氟碳铈与独居石混合型稀土精矿热分解机理研究

Heat Decomposing Mechanism of Mixed Rare Earth Concentrate Composed of Bastneasite and Monazite

用X射线衍射分析和TG DTA热分析技术研究了氟碳铈矿、独居石及混合型稀土精矿在空气中的热分解过程。独居石在 90 0℃以下无明显分解反应 ,当CaO存在时REPO4 在 6 2 0℃以上可分解成RE2 O3 。氟碳铈矿的热分解过程中有CaO时在 72 5℃以上REOF完全分解为RE2 O3 ,并产生CaF2 。混合型稀土精矿中氟碳铈矿在 473℃开始分解 ,在 70 0℃以上时分解产物主要是REOF、RE2 O3 和Ca5F(PO4 ) 3 。

The heat decomposing processes of bastneasite,monazite and mixed rare earth concentrate were analyzed by X ray diffraction and TG DTA measurement. The results show that no clear decomposition happens for monazite below 900℃,and REPO 4 is decomposed to RE 2O 3 above 620℃ in the presence of CaO. Bastneasite begins to decompose at 473℃ in mixed rare earth concentrate and the decomposing products are REOF,RE 2O 3(CeO 2) and Ca 5F(PO 4) 3 above 700℃ for mixed rare earth concentrate.