Building Of The Predominance Area Diagram Of Kivcet Lead Smelting Process And Study On Preparation Of Lead Oxide Melt

Abstract:Kivcet direct lead smelting process is a kind of clean and efficient way to process zinc leaching residue and lead concentrate. It is of a great value to study on the thermodynamics of Kivcet process and build predominance area diagram. In this paper, the predominance area diagram of complex system with multiphase and multielement were built to provide the basic theory of the separation of valuable metals controlled by oxygen-sulfur pressure. By simulating oxidation process of Kivcet process, the influences of preparation of lead oxide melt under a series of process conditions were studied, which can provide the technical support for generating lead by carbon reduction.With the aid of phase rule analysis and mathematical ideas of topology, the a and β plane-topological diagrams of both Pb-S-O system and Zn-S-O system were built respectively under different temperatures based on metallurgical thermodynamics. Thermodynamic analyses showed that the area of Pb、PbS、PbO and PbSO4was instable in a plane-topological diagram, and β plane-topological diagram was in accordance with traditional Me-S-O predominance area diagram. Crude lead can be generated under high oxygen and sulfur pressures during Kivcet process, which followed the thermodynamic process represented by a plane-topological diagram. High oxygen and sulfur pressures was one key technology of direct lead smelting mixed with zinc leaching residue. The a plane-topological diagram of Zn-S-0system was in accordance with traditional Me-S-O predominance area diagram; the β plane topological diagram was instable based on the thermodynamics.The influences of the amount of zinc leaching residue, atmosphere composition, reaction temperature and temperature-holding time on preparing lead oxide melt were studied by simulating the Kivcet oxidation process. The chemical composition and phase of the product were analysed by adopting the method of XRF and XRD. The results showed that lead oxide melt, which consisted metallic element of Pb、Fe、 Zn、Si、Ca、Cu、etc., can be obtained when the amount of zinc leaching residue was0%or60%, reaction temperature was1200、1300or1400℃, temperature holding time was30or60min, oxygen content of the atmosphere was95%or30%.