Effects of Selected Processing Variables on Color Formation in Praseodymium‐Doped Zircon Pigments

Abstract

Although praseodymium yellow pigments have been used in industry for many years, a quantitative description of the effects of the processing parameters does not exist in the literature. A full factorial design has been used to investigate the effects of the particle size of the raw material, the mineralizer content, and the processing temperature on color formation. Results show that strong yellow colors are developed at temperatures of ∼900°C, and little benefit is realized at higher temperatures. The amount of fluoride mineralizer is a critical variable, especially at lower processing temperatures. Overall, color formation correlates strongly with the processing temperature, mineralizer content, and, to a lesser extent, particle size of the zirconia raw material.