Study on separation of titanium and slag during carbonization of titanium-bearing blast furnace slag
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摘要: 高炉冶炼钒钛矿过程产生了大量含钛高炉渣,攀钢针对渣中钛资源的回收利用成功开发出了高温碳化-低温氯化工艺,但是该工艺存在碳化渣磨矿和氯化尾渣利用等技术性难题,还需要继续探索绿色、经济的处理方法。针对高温碳化过程中Ti(C,N) 弥散分布的问题,提出高温碳化过程加铁富集Ti(C,N)的思路,试验考察了铁/渣(质量比)、生铁添加批次、保温富集时间及预配铁量等因素对富集过程的影响。结果表明,熔渣中Ti(C,N)能聚集在熔铁表面并随其下沉至坩埚底部,水淬后附着有Ti(C,N)的铁块可与残渣实现自然分离,按铁/渣为1.50,在原料中预配15%铁,1600 ℃保温30 min后于30 min内分批向熔渣中加入铁的富集效果较好,可将渣中Ti含量从13.79%降低到4.59%,Ti的回收率达到66.72%。Abstract: The technology of high-temperature carbonization and low-temperature chlorination has been successfully developed by Pangang Group Company Limited to recover titanium from a large number of Ti-containing blast furnace slag produced during the application of the BF ironmaking technology to V-bearing titanomagnetite. However, It is also necessary to explore green and economic treatment methods because there are some challenges for this technology, such as grinding of carbide slag and utilization of chlorinated tailings. In view of the dispersion distribution of Ti(C,N) particles in high-temperature carbonization process, the idea of enrichment of Ti(C,N) by adding iron in carbonization process is proposed in this paper, and the effects of factors such as the mass ratio of iron to slag, the batches of adding iron, the holding time for enriching Ti(C,N) and the pre-adding content of iron on the enrichment process were investigated by experiment. The result shows that Ti(C,N) particles in the molten slag can aggregate on the surface of the molten iron which later sinks to the bottom of the crucible, and the lump iron coated by Ti(C,N) can be naturally separated from the residue by water quenching. With a specific iron-slag mass ratio of 1.50, iron added in two steps, i.e. 15%Fe is prepared in the slag and the rest of iron is added in batches within 30 min after holding at 1 600 ℃ for 30 min, shows good enriching effect. The Ti-content in the slag under this enrichment condition can be reduced from 13.79% to 4.59%, the enrichment rate of Ti(C,N) in carbonized slag can reach to 66.72%.
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Key words:
- high-titanium blast furnace slag /
- carbonization /
- iron /
- Ti(C,N) /
- enrichment
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表 1 含钛高炉渣化学组成
Table 1. Chemical compositions of Ti-bearing blast furnace slag
% TiO2 CaO SiO2 Al2O3 MgO 23 28.8 26.2 14 8 表 2 试验方案
Table 2. Experimental scheme
序号 铁/渣 预配铁/% 添加批次 总保温时间
/min富集开始时间/min 1 0.70 0 5 90 30 2 1.50 0 5 90 30 3 2.00 0 5 90 30 4 1.50 0 1 150 60 5 1.50 0 5 150 60 6 1.50 0 10 150 60 7 1.50 15 5 90 30 8 1.50 30 5 90 30 9 1.50 75 5 90 30 -
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