含TOA微胶囊对Cr_2O_7^(2-)萃取的研究

STUDY ON EXTRACTION OF Cr_2O_7^(2-) WITH THE M1CROCAPSULE CONTAINING TOA

用乙基纤维素作膜材将三辛胺(简称TOA)微胶囊化,用于萃取酸性水溶液中的Cr_2O_7^(2-)离子.通过搅拌法萃取实验表明,TOA被微胶囊化后对铬离子仍具有较高的萃取速度,实验测定渗透系数为6.78×10^(-6)m/min,并能有效地防止乳化现象.将微胶囊制备成填充柱对Cr_2O_7^(2-)进行萃取实验,对外相水的流速、微胶囊粒径、柱的重复使用次数与萃取客量的关系进行了研究.当粒径为100—200μm,流速为30ml/min,每毫升微胶囊可萃取铬47.5mg/ml,填充柱重复使用15次,芯材TOA无明显地损失.用NaOH水溶液对已达到萃取饱和的填充柱进行反萃取,可以将含铬190ppm的溶液浓缩到6×10~4ppm以上.

Trioctyl amine (TOA) was microencapsulated with Et-cellulose for the film material. And the microcapsule was used in extraction of Cr2O72- in acid solution. The results show that the microcapsule containing TOA has high extractive efficiency to the ion and its permeable coefficent to the ion was about 10-6m ·min-1. Therefore, it is available to prevent the water and TOA from em unification. The microcapsule was stuffed into a column and used for extraction of the ion. We investigated the relation between flowing velocities of the water phase, the diameters of the microcapsule, and the repeatedly used time of the column, and extraction capacities. When the diameters were 100 to 200um, the flowing velocity was 30 ml · min-1, the extraction capacity was about 47. 5mg · ml-1. After the microcapsule was used repeatedly 15 times, the lost amount of TOA is ignore. The results of stripping of the ion from TOA into NaOH solution show that it could concentrated chromium of 190ppm to over 6×104ppm.