Research On Ultra-light Porous Ceramic Filtering Material

With the development of industry discharge of waste water is growing and the species of waster water is increasing. How to efficiently treat polluted water is a world puzzle. The development of novel filtration material of aeration biologic filter chamber for sewage disposal is very important.At present study, excellent, proper pore size and controllable density lightweight ceramic filtration balls which can be applied to sewage disposal were made from diatomite in which pore-forming agent, flux and other additives were added. Factors that influence ceramic pore feature, density and strength were discussed. The porosity of ceramic filtration balls is 50%～70%. The density is 0.78g/cm~3～1.2g/cm~3. The compressive strength is 4MPa～21MPa. The acid and alkaline resistance is above 95.03% and 97.62%, respectively. These performances were influenced by modifying the quantity of pore-forming agent (coal powder, dolomite, limestone, graphite) and diatomite, red mud, firing temperature. The results showed that with the increasing of pore-forming agent and diatomite, the porosity increase and density and strength decrease. With the increase of dolomite, red mud, limestone, and sintering temperature, the porosity increases and density and strength decrease.XRD analysis shows that the main crystalline phase is quartz and diopside. SEM analysis reveals that there are large quantities of three-dimensional pores whose diameters are about 100μm. The micro pores whose diameters are the range from several hundred nm to severalμm connect with the macro pores each other.Furthermore, pilot-experiment was done for some excellent batch formula, (it was that the lightweight porous ceramics ball by ball-molding machine). Beside the chemical composition of raw materials in batch formula, the process of molding does great influence on the performance of sample. According to the results, factors which influence strength of sample include type of cohesive, frequency of cohesive added and molding time, the body used organic cohesive is more strength than that used water. With the increase of sprayed frequency of water, the frequency of water sprayed to body would enhance the strength of it. Through the primary exploring, lightweight porous ceramic was prepared whose porosity, compressive strength, and buck density is 57.34%, 5.34MPa and 0.9 g/cm~3, respectively.