| 摘要 |
In a method of preparing a pigment on an iron-oxide base from a sulphate solution containing in particular ferrous sulphate and derived from the leaching of zinc residues, said solution is neutralized and oxidized to simultaneously precipitate the hydrolyzable impurities together with a small quantity of iron, then the supernatant remaining liquid is separated from the precipitate and is neutralized and oxidized to precipitate most of the iron as an oxide, and the latter precipitate is treated in a basic medium to remove the small amount of sulphate ion present therein. |
