石油焦灰钒镍浸出特性和赋存形态研究

Leaching characteristics and occurrence forms of vanadiumand nickel in a petroleum coke ash

以一种玻璃工业炉窑副产的高硫石油焦灰为原料,采用单因素实验探究了其赋存形态及浸出条件对钒镍浸出率的影响。结果表明:在浸出温度为95℃,浸出时间为40 min,液固比为9 L/kg,硫酸用量为15 mol/kg的条件下,当水为浸出剂时,浸出液显酸性,钒和镍的浸出率分别为60.47%和71.67%,高于其他种类石油焦灰,这是由于石油焦灰在燃烧过程中有硫酸生成及钠盐的活化作用。当硫酸为浸出剂时,钒的浸出率提高到94.68%,而镍的浸出率增加较小,为74.70%。石油焦灰中钒主要为水溶态和酸溶态,而镍基本为水溶态和酸不溶态。由XRD、FT-IR、SEM-EDS分析结果可知,石油焦灰中的水不溶态钒主要以多种钒酸盐的形式存在,而酸不溶态镍为钒酸镍。

A kind of high sulfur petroleum coke ash,which is a by-product of glass industry furnace,was taken as the raw material.The single factor experiments were adopted to investigate the occurrence forms and the influence of leaching conditions on the leaching rates of vanadium and nickel.The results show that under the conditions of a leaching temperature of 95℃,a leaching time of 40 min,a liquid-solid ratio of 9 L/kg and a sulfuric acid dosage of 15 mol/kg,when water is used as a leaching agent,the leaching solution is acidic,and the leaching rates of vanadium and nickel are 60.47%and 71.67%,respectively,which are higher than those of other kinds of petroleum coke ash,resulting from the formation of sulfuric acid and the sodium salt activation in the roasting process of petroleum coke ash.When sulfuric acid is used as a leaching agent,the leaching rate of vanadium increases to 94.68%,while that of nickel increases slightly to 74.70%.The vanadium in petroleum coke ash is mainly in the form of the water-soluble and acid-soluble,and nickel exists in water-soluble and acid-insoluble state.XRD,FT-IR and SEM-EDS analysis results show that the water-insoluble vanadium consists of various vanadate,and the acid-insoluble nickel is mainly composed of nickel vanadate.