| 摘要 |
Concentrated sulphuric acid aqueous solutions, stably clear through the time, are obtained starting from diluted sulphuric acid aqueous solutions containing Mg and possibly other impurities such as Fe, Al, Cr, V and Mn, by evaporation concentration. The process is characterized in that, before filtering, the slurry obtained by evaporation concentration, is cooled down to 10 DEG -25 DEG C. and maintained at this temperature for not less than 12 hours. |
