Experiment study on new technology of extracting vanadium from stone coal with cyclic oxidation

Proposed to use a kind of new technology in extracting vanadium from stone coal with cyclic oxidation method,in which an independently developed low-sodium compound additive for oxidation roasting was used,diluted acid leaching technology was added after two sections of leaching,acid leaching solution was returned for oxidation roasting after ferrous precipitating vanadium,and the vanadium was finally recovered from the water leaching.Pre-roasting was inserted prior to grinding to remove reducing minerals in the stone coal such as organic materials and pyrite which would depress the vanadium oxidation.This will also makes full use of the low-heat energy of the stone coal and results in enriching vanadium to some degree.Stone coal somewhere in Jiangxi Province was taken as the experimental and studying target.The result shows that optimum conditions and indexes in roasting process are: roasting temperature 750 ℃,roasting time 30 min,less than 2% of remaining carbon in pre-roasting;roasting temperature 780~820 ℃,roasting time 90 min,9% compound additive amount and 3%~5% of product for precipitating vanadium in acid leaching solution in oxidization roasting.The application of the new technology of cyclic oxidation roasting can make the leaching rate of vanadium reach 85.5% and the total recovery rate 76.3%.