Extraction of gold, palladium, and platinum from acidic media with cyclic sulfoxide derivative

The extraction of gold （Ⅲ）, palladium （Ⅱ）, and platinum （Ⅳ） from the acidic media with the cyclic sulfoxide derivative of α-dodecyl-tetrahydrothiophene 1-oxide （dtmso） was investigated. Gold （Ⅲ）, palladium （Ⅱ）, and platinum （Ⅳ） could be separated from the acidic media with suitable sulfoxide concentration and acidity. The extraction reaction of gold （Ⅲ）, palladium （Ⅱ） or platinum （Ⅳ） is exothermic when dtmso is used as an extracting reagent. The coordination number was studied by the slope method. The results indicate that, in high acidity, the dtmso coordination number for extracting gold （Ⅲ） or palladium （Ⅱ） is 3, and that for platinum （Ⅳ） is 2. UV and FT-IR spectra were used to analyze the structure of the complex. Gold （Ⅲ） is coordinated with the oxygen atom in S=O group in dtmso, and palladium （Ⅱ） or platinum （Ⅳ） is coordinated with the sulfur atom in S=O group in dtmso.

A study on the composition and structure of cyclic sulfoxide derivative palladium(Ⅱ) complex

The composition and structure of cyclic sulfoxide derivative Pd(IT) complexwere investigated. The coordinated number was studied with slope method. The coordination number is2 in lower acidity, but it is 3 in higher acidity. Four methods, UV (ultraviolet) spectra, FUR(Fourier transform infrared) spectra, ~1H-NMR (nuclear magnetic resonance) spectra, and ^(13)C-NMRspectra, were used to determine the coordinated atom in complex. Pd is coordinated with O and S atomin S=O group in lower acidity media. The conversion of coordination bond appears with an increasingtime. Pd is coordinated with S atom in S=O group in higher acidity media, and inter-ligand-transferreaction occurs.

Mechanism of extracting palladium(Ⅱ) with cyclic sulfoxide derivatives

The extraction ability of palladium(Ⅱ) from acidic media with cyclic sulfoxide derivatives-α Dodecyl tetrahydrothiophene 1 Oxide (DTMSO), α octyl tetrahydrothiophene 1 Oxide (OTMSO) and α butyl tetrahydrothiophene 1 Oxide (BTMSO) was investigated. The extracting efficiency of cyclic sulfoxide derivatives decreased with the increasing of acidity in the lower acidity, and the efficiency became stable with the change of acidity in the higher acidity. The extraction reaction of palladium(Ⅱ)with DTMSO is exothermic, and extraction reaction of palladium(Ⅱ)is endothermic when OTMSO or BTMSO were used as extracting reagents. The coordination number was studied by slope method. The results indicate that coordination number is 2, and the composition of complex is (PdCl 2)·2RTMSO. FT IR spectra were used to analyze the structure of complex and coordinated atom in complex, Pd is coordinated with both oxygen and sulfur atom in S=O group in sulfoxide derivatives.

Extraction of palladium(Ⅱ) with OTMSO from acidic media

The extraction of palladium(Ⅱ) from acidic media with cyclic sulfoxidedervva-tive-α-octyl-tetrahydrothiophene-1-oxide (OTMSO) was investigated. The extraction efficiencyof palla-dium(Ⅱ) with OTMSO is 97.1% at 0.3 mol·L^(-1) OTMSO. The plots of the extractionefficiency for palla-dium(Ⅲ) appear to lie on a convex curve having a minimum of extractionefficiency at 1-2 mol·L^(-1) HCl. The extraction reaction of palladium(Ⅱ) with OTMSO isendothermic, and ΔH_(OTMSO)~θ = 12.2 kJ·mol^(-1). The coordination number was studied with slopemethod. The result indicates that coordination number is 2. FT-IR spectra were used to analyze thestructure of complex and coordinated atom in complex. Pd is coordinated with both oxygen and sulfuratom in S=O group in OTMSO. The situation and intensity of peaks contributed by complex preparedfrom various acidity were different. The recovery of palladium(Ⅱ) with OTMSO from scrap containingpalladium was discussed. After silver and bismuth were removed, the feed solution was extractedthree times by 40% (volume fraction) OTMSO-kerosene. The loaded organic phase was scrubbed threetimes, and stripped three times by 2 mol·L^(-1) NH_3·H_2O solution. The total recovery ofpalladium was 99.8%, and the purity of palladium was 99.8 %.

Extraction of palladium(Ⅱ) from hydrochloride solutions with 2-n-octyl-4-isothiazolin-3-one as novel extractant

Solvent extraction of palladium （Ⅱ） from hydrochloric acid solution with 2-n-octyl-4-isothiazolin-3-one （OIT）/cyclohexane was studied. Effects of different parameters on extraction efficiency were evaluated. 99.96 % and 98.26 % palladium （Ⅱ） could be effectively extracted with 0.018 mol·L^-1 OIT/cyclohexane of 0.1 and 4.0 mol·L^-1 HCl medium, respectively. Nonpolar solvent and low acidity could improve the extracting efficiency, and successfully strip palladium （Ⅱ） from the loaded organic phase was achieved with 0.5 mol·L^-1 （NH2）2CS solution. It was proposed that the extraction of Pd com-plexes from HCl medium proceeded through the ion-association mechanism by slope method, NMR and FF-IR spectra.

Extraction of uranium(Ⅵ) with di-(2-ethylhexyl) sulfoxide in toluene

The mechanism of extraction uranium(Ⅵ) with di(2-ethylhexyl) sulfoxide (DEHSO)from aqueous nitric acid media has been studied. The influence of the concentrations of nitricacid, cxtractant, salting-out agent, temperature and complex anions (C2O24-) on the distribution ratio was studied.

The pilot test of Pt-Pd and Pt-Rh feeds extracted and separated with a new sulfoxide extractant

Platinum, palladium and rhodium of the raw feeds extracted and separated with a new sulfoxide extractant （MSO） were studied in the paper. The pilot test results showed that the percentage extractions are more than 99% for platinum and palladium in Pt-Pd feed, and the percentage strippings are 100% and 99.2% with HCl and ammonia, respectively. The ratio of palladium to platinum is 0.0016 in stripping platinum solution, and the ratio of platinum to palladium is 0.0020 in stripping palladium solution. The percentage extraction of platinum is 99% in Pt-Rh feed, and the percentage stripping is 100%. The ratio of rhodium to platinum is 0.0002 in stripping platinum solution. Therefore, platinum, palladium, and rhodium feeds are separated effectively with MSO.

吡啶-氧杂二氮唑在钯离子萃取分离中的应用

高放废液中钯的萃取分离对贵金属钯资源的回收利用和核燃料循环中的玻璃固化过程都有重要意义,其关键在于高效高选择性萃取体系的开发和设计。基于氮杂环配体高效配合钯离子的特性,设计合成了一种具有吡啶-氧杂二氮唑结构的萃取剂6,6′-((4-异丁氧基吡啶-2,6-二基)双(1,2,4-氧杂二氮唑-5,3-二基))双(4-异丁氧基吡啶甲腈)(T2),用于酸性条件下钯离子的选择性萃取。以间硝基三氟甲苯为稀释剂且在1 mol/L 2-溴己酸存在下,配体T2对钯离子体现出较好的萃取能力。萃取动力学表明2 h即可萃取68%的钯进入有机相。该体系适用酸度广泛,在0.2~4 mol/L硝酸条件下均对钯展现出定量萃取,表明其优异的酸稳定性。此外,在多种阳离子共存的条件下,该体系能高选择性地分离萃取出钯离子,表明其良好的实际应用潜力。研究不仅提供了一类高效的钯萃取剂,更为其它新型钯萃取剂和萃取体系的开发提供了重要参考。

石油亚砜Ⅱ(2)萃Pd(Ⅱ)机理的研究

研究在盐酸介质中石油亚砜Ⅱ(2)萃Pd(Ⅱ)的机理,并分析水相中影响(Ⅱ)萃取的主要因素及其原因,考察不同盐酸浓度下亚砜的萃合方式,盐酸浓度的萃钯(Ⅱ)实验曲线及其对贵金属萃取分离的意义,还测定了萃合物组成.

PSO-ⅢA(3)亚砜萃取金钯铂的差异及其解释

研究了盐酸介质中PSO-ⅢA(3)石油亚砜(自制)萃取Au、Pd、Pt的性能,提出萃取分离Au、Pd、Pt的可能性.探讨其萃取机理,并从机理的角度解释亚砜萃取Au、Pd、Pt能力上的差异.

石油亚砜萃取铟的机理研究

研究表明，在盐酸介质中，石油亚砜萃取锢的机理与水相酸度有关．低酸度时，亚砜通过氧原子与Ｉｎ（Ⅲ）配位生成萃合物ＩｎＣｌ３．２ＰＳＯ．Ｈ２Ｏ，高酸度时，亚砜则通过氧原子配位溶剂化，并与Ｉｎ（Ⅲ）反应生成离子缔合物［ＰＳＯ→Ｈ］＋［ＩｎＣｌ４．２ＰＳＯ］－

合成亚砜BSO萃取钯铂机理研究

研究了合成亚砜BSO萃取Pd、Pt、Cu、Fe和Ni的性能。结果表明低酸度时,Pd2+几乎完全被萃取,其它金属的萃取率极低。钯易于从Pt、Cu、Fe和Ni金属中分离出来,且反萃容易。利用红外光谱研究了BSO萃取Pd和Pt的机理。低酸度时,在钯萃合物的红外光谱中,出现2个新的吸收峰(1122和931cm-1),表明BSO通过硫和氧原子以中性配位机理萃取钯;高酸度时,没有新的红外吸收峰出现,表明BSO以离子缔合机理萃取钯。BSO以离子缔合方式萃取铂。

亚砜KS0与Pd（Ⅱ）萃合物的组成及结构研究

用斜率法、等克分子比法和饱和容量法确定了亚砜ＫＳＯ－ｐｄ（Ⅱ）萃合物组成（Ｐｄ）／（ＫＳＯ）＝１：１，利用远红外光谱、紫外、可见光谱及萃合物元素分析确定了萃合物结构为桥式双核结构ｔｒａｎｓ－（ＰｄＬＣｌ＿２）＿２。借助于萃合物红外光谱分析确定亚砜ＫＳＯ分子中硫氧原子均能与Ｐｄ（Ⅱ）配位。

石油亚砜在硫脲浸金液中萃取Au(Ⅰ)之机理

研究表明石油亚矾在硫脲浸金液中萃金属于中性络合溶剂化机理。萃合物的组成为Au[SC(NH_2)_2)_2^+·1/2SO_4^(2-)·3PSO。石油亚砜通过亚砜基上硫原子与金(Ⅰ)配位。

聚乙二醇-硫酸铵-二溴羧基偶氮氯膦体系萃取分光光度法测定微量钯

研究了聚乙二醇-2000水溶液在硫酸铵存在下分为液-液两相的条件和二溴羧基偶氮氯膦与Pd（Ⅱ）反应生成的配合物在该萃取体系两相间的分配行为，实现了Pd（Ⅱ）的定量萃取分离。在此基础上建立了非有机溶剂液-液萃取分光光度法测定微量Pd（Ⅱ）的新方法。该方法的检出限为0．03mg／L，线性范围为0．09～2．0mg／L，在最佳实验条件下，萃取率达94％。方法用于铂钯二次精矿和人工合成样品中微量钯的测定，相对标准偏差（RSD，n=5）≤2．4％，加标回收率为96％-103％。

二烷基亚砜—胺二元系从氰化物溶液中萃取金

研究了二烷基亚矾—胺从氰化物溶液中萃取金的反应中,亚矾和胺的化学结构以及萃取条件对萃金效果的影响。结果表明二烷基亚砜—仲胺体系在适当条件下可从较高pH(10～11)的氰化物溶液中有效地萃取金,并能与大多数共存金属元素达到很好的分离。此外,还具易于反萃的优点,是有应用前景的新型萃取体系。

石油亚砜的极性与萃取钯铂性能的关系

研究了石油亚砜(PSO-ⅢA,PSO-ⅢB)的极性与萃取钯铂性能的关系,并从萃取机理进行了解释。

不对称亚砜BSO萃取分离钯、铂的研究

研究了不对称亚砜(BSO)萃取钯、铂的行为及机理。结果表明:酸度对钯、铂的萃取率和萃取机理有很大影响。在低酸度时,BSO萃取钯主要是中性配位萃取机理,对钯的萃取率接近100%,而对铂的萃取率极低;在高酸度时,BSO萃取钯、铂的机理都是离子缔合萃取,且对钯、铂的萃取率均已接近100%。利用BSO在低酸度下萃取钯、铂可以实现钯、铂的有效分离。氨水为钯的高效反萃剂,蒸馏水为铂的高效、经济反萃剂。

亚砜KSO萃取Pd（Ⅱ）的机理

在前文［１］证实亚砜（ＫＳＯ）与Ｐｄ（Ⅱ）形成萃合物为双核ｔｒａｎｓ－（ＰｄＬＣｌ＿２）＿２的基础上考察氢离子浓度、氯离子浓度以及亚枫ＫＳＯ浓度对萃取分配比的影响，推测了ＫＳＯ萃取Ｐｄ（Ⅱ）的机理。

TBP-Pd(Ⅱ)-HCl萃取体系微乳的生成及溶液聚集态的谱学研究

采用动态激光光散射(DLS)、Fourier变换红外光谱(FTIR)、核磁共振波谱(31P-/1H NMR)等谱学技术,研究了TBP-Pd(Ⅱ)-HCl萃取有机相中微乳的形成以及溶液聚集态结构的变化。结果表明:(1)伴随钯的萃取,TBP萃取有机相中形成微乳。(2)萃取有机相中酸含量的变化导致溶液结构发生相应改变:胶团聚集体平均流体力学半径随有机相中酸含量的增加先增大而后又减小。微乳"内核水"的O—H伸缩振动吸收谱带逐渐宽化,与邻近的C—H伸缩振动区形成交迭,且有机相含酸量越高,交迭程度越大。水分子O—H—O弯曲变角振动吸收峰形也发生很大变化。TBP的PO伸缩振动明显向低频移动。核磁共振31P化学位移与活泼氢1H化学位移变化行为相反,说明TBP分子与酸和水分子发生缔合,形成RP=O.H+或RP=O.H3O+,并与PdCl42-存在相互作用。(3)有机相形成微乳水团后,由于大量H+的进入,微乳水团中酸浓度表现出明显的"增浓效应"。微乳水池内部微观环境的改变是导致钯萃取行为变化的主要原因。