Selective nitridation-corrosion process to recover vanadium, titanium, chromium, and iron from vanadium slag.
Selective nitridation-corrosion process to recover vanadium, titanium, chromium, and iron from vanadium slag.
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DOI：
10.1016/j.jenvman.2022.116604
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发表时间：
2022-10
影响因子：
8.7
通讯作者：
Qingqing Hu;S. Pan;Xudong Gao;Yongjie Liu;Qing-yun Huang;Yang You;Zhixiong You;X. Lv
中科院分区：
文献类型：
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作者：
Qingqing Hu;S. Pan;Xudong Gao;Yongjie Liu;Qing-yun Huang;Yang You;Zhixiong You;X. Lv
钒渣(V渣)是一种重要的二次钒资源，但在工业生产中，尾矿中还会有其他有价值的元素被丢弃。提出了一种从钒渣中综合回收有价元素(V、钛、铬、铁)而不产生危险废物的绿色氮化腐蚀工艺。热力学结果表明，氨气(NH3)能选择性还原Fe和氮化物V、Cr、Ti。在最佳条件下，氮化钒渣的主要物相组成为金属铁、氮化物和透辉石，在1000℃焙烧6h后，它们的相对含量分别为42.5%、26.2%和31.3%，并考察了主要参数对腐蚀试验的影响，最高增重率为19.6%。由于金属Fe的氧化，渗氮后的钒渣表面有FeOOH晶化。整个过程的物相演化为尖晶石/橄榄石/透辉石→铁/氮化物/透辉石→FeOOH/氮化物/透辉石。由于颗粒较细，大多数FeOOH通过湿筛分离(<；1400目)。通过酸洗去除多余的铁，可得到纯度为43%的富集态氮化物。铁、钒、钛、铬的总回收率分别为87.76%、95.92%、92.92%、92.11%。为钒渣的综合利用提供了一种可持续的策略，并对其他类似矿物的清洁处理具有指导意义。
Vanadium slag (V-slag) is an important secondary V source, but other valuable elements are discarded in the tailings in industry. Herein, a green nitridation–corrosion process is proposed for the comprehensive recovery of valuable elements (V, Ti, Cr, Fe) from V-slag without producing hazardous waste. Thermodynamic results indicate that ammonia gas (NH3) can selectively reduce Fe and nitride V, Cr, and Ti. The main phase composition of the nitrided V-slag included metallic Fe, nitrides, and diopside under optimal conditions, and their relative contents were 42.5, 26.2, and 31.3%, respectively, after roasting at 1000 °C for 6 h. The effects of the main parameters on corrosion test were investigated, and the highest weight-gain ratio attained was 19.6%. FeOOH crystallizes on the surface of the nitrided V-slag due to the oxidization of metallic Fe. The phase evolution during the entire process is spinel/olivine/diopside → Fe/nitrides/diopside → FeOOH/nitrides/diopside. Owing to finer particle sizes, most FeOOH is separated by wet sieving (<1400 mesh). The purity of the enriched nitrides attained was 43% after pickling to remove excess Fe. The total recovery rates of Fe, V, Ti, Cr were 87.76%, 95.92%, 92.92%, 92.11%, respectively. This paper provides a sustainable strategy for the comprehensive utilization of V-slag, and guides the cleaner treatment of other similar minerals.