HEDTA离子交换色层法分离重稀土

Separation of holmium and lutecium by ion exchange chromatography with HEDTA system

用2-羟乙基乙二胺三乙酸(HEDTA)作为淋洗剂,通过离子交换色层法分离重稀土元素钬和镥,研究室温条件下(25℃)淋洗剂的浓度、酸度、流速、柱比(吸附柱长度与分离柱长度的比值)等对钬、镥分离效果的影响。通过ICP-AES测定淋洗液浓度,绘制淋洗曲线,根据曲线中交叉区大小判断分离效果。结果表明:淋洗液的酸度是影响重稀土分离的关键因素,酸度越高,钬、镥分离效果越好,但分离周期越长;在一定范围内柱比越大,钬、镥分离效果越好,但柱比高于1-6时,分离效果下降。以钬、镥分离工艺进行镱、镥分离,也可以得到满意的分离效果。

Separation of holmium and lutecium by ion exchange chromatography with N-hydroxyethyethylene- diaminetraacetic acid （HEDTA） has been studied. The effects of some factors on the separation of holmium and lutecium have been studied in detail at room temperature, such as pH, concentration, flow rate, column ratio of HEDTA and so on. The results show that the pH value of the HEDTA is the key factor for separating holmium and lutecium, and the higher the acidity, the better the separation efficiency, but the longer the separation time needed; meanwhile, the larger the column ratio, the better the separation efficiency. But on the contrary when the column ratio is higher than 1.6 the separation efficiency is decreased. Nevertheless, the ideal processing parameters of the HEDTA for separating Ho and Lu Can be determined as concentration of 0.024 mol/L, pH of 6.00 and a flow rate of 0.6 mL/min, column ratio of 1：6. In addition, after a small reform, for example changes the column ratio from 1.6 to 1.9, the processing can also be successfully used for separating Yb and Lu.