Abstract: A shaft furnace was used to secondary heat the blue-cokes which were manufactured by different temperatures of carbonization furnaces at the medium heating rate (10℃/min) and final temperatures of 800, 900, 1200, and 1600℃, as a way to simulate the state of the blue-coke during the downward movement of the upper part of the ferrosilicon furnace. The physical and chemical structure and reactivity changes of the incoming blue-coke at different heat treatment temperatures were studied by using nitrogen adsorption, Raman spectroscopy, and thermogravimetric analysis, and the key aspects of the blue-coke affecting the furnace condition were analyzed with the results of industrial experiments. The results showed that with the increase of heat treatment temperature, taking 800 and 1200℃ as the turning points, the specific surface area and pore volume of blue-coke increased, then decreased and then increased until stable; the defects and amorphous structures in carbon chemical composition gradually changed into ordered carbon structures; the reactivity of blue-coke gradually became worse; and taking 1200℃ as the turning points, the resistivity decreased in stages. As the heat treatment temperature increases, the difference in pore structure, carbon chemical composition, reaction properties, and resistivity among different blue-cokes decreased. When the secondary heat temperature was higher than about 1600℃, the pore structure, carbon chemical composition, reaction performance, and resistivity of different blue-coke tend to be stable. In the upper part of the ferrosilicon furnace, the overburning of the blue-coke with a well-developed pore structure and better reaction performance after feeding into the furnace lead to the deterioration of the mechanical strength of the blue-coke and the increase of the charcoal consumption, which were the main factors affecting the difference of the smelting effect of different blue-cokes in the furnace. In the lower part of the ferrosilicon furnace, the physical and chemical properties of blue-cokes with different mass were similar, which was no longer the main factor affecting the furnace condition.

Key words: semi-coke, ferrosilicon furnace, pore structure, carbon chemical composition, reactivity

摘要： 采用井式炉干馏装置分别对兰炭进行不同温度热处理，并以此模拟兰炭在硅铁炉上部区域下行过程中的状态。利用氮气吸附、拉曼光谱、热重分析等方法研究了不同热处理温度下入炉兰炭的理化结构和性能变化，结合工业实验结果分析兰炭影响炉况的关键环节。结果表明，随热处理温度升高，兰炭比表面积和孔容呈先增大后减小再增大直至稳定的变化规律，碳化学结构中缺陷和无定型结构逐渐转变为有序碳结构，兰炭反应性能变差，电阻率呈阶段性降低。热处理温度大于1600℃后，不同兰炭间的孔隙结构、碳化学结构、反应性能和电阻率性能变化趋于稳定。孔隙结构发达及反应性能较好的兰炭入炉后在料面的过度烧损导致兰炭机械强度恶化和炭耗增加，这是影响不同品质兰炭入炉冶炼效果存在差异的主要因素。

关键词: 兰炭, 硅铁炉, 孔隙结构, 碳化学结构, 反应性能