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

GRAPHICAL ABSTRACT

ABSTRACT

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°C, while the temperature dropped to 970°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 Ca₅(PO₄)₃F-C-silica and Ca₅(PO₄)₃F-C-KAlSi₃O₈ systems reached 96.9% and 99.0%, respectively. The potassium gasification rate of the Ca₅(PO₄)₃F-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°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.

KEYWORDS:

• Thermodynamic estimation
• Fluorapatite
• K-feldspar
• Fluxing agent
• Conversion rate

Acknowledgments

The authors wish to acknowledge the financial support on this research from the National Natural Science Foundation of China (No. 21566018).

Funding

National Natural Science Foundation of China ID: 21566018.