Research and development of the process for production of extra pure ammonium aluminium sulphate I

Research and development of the process for production of extra pure ammonium aluminium sulphate, where the concentration of contaminants does not exceed 0.3 ppm for Ca, Co, Cr, Fe, Mg, Mn, Pb, Si, Ti, Zn, 2.0 ppm for Ga, and Na and 3.0 ppm for K. Evaluation of suitable raw materials; analytical methods for determination of contaminant concentrations; determination of phase equilibria in the system sulphuric acid ů ammonium sulphate ů aluminium sulphate ů water