Thermodynamic fundamentals of ferrous cake sulfitization

Abstract

The Pourbaix diagrams of the systems SO₄²⁻−SO₃²⁻−H₂O and iron hydroxide (oxide)–H₂O are refined. The E(pH) dependence of the sulfitization of iron(III) hydroxide is refined with allowance for the regions of predominant phase constituents of the systems. The potential E–pH electrochemical equilibrium diagrams of the systems Fe(OH)₃–H₂SO₄–SO₃²⁻–H₂O, FeOOH–H₂SO₄–SO₃²⁻–H₂O, and Fe₂O₃–H₂SO₄–SO₃²⁻–H₂O are plotted. These diagrams can be considered as a thermodynamic basis for the sulfite conversion of the ferrous cake of copper–nickel production.