冷冻干燥技术是制备纳米铁粉的一项非常重要的技术。超细铁粉（60～1180）在空气中很稳定并具有显著的磁性能，它是由超细赤铁矿粉（30～50）在200℃还原制成的，而这种超细赤铁矿粉又是由冷冻干燥氮化铁前驱体分解制备的。冷冻干燥工艺显然是生产和开发低成本的磁性记录和“抛 Freeze-drying technology is a very important technology for preparing nano-iron powder. Ultrafine iron powder (60 ~ 1180) is very stable in the air and has significant magnetic properties. It is produced by the reduction of ultrafine hematite powder (30-50) at 200 ° C. This ultrafine iron In turn, the ore powder is produced by the decomposition of a freeze-dried iron nitride precursor. The freeze-drying process is clearly the production and development of low-cost magnetic recording and polishing