IMPROVEMENTS IN OR RELATING TO WASTE PICKLE LIQUOR

摘要

1285963 Waste pickle liquors H SILBY 14 Aug 1969 [15 Aug 1968] 40575/69 Heading C1A Waste pickle liquor is treated with NaOCI to obtain Fe 2 O 3 which is removed by filtration and dried. The liquor is preferably filtered before treatment and charcoal or a mixture of activated charcoal and diatomaceous earth may be used as the filter bed, activated charcoal being reactivated after use by heating. The liquor may comprise FeSO 4 and H 2 SO 4 , in which case the final filtrate may be evaporated to dryness to obtain Na 2 SO 4 , or it may comprise FeCl 2 and HCI.