Niobium is a strategic resource because it is useful in a wide number of applications and its global distribution is uneven. It has been reported that kaolin clay from the bottom of the Xuanwei Formation, the Late Permian sequences in southwest China, contains Nb. In this paper, the major, trace, and mineral compositions of kaolin clay were characterized using XRF, ICP-MS, and XRD. The results show that it is mainly composed of kaolinite, anatase, and rutile, with a chemical composition of Al2O3 34.38pct, SiO2 39.97pct, TiO2 8.79pct, Fe2O3 3.24pct, and Nb 491g/g. A process including calcination treatment and acid-alkali leaching with HCl and NaOH was employed to separate Al, Fe, and Si in a leaching solution and to enrich Nb and Ti in the residue. The experimental results indicated that the reaction temperature played a vital role for Al and Fe extractions from acid leaching, while the concentration of alkali was the key factor for Si extraction. Under the optimal conditions, the contents of Nb and Ti in the final product were 4280g/g and 80.5pct, respectively. Publication name | METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE, 49 (6):3552-3558; 10.1007/s11663-018-1405-6 DEC 2018 | Author(s) | Wang, Ning; Gu, Hannian; Wen, Hanjie; Liu, Shirong | Corresponding author(s) | GU Hannian guhannian@vip.gyig.ac.cn Chinese Acad Sci, Inst Geochem, Key Lab High Temp & High Pressure Study Earths In, Guiyang 550081, Guizhou, Peoples R China. | View here for the details
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