硫脲浸出金精矿及石油亚砜矿浆萃取Au(Ⅰ)的研究

本文研究并选择了酸性硫脲浸出金精矿的最佳工艺条件,对石油亚砜从硫脲浸出矿浆中直接萃取Au(Ⅰ)的性能作了初步的探索。     

二-n-己基硫醚萃取Au(Ⅲ)和Au(Ⅲ)的反萃

本文研究了二-n-己基硫醚的二甲苯溶液从盐酸介质小萃取Au(Ⅲ)的规律,提出了萃取机理,较满意解释了萃取过程及萃合物的组成。应用硫脲作反萃剂,可将萃至有机相中的Au(Ⅲ)反萃至水相,效果很好。     

季铵盐类离子液体萃取Au(S2O3)23-性能研究

硫代硫酸盐提金是一种绿色环保的非氰提金方法,但高效回收金浸出液中的金尚待进一步研究。以甲基三辛基氯化铵(TOMAC)为萃取剂,考察了萃取条件（萃取剂浓度、相比、萃取时间）及金浸出液性质（pH、硫代硫酸盐浓度、初始Au(I)浓度）对TOMAC萃取Au(Ⅰ)性能的影响。结果表明：室温条件下,TOMAC为萃取剂能从硫代硫酸盐金浸出液中高效萃取Au(Ⅰ)。当A/O=1、pH=9、硫代硫酸盐浓度0.1 mol/L、TOMAC浓度1.8 g/L时,对低浓度金(0~25 mg/L)几乎能完全萃取;采用1 mol/L NaCl能有效反萃出TOMAC有机相中的Au(Ⅰ)。TOMAC萃取Au(Ⅰ)的机制为：TOMAC通过其表面的Cl-与溶液中的Au(Ⅰ)发生离子交换,形成[C25H54N]3[Au(S2O3)2]络合物。TOMAC对Au(S2O3)23-具有良好的萃取性能,可实现硫代硫酸盐金浸出液中Au(I)的高效回收,具有对硫代硫酸提金技术的潜在应用价值。     

HDEHP—乙酸丁酯有机相萃取硫脲金的研究

本文研究了二－（２－乙基己基）磷酸的乙酸丁酯有机相体系从酸性硫脲溶液中萃取回收金的性能，条件及反萃淬的组成，对萃合物的组成和萃取过程做了简要探讨，证实了稀释剂的作用是不可忽视的。     

N1923-TBP混合体系从多硫化物含金溶液中萃取金的研究

考察了不同性质的萃取剂对N1923/正辛烷从多硫化物含金溶液中萃取Au(I)的影响,并对具有协萃效果的N1923-TBP混合体系进行了深入研究。研究结果表明对N1923-TBP混合体系,水相初始Au(I)浓度对萃取的影响不大;稀释剂的改变对萃取稍有影响,用芳烃稀释剂可使萃取曲线向高碱度方向移动。在低碱度(pH<9)多硫化物含金溶液中用N1923-TBP混合体系萃取时,N1923为主萃取剂,TBP起协萃作用;而从高碱度(pH>9)多硫化物含金溶液中萃取时,TBP为主萃取剂,而N1923则起协萃作用。     

振动筛板塔中石油亚砜矿浆萃取金的研究

就石油亚砜从硫脲浸出矿浆中直接萃取Au（Ⅰ）的性能作了初步的探索,并在振动筛板塔中进行了扩大试验     

用2-(叔-十二烷基硫代)吡啶溶剂萃取Ag(Ⅰ)、Pd(Ⅱ)、Hg(Ⅱ)的研究

为了研究2-(叔-十二烷基硫代硫呲啶刘各种金属的萃取性能,用2-氯吡啶与叔-十二烷基硫醇合成了各种萃取剂。研究发现,在氯化物介质中,该萃耽剂对于Pd(Ⅱ)、Hg(Ⅱ)的萃取选择性要优子Pt(Ⅱ)、Pt(Ⅳ)和贱金属。在硝酸介质中(0.01～5mol HNO_3)Ag(Ⅰ)几乎完全被萃取。在浓度为0.01～2mol/1和0.01～0.5mol/1的盐酸介质中,Pd(Ⅱ)和Hg(Ⅱ)可分别完全被萃取。Pd(Ⅱ)从盐酸介质中被萃取的速率要比使用二烷基硫醚和三异丁基膦硫醚萃取剂快得多。发现硫脲和盐酸混合物的水溶液是Pd(Ⅱ)的有效反萃取剂,其反萃效果取决于硫脲和盐酸的浓度.     

石油亚砜从硫脲浸金液中萃取金的研究

探讨了用石油亚砜从酸性硫脲浸金液中萃取Ａｕ（Ｉ）的性能及用Ｎａ＿２ＳＯ＿３溶液从负载有机相中反萃Ａｕ（Ｉ）的可能性，并在振动筛板塔中进行了扩大试验。     

PSO-ⅢA(3)亚砜萃取金的性能及其机理

本文研究了石油亚砜(PSO-Ⅱ型)中的组分PSO-Ⅲ(3)萃取Au(Ⅲ)时,稀释剂、酸度和亚砜浓度对萃取率的影响。元素分析法、斜率法测出萃合物组成为HAuCl_4·3PSO。根据红外光谱、紫外吸收光谱分析,认为萃取机理与水相酸度有关:在低酸度下为氧配位溶剂化机理,在高酸度下为酸性缔合机理。     

用三烷基氧化膦从氰化浸出液中萃取低浓度金

研究了三烷基氧化膦(TRPO)-磷酸三丁酯(TBP)-煤油萃取体系对氰化浸金液中低浓度金(Ⅰ)的萃取和反萃取能力,结果表明,尽管TRPO体系中添加TBP对金(Ⅰ)的萃取率影响很小,但一定量的TBP能提高体系的反萃效果。考察了料液pH值、硫酸锂浓度等因素对萃取率的影响,探讨了不同的反萃温度、反萃相比对负载有机相中金(Ⅰ)的反萃效果。结果表明,采用TRPO-TBP-煤油组成的有机相,对金(Ⅰ)质量浓度为9.5 mg/L、盐析剂硫酸锂浓度为1.0 mol/L的碱性氰化液在相比A/O=1∶1条件下进行萃取时,金(Ⅰ)的单级萃取率可达95%以上;反萃温度越高,相比(A/O)越大,反萃效果越好,可以将大部分金(Ⅰ)反萃出来。     

A solvent extraction study of silver(I), palladium(II) and mercury(II) with 2-tert-dodecylthiopyridine

2-tert-Dodecylthiopyridine was synthesized from 2-chloropyridine and tert-dodecanethiol in order to examine its extraction properties for various metals. It was found to have good selectivity for the extraction of palladium(II) and mercury(II) over platinum(II) and -(IV) and base metals from chloride media; silver(I) was found to be almost completely extracted from nitric acid (0.01–5 mol/dm³ HNO₃). Palladium(II) and mercury(II) were completely extracted from hydrochloric acid over the range 0.01–2 and 0.01–0.5 mol/dm³ HCl, respectively. The rate of extraction of palladium(II) from hydrochloric acid was much faster than when using dialkylsulfide and triisobutylphosphine sulfide extractants. An aqueous mixture of thiourea and hydrochloric acid was found to be effective as stripping solution for palladium(II). The extent of stripping was dependent on the concentrations of either thiourea or hydrochloric acid.     

用硫脲法从铜阳极泥中提金的研究

本文研究了用酸性硫脲溶液从铜阳极泥中浸取金的方法。通过考察各种因素对浸取金的影响，确定了最佳浸取条件。并进一步研究了活性炭对硫脲浸金液的吸附情况，确定了吸附最佳条件。     

Extraction of gold(III) in hydrochloric acid solution using monoamide compounds

The extraction and separation properties of Au(III) using two monoamide compounds, N,N-di-n-octylacetamide (DOAA) and N,N-di-n-octyllauramide (DOLA), which have different side chain lengths attached to the carbonyl carbon (CH₃ for DOAA and n-C₁₁H₂₃ for DOLA), were investigated. The solvent extraction of some precious and base metals (Au(III), Pd(II), Pt(IV), Rh(III), Fe(III), Cu(II), Ni(II) and Zn(II)) in HCl solutions was carried out using DOAA and DOLA diluted with n-dodecane and 2-ethylhexanol. A good selectivity for Au(III) extraction with 0.5 M extractant is obtained at lower HCl concentrations (< 3.0 M) in both systems. The extractability of Au(III) with DOAA is greater than that with DOLA. In the 0.5 M DOAA–3.0 M HCl system, a third phase is formed when the Au(III) concentration in the initial aqueous phase is over 39 g/L. In contrast, third phase formation is not found in the 0.5 M DOLA–3.0 M HCl system, and its loading capacity of Au(III) is about 79 g/L. The Au(III) extracted in the organic phase is effectively back-extracted by 1.0 M thiourea in 1.0 M HCl solution in both systems, while some thiourea is precipitated using the organic phase containing 20 g/L of Au(III). The back extraction of Au(III) using water is poor in the DOAA system, but possible in the DOLA system.     

溶剂萃取金的研究综述

介绍了多种含金溶液体系的金萃取研究现状及进展,包括卤化物(主要是氯化物和溴化物)体系、氰化物体系、酸性硫脲体系和多硫化物体系等,并对各种萃取剂萃取金的效果、优缺点进行了表述,总结了各种含金溶液体系中颇有前景的一些萃取剂的发展优势。     

用离子交换树脂从硫脲硫酸溶液中回收金银的研究

本文从树脂选型、吸附和解吸等方面,介绍了用离子交换法从含金量较低的硫脲硫酸溶液中,回收金、银的试验研究结果。结果表明,用D61和732牌号的强酸性阳离子交换树脂,能有效地从料液中吸附金、银;用氰化钠碱性溶液作解吸剂,金的解吸率>99％,银的解吸率>70％。     

Solvent extraction of some base and precious metals using 1,3,4-thiadiazole-2-nonylmercapto-5-thiol

This investigation is one of a series of studies in which the fundamental chemistry which underlies the extraction and separation of precious metals is considered. The title compound (TNSTH) was used as a solvent extraction reagent and shows some promise for extracting and separating the chloro-anions of Au(III) and Pd(II) from strong hydrochloric acid solutions (ca. 5 M). The distribution coefficients from such media were in the order of 10⁴. The title reagent may be used to separate the precious metals from each other. For example, the separation coefficients (i.e., ratios of distribution coefficients) for mixed solutions are 10⁶ for Au(III)/Rh(III) and Pd(II)/Rh(III); 145 for Au(III)/Pd(II); 180 for Pd(II)/Cu(I or II); 10⁶ for Pd(II)/Pt(IV). The time for half of the Pd(II) to be extracted is approximately 6 min, which is acceptable for a commercial process. The title reagent provides a means of separating precious metals from base metals as the latter, with the exception of copper, are not extracted. In the case of copper, the extraction is as Cu(I) rather than Cu(II). The stoichiometry of the Pd(II) extraction is Pd:TNSTH is 1:1.5. Some additional information concerning the nature of the complexes formed by the title compound and chloro-anions in alcoholic solution indicates that Cu(TNST), Ag(TNST), Pd(TNST)₂, and RhCl₃(TNST)₂ are formed. Most of the metals, with the notable exception of rhodium(III) and iridium(IV), can be stripped using a thiourea/HCl solution. The reagent TNSTH appears to be a chelating agent with donor N and S atoms.     

Cyanide and Other Lixiviant Leaching Systems for Gold with Some Practical Applications

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.     

The dissolution of gold in acidic solutions of thiourea

In order to evaluate the potential of acidic thiourea as a reagent for leaching gold, a study was made of the dissolution of gold in acidic solutions of thiourea containing various oxidants. Experiments were conducted on rotating disks of pure gold and on ground gold ores. The chemical oxidants used included iron(III), hydrogen peroxide, oxygen and formamidine disulphide; the latter reagent was formed in situ by the action of both hydrogen peroxide and dissolved oxygen on thiourea. Gold was observed to dissolve in these solutions at rates which approached the limiting diffusion controlled rate. Iron(III) as the oxidant caused the most rapid initial rate of dissolution of gold, but this rate soon decreased because of the reaction between iron(III) and thiourea; this resulted in the consumption of an excessive amount of thiourea which made the use of iron(III) as the oxidant unattractive in any ore leaching system based upon the use of thiourea as leaching agent.The results observed in the rotating disk study were applied to the leaching of crushed ores. A large proportion of the oxidant necessary for the extraction of the gold was derived from the ore itself; the remainder of the oxidant required could be supplied as hydrogen peroxide during preparation of the leach liquor, and by agitation of the slurry by a flow of air. When solutions containing 1.2 M thiourea were used it was possible to extract the gold from an ore within one hour; under these conditions the consumption of thiourea was about 1.4 kg thiourea per ton of ore treated. This figure could be reduced to 0.4 kg thiourea/ton if 0.1 M thiourea was used; complete extraction of the gold then occurred within eight hours.Gold can be leached at a much greater rate by acidic solutions of thiourea than is possible by conventional cyanidation techniques. However on economic grounds the latter technique must be preferred unless a really rapid rate of dissolution of gold is required.