微色谱柱分离分光光度法连续测定包头稀土精矿中铈组稀土和钍

Continuous determination of cerium-group rare earth elements and thorium in Baotou rare earth concentrate by spectrophotometry after separated with a chromatographic micro-column

通过阳离子交换树脂微色谱柱分离,建立了分光光度法连续测定稀土精矿中铈组稀土和钍的方法。含大量稀土元素和钍的1 mol/L HCl试液流经HD-8阳离子交换树脂微色谱柱,钍和稀土同时被保留在树脂上,用1 mol/L HCl淋洗杂质元素,4 mol/L HCl-2 mol/LNH4Cl洗脱液洗脱稀土,然后柱子用200 g/L NH4Cl溶液转型,水洗去多余的铵根离子,40g/L草酸铵溶液洗脱保留在柱子上的钍。从柱子洗脱下来的稀土和钍以偶氮胂Ⅲ作显色剂光度法分别测定。该法用于测定包头稀土精矿中铈组稀土和钍,相对标准偏差(RSD)分别为0.24%和2.7%。

A method for the continuous spectrophotometric determination of the cerium-group rare earth elements and thorium in Baotou rare earth concentrate was established by using cation exchange resins chromatographic micro column separation method.Thorium and rare earth elements were retained in the HD-8 cation exchange resins chromatographic micro-column when 1 mol/L HCl test solution containing large amounts of rare earth elements and thorium passed through the column.The column were washed by 1 mol/LHCl solution to elute impurity elements.Rare earth elements were eluted with 4 mol /L HCl-2 mol /L NH4Cl solution.Then,the column was restructured with 200 g/L NH4Cl solution and washed with water.Thorium was eluted with 40 g/L ammonium oxalate solution.The rare earth elements and thorium eluted from the column were determined by spectrophotometry with arsenazo Ⅲ as chromogenic reagent.The RSD for the determination of cerium-group rare earth elements and thorium in Baotou rare earth concentrate are of 0.24% and 2.7%,respectively.