జర్నల్ ఆఫ్ పౌడర్ మెటలర్జీ & మైనింగ్

నైరూప్య

Study on the Rare Earth Containing Phosphate Rock in Guizhou and the Way to Concentrate Phosphate and Rare Earth Metal Thereof

Qin Zhang1, Yueqing Qiu1, Jianxin Cao1, Yibo Wang2, Jinping HU3, Wei Cheng1 and Tiancun Xiao1,3*

Guizhou province is one of the main phosphate resources base in China, characterized with the co-existence of rare earth in the phosphate rock. In this work, the phosphate rock samples in Zhijin County, Guizhou province have been collected and analyzed using ICP, X-Ray diffraction, Scanning microscope, Infrared spectra and X-ray photoelectron spectroscope. It is found that the total content of rare earth elements in the phosphate rock is about 0.1 wt%, amongst which Y, La, Ce, Pr, Nd and Sm are the main rare-earth components and co-sit the lattice of the apatite. The phosphate content in the as-collected rock is more than 20 wt%, and impurities such as quartz, calcite and clay are also present. The raw phosphate rock physically was treated with flotation to remove the impurities such as quartz and calcite; a refined phosphate with rare earth elements of more than 0.1 wt%. The refined phosphate rock is then treated with excessive H3PO4 to dissolve the apatite; the residue from the dissolution gives an earth enriched precipitation, which contains up to 2 wt% rare earth elements. Compared to the conventional way to use H2SO4 to extract phosphate, the treatment of the refined phosphate with phosphoric acid leads to significantly improved rare earth oxide extraction.