萃取光度法测定钨精矿中钍

Spectrophotometric Determination of Thorium in Tungsten Minerals with Extraction Separation

试样经碱熔、溶液浸取后 ,以 Mg Cl2 为载体沉淀钍 ,再经沉淀溶解、萃取和反萃 ,在 3.6mol/L 盐酸介质中对钍进行光度法测定。钍量在 0～ 2 0 μg/2 5m L浓度范围符合比耳定律。钨精矿中常见杂质元素及其含量对钍的测定无明显影响。方法的标准偏差为 5.0× 1 0 -5～ 1 .1 7× 1 0 -4 ,相对标准偏差为 1 .87%～1 0 .8%。

After alkali melting the sample and dissolving,the thorium was precipitated with MgCl 2 as carrier,through dissolving,extracting and reverse extracting, the thorium was determined in the medium of 3.6 mol/L HCl with spectrophotometry. Absorbance obeys Beer's law in the range of 0～20 μg/25 mL. The coexistent elements do not interfere with the determination of thorium. The standand deviation is 5.0×10 -5 ～1.17×10 -4 and RSD 1.77%～10 3%.