The stone coal from Yunxi,Hubei was selected as raw materials.The influence of additive-free roasting tech-nique on the mineral phase,vanadium speciation and bioleaching vanadium process was investigated.The detection methods of X-ray fluorescence(XRF),X-Ray Diffraction(XRD) and Fourier Transform Infrared Spectroscopy(FTIR) were used to ana-lyze the ore stone coal and the roasted residue.The results showed that①the vanadium leaching rate could reach 92.62% and the highest concentration of Si was 53.93 mg/L,when the sample was roasted at 900 ℃ for 2 h.After leaching,the maximum of Al and Fe in the system was less than 10 mg/L and 2 mg/L,respectively.②The V was chiefly present in the residual frac-tion in the stone coal,which account for 88.62%.The content of V increased to 85.52% in the extractable fraction and it is only 9.28% in the residual fraction after additive-free roasting in 900 ℃.③the additive-free roasting caused the changes of the hydrogen bonding of interlayer water in muscovite and the disappearance of OH;the unstable of structure of alumina tetra-hedron;the distorted and collapsed of basic composition unit;the reduced of chemical bond energies of the vanadium and a-round elements,which weaken the bond of vanadium.It provided favorable conditions for bioleaching process.%以湖北郧西某石煤为原料,研究了石煤空白焙烧对石煤物相、钒形态及微生物浸出过程的影响,并采用XRF、XRD和FTIR等检测手段对石煤原矿及焙烧熟料进行了表征.结果表明:①石煤试样在900 ℃空白焙烧预处理2 h,在细菌作用下,钒浸出率达到92.62%,浸出体系中Si的最大浸出量为53.93 mg/L,浸出结束后,体系中Al的最大浸出量小于10 mg/L,Fe的最大浸出量小于2 mg/L.②石煤中88.62%的钒存在于残渣态中,900 ℃空白焙烧熟料中,存在于残渣态中的钒仅占9.28%,可交换态中的钒增至85.52%.③空白焙烧使钒云母的层间水分子发生了变化,羟基脱除,铝氧四面体的结构失稳,基本构成单元发生畸变和垮塌,晶格中钒与周围元素的化学键能降低,削弱了对钒的束缚,为细菌浸出钒创造了条件.
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