The Effect of bone china scraps addition on sintering behavior of hard porcelain body

One way to environmental protection and avoid raw materials waste is using bone china scraps in body composition. In this paper, the influence of bone china scraps addition on sintering behavior of hard porcelain body has been investigated. For this purpose, hard porcelain bodies produced with 0, 5.6, 10.7, 15.2 wt% bone china scraps and mixed in Jar mill and fired at temperatures 1340°C and 1250°C in kiln and their properties such as mechanical strength, bulk density, thermal expansion coefficient were investigated. The microstructure of fired specimens was studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results indicated that increasing of Bone china scraps, increase Mulite and decrease Quartz crystals in fired body. Also, addition of this waste cause to rising of Anorthite phase in fired body at 1250oC. The further results show, an increase in bone china scraps (up to 5.6 wt%) increase fired mechanical strength tow times in fired body at 1340°C and an increase of 15.2% bone china scraps increased mechanical strength of fired body in 1250oC for 4 times. Bulk density increasing in fired body in 1250oC, reducing bulk density and thermal expansion coefficient in fired body at 1340°C are the other result of addition of these scraps.