熔盐法从提钒尾渣中制取白炭黑的研究

Preparation of Precipitated Silica from Vanadium Extraction Tailings by a Molten Salt Method

以提钒尾渣为原料,NaOH为熔盐,NaF为氧化剂,研究熔盐法提取硅的实验过程。以浸取硅酸钠溶液作为硅源,利用化学沉淀法制备无定型白炭黑。结果表明:硅浸出率随着碱渣比、煅烧温度及煅烧时间的增大而先增大后减小;通过正交试验对实验数据进行分析,对硅浸出率的影响由大到小为:碱渣比>煅烧温度>煅烧时间;最佳试验条件为碱渣比3∶1、反应温度550℃、反应时间3h,此条件下硅浸出率可达到96%以上。对制备白炭黑样品进行XRD、红外光谱、SEM表征和粒度分析,结果表明:白炭黑为无定形结构,粒子呈球形,粒径大小均一,平均粒径为200nm。

By using vanadium extraction tailings as raw material,NaOH as molten salt and NaF as oxidant,the experimental process of extracting silicon by molten salt method was studied.The precipitated silica particle was prepared using sodium silicate as a source of silica by chemical precipitation mothed.With the increase of alkali slag ratio,calcination temperature and calcination time,the leaching rate of silicon increases first and then decreases.The orthogonal test results show that the effect of silicon leaching rate is as follows:alkali slag ratio > calcination temperature > calcination time.The optimum test conditions are an alkali slag ratio of 3∶ 1,a reaction temperature of 550 ℃,and a reaction time of 3 hours.On the conditions,the leaching rate of silicon can reach more than 96%.The component,morphology and structure of the synthesized particles were characterized by X-ray diffraction (XRD),FT-IR analysis,scanning electron microscopy (SEM),and particle size analysis.The results show that the silica is amorphous,the particles are spherical,the particle size is uniform,and the average particle size is 200 nm.