冷冻法硝酸磷肥工艺中酸不溶物提纯研究

Purification of Acid Insolubles Substance in the Process of Freezing Nitrophosphate Fertilizer

采用酸浸、磁选酸浸、水淬/研磨酸浸等不同工艺对冷冻法硝酸磷肥生产工艺中的废渣-酸不溶物进行了提纯处理,利用X射线荧光光谱仪(XRF测试)对酸不溶物提纯前后各成分含量的变化进行了分析,从中得出了不同工艺流程对酸不溶物纯度的影响,最终确定了最佳的酸不溶物处理工艺。结果表明:在酸浸实验中,盐酸酸浸效果最佳,可将酸不溶物中SiO_2纯度达到82.43%;在酸浸工艺前加入磁选、水淬、研磨的工序均可有效提升酸不溶物的提纯效果;冷冻法硝酸磷肥工艺中酸不溶物最佳的提纯工艺路线为:干燥、筛分、水洗、磁选、研磨、盐酸酸浸,处理后酸不溶物中SiO_2纯度达到88.92%,符合微硅粉的生产要求。

The acid insolubles waste in the production process of freezing nitrophosphate fertilizer was purified by acids leaching,magnetic pickling,water quenching/grinding acid leaching.The content of each component before and after purification of acid insolubles was analyzed by X-ray fluorescence spectrometer(XRF).The influence of different processes on the purity of acid insolubles was investigated,and the optimal acid insoluble treatment process was explored.The results show that the hydrochloric acid leaching provides the best treatment efficiency in the acid leaching experiment,and the purity of SiO2 in acid insolubles can increase to 82.43%.Furthermore,the process of magnetic separation,water quenching and grinding before the acid leaching process can effectively improve the purification quality of the acid insoluble matter.Eventually,the optimal purification route of acid insolubles in the process of freezing nitrophosphate is summarized as following,drying,sieving,washing,magnetic separation,grinding,hydrochloric acid leaching,through which the SiO2 content in the acid insolubles can increase to 88.92%and reached the standard for the production of micro silicon powder.