Kinetics Of Interactive Reaction Between Lead Sulfiude And Lead Oxide

Lead is a widely used non-ferrous metal. The smelting process of lead are the sintering-blast furnace lead smelting and direct lead-smelting process mainly. Compared to the sintering-blast furnace lead smelting, direct lead-smelting process showing a good development prospects as simple process, low energy consumption, environmentally friendly etc. However, the dynamics research on the reduction stage by using lead sulfide as reductant of directly lead-smelting process is not enough. The dynamics of the interactive reaction between lead sulfide and lead oxide with non-isothermal method and isothermal method were studied to provide theoretical support for optimize the process in the paper.Firstly, the dynamics of the interactive reaction between lead sulfide and lead oxide was studied by thermal analysis method. The experiment was made in Argon gas flow100ml/min atmosphere at different temperature rise as40K/min,30K/min and25K/min. The activation energy was calculated by Kissinger equation and Ozawa equation. The results show that when the molar ratio of lead sulfide to lead oxide was1:2, the reaction order between lead sulfide and lead oxide was1.077, the activation energy calculated by Kissinger equation and Ozawa equation were184.29kJ/mol and191.90kJ/mol respectively.And then, the interaction kinetics of lead sulfide and lead oxide was studied by isothermal method, and the effects of carrier gas flow, temperature and the ratio of lead sulfide and lead oxide on the interaction reaction was investigated. The results show that:the carrier gas flow rate for80L/h can eliminate external diffusion effect on the rate of interactive reaction; The temperature has a great effect on the reaction, and the reaction rate increases greatly with the increase of temperature; when carrier gas flow for80L/h, the prophase of the interactive reaction is controlled by interfacial chemical reaction at750～850℃, which accord with (1-α)-0.744-1=Kt; the apparent activation energy trends to decrease with the increase of lead sulfide content; the apparent activation energy is E=184.40kJ/mol at the ratio of1.0(nPbS:nPbO=1:2), which agree with the result calculated by non-isothermal method basically.