Liquid/liquid extraction of acidic aqueous streams comprising sulfate/titanium/iron values

摘要

Acidic aqueous phases comprising sulfate ion and particularly sulfuric acid values, titanium ion and particularly titanium (IV) values, and iron ion, particularly iron (II) values, and advantageously waste streams emanating from a sulfate process for the production of TiO.sub.2, are extracted with an initial organic phase which comprises at least one neutral organic extractant having the general formula: ##STR1## in which A and B, which may be the same or different, are the groups R.sub.1 or OR. sub.2, wherein R.sub.1 and R.sub.2 are straight or branched chain alkyl, alkenyl, alkynyl, alkoxyalkyl, aryl or alkylaryl radicals, or halogen substituted such radicals; and R is either R.sub.1 or R.sub.2 as above- defined, with R, R.sub.1 and R.sub.2 either being the same or different, or R is a group having the general formula: ##STR2## in which Y is a straight or branched chain alkylene radical, and A and B are as defined above, to provide a final aqueous phase comprising substantially all of said iron (II) values present in said initial aqueous phase and a final organic phase comprising substantially all of said sulfuric acid values and substantially all of said titanium values present in said initial aqueous phase; the respective iron/sulfate/titanium values may then be facilely recovered from their respective final phases.