Liquid-liquid extraction of molybdenum(VI) from aqueous acid solutions by TBP and TOPO

Abstract

The extraction of molybdenum(VI) from hydrochloric, nitric or sulphuric acid solutions has been investigated by using tributyl phosphate (TBP) and trioctylphosphine oxide (TOPO). The equilibrium expressions are proposed on the basis of the distribution data obtained: For the extraction by TBP from hydrochloric or nitric acid solutions, at low aqueous acidities H 2MoO 4(aq)+3TBP(org)⇌H 2MoO 4·3TBP(org) and at higher aqueous acidities MoO 2X 2( aq)+2TBP(org)⇌ MoO 2X 2·2TBP(org) where X=Cl or NO 3. For the extraction by TOPO from hydrochloric, nitric or sulphuric acid solutions, at low aqueous acidities H 2MoO 4(aq)+TOPO(org)⇌H 2MoO 4·TOPO(org) and from hydrochloric or nitric acid solutions at higher acidities MoO 2X 2( aq)+2TOPO(org)⇌ MoO 2X 2·2TOPO(org) and from sulphuric acid solutions at higher acidities MoO 2SO 4(aq)+2TOPO(org)⇌MoO 2SO 4·2TOPO(org) .