The recovery of xanthate ion from metal-xanthate scum is of economical importance in the ion flotation, in which heavy metal ions are removed selectively from waste water forming a metal-xanthate scum by the addition of xanthate ion.
The present paper describes the sulfidization method by the following reaction;
Cd (RX) 2+S2-→CdS+2RX-
2RXwhere RX-means an alkyl xanthate ion. The recovery of 90% of amyl xanthate was found to be possible by the addition of Na2S 1.0 to 1.2 equivalent to Cd (AX) 2. It was recommended that the sulfidization should be applied without an extreme dewatering of the scum floated. But, even in these case where Cd-xanthate scum was obtained hydrophobic by dewatering, successful recovery was obtained by the treatment of the scum with NaOH solution prior to sulfidization.
The recovery of xanthate ion by the other method, such as NaOH treatment and oxidation by I2, was also examined.
