| 摘要 |
PURPOSE:To readily and purify a waste liquor from acid cleaning with hydrochloric acid, by adding iron to the waste liquor of acid cleaning generated in acid cleaning of steel with hydrochloric acid, collectively separating and removing most of Al, Cr, Cu and P contained in the waste liquor as an insolubilized substance. CONSTITUTION:Iron (e.g. high-purity small-gage wire or iron powder) is added to a waste liquor from aid cleaning with hydrochloric acid generated in acid cleaning of steel with the hydrochloric acid and free hydrochloric acid is consumed to moderately increase the pH of the waste liquor and collectively precipitate most of Al, Cr, Cu and P contained therein as an insolubilized substance. The resultant precipitates are then separated and removed to purify the waste liquor from acid cleaning with the hydrochloric acid. The purified waste liquor from acid cleaning with the hydrochloric acid can be subsequently roasted or subjected to silica removal and roasted to provide iron oxide powder with hardly any impurities suitable for producing high-performance soft ferrite. The resultant iron oxide powder with hardly any impurities can be reduced in a reducing atmosphere at a high temperature to produce high-purity iron powder. |
