Extraction of the valuable substances from steelmaking slag in carbonic acid solution

点击翻译按钮获取中文摘要

Elution behavior of slags discharged from electric arc furnaces to the carbonic acid solution, which was weak acid, was investigated in order to extract the valuable substances included in the slags, The pH in the aqueous solution decreased with an increase of the partial pressure of carbon dioxide, Therefore, the elution of each substance of slag increased with the increase of the partial pressure of carbon dioxide. In the process of wet grinding of slag at atmospheric pressure of carbon dioxide, the recovery of zinc from the oxidizing and the reducing slag discharged from normal steelmaking process to the water solution was less than about 10%, whereas it for the oxidizing and the reducing slag discharged from smelting process of stainless steel was more than approximately 80%. The recovery of chromium during wet grinding was less than 1.4×10^<-4>%, and it was very small. Therefore, most chromium could be remained in the slags. Calcium carbonate was formed by the wet grinding of slag at atmospheric pressure of carbon dioxide, and it also formed in the water solution after tank leaching.