Study On The Preparation And Permeability Of Porous Ceramics For Filtration

Human beings are faced with two serious problems about resources andenvironment in current society. As a new type of filtration materials, porous ceramicshave been applied widely in lots of fields. However, many shortcomings still exist,such as complex production process, high fabrication cost, insufficient strength, lowporosity, weak separation effect, low filtration efficiency, short service life, ect.Therefore, it seems significative to fabricate environmental porous ceramics used forfiltering with high strength, high porosity, adjustable pore size and good separationeffect.First, with the methods of particle accumulation and adding pore-forming agent,porous ceramics with high strength and high porosity were fabricated in this paper.The measurement device for penetration performance of porous ceramics was alsoestablished. By comparison, the pore-forming agent had been chosen and the formulaof inorganic binder had been optimized. In the Angle of wetting, connection effect ofthe inorganic binder on the aggregates was discussed. Two basic conditions should bemeeted: Sintering temperature must be above the melting temperature of the inorganicbinder and the binder should have good wettability with the aggregates. The influenceof sintering temperature, holding time, inorganic binder content, molding density andpore-forming agent content on the structure and performance of the porous ceramicswas also disscussed intensively. LiF and CaF2were added into the inorganic binderrespectively, then their effects on the porous ceramics were compared and analysized.The performance of the porous ceramics could be improved with the addition of CaF2while it turned worse after adding LiF.Next, with the screen-printing method, ceramic membranes with differentcharacteristics were coated on the surface of the support. Then, gradient ceramicswere obtained, which can be used for filtration and separation with high precision.With the help of the gradient ceramics, production cost can be saved and filtrationefficiency can be improved.In addition, characteristics of corundum based and quartz based porous ceramicswere compared, which included bulk density and bending strength. At the same time,by means of theoretical derivation, relevant function fittings were done. And, the bulkdensity and the bending strength of ideal dense ceramic had been calculated.At the end, with different particle-sized corundum as aggregates, ceramic discs with series of apertures were prepared and their technical parameters were determined.With the drilling fluid as medium, the leakage characteristics of ceramic discs weremeasured and the seepage loss with the same standard products was more or less. Itshowed that the balance of the ceramic discs was favorable.