铁精矿氧化球团微波加热直接还原新方法

传统加热直接还原具有热效率低、球团"冷中心"和废热废气量大等问题,造成还原时间长、能耗高和污染大。试验利用微波的选择加热、快速加热、体积加热和清洁干净等优点,以及铁矿球团和无烟煤强的吸波特性,开发了铁矿球团煤基微波竖炉直接还原这一新工艺。研究表明,铁矿球团外配煤粉在1 050℃的微波加热条件下还原焙烧65min,可以获得95.25%的金属化率,同时具有1718.88N/个的抗压强度。与常规加热相比,微波加热还原焙烧的时间可以缩短27.78%,抗压强度增加近1倍,而且还原过程产生的废热废气量很少。

A New Method of Direct Reduction on Iron Concentrate Oxidized Pellets by Microwave Heating

Traditional heating for direct reduction had a low thermal efficiency and "cold center",even the large amount of waste heat and gas emissions,which made the long time,high energy consumption and heavy pollution for reduction of oxidized pellets.The major advantages of using microwaves in the experiment were rapid heat transfer,volumetric and selective heating and pollution-free environment,in addition,iron concentrate oxidized pellets and anthracite had a strong microwave absorbency,on the basis,a new coal based direct reduction technology on iron concentrate oxidized pellets was developed in microwave shaft furnace.The results show that iron concentrate oxidized pellets coal based direct reduction by microwave heating in 1 050 ℃ at 65 min,can obtain 95.25% the metallization rate,and has 1 718.88 N/a compressive strength.Compared with conventional heating,the time of microwave heating reduction roasting can shorten 27.78%,and compressive strength nearly doubled increase,even has little waste heat and gas emission.