当社グループは 3,000 以上の世界的なカンファレンスシリーズ 米国、ヨーロッパ、世界中で毎年イベントが開催されます。 1,000 のより科学的な学会からの支援を受けたアジア および 700 以上の オープン アクセスを発行ジャーナルには 50,000 人以上の著名人が掲載されており、科学者が編集委員として名高い
。オープンアクセスジャーナルはより多くの読者と引用を獲得
700 ジャーナル と 15,000,000 人の読者 各ジャーナルは 25,000 人以上の読者を獲得
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.