product description:
Zinc oxide powder is a white or slightly yellow fine powder. Calcined zinc oxide has the characteristics of high calcination temperature, stable quality, high purity, complete specifications, and sufficient calcination. It is widely used in various industries such as rubber, ceramics, enamel, metallurgy, pesticides, magnetic materials, feed, glass medicine, plating, catalysts, electronics, paint, printing and dyeing, military industry, and coatings. Calcined zinc oxide has excellent performance and excellent quality, and is extremely suitable for ceramic and sanitary ware industries.
Production Process:
1. Leaching: Using ammonia water and ammonium bicarbonate as the leaching solvent, the zinc in the secondary zinc oxide is leached to make a zinc ammonia complex solution.
2. Oxidation to remove iron and manganese: add potassium permanganate to the leaching solution obtained in step 1 for oxidation reaction, and oxidize fe;2+;, mn;2+; in the leachate into insoluble fe;3+;, mn;4+; precipitated out and was removed by filtration to obtain a filtrate.
3. Zinc powder replacement to remove copper, cadmium and lead: add zinc powder to the filtrate obtained in step 2 for replacement reaction, so that copper, cadmium and lead are precipitated and removed by filtration to obtain a purified solution.
4. Ammonia distillation: send the purified solution obtained in step 3 into the ammonia distillation tank to distill ammonia, and directly pass water vapor above 100°C into the purified solution under negative pressure, so that the zinc ammonia complex is decomposed into basic zinc carbonate by heat , ammonia and carbon dioxide to obtain a basic zinc carbonate suspension.
5. Calcination: Wash the basic zinc carbonate suspension obtained in step 4 with water, filter, and send the filter residue to a rotary kiln for calcination at 1000-1200°C for 2-5 hours to obtain calcined zinc oxide. Zinc oxide calcined at high temperature is light yellow, and its melting point is 1975°C. Calcined zinc oxide is an important raw material of ceramic chemical flux, especially in architectural ceramic wall and floor tile glazes, low-temperature enamel glazes and ceramic pigments. It is also widely used in artistic ceramic glazes.
