氟磷灰石固态还原过程的实验研究

以氟磷酸钙、分析纯二氧化硅和试剂级活性炭的粉粒做成型料进行氟磷灰石热炭固态还原反应机理和速率控制步骤的实验研究，提出了氟磷灰石首先与二氧化硅进行脱氟反应生成2CaF_2·SiO_2和Ca_3（PO_4)_2，后者再通过熔液相扩散至炭表面还原的反应机理高硅钙比时氟完全以SiF_4逸去，低硅钙比时则主要以2CaF_2·SiO_2存在于残渣中，随硅钙比增加而减少.

INVESTIGATION ON THE SOLID STATE REDUCTION OF FLUORAPATITE

The reaction mechanism and rate-controlling step for the carbon reduction of fluorapatite were investigated with the shaped feeds of fluorapatite,silica（AR）and active carbon（reagent）Powders.The reaction mechanism is suggested as that 2C_a F_2 SiO_2 and Ca_3（PO_4)_2are formed in the defluorination between f1uorapatite and silica,and then the Ca_3（PO_4)_2 diffuses through the molten liquid onto the surface of carbon particle where it is reduced by carbon.The steps are The fluor is evolved in the form of SiF_4 at a higher silica-lime molar ratio.When the silica-lime molar ratio is rather lower,the fluor remains in the residue in the form of 2CaF_2·SiO_2.