MECHANISM OF SODIUM PHOSPHITE SYNTHESIS FROM PHOSPHORUS SLIME

The selectivity and yield (based on phosphorus) of sodium phosphite pr oduction by the interaction of 60-70% phosphorus slime with a concentr ated NaOH solution have been studied as functions of the P:NaOH and P: H2O ratios in the reaction mixture, the order of adding reagents (alka li solution to a slime suspension or vice versa), and the stirring rat e. The concentrations of sodium phosphite and hypophosphite and of pho sphates in the liquid phase have been analyzed. Kinetic curves of phos phite and hypophosphite formation for various values of the parameters are presented. The possible contribution of various reactions to the process and their influence on the process selectivity are analyzed.