碳热氯化法分解包头混合稀土精矿提取稀土

Extraction of Rare Earths from Mixed Bastnaesite-Monazite Concentrate by Carbochlorination Reaction

研究包头氟碳铈-独居石混合稀土精矿的碳热氯化反应,考察反应时间、反应温度和脱氟剂对稀土提取率的影响。结果表明,包头氟碳铈-独居石混合稀土精矿的碳热氯化反应的较佳工艺条件为反应温度800℃,反应时间2h。在脱氟剂AlCl3存在下,800℃时氯化反应2h,稀土提取率高达98%。X射线衍射结果表明,在脱氟反应过程中,AlCl3和矿物分解产生的REOF发生了脱氟反应,使氟碳铈矿中的氟被转化为难溶于水的AlF3而留在滤渣中,同时AlCl3促进了独居石的分解反应。

The carbochlorination process for extracting rare earths from mixed bastnaesite-monazite concentrate is investigated. The effects of reaction time and reaction temperature on the rare earth yield are studied. The results show that the optimal condition is 800°C reaction for 2h, and the rare earth yield can be reached 98 % with AlCl3 as defluorinating agent under optimal condition. It is indicated by XRD that during the defluorinating process, AlCl3 reacts with REOF derived from mineral decomposition, the F in the ore is remained in the residue in the form of AlF3. The monazite decomposition is also accelerated by AlCl3.