Effect of sodium sulfate on the crystal growth rate of boric acid from aqueous solutions

摘要

In this work the effect of sodium sulfate on the growth rate of boric acid was studied by the Competitive Adsorption model. The temperatures and impurity concentrations range from 30 to 40 deg C and 0 to 0.40 gNa_(2)SO_(4)(centre dot)g~(-1)H_(2)O respectively. It was found that the reduction of the growth rate of boric acid by sodium sulfate can be explained because of this salt is very mobile impurity; this is due to it is adsorbed at actives sites on the crystal surface, hindering the advance of steps at the crystal surface. In addition the sodium sulfate does not inhibits completely the growth rate since it is adsorbed moderately over the crystal surface of boric acid while the sodium sulfate effect is not promoted by temperature increases.