Journal
RUSSIAN JOURNAL OF APPLIED CHEMISTRY
Volume 89, Issue 7, Pages 1196-1205Publisher
PLEIADES PUBLISHING INC
DOI: 10.1134/S1070427216070211
Keywords
-
Categories
Funding
- National Natural Science Foundation of China [51164004]
Ask authors/readers for more resources
In the study the organic/inorganic chemical leaching and enrichment technology were used for selective extraction of the dolomite which co-existed in the Zhijin low-grade phosphate ore for beneficiation phosphorous and rare earths (RE) by using citric acid as leaching agent. The effects of acid concentration, reaction time, reaction temperature, liquid/solid ratio, and particle size on P2O5 and rare earths grade and the recovery ratio of them were investigated. The results show that under the optimized experimental conditions (acid concentration 9%, reaction time 240 min, reaction temperature 40A degrees C, liquid/solid ratio 50: 1, and ore particle size 0.18-0.125 mm) the P2O5 grade can be increased from 15.47 to 34.82%, and P2O5 recovery rate comes up to 88.02%. The rare earths are mainly enriched in the leaching residues. Meanwhile, the recovery rate of rare earths is 72.08%. I REO pound grade can be increased from 978.06 x 10(-4) to 1998 x 10(-4)%. In addition, the reaction kinetics of the chemical reaction between citric acid and dolomite are also discussed, the results show that the leaching process is controlled by chemical reaction. The activation energy for leaching was found to be 36.6337 KJ mol(-1) and k (0) was 3.67x104 s(-1), and the rate of the leaching based on the chemical reaction-controlled process could be expressed as 1-(1-a)(1/3) = 3.67 x 10(4)e(-36.63/RTt) . Compare to the conventional process, the method provided in this study not only has advantages including higher phosphate concentration and rare earth grade, and higher recovery rate, but also using less amount of chemicals. Meanwhile, the citric acid can be recycled, avoiding discharge wastewater.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available