磷铁制备电池级磷酸铁放大实验研究

以磷铁、硝酸和磷酸为原料，采用液相结晶法制备电池级磷酸铁，并对磷酸铁结晶产物进行结构和元素分析。500 L结晶反应器的放大实验表明，制备出的磷酸铁热稳定性好，晶体结构和元素含量符合市场所售电池级磷酸铁的行业标准，磷铁中铁元素回收率高达98 %以上，具有较好的工业化应用前景。同时以不同来源的磷铁来探讨原料磷铁的适用性，发现硅质量分数在大于0.5%时，无法结晶制得产品。通过添加晶种对产品粒度、产量、结晶时间、形貌特征影响做了分析， 发现添加晶种的方式可以提升生产效率。电镜扫描照片显示，片状磷酸铁与市场所售产品相比表面光滑，团聚现象明显改善，并进一步分析了差异形成的原因。

Amplification experiments of preparing battery-grade ferric phosphate by ferrophosphorus

Battery-grade ferric phosphate was prepared by liquid crystallization method with ferrophosphorus，phosphoric acid，and nitric acid as raw materials.The elements and structure of the as-prepared ferric phosphate were analyzed.Results of amplification experiment in a 500 L crystallization reactor showed that the products not only had the advantage of thermal stability，but also the structure and elements accorded with the industrystandard of battery-grade ferric phosphate.Meanwhile，the iron recovery of the ferrophosphorus was as high as 98%. At the same time， the applicability of the raw materials with different sources of ferrophosphorus was explored.It was found that products can′t be got when the mass fraction of Si was more than 0.5%.Through analyzing the impacts of adding crystal seed on particle size，yield of products，crystallization time，and morphology characteristics，it was found that adding crystal seed could improve the efficiency of production.Products seemed more smoothly compared with products purchased from market through the SEM pictures and agglomeration phenomenon was obviously improved.