Preparation and mechanical properties of palygorskite-based porous ceramsite

Palygorskite-based porous ceramsite (PC) was prepared by calcination with palygorskite, sawdust and sodium silicate. Effect of the mass ratio of reaction materials and clacination technique on the properties of ceramsite was investigated. Furthermore, in various tests for the ceramsite, compressive strength was the principal factor to determine the mechanical properties of ceramsite. To choose the most suitable product, porosity, calcination temperature and time were introduced as factors in orthogonal experiment design to determine the preparation of PC. XRD and SEM were used for the characterization of porous ceramic characteristics. The results show that a promising combination of palygorskite clay, sawdust, and sodium silicate would ensure PC conforming to the state industrial standards of water treatment, when the mass ratio is 10:2:1, the calcinations temperature is 700℃ and the calcinations time is 3 h. The uniform and interconnected pores in PC are suitable for the microbial growth.