EFFECTS OF MANGANESE DIOXIDE, NICKEL OXIDE, AND COPPER OXIDE ON COLOR APPEARANCE OF FELDSPAR GLAZE AT 1230 ๐C

Abstract

     This research aims to: 1) study the amounts of manganese dioxide, nickel oxide, and copper oxide that affect the color appearance of feldspar glaze, and 2) study the amounts of manganese dioxide, nickel oxide, and copper oxide that affect the surface characteristics of the feldspar glaze. To conduct the study, base glazes with specific compositions of manganese dioxide, nickel oxide, and copper oxide were prepared according to a ternary diagram, resulting in 15 different formulations. These formulations were processed by weighing and grinding at high speed for 5 minutes, followed by firing at 1230°C in an oxidation atmosphere. The analysis of color development, brightness, and color values of the glazes was conducted using a colorimeter. The findings revealed six color groups: 1) RAL-LS 7043, 2) RAL-LS 7024, 3) RAL-LS 7009, 4) RAL-LS 7010, 5) RAL-LS 7013, and 6) RAL-LS 7003. The brightness and color values of the glazes were as follows: L* values ranged from 25.05 to 37.33, a* values ranged from -0.65 to 0.54, and b* values ranged from -2.26 to 6.58. Two surface characteristics were observed: 1) semi-matte surfaces in formulations 7, 11, and 12, and 2) glossy surfaces in formulations 1, 2, 3, 4, 5, 6, 8, 9, 10, 13, 14, and 15, with gloss levels ranging from 30 to 85 GU. Additionally, formulations 4, 7, 8, and 11 exhibited a coating surface resembling the texture of an orange peel. The compositions, which can be applied in ceramic art and glaze development for industrial applications, include: 45% feldspar, 10% dolomite, 13% calcium carbonate, 7% kaolin, and 25% quartz. Oxides that can be used are: 1) manganese dioxide (2–6%), 2) nickel oxide (2–3%), and 3) copper oxide (2–6%).