R.T. Padmaningrum, S. Marwati, Sunarto, Sulistyani
This study aims to determine the effect of combustion temperatures and copper(II) oxide concentrations on ceramic glaze color. Electrocoagulation process was carried out using optimum conditions: pH 8, electrocoagulation time of 120 minutes, Al-Fe electrodes, and current density of 1.25 mA/cm2. Experiment variables include combustion temperatures (999, 1060, 1101 °C) and copper(II) oxide concentrations (0.88; 1.76, 2.64, 3.53% ). The results of the coagulant characterization with XRF showed copper(II) content of (22.04 ± 0.73)%. Besides that it also contains of other metals such as Cr, Cd, and Pb however below the detection limit. Coagulant is a metal hydroxide which is dried and calcined formed the oxide. Then, it was applied as a glaze ceramic dye. Based on the analysis of homogeneity using chromameter, the brightness value (L∗) increased at the combustion temperature of 999 and 1060 °C, but at a temperature of 1101 °C it decreased. The green color value (a∗) decreases when the combustion temperature is raised but the yellow value (b∗) increased. When the metal oxide concentration was increased, L∗ and a∗ values decreased. While the b∗ value increased at a concentration of 0.88 to 1.76%, but at a concentration of 2.64 to 3.53% decreased. © Published under licence by IOP Publishing Ltd.
Department of Chemistry Education, Faculty of Mathematics and Natural Sciences, Yogyakarta State University, Jl Colombo 1, Yogyakarta, 55281, Indonesia
