为了综合利用低品位煤矸石,首先对其原矿进行低温(400℃以下)煅烧和酸洗除杂的预处理,然后以预处理后的煤矸石为主要原料,适量添加氧化铝使n(Al2O3):n(SiO2)=1:1,以平均粒径5.6~6.2μm的交联丙烯酸树脂做造孔剂,PVA溶液为结合剂,经反应烧结制备多孔莫来石,并研究了造孔剂添加量对多孔莫来石显微结构和性能的影响。结果表明:以低品位煤矸石为主要原料,经过低温煅烧和酸处理后,适量添加氧化铝和造孔剂.经1600℃2h反应烧结可一步制备出主晶相为莫来石的多孔莫来石;随着造孔剂添加量的增加,多孔莫来石的显气孔率和线收缩率明显增大,体积密度、热导率和耐压强度显著降低,但其质量分数增加到30%后.这些性能的变化趋于平稳。
Natural low grade coal gangue was calcined below 400℃ and pickled to remove impurities for its comprehensive utilization. Porous mullite was prepared by reaction sintering using the pretreated coal gangue as main starting material,adding alumina to make n(Al2O3 ): n(SiO2) = 1 :1 ,crosslinking acrylic resin with average size of 5.6-6.2 μm as pore-forming agent,and PVA solution as binder. Effect of pore-forming agent addition on microstructure and properties of porous mullite was researched. The results show that:por- ous mullite with main crystal phase of mullite can be prepared by using low grade coal gangue after low temperature calcining and pickling,adding alumina and pore-forming agent,and reaction sintering at 1600℃ for 2 h;with the increased pore-forming agent addition,the apparent porosity and shrinkage in dimensions increase, bulk density, thermal conductivity and compressive strength decrease obviously, however, when pore-forming agent addition increases to 30 mass%, the change of properties tends to be stable.