摘要：采用LNJST-120HT型闭路循环氮气保护气流粉碎分级系统对磷酸铁锂粉进行超细加工、干燥;对粉碎、分级、收集、输送和包装系统的操作参数、设备结构及系统运行过程中出现的流动性、水分增加等问题进行分析探讨, 并优化改进;通过加工超细磷酸铁锂粉的工业试验, 对改进后的超音速气流磨进行测试。结果表明, 控制螺杆加料机和分级机转速分别为62和1 072 r/min, 气源压力和温度分别为0.5 MPa和120℃, 包装房露点温度控制在-20℃以下, 磷酸铁锂粉成品水分含量维持在0.35‰~0.55‰, 成品粒径d₅₀=0.8~1.2μm、d₁₀₀<8μm, 产量为200~230 kg/h。

关键词：闭路系统；超音速气流磨；磷酸铁锂粉

Abstract：According to the moisture absorption of ultrafine lithium iron phosphate powder and its crushing requirements, the LNJST-120 HT closed-cycle airflow grinding and grading system with nitrogen gas protection were applied to the superfine processing and drying of the lithium iron phosphate powder. The operating parameters and equipment structure in the system of grinding, grading, collecting, packaging and transporting were analyzed and improved. Meanwhile, the liquidity and moisture content of the powder in the running process were also studied.Through the industrial test of processing ultrafine lithium iron phosphate powder, investigation on the improved supersonic jet milling was adopted. The results show that, when the rotational speed of the screw feeding machine and the classifier are 62 and 1 072 r/m in respectively, the air pressure and temperature are 0.5 MPa and 120 ℃, and the dew point of the packing room is controlled below-20 ℃, the moisture content of lithium iron phosphate powder is maintained from 0.35 ‰ to 0.55 ‰, the mean particle size (d₅₀) is 0.81.2 μm, the maximum particle size (d₁₀₀) is smaller than 8 μm, and the powder yield is 200~230 kg/h.

Keywords：closed system；supersonic jet milling；lithium iron phosphate powder