Characteristics of porous ceramics prepared from sandblasting waste and waste diatomite by co-sintering process

The purpose of this research is to recycle sandblasting waste from the surface treatment process of solar cell industry to replace waste diatomite (with a replacement ratio of 0-20%) to make water-retention porous ceramics, and adopts the method of molding by semi-dry pressing under a pressure of 5 MPa, as the heating temperature fluctuated between 1000, 1100, 1200, and 1270 degrees C. With a heating rate of 5 degrees C/min, the heating process continued for 120 minutes. The sintered samples were then examined to determine whether its mechanical properties were met the CNS 382 R2002 Brick Criteria in terms of compressive strength (>3 MPa); while FTIR, and MIP instruments were used to measure the changes in the sintered samples according to pore size and total pore volume. The results indicated that the waste diatomite and sandblasting waste consisted of quartz, and porosities of porous ceramics with sandblasting waste about higher than 58.5-64.7%, water absorption of about 72.2-92.2%, and compressive strength of about 2.4-7.3 MPa can be produced using a porous ceramics of raw materials. The porous ceramics samples with 0-20% sandblasting waste prepared at the heating temperature of above 1100 degrees C meet the Standards for Japan Interlocking Block Pavement Engineering Association (compressive strength > 3 MPa, water absorption > 70%). Moreover, the thermal conductivity of cement paste was 0.57 W/m.K, which was significantly higher than 0.28-0.49 W/m.K of porous ceramics with sandblasting waste, the porous ceramics have good heat insulation effects. (c) 2018 American Institute of Chemical Engineers Environ Prog, 38: 321-328, 2019