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- Title
Preparation of Double Ammonium-Sodium Paratungstate and Its Transformation to Ammonium Paratungstate.
- Authors
Li, Xiaobin; Lu, Zhigang; Yun, Weitao; Zhou, Qiusheng; Peng, Zhihong; Liu, Guihua; Qi, Tiangui
- Abstract
For the circulation of sodium carbonate in treating tungsten concentrate by the autoclave soda leaching, preparation of double ammonium-sodium paratungstate (DASP) from Na2WO4-Na2CO3 solution and its transformation to ammonium paratungstate (APT) were studied experimentally. The result shows that DASP can be obtained by the reaction of CO2-(NH4)2CO3 with Na2WO4-Na2CO3 solution, and almost all of Na remain in the spent liquid, which can be returned to the leaching process of tungsten concentrate. Moreover, the transformation of DASP to APT can be achieved by the reaction of DASP with (NH4)2CO3 or (NH4)2SO4. In (NH4)2CO3 solution, APT can be prepared by hydrothermal reaction at 120°C, but the tungsten conversion ratio is only 63.94% for 6 h. In the (NH4)2SO4 system, irregularly stacked APT and more than 90% of the tungsten conversion ratio can be achieved by hydrothermal transformation, whereas DASP can completely transform to quadrate APT by in situ reaction at 120°C for 6 h. The results presented are conducive to improve the soda leaching method and achieve cleaner, economical, and efficient preparation of APT.
- Subjects
AMMONIUM paratungstate; SODIUM carbonate; TUNGSTEN; SODIUM tungstate; AUTOCLAVES; ION exchange (Chemistry); POLLUTION
- Publication
JOM: The Journal of The Minerals, Metals & Materials Society (TMS), 2018, Vol 70, Issue 11, p2523
- ISSN
1047-4838
- Publication type
Article
- DOI
10.1007/s11837-018-3037-3