| In this work, waste glass, coal gangue, fly ash and slag gasification were used as main raw materials to prepare inorganic porous materials by sintering method after molding or extrusion together with binder and pore-forming agent. A series testing means were used to characterize the phase composition, porosity, bending strength, pore size distribution and microstructure of the samples. The obtained porous ceramic materials have potential applications in water treatment and air purification, which could not only consume solid waste, but also reduce the cost of environmental technology. The output of this project will obtain a significant progress in science and engineering perspective.Porous glass was prepared by sintering pure glass powders at low-temperature. When the holding time was 30min, with the temperature rose from 640? to 670?, the opening porosity of porous glass decreased from 37.4% to 29.4%, while the bending strength increased from 2.5MPa to 12.8MPa. The average pore size increased at first and then reduced. At the same sintering temperature, the porosity of the porous glass increased with the rising of pore forming agent content, however, too much starch content (16%wt) made an adverse effect on strength. The suitable sintering temperature range of porous glass is narrow, samples with pore-forming agent content of 8% and sintered at 670? for 30min had optimal mechanical properties, when the average pore diameter was 10.70?m, nitrogen flux and water flux was 13600m3m-2h-1bar-1 and 693.4m3m-2h-1bar-1 respectively.Porous ceramic with good porosity, permeability and strength was prepared from waste glass and coal gangue obtained from Huainan Guqiao Coal Mine by sintering the green materials at 950? to 1100? for 3h, the average pore size of the porous ceramic is about 2?m, and the main phase is quartz and tridymite. When the glass content of the samples was 20%, the porosity of the porous ceramic decreased from 45.3% to 32.9% with the rise of sintering temperature, while the flexural strength increased to from 5.99MPa to 20.42MPa, the average pore size and a nitrogen flux increased at first and then decreased. The glass content of samples also had a significant impact on properties. For samples sintered at 1050?, when the glass content ranged from 0 to 30%, the porosity decreased from 46.0% to 22.4%, while the bending strength increased to from 9.15MPa to 21.6MPa, the average pore size and nitrogen fluxes are increased first and then decreased, samples with glass content of 10% had the best nitrogen permeability, and the average nitrogen flux was 4131m3m-2h-1bar-1.For the porous ceramics prepared from gasification slag (obtained from Shenhua Energy Company Limited), when the sintering temperature increased from 1000? to 1200?, the overall trend of its porosity and bending strength was decrease and increase respectively, the average pore diameter and nitrogen flux increased gradually with the increasing of temperature. However, the anti-densification process happened at 1150?, which resulted in the increase of porosity and the decrease of bending strength. Porosity and bending strength of samples sintered at 1200? was 39.2% and 13.17MPa, average pore diameter was 8.37?m, and the nitrogen gas flux was 23000m3m-2h-1bar-1.For the porous ceramics prepared only by fly ash, the porosity increased with the sintering temperature rose from 1100? to 1200?, and then decreased with the temperature rose to 1300?. Porosity had the minimum value at 1300? of around 47.1%, the flexural strength increased gradually with the increase of temperature and reached 14.84MPa at 1300?. The average pore size of samples increased from 2.03?m at 1100? to 5.28?m at 1300?. The gas flux increased gradually from 1100? to 1250?, and decreased slightly at 1300? for the average nitrogen flux was 4295m3m-2h-1bar-1. This work also tried to prepare 19 channels porous ceramic tubes from fly ash. The prepared ceramic membrane tube had a small shrinkage and high strength, which is suitable for use as ceramic membrane support. |
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