| With the development of science and technology,coal has been mined in large quantities.Coal gangue,an associated product of coal,has become the largest industrial solid waste in my country,causing serious pollution to the environment.At present,the main resource utilization of coal gangue is limited to low-value utilization methods such as roadbed,brick making,and backfilling.Many scholars have devoted themselves to the research in the field of porous ceramics prepared from coal gangue,but less research has been done on multiphase porous ceramics.In this paper,mullite porous ceramics were first prepared by using coal gangue as the main raw material.The particle size of coal gangue,the types of pore-forming agents,the content of pore-forming agents and the sintering temperature on the physical properties and microscopic morphology of mullite porous ceramics were studied.Impact.Secondly,mullite porous ceramics were prepared by adding clay,and the effects of clay content and sintering temperature on the density and mechanical properties of ceramics were explored.However,the performance of a single porous ceramic is not ideal.Finally,zirconia mullite composite porous ceramics were prepared by introducing zirconia,and the effects of zirconia addition and sintering temperature on ceramic porosity,bulk density,flexural resistance,pore structure,and microscopic morphology were mainly studied.The following conclusions are drawn from the above research:(1)Through the orthogonal experiment,the influence of the three factors of pore former,sintering temperature,and different coal gangue particle size ratio on the porosity,bulk density and volume shrinkage rate of the sample is studied.The results show that the 60 mesh Coal gangue under the sieve and 80 mesh sieve is the main raw material,starch is selected as the pore former,and the sintering temperature is controlled between 1250℃～1400℃to further explore the influence of pore former content on the performance of porous ceramics.The study found that the pore former was added at 15 wt.%,and the sintering temperature was controlled at 1350℃,which increased from 16.74%to 20.76%.Under these conditions,mullite porous ceramics with higher porosity,continuous compact body and reasonable pore structure can be prepared.(2)Using coal gangue and clay as the main raw materials,starch as the pore former,the mullite porous ceramics were prepared by the hydraulic forming method and the solid sintering method,and the sintering temperature and clay were studied.The effect of the additive amount on the performance of mullite porous ceramics.Through thermogravimetric analysis(TG-DSC),flexural properties,X-ray diffractometer(XRD),scanning electron microscope(SEM),mercury intrusion method and other technical methods,the thermal stability,mechanical strength,crystal phase composition,Indicators such as microscopic morphology and pore size are characterized.The results show that the mullite porous ceramics prepared under the conditions of sintering temperature of 1300℃and clay content of 40wt.%have the best performance,with a porosity of 34%,a bulk density of 1.79 g/cm~3,and a volume shrinkage rate.11.88%,flexural strength of 33.28 MPa,uniform pore distribution and more mature mullite crystals.The research results have opened a new way to explore the high-value utilization of coal-based waste.(3)Using coal gangue and zirconia as the main raw materials,starch as the pore former,the zirconia mullite composite ceramics are prepared.The effects of zirconia content and sintering temperature on the phase composition,density,pore structure,element distribution and other properties of the composite ceramics are studied.The results show that the composite porous ceramic prepared at a sintering temperature of1400℃at a sintering temperature of 12 wt.%of zirconia has a porosity of 39.9%,a volume shrinkage of 7.1%,and a flexural strength of 67.3 MPa.Realize the high-value utilization of coal gangue.Figure[34]Table[11]Reference[105]... |
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