碳热预还原及二次氢还原试制超细铁粉研究

Experimental research on preparation of ultra-fine iron powder by carbothermal pre-reduction and hydrogen reduction

在钢带试验装置上开展了低温碳还原及氢二次还原试验试制超细金属铁粉。研究了3种不同成分的碳粉对金属铁粉产品质量的影响,结果表明低灰分、高固定碳含量碳粉符合纯金属铁粉制备的要求;添加少量催化剂,能够显著提高低温碳的还原效果,并能提高低温下的间接还原率。还原温度为850℃、加热时间为2 h、还原碳为原料中氧含量的80%,碳酸钾的加入量为0.5%~1.0%,可以得到全铁含量大于91.7%的铁粉,在此基础上750℃氢还原2 h,可以得到成分合格的超细金属铁粉,产品的D50为5~6μm,D90为10~12μm,松装密度为1.35 g/cm3。

The low-temperature carbon reduction and hydrogen secondary reduction tests were carried out on a steel strip test device to trial-produce ultra-fine metal iron powder. The effects of carbon powder with three different components on the quality of metal iron powder products were studied. The results show that low-ash and highfixed carbon content carbon powder meet the requirements for the preparation of pure metal iron powder;adding a small amount of catalyst can significantly improve the reduction effect of low-temperature carbon and the indirect reduction rate at low temperatures. When the reduction temperature is 850 ℃,the heating time is 2 h,the reduced carbon is 80% of the oxygen content in the raw material,and the addition amount of potassium carbonate is 0.5%-1.0%,theTFe of the iron powder is greater than 91.7%. It can be reduced by hydrogen at 750 ℃ for 2 h to obtain qualified ultrafine metal iron powder. The D50 of the ultra-fine iron powder is 5-6 μm,and the D90 is 10-12 μm,the apparent density is 1.35 g/cm3.