Replacing K‐feldspar with a siliceous solid by‐product of zeolite industry for medium‐temperature calcium matte glazes

• Published in: International journal of applied ceramic technology Vol. 17; no. 3; pp. 1167 - 1176
• Main Authors: Lu, Xilong, Cheng, Kemu, Cao, Chun‐e, Chen, Yunxia, Shi, Wei, Wang, Peng
• Format: Journal Article
• Language: English
• Published: Malden Wiley Subscription Services, Inc 01.05.2020
• Subjects: Calcium; calcium matte glazes; Chemical composition; Differential thermal analysis; Glazes; Incident light; Raman spectroscopy; solid wastes; Substitutes; Thermodynamic properties; Wollastonite; Zeolites
• ISSN: 1546-542X; 1744-7402
• DOI: 10.1111/ijac.13424

To recycle a multicomponent siliceous solid waste (MSW), a by‐product of the zeolite industry, as a K‐feldspar substitute for the preparation of medium temperature calcium matte glazes, the chemical composition, phase evolution, and thermal behavior of the waste versus temperature were characterized using multiple techniques. Based on the TG‐DTA results, the waste was thermal treated at an optimum temperature of 1200°C prior to glaze preparation. Then, the calcined MSW was substituted for various amounts of K‐feldspar and calcium matte glazes were prepared that produced high‐quality smooth surfaces with a velvety appearance after firing at 1200°C. The results indicate that the matting effects originate from the scattering of the incident light by densely populated columnar wollastonite crystals embedded in the glazes with the b‐axis parallel to the glaze layer, which facilitates the well‐resolved Raman peaks of the calcium matte glazes. In the matte glaze layer, the length of the columnar wollastonite particles is oriented horizontally with the b‐axis normal to the incident laser beam of Raman spectrometer (the left) resulting in a well‐resolved Raman spectrum. In contrast, pure wollastonite without any specific orientation or parallel to the laser beam (the right) lead to poorly‐resolved Raman bands.