湿法磷酸浸提料浆中着色物质的鉴别

Identification of colored substances in wet process phosphoric acid leaching slurry

收集磷酸生产过程中的磷酸浸提料浆,通过N,N-二甲基甲酰胺、正己烷溶解得到溶液,水洗脱除可溶性磷酸及盐类后得到固体。采用气相色谱-质谱联用仪(GC-MS)判断小分子有机物组成及着色情况;利用X射线衍射(XRD)、X射线荧光光谱(XRF)表征手段,对水洗后固体样品进行鉴定,确定磷酸浸提料浆中着色物质的组成;利用热重和红外光谱对有机质的组成及含量进行测定;采用扫描电子显微镜对样品的存在状态进行表征。研究表明,磷酸浸提料浆中主要着色物质为二硫化铁与有机质组成的复合体,其赋存状态为有机质不完全包裹二硫化铁的形式,其中二硫化铁质量分数为10.70%(以铁元素计),有机质质量分数为2.39%(以湿基计)。

The phosphoric acid leaching slurry was collected in the phosphoric acid production process section.The solution was obtained after dissolving by N,N-Dimethylformamide and n-hexane,the solids obtained by removing soluble phosphoric acid and salts by water washing were used to judge the composition and coloring of small molecule organic matter by gas chromatography-mass spectrometry.The solid samples after washing were identified by XRD and XRF,and the composition of coloring substances in phosphoric acid leaching slurry was determined.The composition and content of organic matter were determined by TG and FT-IR spectrometer.The existence of samples was determined by SEM.The experimental results showed that the main coloring material was a complex composed of FeS_(2)and organics,its existence form was organic matter incompletely encapsulating FeS_(2).The mass fraction of FeS_(2)was 10.70%(based on Fe)and the mass fraction of organic matter was 2.39%(of wet based raw phosphoric acid extraction slurry).