价铜氨络离子在金表面直接还原,生成的一价铜氨络离子进入溶液后,迅速被氧化再生为二价铜氨络离子,后者又到金粒表面上还原。根据硫代硫酸盐浸金阳、阴极过程电化学研究的结果,提出了氨性硫代硫酸盐浸金的电化学—催化机理及模型。从本质上揭露了铜、氨在硫代硫酸盐浸金过程中的作用,填补了硫代硫酸盐提金理论的空白。 相似文献
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硫代硫酸盐提金理论研究—金溶解动力学 总被引:6,自引:2,他引:4
采用腐蚀电化学方法研究了金在硫代硫酸盐溶液中溶解的动力学。无铜、氨时,金的溶解活化能为27.99kJ/mol,Cu(NH_3)_4~(2+)为0.01mol/L,总氨浓度为0.5mol/L时活化能降为15.54kJ/mol;在0.001~0.1mol/L范围内,Cu(NH_3)_4~(2+)的反应级数为1。动力学研究的结果进一步揭示了铜、氨在浸金过程中的催化作用,并再次证实了作者提出的氨性硫代硫酸盐溶液浸金的电化学—催化机理。 相似文献
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用于金湿法冶金的硫代硫酸盐浸出 总被引:2,自引:0,他引:2
本文研究了用硫代硫酸盐浸出贵金属,并以此作为可取代传统氰化法的一种无毒性浸出技术。该工艺在减少外来阳离子干扰和降低环境影响方面都优于氰化法。氨的硫代硫酸盐溶液可使金溶解而生成稳定的阴离子络合物,从而使金的浸出以相当大的溶解速率进行。本工作的目的是通过实验室规模研究,对从贵金属矿石中提取金的硫代硫酸盐浸出进行初步可行性评价。通过对取自多米尼加共和国(DominicanRepublic)的矿石所做试验,作者指出了温度、硫代硫酸盐浓度、氨浓度和硫酸铜浓度对金溶解的影响。采用活性炭吸附或电解从浸出液中回收金。在类似传统氰化法的最佳工艺参数条件下,金的回收率可达80%。 相似文献
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ZhaoJin,WuZhichun,ChenJiayong研究了用氧化胺及其与胺的混合物从硫代硫酸盐溶液中萃取金。氧化胺(TRAO)是通过氧化叔胺而制备的。研究发现,在从硫代硫酸盐溶液中萃取金时,氧化胺的行为不同于氧化膦,其萃取能力强于氧化磷。从中性和弱碱性溶液中萃取金时,其萃取能力强于叔胺,而与伯胺相似。氧化胺的加入,可提高伯胺、仲胺、叔胺萃取金的能力。用斜率分析法研究了用伯胶N1923和氧化胺TRAO的混合溶液从硫代硫酸盐溶液中萃取金时萃合物的组成。对于不含氨的硫代硫酸盐溶液.萃取反应可表示为,对于含氨的硫代硫酸盐溶液,萃取… 相似文献
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在氨硫代硫酸盐浸金体系中,重金属离子对金溶解行为的影响,主要取决于离子类型和浓度及硫代硫酸盐浓度。Zn在低浓度时,有利于金溶解;在高浓度时,阻碍金的溶解。 相似文献
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探索了超声波作用对铜氨硫代硫酸钠浸金体系稳定性的影响。考察了不同浸出时间、温度、超声波功率、pH和氨水浓度条件下,浸金体系内硫代硫酸根离子浓度以及Cu(NH_3)_4~(2+)络合离子浓度变化规律。结果表明,超声波作用使硫代硫酸盐浸金体系稳定性有所降低,一定条件下可显著促进硫代硫酸根离子和Cu(NH_3)_4~(2+)络合离子浓度的降低。金矿石浸出试验表明,当Na_2S_2O_3浓度为0.1mol/L、CuSO_4浓度为0.03mol/L、NH_3·H_2O浓度为0.45mol/L时,超声波作用能够显著提高浸金率,在较低浸出温度下引入超声波辅助浸出就能达到常规较高温度下的浸出效果。本研究为降低硫代硫酸盐浸金反应的温度开辟了新的路径。 相似文献
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某难处理金矿石中含有大量铜,如果直接氰化浸出,除了消耗大量氰化物外,还会在金表面形成一层薄膜,减慢金的溶解速度,金回收率低于30%;如果预氧化处理后再氰化提金,操作复杂、过程冗长、有污染、成本高,而且回收率并无实质性提高。为提高金回收率,降低生产成本,试验将该难处理金矿石破碎细磨后采用低浓度的NH4Cl和氨水混合浸出,利用氯离子与金形成稳定的配合物进行提金,矿石中的铜离子起氧化作用,促进金的反应,金浸出率可达87%以上。该方法无需进行预氧化处理,避免添加有毒有害药剂,消除对环境的污染。 相似文献
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To understand how various sulfide minerals affect the dissolution behavior of gold in the ammoniacal thiosulfate leaching
system, an extensive study has been carried out on gold leaching in the presence of sulfides using pure gold plates. Special
emphasis has been placed on gold leaching in association with sulfide dissolution, thiosulfate decomposition, and dissolved
oxygen depletion in leach solutions. The results demonstrated that the leaching behavior of gold depended strongly on the
solubilities of the sulfides, the thiosulfate decomposition, and the oxygen concentration in slurries. Gold dissolution was
enhanced or diminished, depending on the sulfide types and the sulfide concentrations in slurries. An increase in the stirring
speed accelerated the gold dissolution rates due to the improved mass transfer occurring in the gold leaching process and
the increased dissolved oxygen content in leach solutions. The addition of sulfate in the sulfide slurries increased the gold
leaching rates because of the depression of the sulfide dissolution in the leaching systems. Topological studies by scanning
electron microscopy (SEM) demonstrated that the existence of passivating layers at the leached gold surfaces could result
in the retardation of gold dissolution in the presence of sulfide minerals.
An erratum to this article is available at . 相似文献
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GRAHAM J. SPARROW JAMES T. WOODCOCK 《Mineral Processing and Extractive Metallurgy Review》2013,34(3-4):193-247
Selection of a leaching system for gold involves consideration of ore texture and mineralogy, chemical requirements, leaching techniques, the development of flowsheets, and environmental management. Aqueous dissolution chemistry for alkaline, neutral, and acid systems is mainly considered here. All systems require an oxidant to oxidise gold and a ligand to complex with gold in solution. Adjustment of pH is usually necessary. Alkaline lixiviant systems (pH > 10)include cyanide, ammonia-cyanide, ammonia, sulphide, nitriles, and a few other minor possibilities. Oxygen is the main oxidant. Cyanide, which is the main ligand in these systems, forms an anionic complex, “Au(CN)2”, with Au(I). Gold dissolution rates are controlled by oxygen solubility in solution. Neutral lixiviant systems (pH 5-9)include thiosulphate, halogens, sulphurous acid, and bacteria plus natural organic acids as the ligand. Oxygen is the normal oxidant and either Au(I) or Au(III)complexes are formed. Acid leaching systems (pH ? 3)may contain thiourea, thiocyanate, chlorine, aqua regia, or ferric chloride. Chloride is the ligand in the last three systems and the oxidants include chlorine, ferric chloride, hydrogen peroxide, and nitric acid which produce Au(III) anionic complexes, e.g. [AuClJ". Fast gold dissolution is possible but reagent consumptions are high. Thiourea is unusual in producing a cationic Au(I)complex, “Au(NH2CSNH2)2” and gold dissolution is slower. For treating simple auriferous oxide-silicate-carbonate ores, and many otfier materials, cyanide remains the preferred lixiviant. Most non-cyanide leaching systems appear to have little wide-spread practical application. Possible niche applications include the use of chlorine or aqua regia to dissolve coarse gold from gravity concentrates, oxidising acid chloride solutions for die treatment of auriferous base metal sulphide concentrates, thiosulphate for dissolving gold from gold-copper ores, and thiourea for auriferous hydrometallurgical intermediates. 相似文献
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研究采用一种环保、高效的硫代硫酸盐—铁氰化钾体系替代广泛使用的氰化法提取物料中的金银。在这种新的硫代硫酸盐体系中,利用更加稳定的K3Fe(CN)6替代传统的四氨合铜作为氧化剂。考察了硫代硫酸盐浓度、K3Fe(CN)6浓度以及溶液的初始p H值对浸出效果的影响。实验证明,这种新的体系能够快速有效地溶解金银,反应初始阶段铁氰化钾作氧化剂时,银的溶解速度非常快,铁氰化钾消耗完之后,银的溶解机理转变为氧气驱动的过程,此时银的溶解速率下降较多。该体系在浸出剂略微过量的情况下即可实现对金银的有效浸出。将该体系用于硫酸渣中金银的提取,在浸出条件为:0.05 M五水合硫代硫酸钠、1 m M铁氰化钾、p H=8时,浸出48 h后,金银的提取率分别为88%和92%。 相似文献