The Influence of Firing Conditions on the Color Properties of Pr-ZrSiO₄Pigments Synthesized Using Rice Husk Ash

Synthesis of zircon pigments from rice husk ash and their performance in ceramic glaze

“…In this case, the tallest peaks of zircon and zirconia are in the 26º and 27º range, respectively. The weight fractions of unreacted ZrO2 and reacted ZrSiO4 have been reported by using a relatively similar method of calculation including the linear absorption coefficients [11] and the peak area of tetragonal ZrO2 [2]. However, the impurity in our study was monoclinic ZrO2 instead of tetragonal ZrO2.…”

“…Longer firing times of more than 12 h did not significantly improve phase formability. Although the degree of crystallinity could not be obtained from X-ray Diffraction, utilizing the tallest peaks of all occurring phases could be used as a qualitative guide to indirectly compare the amounts of each phase [2]. The area under the peak (integrated intensity) was obtained by fitting the peak with Lorentzian function.…”

“…A dominant band could be observed in the 570 nm range, corresponding to the yellow light region (565 nm to 580 nm) [14,22]. Given that the complimentary color of yellow is blue, a minimum of the reflectance spectrum occurred in the 400 nm to 450 nm range; this range was also claimed to be part of characteristic absorption band of yellow [2]. The high intensity (> 80%) of the 570 nm reflectance band in the current study was accompanied by a very high value of the b parameter of +49.0 as shown in.…”

“…Zircon-based pigments have been widely known to be thermally and chemically stable in various matured glazes [1,2]. This zirconium silicate (ZrSiO4) is part of the neosilicate group with a tetragonal crystal system [3].…”

“…Extraction of pure SiO2 from RHA using alkali and acidic treatment is a laborious and costly process and could have made this alternative source not being advantages to other sources [14]. Several studies on zircon pigment synthesis used RHA without chemical extraction but the chromophores were still limited to vanadium and praseodymium [2,15,16].…”