Production of coloured zircon pigments from zircon

Abstract

Zircon (ZrSiO4) pigments are commonly used in the ceramic industry for glazes due to their high chemical stability and superior resistance to the dissolution during firing in glazes. These pigments are made by calcining a mixture of SiO2, ZrO2, a dopant ion which produces the colour and mineralizer. In the present work, synthesis of coloured zircon ceramic pigments from intermediate products obtained by decomposing zircon sand with NaOH was undertaken. After decomposing zircon with NaOH at around 850 degrees C, decomposed products (Na2ZrSiO5 and Na2ZrO3) were used as raw materials to produce zircon pigments and Pr, Fe and V oxides were used as colouring agents. The crystalline phases formed after decomposition and pigment production steps were determined by using X-ray diffraction (XRD) technique. XRD analysis showed that Na2ZrSiO5 and Na2ZrO3 phases were formed after decomposition and when these products used as a raw material, zircon containing colouring ion can be obtained. Prepared pigments were used in transparent glazes and porcelainized tile and their colour properties were determined. As a result in this work it was shown that it is possible to obtain zircon pigments from zircon sand instead of using pure ZrO2 and SiO2