纳滤处理重铀酸铵沉淀母液的研究

Treatment of Ammonium Diuranate Mother Liquor by Nanofiltration

摘要: 重铀酸铵沉淀母液是一种含常量硝酸铵的高盐分废液，目前主要采用硅胶吸附法进行处理，产生的二次废物量大。纳滤膜能透过硝酸铵等单价盐，而截留铀等以多价离子或大体积分子形态存在的组分。本文在铀浓度为40 mg/L、硝酸铵浓度为35 g/L的模拟重铀酸铵沉淀母液中，开展了纳滤技术处理重铀酸铵沉淀母液的研究。结果表明：在所筛选的4种商用纳滤膜中，NF270具有最优的综合性能；当跨膜压差为1.0 MPa、膜面流速为40 cm/s、料液温度为25 ℃时，NF270纳滤膜的铀截留率为97%，与之对应的透膜通量为60 L/(m²•h)。

Abstract: Ammonium diuranate (ADU) mother liquor is a high salt content liquid waste. At present, silica gel adsorption method is adopted to treat it, but large amount secondary wastes will be produced in this process. NH₄NO₃ could easily permeate nanofiltration (NF) membrane, while uranium will be rejected by the membrane. In this paper, the study of uranium retention by NF membrane was carried out in simulated ADU mother liquor with 40 mg/L uranium and 35 g/L NH₄NO₃. The results show that NF270 membrane has the optimum performance among the four chosen commercial membranes. When trans-membrane pressure is 1.0 MPa, cross flow velocity is 40 cm/s, and feed temperature is 25 ℃, the uranium rejection rate by NF270 membrane is 97% and the permeate flux reaches 60 L/(m²•h).