Addition of feldspart minerals as a substitution material on ceramics clay manufacture

The use of clay minerals as the main raw material for pottery and sand additives has many weaknesses, among others, easy to crack, have high water absorption and low compressive strength. Therefore it is necessary to develop a better method of making traditional ceramics by providing additional materials such as mineral feldspar. Mineral feldspart can be used as a ceramic raw material because it is functional as filler and glass forming phases. Clay and mineral feldspart raw materials were analyzed using XRF method, followed by mixing with the composition of clay soil mixture as much as 65% compared to feldspart by 35%, printed with the shape of cube size 50x50x50mm. Drying in oven with temperature 110°C for 8 hours. Combustion in muflle furnace at temperature variation is 800°C, 900°C, 950°C and 1000°C and holding time is 2 hours, 3 hours, 4 hours and 5 hours. Test of compressive strength and porosity is done to see the physical properties of pottery ceramics and characterization by using XRF and XRD. The result of compressive strength test shows the temperature of 1000°C with 3 hours reaches the optimum value of compressive strength which is 9.52 Mpa, while the porosity value reaches the optimum point at heating temperature 1000°C with time of 5 hours that is equal to 16,19%. Characterization of XRF shows that ceramic pottery contains SiO₂ of 64.074%, and Al₂O₃ of 25.287% according to XRD characterization indicates the dominant phase formed by mineral quartz or silica oxside (SiO₂).