Evaluation of selective separation of phosphorous components from plating baths using schwertmannite

Abstract

Selective separation of phosphorous ion compounds in plating baths is of great interest. Schwertmannite, found as a strong P-sorbent in our pervious works, was used for this purpose as an inorganic chemical adsorbent. The effect of pH as a significant operating parameter on P-adsorption on schwertmannite in this process as well as on the stability of schwertmannite was thoroughly investigated. The experimental results showed that the hypophosphite H 2PO2- was relatively difficult to exchange with sulfate units in schwertmannite in comparison with monoorthophpsphite H 2PO3- and monoorthophosphate H 2PO4-. Moreover, batch kinetic trials revealed that the obtained data was fairly fitted to pseudo-second-order models. © 2008 ISIJ.