The crystal form of preheating pellets interlink well and the structure is well-proportioned and compact, fine magnetites are oxidized to form hematite which are connected with each other.

• 采用微波加热，预热球团内部矿物结构较均匀、紧密，细粒磁铁矿氧化成赤铁矿，并在大颗粒之间连接成片，球团强度明显提高。