부산대학교 도서관

General data and methods for calculations of the principal parameters of semicountercurrent extraction processes are presented. Examples of solving practical problems, based on application of the semicountercurrent extraction method to treatment of waste solutions containing various valuable components, are given. Deep purification of concentrated zinc chloride solutions to remove iron impurity with the aim of utilization of fluxing solutions was carried out. The process was performed in two semicountercurrent steps filled with VIK-II extractant in the form of zinc soap, through which the initial solution containing 250 g l ZnCl and 0.25 g l FeCl was passed (β ≥ 1500). The 100-fold amount of the solution relative to the working volume of the extractor was passed. The Fe concentration in the purified solution did not exceed 0.0025 g l (<10%). A scheme of treatment of electrolytic chromic acid solution to remove iron was developed. Technical-grade HDEHP was used as extractant (β > 200). The process was performed in one semicountercurrent step filled with a solution containing 250 g l chromic acid, 8.4 g l Cr(III), and 13 g l Fe(III), through which the extractant was passed in a volume equal to 0.66 of the initial aqueous solution volume. The Fe recovery was 98.5%. With W = V, the Fe recovery was as high as 99.9%. A minor fraction of Cr (<8%) coextracted with Fe can be returned to the process. [ABSTRACT FROM AUTHOR]