In-Situ Crystallization and Characteristics of Alkali-Activated Materials-Supported Analcime-C from a By-Product of the Lithium Carbonate Industry

Abstract

The present study proposes a new process for synthesis of alkali-activated materials (AAM)-supported analcime-C foam materials (AFs), utilizing a by-product of the lithium carbonate industry. This material has great application value as a bulk-type solid adsorbent. Characterization analyses show that the alkaline activator modulus greatly affects the crystallinity of analcime-C in AFs. Furthermore, the compressive strength, zeolite yield, and microstructure of AFs are significantly affected by the saturated steam parameters, including crystallization pressure, temperature, and time. The synthesized materials comprise pores of different sizes (micro to macro). They combine the functional micro-porosity of the analcime-C, the meso-porosity of the gel matrix, and the macro-porosity of the foamed AAM. The maximum compressive strength, density, total porosity, and Pb2+ adsorption capacity of AFs investigated in this study are 1.15 MPa, 350 kg/m3, 76.5%, and 69.3 mg/g Pb2+, respectively. Unlike many granular adsorbents, the bulk AFs adsorbent produced by this process is easy to recycle. In addition, it also contributes to the comprehensive utilization of a by-product of the lithium carbonate industry.