| 地球化学样品中铂族元素分析方法的研究-以铬铁矿为例 | |
| Alternative Title | A study on the analytical methods of PGE in geochemical samples: taking chromite as an example |
| 任曼 | |
| 2003 | |
| Degree Grantor | 中国科学院地球化学研究所 |
| Place of Conferral | 中国科学院地球化学研究所 |
| Degree Name | 博士 |
| Degree Discipline | 地球化学 |
| Keyword | 铂族元素 铬铁矿 分解方法 分离富集 等离子体质谱仪 |
| Abstract | 铂族元素和金银统称为贵金属，他们在石油化工、冶金、能源、地球化学、材料、环境科学、电子、航空航天、生物和医学等诸多领域中有广泛的应用。贵金属分析测试是贵金属研究与应用的必要组成部分，具有非常重要的意义。本文以铂族元素标准样品GPt-5（铬铁矿）为主要研究对象，采用阴离子交换树脂和磅共沉淀分离方法富集铂族元素，探索最佳实验条件：其次考察铂族元素的分离富集过程，探讨磅共沉泞分离富焦铂柞矛青的和理。然后通过碱熔、常压酸溶解-碱熔分解不溶物两种方法分解地质样品，在此基础上建立了电感耦奋寺离子体质谱分析钼族元素的方法，为地质地球化学样品中痕量或超痕量铂族元素含量分析提供了可行的途径，并为分析方法的进一步改进提供理论和方法依据。本文通过实验，得到以下结论：1．碲共沉淀具有操作简单，铂族元素的回收率很高能将铂族元素和贱金属彻底分离等诸多优点，便于广泛运用。2．阴离子交换树脂能很好吸附Au、R、Pd、Os、Ir（W），但对Ru、特别是Rh的回收率很低。通过在上柱前加入 SnCl_2能提高Ru、助的吸附率。3．碱熔分解能力强，操作简单，价格低廉，通过改进的分层碱熔法明显提高了Ru的准确度，对其它铂族元素没有影响；酸浸取结合碱熔对Au、Pt、Pd的分析结果较好，但是对于Ru、．Ir的结果偏低，整个流程较长。4．等离子体质谱法能快捷、精确测试铂族元素，一般用内标标准曲线法测单同位素元素Rh、Au，而用同位素稀释法测其它铂族元素。5．铂族元素经过蹄共沉淀后生成能溶于浓HNO_3和王水的产物，Au主要转化为单质Au，Pt、Pd都形成磅化物。其它铂族元素的富集机理需要进一步深入研究。 |
| Other Abstract | Platinum group elements (PGE), gold and silver together, are called precious metals. Chemical analysis of the precious metals has attracted considerable interest of researchers in many fields, such as petrochemistry, metallurgy, geochemistry, materials science, environmental science, electronics, biology, medicine, etc. in this thesis, one of Chinese reference materials, GPt-5, was used to evaluate analytical methods applied. PGE were enriched by anion exchange resin and Te coprecipitation respectively, and the optimal experimental factors and mechanisms were studied. Samples were digested by alkali fusion, and acid leaching prior to alkali fusion respectively, and some modifications were made. Based on the work above, a method was presented for determination of PGE with inductively coupled plasma-mass spectrometer (ICP-MS), which provides a way of quantitative analysis of PGE in geochemical samples, and a good basis for further work on PGE analysis in future. The conclusions of the thesis are as follows: 1. Te coprecipitation was widely applied to enrich trace or ultra-trace level PGE because of its excellent recoveries, wonderful separation efficiencies for PGE from. the base metals, and convenient handling. 2. Anion exchange resin can strongly adsorb Au, Pt, Pd, and Os, except for Ru, especially for Rh, A modified method can elevate the adsorption efficiencies of Ru and Rh, by adding SnCl2 in sample solution. 3. Alkali fusion has several advantages that are (1) 'easy attack of the; refractory samples and PGE minerals; (2) simple handling; (3) low cost; (4) better accuracy of Ru analysis with a modified alkali fusion, nafriely, sarriple and flux added in sequence while analyses of Rh, Pd, Ir, Pt weren't affected. Acid leachirig-alkali fusion is suitable to large samples and PGE minerals that are difficult to be digested completely. The analyses of Au, Pt and Pd were better than those of Ru, especially of Ir, which were lower than the certified values. Moreover, it was more difficultly handled than alkali fusion, 4. ICP-MS can determine PGE rapidly and precisely. Rh and Au are usually determined with internal calibration, while Pt, Pd, Ru and Ir are measured with isotope dilution. 5. Through Te coprecipitation, the precious metals are converted to the products that can be dissolved by concentrated nitric acid and aqua regia. Most of Au is changed to simple element, and Pt and Pd are changed to their tellurides. Further research is needed for other PGE during Te coprecipitation. |
| Pages | 66 |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | http://ir.gyig.ac.cn/handle/352002/3664 |
| Collection | 研究生_研究生_学位论文 |
| Recommended Citation GB/T 7714 | 任曼. 地球化学样品中铂族元素分析方法的研究-以铬铁矿为例[D]. 中国科学院地球化学研究所. 中国科学院地球化学研究所,2003. |
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