化学学报 ›› 1988, Vol. 46 ›› Issue (1): 69-72. 上一篇    下一篇

研究论文

用TPAC重量法测定钽的新方法

沈志洪;许荣   

  1. 中国科学院沈阳金属研究所
  • 发布日期:1988-01-15

A new gravimetric method for determination of tantalum

SHEN ZHIHONG;XU RONG   

  • Published:1988-01-15

研究了TPAC作为沉淀剂用重量法测定含铌复杂基体中钽的可能性. 结果表明,TPAFTa经分解定量地转化为五氧化二钽, 并以此为称量形式. 对20多种共存离子的吸附或共沉淀的杂以质量均小于万分之四. 随着老化时间的增加晶体明显增大, 吸附或共沉淀的杂质显著减少. 选择了最佳实验条件、详细研究了TPAFTa的物理化学性质. 钽的回收率为98.1-101.8%、镍基高温合金试样分析结果为1.80±0.027%, 可认为TPAC是钽的特效沉淀剂.

关键词: 特效试剂, 氯化物, 钽, 苯 P, 氢氟酸, 重量法, 沉淀剂, 磷翁盐

A gravimetric method was developed for the determination of tantalum in samples containing many other kinds of metal and nonmetal ions such as niobium. Tetraphenylarsonium chloride hydrochloride (TPAC) was used as a highly selective precipitant for Ta as fluorotantalate in a medium containing 0.11-0.22 mol/L NH4HF2. An ion associate, (C6H5)4AsTaF6, which is a white needle with good thermal stability is formed. The ion associate is decomposed to tantalum pentoxide after heating to 900? Twenty foreign ions present in the original sample do not interfere. Thermal properties of (C6H5)4AsTaF6 were studied in detail. The recovery of tantalum was 98.1-101.8% and the result of analyses of a nickel-based alloy was 1.80 ?0.027% Ta.

Key words: SPECIFIC REAGENTS, CHLORIDE, TANTALUM, BENZENE P, HYDROFLUORIC ACID, GRAVIMETRIC METHOD, SEDIMENTATING AGENTS, PHOSPHONIUM COMPOUNDS

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