Parameter optimization, characterization, and crystallization mechanisms underlying the synthesis of zeolite A using liquid crystal display waste glass and sandblasting waste as alternative raw materials

This paper examines the synthesis of zeolite A via hydrothermal alkali fusion using liquid crystal display waste glass (LCDWG) and sandblasting waste (SB). The design of the experiments was determined using the Box-Behnken method in conjunction with response surface design. Three factors were shown to have a pronounced effect on synthesis outcomes: (i) Si/Al molar ratio, (ii) crystallization temperature, and (iii) crystallization period. Synthesis parameters were optimized in accordance with the crystallinity (%) of the zeolite. XRD results revealed that increasing the Si/Al ratio improved the crystallinity and phase purity of the synthesized zeolite A. Increasing the crystallization temperature altered the crystal type and enhanced crystal purity; however, excessive temperatures reduced crystallinity and led to decomposition of the zeolite A phase. SEM results revealed that the resulting zeolite A possessed a cubic structure. ANOVA revealed that the Si/Al molar ratio had the most profound effect on the synthesis of zeolite A, followed by crystallization duration and crystallization temperature. The fact that the R2 value (0.95) was similar to the adjusted R2 value (0.8736) confirmed the efficacy of the proposed polynomial model. A highly significant F-value of 11.75 confirmed that the proposed model could be used for design purposes. The excellent water adsorption/desorption performance of the proposed zeolite A (49.83 g/ m2; meeting JIS A 1470 standards) indicates its suitability as a low-cost construction material for a variety of applications. The ultimate objective of this study was to overcome difficulties encountered in the disposal of industrial waste by converting LCDWG and SB into zeolite A.