Preparation blue glasses from scraps of soft drink bottle

Abstract

This research developed a process for preparing green glass from rice husk ash using microwave technology. Chemical composition analysis of the rice husk ash samples before and after firing revealed that SiO2 was the main component, along with trace elements that influence the color, including MnO, Fe2O3 and CuO. The fired rice husk ash was then used to replace SiO2 in the glass formula 10SiO2: (50-x)B2O3: 10Na2O: 30ZnO: xCoO, in molar percentages, where x represents the concentration of Cobalt(II) oxide (0.00, 0.01, 0.05, 0.10, 0.15, and 0.20 mol%). The properties of the glass were analyzed, including density, refractive index, light absorption, and color in the CIE L*a*b* system. The results showed that the density and refractive index tended to increase with higher CoO concentrations, while the molar volume decreased as the CoO concentration increased. The light absorption values in the wavelength range of 200 – 1,100 nanometers showed peaks at approximately 534, 595, and 643 nanometers, which corresponded to energy level transitions from the 4T1g (F)  2T1g(H) 4A2 (4F)  4T1(4P) and 2T2  2T, respectively.