含锌粉尘转底炉直接还原及工程化

Engineering of Direct reduction process using a rotary hearth furnace for recycling metal from Zinc bearing dusts

对钢铁厂含锌粉尘采用配料—混料—压球(或造球)—烘干—转底炉直接还原的工艺流程进行了中试试验研究,获得较佳的条件是:混合料TFe品位4 3.04%,原料配料C/0为1.1,焙烧温度1 300℃、焙烧时间20~30min,此时获得球团金属化率大于92%,TFe品位达到67.48%,96.16%的K、90.19%的Na、大于75%的Pb和大于96%的Zn进入烟气,Zn、Pb、K、Na可通过烟气回收系统进行回收。对通过中国金属学会鉴定的沙钢转底炉的运行情况、工艺数据和能耗进行了分析。

Pilot scale tests of zinc bearing dusts obtained from iron and steel works have been carried out in the current study,the test flow-sheet was consists of:blending,mixing,briquetting(or pelletizing) and direct reduction in a rotary hearth furnace(RHF).Reduction roasting of the mixture(with iron grade of 43.04%and C/O ratio of 1.1) was conducted at 1300°C for 20 to 30 min,the results indicated that reduced pellets with high metallization(>92%) could be produced containing 67.48%Fe.Upon the reduction roasting,some of the valuable metal could be volatilized and collected subsequently from flue gas,including 96.16%of the K,90.19%of the Na,>75%of the Pb and >96%of the Zn.In addition,analysis of the RHF located at Shagang Group Ltd,which has been authenticated by The Chinese Society for Metals,was provided in terms of operating conditions,process data and energy consumption.