Vanadium containing sludge is a by-product of vanadium pentoxide obtained by hydrometallurgical methods from vanadium slag that can be estimated as a promising technogeneous raw material for vanadium production. The phase analysis of vanadium-containing sludge by the X-ray diffraction method showed that it contains vanadium in spinel form (FeO∙V₂O₃). The various oxidation roasting methods for sludge treatment were studied for increasing vanadium extraction into the solution. It showed that the most effective additive is 1% CaCO₃ at a roasting temperature of 1000 °C. Oxidation roasting of vanadium-containing sludge with the additive led to an increase in the acid-soluble form of V₂O₅ from 1.5% to 3.7% and a decrease in the content of FeO∙V₂O₃ from 3% to 0.4%. These results confirm the efficiency of the application of oxidation roasting to convert vanadium compounds into acid-soluble forms. The conversion mechanism of spinel to acid-soluble phases during oxidation roasting with additives was investigated by thermogravimetric analysis and thermodynamic simulation. It showed that the formation of acid-soluble calcium vanadates during oxidation roasting without additives occurs at temperatures above 800 °C while CaCO₃ addition allows one to reduce this temperature to 600 °C.

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含钒污泥氧化焙烧钒萃取工艺研究

含钒污泥是通过湿法冶金从钒渣中获得的五氧化二钒的副产品，据估计，钒渣是生产钒的有希望的技术原料。X射线衍射法对含钒污泥的相分析表明，它含有尖晶石形式的钒（FeO∙V ₂ O ₃）。研究了用于污泥处理的各种氧化焙烧方法，以提高溶液中钒的萃取率。结果表明，在1000°C的焙烧温度下，最有效的添加剂是1％CaCO ₃。含添加剂的含钒污泥的氧化焙烧导致V ₂ O _5的酸溶形式增加从1.5％降低到3.7％，FeO∙V ₂ O ₃的含量从3％降低到0.4％。这些结果证实了应用氧化焙烧将钒化合物转化成酸溶形式的效率。通过热重分析和热力学模拟研究了尖晶石在添加剂氧化焙烧过程中向酸溶相的转化机理。结果表明，在没有添加剂的情况下进行氧化焙烧过程中，酸溶性钒酸钙的形成发生在高于800°C的温度下，而添加CaCO ₃可使温度降至600°C。