利用高含碳金属化团块实现高炉炼铁的节焦

 高炉炼铁是主要的铁水生产工艺,低焦比炼铁一直是高炉节能的重要指标。研究了高含碳金属化团块在高炉中的应用,以达到节约焦炭的目的。利用超细氧化铁粉和非焦煤煤粉为原料在管式加热炉中通过直接还原制备了碳质量分数为15.6%的高含碳金属化团块;在模拟高炉环境的条件下,考察了团块质量变化、团块部分反应后抗碎强度变化和团块微观结构变化;利用自制的热重装置考察了团块内碳的气化动力学;以试验结果为基础,结合高炉数学模型,对利用高含碳金属化团块实现高炉炼铁节约焦炭的效果进行了定量分析。试验结果表明,在高炉环境下,团块部分反应后抗碎强度可以保持在1 200 N/个以上,团块的反应主要为碳溶损反应,且团块有较高的CO₂反应性。对2 500 m3高炉的模拟结果表明,在高炉的含铁炉料层中添加质量分数为5%的高含碳金属化团块,生产率可以提高419 t/d,生产1 t铁水可以节约焦炭11.3 kg,且高炉的操作参数不需要进行调整。

Applying high-carbon metallic briquette in blast furnace for coke saving

The blast furnace (BF) ironmaking is the dominant process for hot-metal production and the low-coke operation in BF ironmaking has been long focused. Applying high carbon metallic briquette (HCMB) in BF for coke saving has been studied.The HCMB was prepared using ultrafine iron oxide and non-coking coal fines, and the mass percent of the HCMB sample was 15.6%. Under the simulated BF conditions, the behavior of the HCMB, including mass change, crushing strength change, and microstructure evolution was examined. The gasification kinetics of the HCMB carbon was investigated using the custom-built experimental setup. The coke saving effect of applying HCMB in the BF was analyzed by simulations. Experimental results show that an iron crust was formed in the outer periphery of the briquette under the BF simulation conditions and the briquette has a good anti-pulverization capability; the main reaction of the briquette is carbon-solution loss reaction, and the briquette has a high CO₂ reactivity in the BF. Simulation results on a BF of 2 500 m3 indicate that by mixing 5% HCMB in the ore burden, the BF can realize coke reduction of 11.9 kg for producing 1 t hot metal from the ore, and a productivity increase of 419 t/d; moreover, change of the BF operation condition is not required.