DHDECMP-TBP/煤油萃取 HNO_3-稀土过程中防止形成第二有机相的研究

STUDIES ON AVOIDING SECOND ORGANIC PHASE IN DHDECMP TBP/KEROSENE WITH THE EXTRACTION OF HNO_3 Gd

研究了ＤＨＤＥＣＭＰ－ＴＢＰ／煤油萃取ＨＮＯ３后形成和防止形成第二有机相的各影响因素。以Ｇｄ代表稀土，探讨了ＤＨＤＥＣＭＰ－ＴＢＰ／煤油萃取稀土时ＤＨＤＥＣＭＰ浓度、ＴＢＰ浓度、水相ＨＮＯ３浓度和温度对有机相萃取负载量的影响。结果表明：０．６０ｍｏｌ／ＬＤＨＤＥＣＭＰ－１．４０ｍｏｌ／ＬＴＢＰ／煤油能有效避免第二有机相的形成，又能满足工艺负载量的要求。

The bidentate extractant of DHDECMP(CMP) may by more practical in the treatment of high level liquid waste(HLLW) if it could be diluted by kerosene. But it is difficult to avoid the formation of second organic phase in CMP/kerosene with the extraction of HNO 3 and RE. It is advantageous to avoid the formation of second organic phase after the extraction of HNO 3 and Gd by adding TBP. The formation conditions of second organic phase are studied and the loaded capacity of RE HNO 3 is measured. The results are as follows. Raising temperature has a slight advantage to avoid formation of second organic phase. The addition of TBP is beneficial to avoid second organic phase. An organic system of 0 60 mol/L CMP 1 20 mol/L TBP/kerosene contacting with an aqueous solution containing 6 0 mol/L HNO 3 does not appear second organic phase. The extraction of RE leads to form second organic phase which does not occur when it only extracts HNO 3. It is able to avoid second organic phase with a low concentration of CMP. The higher concentration of CMP, the higher loaded capacity of Gd 3+ and HNO 3. It is advantageous to avoid second organic phase formation and also to get a higher loaded capacity of Gd 3+ and HNO 3 with increasing concentration of TBP. The loaded capacity of Gd decreases with an increasing initial concentration of HNO 3 in aqueous phase because of an increasing concentration of HNO 3 in the organic phase.The loaded capacity of Gd increases with raising temperature.To treat HLLW, the organic system containing 0 60 mol/L CMP and 1 40 mol/L TBP is recommended.