Influence of quartz replacement by Iraqi porcelanite and silica fume on the properties of porcelain products

In this work, Iraqi porcelanite and silica fume were used as a silica source with replacement of quartz in the manufacture of porcelain products to investigate their influence on properties of these products. The specimens were prepared with composition (50: 30: 20) % as kaolin, silica source and feldspar respectively. Then, they dried at (383 K) temperature for 3 hrs. and sintered at (1473 K) temperature by soaking time for 2hrs. The fracture strength, hardness, apparent porosity, bulk density, linear shrinkage, and XRD, SEM and EDS analyses of the specimens were examined. The test results indicated that replacement of quartz by these sources improves the densification behavior and mechanical strength due to form of more amount from the glassy phase and interlocked crystals from mullite phase within the microstructure. Also, this replacement gives an economic interest for the energy saving and reduction of the material consumption, in addition to produce porcelain products with the best mechanical properties.