Study On Membrane Of Cordierite Wall-flow Honeycomb Ceramic For High Temperature Dust-laden Exhaust Gas Purification

Under the current serious circumstance of energy saving and emission reduction,the requirement for smoke and gas emission from coal combustion for industries such as steel,electric power,metallurgy,chemicals,cement and ceramics had become increasingly strict.There are various processing methods for smoke and gas,but current methods such as bag filter,electrostatic Precipitator,ceramic tube filter are far below the standard required.However,wall-flow honeycomb of cordierite has become the most ideal component for high temperature smoke-gas processing,because of its excellent performance under high temperature,less pressure loss and chemical stability.But the trouble is hard to cleaning.Therefore,it is must to the research on Surface-modification of wall-flow honeycomb ceramic of cordierite,in order to improve the performance,the filtration efficiency and prolong the service life of wall-flow honeycomb of cordierite.This thesis is writing for the research on membrane of wall-flow honeycomb ceramic of cordierite and synthesis of low thermal expansion cordierite material.The experiments were systematic research on effect of stability of the slurry on dispersant type,pH-value of slurry,viscosity of slurry and sedimentation time,research on effect of thickness of membrane on dipping time,solid content,viscosity of slurry,research on effect of bore diameter of membrane and bonding strength of membrane on formulation,grain composition,sintering system,research on filtering quality of cordierite wall-flow honeycomb ceramic for before and after coating,research on effect of thermal expansion on firing temperature,content of(silicon,aluminum,magnesium)in formulation and type of kaolin.The experimental results showed that the best preparation technology which had 8 pH-value,0.16wt%polyacrylate sodium and 14wt%cordierite for 15 seconds,in the drying oven 60? drying,through 1240~1260?,heat preservation 60min firing to get the thickness of membrane about 70~80?m.By the increase in large particles,rise the firing temperature,prolong the heat preservation time and join the cosolvent,bore diameter of membrane got bigger and bore diameter of roof membrane can be adjustable between 1~5 ?m.By the increase in small particles,rise the sintering temperature and join the cosolvent,bonding strength of membrane got better and membrane does not fall off under 1.5MPa recoil pressure.Finally,through testing,membrane of cordierite wall-flow honeycomb ceramic filtration pressure for 437Pa higher than support filtration pressure for 374Pa 16.8%under the condition of room temperature and filtration velocity of 1.88crm/s,lower than filtration pressure of Japan's similar products pressure for 720Pa 39.3%.Filtration pressure grew with the increase of membrane thickness.membrane of cordierite wall-flow honeycomb ceramic are easier to clean than support,need to recoil pressure less than support,with extended their run,the advantage is more outstanding,with the increase in velocity of gas and filtration pressure,we need lager pressure recoil the ceramic membrane to cleaning,It was examined that filtration efficiency of membrane of cordierite wall-flow honeycomb ceramic was 99.9%and running stability is good.The lowest thermal expansion was 1.24+10-6/? of the experimental synthetic cordierite material,Formulas for the experiments were 82.4wt%1#kaolin,9.3wt%talc and 8.4wt%magnesium oxide.