Fabrication of diatomite cartridge filters

The diatomite is a high potential material in fabrication of high porosities ceramic materials because of that it has micro-porous structure and also its structural particle size is narrow. But inorganic additives such as clay are required for shaping of the material; however these additives fairly decreased the micro-porous structure during sintering. In this study, the diatomite structure is produced without inorganic additives. For this purpose, a filter with large porosities is designed and the natural diatomitic material grinded to small size and later filled the filter pores by the filtration technique. The filters sintered at differed temperatures (600-800 oC) are directly tested for water filtration. Besides the filters are exposed to hot acid leach (75 oC 5M HCl) at different times and so their permeability is increased. The filtration performances of these filters are compared to the filters which are not leach. The periodic filtration performances of the filters are also investigated. The periodic filtration is formed with pressure of 5 bar every 5 minutes. While the back flush cleaning pressure is chosen from different values (2-6 bar), the most backflush cleaning pressure which can be performed to the filters is determined as 5 bar. The filters are tested at the filtration of the overflow sample (100 ppm) after the sedimentation process of the marble wastewater and the particle sizes are under 2µm. The periodic filtration capacity of the present filters for 5 minute intervals is of 1,5 m3/m2.