Interaction of dolerophanite Cu2OSO4 with water

The interaction of synthetic dolerophanite Cu2OSO4 (I) with water (in weight ratios of 1:10, 1:100, and 1:500) was studied at 25 and 80°C. Depending on the interaction conditions and duration, the solid reaction products are poznyakite Cu4(OH)6SO 4·H2O (II), brochantite Cu4(OH) 6SO4·xH2O (x = 0.75-1.25) (III), and antlerite Cu3(OH)4SO4·0.25H2O (IV) or mixtures of compounds II and III, II-IV, or III and IV. The formation of compound III is always preceded by the formation of compound II, which is the primary product of the interaction of compound I with water at 25°C; the same occurs at 80°C given a low CuSO4 concentration of the solution.