钒渣钠化焙烧过程中钒尖晶石和铁橄榄石的变化规律表征

Characterization of Variation of Vanadium Spinel and Fayalite During the Calcination of Vanadium Slag

为了提高钠化提钒中钒的回收率,采用矿相显微镜、扫描电子显微镜和矿物自动解理系统(MLA)对钒铬渣和碳酸钠混合后的熟料在焙烧过程中的物相变化进行了详细研究,重点研究了混合料中钒尖晶石和铁橄榄石的形貌、结构变化规律。结果表明:钒渣氧化开始于铁橄榄石的氧化分解,随着焙烧时间的增加,铁橄榄石逐渐转变化为钠长石和钛辉石,后又形成硅酸钠和钠长石的包裹体;铁橄榄石结构的破裂导致钒尖晶石的暴露,钒尖晶石的氧化主要包括前期Fe2+的快速向外迁移和后期晶体内部铁板钛矿和钒酸锰晶体的缓慢形成、长大两个阶段。

In order to improve the recovery of vanadium in sodium vanadium extraction,analysis on the phase changes in clinker during the roasting process were studied in detail by using mineral microscope,scanning electron microscope and mineral liberation analysis system（ MLA）. The morphologies and structural changes of vanadium spinel and ferric olivine in the mixture were studied emphasically. The result shows that,the oxidation of vanadium slag begins with the oxidation decomposition of olivine. With the increase of calcination time,fayalite gradually changes to albite and titanaugite,and then forms inclusions of sodium silicate and albite. Rupture of fayalite structure leads to the exposure of vanadium olivine spinel,and the oxidation of vanadium spinel mainly includs previous rapid outward migration of Fe^2 ＋and later two stages of slow formation and grow-up of pseudobrookite and manganese vanadate crystals in the crystal.