We attempted to produce calcium tungstate (CaWO4) using metal corrosion reaction, and compared it with that produced by solid-state reaction. Tungsten corroded in hydrogen peroxide containing ammonia and eventually dissolved completely. When calcium was added to this solution, the calcium corrosion reaction proceeded easily without the addition of a corrosion-accelerating substance. Oxide powder was obtained by drying and calcinating the above mixed solution. It was identified that the powder which was calcinated at 973 K was CaWO4 and the particle size was 1.8 ~ 18.5 μⅿ. In the case of the solid-state reaction method using tungsten oxide and calcium carbonate as raw materials, CaWO4 powder with particle sizes ranging from 0.4 μⅿ to 22.0 μⅿ was synthesized at 1173 K.
Sasaki et al. (Thu,) studied this question.