Abstract:Two reaction systems of carbonthermal reduction of fluorapatite were investigated in the tube furnace with protecting nitrogen

one of which contained 5%Al2O3

and the other didn’t contain any Al2O3.The results showed that the conversion fraction and the conversion rate of fluorapatite with 5%Al2O3 are both higher.The analysis of XRD for the compositions of solid state products is consistent with the analysis of thermodynamics.The products of Al2SiO5

AlPO4 and CaAl2Si2O8 in 5%Al2O3 reaction system cause the amount of liquid phase the increase of and then enhance the carbonthermal reduction.The solid state carbothermal reduction reaction of fluorapatite in the present of SiO2 and Al2O3 belongs to gas-liquid-solid reaction and the reaction process meets the kinetic equation which was derived from the theory of layer growth based on reaction-diffusion.And more

the enhanced effect of adding Al2O3 is more prominent at relative lower temperature or at the initial reaction stage especially.