含铱废料直接制备高纯铱粉的研究

采用碱熔融活化溶解-氯化铵沉淀-硫化沉淀-氧化再沉淀-煅烧氢还原-混酸煮洗联合工艺，用铱废料直接制备高纯铱粉。结果表明，含铱废料经碱熔融水浸、王水溶解，得到的铱溶液通过氯化铵沉淀、硫化沉淀除杂，氧化再沉淀、煅烧-氢还原得到的金属铱经混酸煮洗，进一步去除杂质元素，获得纯度99.999%的高纯铱粉。     

分子识别技术分离提纯钯的工艺实验

采用分子识别材料SuperLig^ò2从含铂钯的溶液中选择性分离钯,钯吸附率大于99%,吸附、洗脱过程钯的直收率为95.87%,总收率为98.04%;得到的洗脱液氧化处理后生成钯沉淀,再经水合肼还原即可得到纯度为99.99%的钯粉。与传统的沉淀分离工艺相比,分子识别技术的生产流程短、铂不容易分散、操作方便、三废量少。     

二氯二氨合钯用氧化法制备氯化钯的研究

研究了以二氯二氨合钯为原料,用盐酸溶液加热溶解使其转化成氯钯酸铵,以氯酸钠作为氧化剂氧化除去铵,氢氧化钠沉淀钯得到纯氢氧化钯,再用浓盐酸溶解之并浓缩结晶得到纯氯化钯的制备工艺。研究结果表明:当每公斤Pd(NH3)2Cl2的氯酸钠用量为2.48kg,HCl(36%)用量为2.75L,钯的浓度为20g/L,氧化时间60min,氧化温度100℃,沉钯pH=10,沉降时钯的浓度为10g/L,洗涤3次,其氢氧化钯的纯度>99.9%(钯的含量75.64%)。制备的氯化钯中钯含量>59.5%,其中铁含量<0.002%,硝酸根含量<0.02%,氯化钯中的杂质总量<0.05%。直收率>99.9%。另外采用此工艺不产生NO等的污染。     

水合肼-氢还原重量法测定硫酸钯溶液产品中的钯含量

采用水合肼作还原剂,还原后的金属钯黑再通氢还原纯化,建立了水合肼-氢还原重量法测硫酸钯溶液中的钯含量。在优化后的测定条件下,测定了4.00%~14.50%含量的钯,分析结果的极差、相对标准偏差(RSD,n=6)分别为0.02%、0.062%~0.16%。与GB/T 23276-2009法相比较,测定结果的准确度和精密度更高。     

从沉钨钼后液中制备高纯铼酸铵

沉钨钼后液首先经氯化钾沉淀反应得到铼酸钾,其次采用离子交换法将铼酸钾溶液转为高铼酸溶液,最后经氨水中和-浓缩结晶-重结晶得到高纯铼酸铵。结果表明：向沉钨钼后液中加入KCl固体再浓缩析出KReO₄白色晶体,其主要杂质Na、Ca、Fe、Cl含量均小于1%,特别是W、Mo含量均小于0.1%,且Re结晶率可达94%~98%。采用动态法脱K,选用C160(H^₊型)树脂,当KReO₄溶液pH为中性,料液流速控制为2 BVs.h^_-1时,C160树脂对K^₊穿透容量和饱和容量分别为117.865 g.L^_-1和128.385 g.L^_-1,且树脂利用率达到91.81%;所得纯HReO₄溶液中K、Na、Ca、Fe、W、Mo、Mg浓度均降至0.5 mg.L^_-1以下。通过添加优级纯氨水中和HReO₄溶液,控制终点pH为7~8,再经浓缩结晶+1次重结晶,所得铼酸铵纯度达到99.99%以上,其SEM形貌为树枝状。     

银钯合金靶材废料的综合回收研究

采用硝酸浸出-选择性分离钯-沉淀分离铟-抗坏血酸还原银的湿法工艺分离回收银钯合金靶材废料中贵金属银钯。结果表明,用4 mol/L硝酸,90℃加热,120 min即可完全浸出所有金属;浸出液采用理论量1.6倍的丁二酮肟可以完全沉淀分离99.9%以上的钯;将滤液调节至pH=5,其中的铟、铁、镓等可被沉淀分离得到纯净的硝酸银溶液;控制富银液pH 8~10,用0.8倍银质量的抗坏血酸可将银完全还原,银粉直收率大于96%。     

蒸发材料用高纯金的制备研究

采用盐酸+氯酸钠溶解-沉淀除杂-选择性液相还原-煮洗等联合工艺制备蒸发材料用高纯金并进行应用性能分析。结果表明,溶解后的金溶液采用氢氧化钠调整溶液pH值去除部分杂质元素;金溶液采用还原剂选择性还原;得到的金粉用稀硝酸、盐酸煮洗,获得纯度99.999%以上,碳和硫含量均小于1×10~(-6)的高纯金;以制备的高纯金为原料加工的蒸发材料清洁性好,可作为集成电路芯片制造用蒸发材料。     

钯和铂中痕量杂质元素锭状固体标准样品制备的研究

详细介绍了制备钯和铂锭状固体标准样品的实验方法。该固体标样可用于测定固体样品的电弧/火花发射光谱、火花烧蚀发射光谱和辉光放电质谱(GD-MS)等仪器分析方法。在标准样品的制备过程中,首先将含有33种待测杂质元素的钯或铂溶液进行沉淀和共沉淀得到“贮备”粉末,然后将粉末与99.999%纯金属钯或铂进行熔炼,从而获得杂质元素含量在(5~10)×10-6的固体标准样品。部分杂质元素在沉淀和共沉淀过程、热处理环节会发生损失,在最终得到的锭中,钯标准样品有25个元素、铂标准样品有26个元素得到定量回收,发生污染的元素主要包括金、硼、铁和硅。     

控制电位还原法回收氯化浸出液中的贵金属

以亚硫酸钠为还原剂,研究采用控制电位还原法回收氯化浸出液中的贵金属。结果表明:当控制金还原电位为530~550mV时,氯化浸出液中98%以上的Au将被还原沉淀至粗金粉中,同时Pt、Pd和Te基本不被还原沉淀,所得粗金粉中Au含量在98%以上,Se、Te、Cu和Pb等杂质的含量均低于0.10%(质量分数),而且该金还原电位对不同Au浓度或酸度的氯化浸出液都具有良好的适应性;然后当控制铂钯还原电位为390~420mV时,金还原后液中的Au、Pt和Pd将被还原沉淀至1mg/L以下,而Te基本不被还原,所得铂钯精矿中贵金属含量高、杂质含量少,且所确定的铂钯还原电位对不同铂钯浓度或酸度的金还原后液以及反应温度均具备较好的适应性。可见,通过控制电位还原,可将氯化浸出液中贵金属选择性沉淀并与其他元素初步分离。     

辉光放电质谱法测定纯铂中杂质元素

采用辉光放电质谱法(GDMS)测定纯铂中杂质元素含量，获得了仪器最佳工作条件，并对比了不同样品制备方式对测定结果的影响。结果表明，GDMS对大部分杂质元素的检出限低至10^-9量级，对含量在10^-6的杂质元素，测定相对标准偏差(RSD)在10%以内，可满足高纯铂的测定要求。与ICP-AES和ICP-MS测定结果对比表明，采用仪器提供的相对灵敏度因子(RSF)所得到的半定量结果与前二者存在一定的偏差，有必要采用标准样品进行RSF的校准。纯铂样品采用金属片、铟片粘附或粉末压片均可得到相似的检测结果，其中粉末压片法在标样制作中具有较好的应用前景。     

从钯银合金废料中回收钯的实验研究

以钯银合金废料为原料,采用硝酸溶解-盐酸沉银-二氯二氨络亚钯法提纯-水合肼还原工艺回收钯。结果表明,当浓盐酸用量为2 m L/200 m L混合酸液,反应时间1 h时,银沉淀率为99.98%;当氨络合和盐酸酸化沉淀过程溶液最佳p H分别为8和1.5,并经温水洗涤3次,二氯二氨络亚钯纯度达到99.99%以上;该工艺钯回收率大于90%,并制得纯度大于99.99%的海绵钯,其平均粒径不大于0.5μm。     

Copper patterned polystyrene panels by reducing of surface bound Cu (II)-sulfonyl hydrazide complex

A modified electroless metal deposition method has been developed for copper plating of polystyrene (PS) surfaces. The modified procedure avoids the plasma conditioning and surface activation steps in the classical electroless metal plating process.First step of the present procedure is chlorosulfonation of PS surface by soaking into chlorosulfonic acid, yielding chlorosulfonated surface with density of 0.046-0.110 mmolcm^− 2 depending on contact time (10-60 min).In the second step chlorosulfone groups on the surface are converted to sulfonyl hydrazides almost quantitatively by reaction with hydrazine solution (80%). Green Cu (II)-sulfonylhydrazide complex is formed at the surface, in the third step, by interaction with ammoniacle Cu (II) solution at room temperature. The copper in the complex is reduced rapidly in the fourth step, by immersing the specimen into 5% of hydrazine solution. The elemental copper deposited onto the surface serves activating sites to accumulate more (5-7 mg per cm²) elemental copper from electroless copper solutions in the final step. The present method avoids the surface activation with palladium and allows preparing copper patterns with reasonably high pull-off strengths (3.77 Nmm^− 2) on PS panels.In the study the copper deposition has been investigated using standard analytical procedures, X-ray photoelectron spectrometry (XPS) and Scanning Electron Microscopy.     

Selection of reductants for extracting selenium and tellurium from degoldized solution of copper anode slimes

This paper focused on investigating high-efficient reductants of recovering selenium and tellurium from degoldized solution of copper anode slimes. Firstly, the effect of various reductants on recovery rates of Se and Te was investigated based on thermodynamic analysis of various metallic ions in degoldized solution. Secondly, the single factor experiments were made to investigate the effect of the process parameters on recovering Se and Te with hydrazine hydrate. Finally, the hydroxylamine hydrochloride was added to intensify the extraction efficiencies of Se and Te. The results indicated that hydrazine hydrate was the most suitable reductant, and the recovery rates of Se and Te are 71.23% and 76.50%, respectively; the recovery rates of Se and Te were 92.07% and 97.81%, respectively, under the optimal process conditions of hydrazine hydrate dosage of 0.2133 mol/L, H⁺ concentration of 4.305 mol/L, reaction temperature of 85 °C and reaction time of 5 h; the recovery rate of Se was 97.59%, and that Te reached up to 100% when hydroxylamine hydrochloride dosage was 1.5116 mol/L.     

水合肼还原-重量法测定氯化浸金液中金含量

采用水合肼还原氯化浸金液(氯金酸溶液)中的金，称量析出海绵金的质量，实现了海绵金的准确测定，考查了反应温度、试液金浓度、水合肼使用量等对于测定结果的影响，并与其它测定方法进行了比对。调整氯化浸金液金浓度约为40 g/L，加入水合肼(用量1.5 mL/g-Au)还原后加热溶液微沸20 min，损失在滤液中的金量可忽略。测定结果的相对标准偏差(RSD)小于0.2%。方法操作简便，可满足生产分析的要求。     

活化-溶解法规模化生产硝酸钯的工艺研究

通过对稀王水控量溶解钯的条件、活性钯粉的还原条件、硝酸溶解钯的条件研究,解决了部分钯粉不能完全溶解的困难,建立了活化-溶解法规模化生产硝酸钯的工艺条件。对活化前后钯粉的粒度、比表面积和表面形貌分析的结果表明,活化后钯粉颗粒变小,表面积增大,扫描电镜显示,活化后钯粉粒径变小,呈海绵状,钯的溶解活性提高,有利于钯粉的完全溶解。     

Separation of precious metals using selective mesoporous adsorbents

The mesoporous NH₂-MCM-41 adsorbent prepared by grafting aminopropyls on MCM-41 is selective towards gold and palladium adsorptions and can separate these precious metals from complex solutions containing other metal ions such as cobalt, nickel, copper and zinc. Adsorption is rapid and the adsorbent’s capacity for gold is better or comparable to most carbonaceous adsorbents including activated carbons. Furthermore, NH₂-MCM-41 can separate palladium from gold solution at pH1.0 with excellent selectivity and capacity. Thus, it is possible to design a two steps separation process for the separation of palladium and then gold from the complex solution. A simple acid wash was sufficient to recover the adsorbed palladium and gold as concentrated, high purity (i.e., > 95%) metal salt solutions and the regenerated adsorbent was reused without lost of performance.     

双[2-(对甲苯基)吡啶]乙酰丙酮合铱的合成及结构表征

以水合三氯化铱为原料,2-(对甲苯基)吡啶作环金属配体、乙酰丙酮作辅助配体合成了双[2-(对甲苯基)吡啶]乙酰丙酮合铱[(tpy)2Ir(acac)],通过质谱、氢谱、X射线单晶衍射分析表征手段确证了其分子结构。通过紫外可见光谱和光致发光光谱分析,研究了该配合物的光物理性能,在410和461 nm处有单重态和三重态吸收,在516 nm处有较强的绿光发射,表明该配合物是一种绿光材料。     

水合肼蒸发器加热管腐蚀原因分析及防护方法

叙述了水合肼蒸发器加热管的腐蚀情况与腐蚀特征，分析其腐蚀原因主要是空泡腐蚀，水合肼溶液的化学腐蚀又加剧了空泡腐蚀，提出了解决加热管空泡腐蚀的主要途径。     

Extraction of palladium(Ⅱ) with OTMSO from acidic media

The extraction of palladium(Ⅱ) from acidic media with cyclic sulfoxide derivative-α-octyl-tetrahydrothiophene-l-oxide (OTMSO) was investigated. The extraction efficiency of palladination number was studied with slope method. The result indicates that coordination number is 2. 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 OTMSO .The situation and intensity of peaks contributed by complex prepared from various acidity were different. The recovery of palladium(Ⅱ) with OTMSO from scrap containing palladium was discussed. After silver and bismuth were removed, the feed solution was extracted three times by 40% (volume fraction) OTMSO-kerosene. The loaded organic phase was scrubbed three times,and stripped three times by 2 mol@L-1 NH3·H2O solution.The total recovery of palladium was 99.8%,and the purity of palladium was 99.8%.