循环氧化法石煤提钒新工艺试验研究

提出一种采用自主开发的低钠复合添加剂进行氧化焙烧，在两段水浸后增加稀酸浸出工艺，然后将酸浸液亚铁沉钒后作为中间产品返回再氧化焙烧，最后从水浸出产品的循环氧化法石煤提钒新工艺.并在氧化焙烧之前，增加预焙烧，除去石煤中的有机质和黄铁矿等还原性矿物对钒的氧化抑制，同时能充分利用石煤的低热值能源，还可使钒得到一定程度的富集.并应用新工艺以江西某地石煤为对象进行了实验研究.研究结果表明，实验过程最佳条件和指标分别为：预焙烧中焙烧温度750 ℃,焙烧时间30 min,残碳量小于2％;氧化焙烧中焙烧温度为780~820 ℃,焙烧时间90 min,复合添加剂用量9%,酸浸中间产品3%~5%.在此条件下，钒的浸出率可达85.5%，总回收率可达76.3%.

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%.  