D_(302-Ⅱ)树脂吸附铼的性能研究及应用

Application and Characteristics of Adsorption Rhenium with D_(302-Ⅱ) Resin

针对地浸采铀浸出液低含量铼的回收,研究了D302-Ⅱ弱碱性阴离子交换树脂吸附和解吸铼的性能和机制。通过静态试验考察温度、酸度、时间对树脂吸附的影响;通过动态试验考察了溶液酸度和流速的影响,并进行了解吸剂及其浓度影响试验、抗干扰试验及树脂再生的试验;用地浸采铀浸出液通过D302-Ⅱ树脂,进行模拟回收铼试验。结果表明,D302-Ⅱ树脂对铼的吸附速率快,吸附反应速率常数k=1.6×10-3s-1,半交换期t1/2=433 s。吸附酸度在pH 2.0～5.0范围内,有利于铼的吸附。吸附平衡服从Freundish吸附等温式,吸附反应放热,反应可在常温下进行。动态上柱酸度选择为pH 2.0～5.0,流速1～2 ml.min-1,铼的吸附率可达95%以上;洗脱液选择NH4OH,25倍树脂床体积的3 mol.L-1NH4OH溶液可将铼洗脱完全。地浸采铀浸出液中的共存离子不影响铼的吸附和解吸,0.5 mol.L-1H2SO4溶液可使树脂再生。树脂对铼的静态和动态吸附容量分别为166和162 mg.g-1干树脂,对浓度低至0.03 mg.L-1铼溶液吸附和解吸,回收率可达96%～102%,表明该树脂有较好的应用前景。

The properties and mechanism of weakly basic D3o2-II resin in adsorbing and rinsing rhenium were investigated for collecting low concentration rhenium from the in-situ leach uranium solution. In static experiments, the effects of temperature, solution acidity and adsorption time were examined. In dynamic experiments, the effects of solution acidity and solution flow speed, strippant and its concentration, regeneration and recycle of the resin were determined. When making the in-situ leach uranium solution pass through D302-II resin, the simulate collecting rhenium experiments was done. The results showed that the adsorbing rate to rhenium with D302-II resin was fast, the adsorption reaction parameter was k = 1.6 x 10^-3 s^-1 , half-time of exchange was t1/2 =433s. pH 2.0～5.0 was op- timal acidity for adsorption of rhenium. Adsorption balance obeyed Freundish isothermal formula, and adsorption was exothermal reaction and could happen in normal temperature. Adsorption efficiency to rhenium beyond 95% when choosing condition was acidity pH 2.0 -5.0 and flow rate 1 -2 ml .min-1. NH4 OH was chosen as eluting solution and 3 tool.L-1 NH4 OH could elute rhenium complete- ly with volume of 25 times the volume of resin. The coexisting ions in the in-situ leach uranium solution had no disturbance to adsorbing and rinsing rhenium. The resin could be regenerated using 0.5 mot.L-1 H2SO4. The static and dynamic adsorption capacities to rheni- um were 166 and 162 mg respectively per gram resin, and its recovery ratio could reach 96%～102% even rhenium concentration at low level of 0.03 mg.L-1, indicating that the resin had better applied prospect.