Synthesis of zeolite-X from waste metals

This paper describes the synthesis of zeolite-X from waste metals; in this synthesis, silicon sludge and AI(OH)₃ from aluminum dross are separately solved in NaOH solution, leading to the generation of hydrogen, and then mixed with the desired molar ratio to synthesize zeolite-X; and residual liquid was repeatedly used as raw material to save Si and Na sources. During the synthesis, the effect of the cyclic use of residual liquid on the property of zeolite was examined and it was compared with the product synthesized from reagents of AI(OH)₃, Si, and NaOH. Although the original raw materials used were industrial wastes, all products showed the same XRD patterns, Si/AI molar ratio (1.0-1.5), and BET surface area (500-600 m2/g) as the commercially available product. The use of the residual liquid increases the utilization ratio - 21.4 mol% in Si and 7.8mol% in Na - after three times of cyclic use. Inverse manufacturing of zeolite-X was experimentally validated.