A two-step zircon decomposition method to produce zirconium oxychloride: alkali fusion and water leaching

• Published in: Rare metals 2020-04, Vol.39 (4), p.448-454
• Main Authors: Song, Jing, Fan, Jing-Fei, Liu, Jing-Chong, Liu, Ran, Qu, Jing-Kui, Qi, Tao
• Format: Article
• Language: English
• Subjects: Biomaterials; Chemistry and Materials Science; Crystal structure; Decomposition; Energy; Fusion temperature; Leaching; Materials Engineering; Materials Science; Metallic Materials; Nanoscale Science and Technology; Physical Chemistry; Sand; Silicon dioxide; Sodium silicates; Zircon; Zirconium dioxide; Zirconium silicate
• ISSN: 1001-0521; 1867-7185
• DOI: 10.1007/s12598-015-0537-y

In this work, a two-step zircon method to produce zirconium oxychloride was introduced, and the alkali fusion technique with NaOH and water leaching process were investigated. The effects of the operating conditions on the decomposition of zircon were determined, and the optimal conditions are as follows: alkali/zircon mass ratio of 0.7 at the first step and 0.6 at the second step (0.7 + 0.6), fusion temperature of 700 °C and fusion time of 0.5 h at the first step and 0.5 h at the second step (0.5 + 0.5 h). Under these conditions, the decomposition alloy of zircon sand can reach 97.25 %. In the fusion process of zircon sand, the products of first step are mainly Na 2 ZrO 3 and ZrSiO 4 , the products of second step are Na 2 ZrO 3 and Na 2 SiO 3 , and the diffraction peaks of Na 2 ZrSiO 5 are not observed. The conditions of water leaching process were investigated as well, and the optimal conditions are as follows: liquid–solid ratio of 5:1, leaching time of 0.5 h, leaching temperature of 50 °C and leaching three times. Under these conditions, the contents of leaching products SiO 2 and Na 2 O are 3.51 % (40 % ZrO 2 ) and 4.46 % (40 % ZrO 2 ), respectively. The crystal phase structures of Na 2 ZrO 3 and Na 2 SiO 3 are formed in water leaching process.