Study of the Silica or K-feldspar as fluxing agent for the yellow phosphorus production

The thermodynamic estimation and experimental research on a laboratory scale with different fluxing agents (silica, K-feldspar) in yellow phosphorus production by the electric furnace method were investigated. The thermodynamic calculation showed that the reaction temperature of silica system is 1120 degrees C, while the temperature dropped to 970 degrees C with K-feldspar as a fluxing agent. The production efficiencies of phosphorus and potassium from this process were investigated and different reaction times and temperatures were studied. The experimental results demonstrated that the phosphorus conversion rates of the Ca-5(PO4)(3)F-C-silica and Ca-5(PO4)(3)F-C-KAlSi3O8 systems reached 96.9% and 99.0%, respectively. The potassium gasification rate of the Ca-5(PO4)(3)F-C-KAlSi3O8 system reached 44.3%. The characteristic of slag was studied by flow temperature and viscosity experiments, and the flow temperature was reduced by 61 degrees C, the residual viscosity was clearly increased. Finally, the mechanisms of yellow phosphorus production with different fluxing agents were analyzed by XRD, SEM and TEM methods. [GRAPHICS] .