串级微色谱柱分离富集光度法连续测定矿石中痕量铀和钍

Sequence Determination of Trace Uranium and Thorium by Preconcentration with Counter Current Micro-Column Extraction

采用串级法将D206阴离子树脂微色谱柱与HD-8阳离子交换树脂微色谱柱联用,连续测定了矿石中的痕量铀及钍元素。在4mol/L HCl介质中铀以阴离子形式存在,首先被首级微色谱柱D206阴离子树脂吸附分离,适量的水即可将其洗脱。而钍呈阳离子形态存在,被HD-8阳离子交换树脂吸附分离。用氯化铵溶液转型后,3ml 40g/L草酸铵溶液即可洗脱HD-8阳离子交换树脂中的钍。实现了痕量铀和钍的连续测定。方法简便、快速,适合于含铁、稀土较高的矿石样品中痕量铀、钍的的连续测定。

Anion ion-exchange resin D206 and cation ion-exchange resin HD-8 were connected for Counter Current Extraction and determination of trace uranium and thorium in ore. In 4mol· L^- 1 hydrochloride acid media, the uranyl ion in the form of UO2 Cl4^2- can be extracted firstly by D206 resin and the thorium can be extracted by HD - 8 resin. The water and ammonium oxalate 40g·L^-1 was used to elute the uranium and thorium from D206 and HD-8, separately, and followed by determination spectrophotometrically using Chlorophosphonazo Ⅲ and ArsenazoⅢ as chromogenie reagent. The separation methodology was tested using national standard rock sample （GBW04119, GBW04121 ） for the Counter Current Micro-Column Extraction and determination of Th and U. This simple preeoneentration technology can be applied for sequence and rapid determination of trace uranium and thorium in high ion and REE bearing ore.