摘要 |
<p>In a process for the treatment of a material containing zinc and soluble silica by dilute aqueous solutions of sulphuric acid at a temperature below its boiling point under atmospheric pressure, the acid is progressively added to the zinc containing material over a period of at least 3 hours, in such a quantity that the final acidity of the solution will be 1.5 to 15 g/l, while carefully maintaining the temperature at 70 DEG to 90 DEG C, thereby inducing the lixiviation of the material and simultaneously the reprecipitation of silica in a crystalline form which can readily be eliminated by filtration.</p> |