关键词: 煤矸石, 磁性, X型分子筛, 铅离子吸附

Abstract:

In order to improve the adsorption performance and recyclability of molecular sieves，a magnetic molecular sieve with the corresponding structure was prepared by hydrothermal synthesis using coal gangue with a silicon⁃aluminum ratio suitable for X zeolite，and it was used in the treatment of wastewater containing heavy metals.The results showed that the optimal preparation conditions for magnetic X zeolite were：n（H₂C₂O₄）/n（Fe³⁺） was 5，crystallization time was 10 h，and crystallization temperature was 85 ℃，n（citric acid）/n（Al₂O₃） was 0.85，and ultrasound promoted the complexation of molecular sieves and citric acid，which had a better synergistic effect.The synthesized molecular sieves were characterized and analyzed by XRD，SEM，FT-IR，XPS and carbon dioxide adsorption.The effect of parameters such as iron content，adsorption time，pH，initial concentration and amount of molecular sieve added on the adsorption of lead ions were considered.When the iron content of the molecular sieve was 0.33%，the adsorption time was 14 min，the solution pH was 5，the lead ion concentration was 50 mg/L and the molecular sieve dosage was 0.2 g，magnetic X zeolite showed the best adsorption effect on lead ions.Moreover，the magnetic recovery rate of magnetic molecular sieve still reached more than 90% after being recycled 8 times in an external magnetic field，achieving the goal of saving resources，low carbon and environmental protection.

Key words: coal gangue, magnetic, X zeolite, Pb²⁺ absorption