We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Kinetics of Scheelite Conversion in Sulfuric Acid.
- Authors
Li, Xiaobin; Zhou, Qiusheng; Peng, Zhihong; Liu, Guihua; Qi, Tiangui; Shen, Leiting; Taskinen, Pekka
- Abstract
Complete conversion of scheelite in H2SO4 solution plays a key role in exploration of cleaner technology for producing ammonium paratungstate. In this work, the factors influencing scheelite conversion were investigated experimentally to model its kinetics. The results indicated that the conversion rate increases with increasing temperature and reducing particle size, but is almost independent of stirring speed. Moreover, although the conversion rate increases with increasing initial H2SO4 concentration (≤ 1.25 mol/L), it decreases rapidly at 1.5 mol/L H2SO4 after 10 min due to formation of a H2WO4 layer. The experimental data agree quite well with the shrinking core model under chemical reaction control in ≤ 1.25 mol/L H2SO4 solution, and the kinetic equation was established as: 1-(1-α)1/3=222546.6·CH2SO41.226·r0-1·e-39260RT·t (t, min). This work could contribute to better understanding of scheelite conversion in H2SO4 solution and development of a new route for ammonium paratungstate production.
- Subjects
SCHEELITE; SULFURIC acid; AMMONIUM paratungstate; TUNGSTEN; SODIUM hydroxide; TUNGSTIC acid; WOLFRAMITE
- Publication
JOM: The Journal of The Minerals, Metals & Materials Society (TMS), 2018, Vol 70, Issue 11, p2499
- ISSN
1047-4838
- Publication type
Article
- DOI
10.1007/s11837-018-2787-2