钠化焙烧转炉钒渣粉体分形生长的演化行为

转炉钒渣焙烧提钒技术效率低，过程涉及化学反应、传递及相变过程，蕴含物相分形生长的动力学行为。对钒渣分形变化规律的研究有助于促进钒的定向转化，进而对工业提钒具有指导意义。根据金相电镜图，使用“周长-面积法”对不同焙烧条件下钒渣粉体分形维数进行计算，得到分形维数变化与物相转化的规律。结果表明，焙烧前硅相、钒相紧密包裹，分形维数数值为1.60~2.00；加入碳酸钠焙烧后尖晶石破坏，钒相逐渐分离，使分形维数小于1.20；随着钠盐加入量的增加，物相分形维数逐渐下降；二次焙烧后，稳定的钒酸钠生成，体系趋于稳定，使得分形维数进一步下降为1.10~1.20。

Evolution behavior of fractal growth of sodium roasting converter vanadium slag powder

The vanadium slag roasting and vanadium extraction technology is inefficient, and the process involves chemical reaction, transmission and phase transformation process, and contains the dynamic behavior of fractal phase growth. The study of fractal variation of vanadium slag is conducive to promoting the directional transformation of vanadium and has a guidance for industrial vanadium extraction. According to the metallographic electron micrograph, the fractal dimension of vanadium slag powder under different roasting conditions was calculated by using the “circumference-area method”, and the variation of fractal dimension and phase transformation was obtained, and the law of fractal dimension change and phase transformation was obtained. The results showed that silicon phase and vanadium phase were packed tightly before roasting, and the value of fractal dimension was 1.60－2.00. The spinel was destroyed and vanadium phase was separated gradually after roasting with sodium carbonate, causing the fractal dimension to decrease below 1.20. With the increase of sodium salt addition, the fractal dimension gradually reduced. The second roasting made the system tended to be stable with sodium vanadate formed, and the fractal dimension further reduced to 1.10－1.20.