REGENERATION OF HYDROCHLORIC ACID PICKLING WASTE BY H{11 SO{11 {0 ADDITION, DISTILLATION AND FeSO{11 {0 Precipitation

摘要

In recovering hydrochloric acid from a spent hydrochloric acid pickle liquor the process is characterized by adding sulfuric acid to hydrochloric acid waste to convert FeC12 in said waste to HCl and FeSO4 and to obtain a mixture containing at least 38 percent by weight of free sulfuric acid, distilling said resultant mixture to vaporize substantially all of the HCl therefrom together with water and to precipitate ferrous sulfate, condensing said HCl and water thus vaporized to recover hydrochloric acid, separating the precipitated ferrous sulfate from the residual liquid and circulating the resultant liquid free of ferrous sulfate as a sulfuric acid source.