| The process of potassium recovery under acidic condition from iron slag containing chromium derived from cleaner production process of chromium salts is investigated. The products are iron-rich slag for iron smelting and filtrate containing potassium for relevant product preparation. The effects of pH, temperature, ratio of liquid to solid, and reaction time on the removal of potassium are described and the reaction conditions are optimized. The results show that more than 80% of potassium in iron slag are removed under acidic slurry medium with a moderate reaction condition, pH 3.5~4.5, temperature 100℃, L/S 7:1, reaction time 90min. The reagent for removal of potassium is ferrous sulfate, which also plays a role of Cr6+ reductant and detoxicant, and thus is more suitable for industrial applications. |