PURPOSE: To obtain a high-quality active zinc white readily, by eluting a zinc-containing dust and/or zinc in sludge with sulfuric acid or hydrochloric acid, removing impurities in the eluted solution, followed by reacting the prepared solution with a NaOH solution under specific condition.
CONSTITUTION: A zinc-containing dust and/or zinc in sludge is eluted with sulfuric acid or hydrochloric acid to give a zinc sulfate solution or a zinc chloride solution. Na2CO3, NaOCl, etc. is added to the solution so that Fe and Mn are removed and Zn powder is added so that Cd, Pb, Cu, NiCo, etc. are removed, to purify the eluted solution. The prepared purified solution is reacted with a NaOH solution in pH 7W11 at a solution temperature not lower than 50°C, to give the desired active zinc white only by drying process without requiring distillation and calcination process.
TSUBURA TAKUMA
MURAKI MITSUO
| JPS53116296A | 1978-10-11 | |||
| JPS5361593A | 1978-06-02 |