Process of Preparing Aurichalcite by Ammonia Distillation Method.

In this paper, aurichalcite was synthesized by ammonia distillation method, using basic copper carbonate, basic zinc carbonate and concentrated ammonia as raw materials. The effects of process conditions on the crystal structure of aurichalcite were studied by XRD, TGA, SEM-Mapping and FT-IR. It is demonstrated that when the copper concentration is fixed at 120 g/L, and the molar ratios of copper to zinc are set at 3:2, 1:1 and 2:3, respectively, the crystals in the precipitation product consist of aurichalcite and malachite. As the molar ratio of copper to zinc decrease, the number of malachite crystals decrease. When the molar ratio of copper to zinc is 2:3, a further reduction in the number of malachite crystals is observed when the copper concentration reduce from 120 g/L to 80 g/L. Finally, under the condition that the molar ratio of copper to zinc is 2:3 and the copper concentration is 80 g/L, single-phase aurichalcite crystals are precipitated. This provides basic data for controlling the synthesis of aurichalcite by ammonia distillation method. [ABSTRACT FROM AUTHOR]