Abstract: 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.