酒钢复配除尘灰直接还原-磁选试验研究
Experimental study of direct reduction-magnetic separation of JISCO compound dust ash
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摘要: 除尘灰的处理一直是冶金领域的难点问题。为实现除尘灰的资源化利用,减少除尘灰中有害元素对周边生态环境的影响,对酒钢6种除尘灰复配设计,验证火法工艺处理除尘灰的可行性及有害元素脱除效率,并根据直接还原实验结果确定合适的窑渣磁选实验配料。实验结果表明,按照质量百分比复配,高炉布袋灰∶炼钢二次除尘灰∶堆存高炉布袋灰∶混合除尘灰∶高炉重力除尘灰∶炼钢OG泥=28.50∶7.50∶15.50∶6.50∶28.50∶13.50,配碳量30%,焙烧温度1 100 ℃,焙烧时间60 min,焙烧后烧损率为36.62%,锌、钾、钠的脱除率分别为67.86%、75.56%、72.41%,铁品位为30.77%,焙烧物料经过细磨磁选后,得到的铁精粉铁品位为80.84%,铁回收率高达81.44%。多种除尘灰复配后直接还原-磁选回收金属铁的试验及机理分析,有望为除尘灰的处理开拓新途径。Abstract: The treatment of dust removal ash has always been a serious problem in the metallurgical field. To realize the resource utilization of dust removal ash and reduce the impact of its harmful elements on the surrounding ecological environment, six kinds of dust removal ash from JISCO were compounded and designed to verify the feasibility and efficiency of removing harmful elements from them by the pyrometallurgical process. According to the results of the direct reduction experiments, suitable experimental ingredients were determined for the kiln slag magnetic separation. The experimental results showed that the burn loss rate was 36.62% after roasting under the conditions of the mass percentage compounding of BFBD (Blast Furnace Bag Dust)∶ SSDA (Secondary Steelmaking Dust Ash)∶ SBFBA (Stored Blast Furnace Bag Ash)∶ MDA (Mixed Dust Ash)∶ BFGDA (Blast Furnace Gravity Dust Ash)∶ OG (Oxygen Gas Mud) = 28.50∶7.50∶15.50∶6.50∶28.50∶13.50, with a carbon content of 30%, roasted at 1 100 ℃ for 60 min. The rates of dezincification, depotassication and desodium were 67.86%, 75.56% and 72.41%, respectively. Furthermore, the iron grade in the roasted material was 30.77%, and the iron concentrate powder with 80.84% grade was obtained after fine grinding and magnetic separation, achieving an iron recovery rate of 81.44%. The experimental study and the associated mechanism analysis of metallic iron recovery with direct reduction and magnetic separation after compounding multiple dust removal ash are expected to provide a promising new approach for treating dust removal ash.