无灰煤的热解行为及其在配煤中的添加效果

摘要

为清洁有效地利用褐煤参与配煤炼焦,改变温度和溶剂,采用高温萃取鄂尔多斯褐煤制备无灰煤,通过热重分析研究无灰煤的热解特性,随后将无灰煤与唐山1/3焦煤按质量比1∶9制备混煤,并炼制坩埚焦,测试混煤的吉氏流动度及焦炭的热性质,分析无灰煤的热解行为及添加无灰煤对炼焦煤热塑性及坩埚焦质量的影响.结果表明:无灰煤相较原料煤,煤中的中小型分子增多,挥发分增高,热解初始温度降低到250℃左右,解热区间增大,热失重增加.添加无灰煤后,混煤具有理想的塑性区间,坩埚焦热性质得到改善,特别是380℃下洗油萃取所得无灰煤,其塑性区间与唐山1/3焦煤有良好的重合,混合后混煤热塑性提高,最高流动度为2 602 ddpm,所得焦炭形貌平滑致密,大孔减少,反应后强度可达84％以上.%For the clean and effective use of lignite to participate in coking,the hypercoal was high-temperature extracted with Erdos lignite under different temperatures and solutions,and the pyrolysis characteristics of hypercoal were studied by thermogravimetric analysis.The hypercoal was added with the proportion of 10％ to Tangshan 1/3 coke coal to study the thermoplasticity of the blending coal by Gieseler fluidity test.The crucible cokes were prepared with the blending coal,and their thermal property were studied.The results showe that,hypercoal contain more medium molecular compared to the raw coal,the initial pyrolysis temperature is reduced to about 250 ℃,the weight loss of pyrolysis increase and pyrolysis temperature get lower.The thermoplastic of the blending coal and thermal property of coke are both improved by adding hypercoal.When using wash oil as solvent,the plastic range of hypercoal has good coincidence with basic coal,the maximum liquidity is 2 602 ddpm,so the crucible coke has high strength and smooth surface,a few macropore,post-reaction strength of coke can be increased to over 84％.