通过对利用湿法磷酸副产物氟硅酸与氢氧化铝直接制备工业级氟化铝的工艺进行研究与优化，以期提高氟化铝产品的质量。这不仅充分利用了氟资源，优化了合成工艺，而且对添加聚乙二醇（PEG）提高氟化铝产品的松装密度着重开展了研究。结果表明，当氟硅酸预热温度为80 ℃、氟硅酸质量分数为19.1%、n（氢氧化铝）∶n（氟硅酸）为1.8∶1、氢氧化铝干粉快速投料，控制反应温度为95~107 ℃、搅拌速率为400 r/min、反应时间为16 min、添加氟化铝为晶种、结晶时间为5.0 h、结晶温度为107 ℃时，氟化铝收率为77.56%，氟化铝的松装密度为0.70 g/cm³。以聚乙二醇为结晶改性剂制备氟化铝，添加聚乙二醇的用量为7.40%、结晶时间为5.0 h、结晶搅拌速率为200 r/min、结晶温度为107 ℃时，氟化铝收率为81.45%，氟化铝松装密度达到0.83 g/cm³，松装密度提高了18.57%。氟化铝产品的化学成分和物理性能均能达到GB/T 4292—2017《氟化铝》的要求。以磷化工副产氟硅酸和工业级氢氧化铝为原料，优化了氟硅酸湿法制备氟化铝的工艺，使得氟化铝产品的收率和松装密度有所提高，为磷化工行业副产品氟硅酸的推广应用提供了技术支撑。

In this paper，the process of directly preparing industrial grade aluminum fluoride by using fluorosilicic acid and aluminum hydroxide，a by-product of wet-process phosphoric acid was studied and optimized in order to improve the quality of aluminum fluoride products.It not only made full use of fluorine resources and optimized the synthesis process，but also focused on the study of adding polyethylene glycol（PEG） to improve the apparent density of aluminum fluoride products.The results showed that when the preheating temperature of fluorosilicic acid was 80 ℃，the mass fraction of fluorosilicic acid was 19.1%，the molar ratio of n（aluminum hydroxide）∶n（fluorosilicic acid） was 1.8∶1，the dry powder of aluminum hydroxide was rapidly fed，the reaction temperature was 95~107 ℃，the stirring speed was 400 r/min，the reaction time was 16 min，aluminum fluoride was added as seed crystal，the crystallization time was 5.0 h，and the crystallization temperature was 107 ℃，the yield of aluminum fluoride was 77.56%，and the apparent density of aluminum fluoride was 0.70 g/cm³.Aluminum fluoride was prepared by using polyethylene glycol as a crystal modifier.When the amount of polyethylene glycol was 7.40%，the crystallization time was 5.0 h，the crystallization stirring speed was 200 r/min，and the crystallization temperature was 107 ℃，the yield of aluminum fluoride was 81.45%.The apparent density of aluminum fluoride reached 0.83 g/cm³，and the apparent density was increased by 18.57%.The chemical composition and physical properties of aluminum fluoride products could meet the requirements of GB/T 4292—2017 “aluminum fluoride”.In this paper，the process of wet preparation of aluminum fluoride by fluorosilicic acid was optimized by using fluorosilicic acid and industrial grade aluminum hydroxide as raw materials，which improved the yield and apparent density of aluminum fluoride products，and provided technical support for the popularization and application of fluorosilicic acid，a by-product of phosphorus chemical industry.