钙化焙烧-酸浸提钒过程中含钒物相结构及其演变规律研究

对钒渣、熟料和残渣中含钒物相微观结构、形貌以及钒元素走向进行了分析, 考察了钙化焙烧-酸浸提钒过程中含钒物相结构及其演变规律。结果表明: 钙化焙烧过程中钒尖晶石由初始光滑致密的多边形逐渐氧化成多孔状态, 直至最后生成凹凸不平的“圆粒状”氧化铁和“短柱状”铁板钛矿, 钒元素也由最初富集在钒尖晶石中逐渐向钒酸钙、氧化铁、铁板钛矿和硅酸盐中转移; 酸浸过程中熟料中凹凸不平的含钒氧化物(氧化铁、铁板钛矿和钒酸钙)逐渐变为“镂空状”铁板钛矿相, 大部分钒元素被硫酸浸出, 残留的钒元素主要赋存于氧化铁、铁板钛矿和硅酸钙中。

Vanadium Phase Structure and Its Evolution Rule in Vanadium Extraction by Process of Calcification Roasting-Acid Leaching

Based on the analysis of microstructure, morphology and form of existence of vanadium element in vanadium slag, wrought material and residue, the vanadium phase structure and its evolution rule in  vanadium extraction by process of calcification roasting-acid leaching were investigated. Results showed that the vanadium spinel was oxidized in the roasting process, from initial dense and smooth polygon progressively turning to be porous, and finally forming uneven “granular” iron oxide and short cylindrical pseudobrookite. The vanadium element was also initially enriched in vanadium spinel, which was transferred gradually into calcium vanadate, iron oxide, pseudobrookite and silicate. The rugged vanadium-containing oxide in the wrought material (iron oxide, pseudobrookite and calcium vanadate) was progressively turning to be pseudobrookite phase with “hollow” structure in the acid leaching, with most part of vanadium leached by sulfuric acid and the remaining vanadium existed in iron oxide, ilmenite and calcium silicate.