核-壳型KHCO3/赤泥复合粉体的甲烷抑爆特性
Suppression characteristics of KHCO3 / red-mud composite powders with core-shell structure on methane explosion
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摘要: 为了获取新型经济、环保、高效的粉体抑爆材料,以制铝工业废料赤泥为原料加以改性作为载体,采用反溶剂-溶析法制备出具有核-壳结构的KHCO3/赤泥复合粉体。通过20 L球形抑爆实验系统,测试新型复合粉体对甲烷爆炸压力参数的影响,并与单一赤泥粉体和KHCO3粉体的抑制效果对比。结果表明:核-壳型KHCO3/赤泥复合粉体具有更好的抑爆效果。其中,负载含量为30%的KHCO3/赤泥复合粉体使9.5%的甲烷-空气预混气体的爆炸最大压力降低37.5%,最大升压速率降低93.2%,爆炸延迟时间大幅度延长。并对核-壳型KHCO3/赤泥复合粉体的抑爆机理进行了讨论分析。Abstract: The KHCO3 / red-mud composite powder was successfully prepared by the anti-solvent method for gas explo- sion suppression. The aluminum industry solid waste red mud was used as the support,and the traditional suppressant KHCO3 was used as the active species. The as-prepared samples were analysized by the techniques of XRD,TG-DSC, SEM,TEM. The analysis results indicated that the composite powder possesses the special core-shell structure,which has an impact on inhibitory property. The suppression property of the as-prepared sample for CH4 explosion was tested by a 20 L spherical explosion experimental system. The results show that the potassium bicarbonate / red mud composite powder has better suppression property than that of pure red mud or pure potassium bicarbonate. The explosion pres- sure of 9. 5% methane-air premixed gases was reduced by 37. 5% with 30% loaded content. The maximum value of pressure rising rate was reduced by 93. 2% ,and the sensitive period of the explosion was extended from 25 to 250 ms. The explosion suppression mechanism of this potassium bicarbonate / red-mud composite powder was also investigated.