PROCEDE DE RECUPERATION DE SUBSTANCES CHIMIQUES DE VALEUR HORS D'UN EFFLUENT DE PRODUITS RESIDUAIRES PROVENANT D'UN PROCESSUS OPERATOIRE

摘要

1360174 Treating sodium hydrosulphite effluent VIRGINIA CHEMICALS Inc 12 Jan 1972 [13 Jan 1971] 1456/72 Heading C1A [Also in Division C2] Chemical values are recovered from the waste liquor obtained from the production of sodium hydrosulphite by the reaction of sodium formate with SO 2 in methanol, by introducing a strong acid into the waste liquor, boiling to expel SO 2 and continuing boiling to distil with reflux and recover methyl formate and methanol. The acid may be sulphuric, hydrochloric, nitric or phosphoric and after distillation salts of the acid may be recovered by evaporation, flash drying or spray drying.