煤气化渣合成4A分子筛及其吸附性能研究

Preparation of 4A Molecular Sieve from Coal Gasification Slag and Its Adsorption Performance

本文针对煤气化渣(CGFS)资源化利用困难的问题,以CGFS为原料,采用碱熔活化-水浸-水热法合成4A分子筛。在水钠比(n(H_(2)O)/n(Na_(2)O),摩尔比)为80、硅铝比(n(SiO_(2))/n(Al_(2)O_(3)),摩尔比)为2的条件下,探讨了反应时间、水热温度和前驱液老化对合成的4A分子筛物相结构和微观形貌的影响,提出了活化CGFS-P1分子筛-4A分子筛快速高效的转晶合成机理,并利用硫酸铜溶液模拟含重金属离子工业废水,测试了制备的4A分子筛对Cu^(2+)的吸附性。结果表明,在100℃反应12 h条件下能够制备出尺寸均一且结晶良好的4A分子筛,其对Cu^(2+)的吸附主要发生在前10 min,吸附率达69.7%,90 min时的最大吸附率高达97.3%,饱和吸附容量为196.4 mg/g,制备的4A分子筛表现出良好的吸附性能,为CGFS高值化利用提供了理论依据和试验基础。

In order to solve the difficult problem of comprehensive utilization of coal gasification slag(CGFS),4A molecular sieve was synthesized with CGFS as raw material by an alkali fusion-water leaching-hydrothermal method.Under the conditions that the molar ratio of water to sodium(n(H_(2)O)/n(Na_(2)O)) is 80 and the molar ratio of silicon to aluminum(n(SiO_(2))/n(Al_(2)O_(3))) is 2,the effects of reaction time,hydrothermal temperature and precursor aging time on the phase structure and microstructure of prepared 4A molecular sieve were investigated.The phase transformation and synthesis mechanism for activated CGFS-P1 molecular sieve-4A molecular sieve were proposed.Meanwhile,the adsorption performance of the prepared 4A molecular sieve for Cu^(2+) in the solution was tested by using copper sulfate solution to simulate industrial wastewater containing heavy metal ions.The results show that 4A molecular sieve with uniform size and well crystallization could be prepared at 100 ℃ for 12 h.The adsorption of Cu^(2+) by 4A molecular sieve mainly occurrs in the initial 10 min and the adsorption rate reaches 69.7%.The saturated adsorption rate reaches 97.3% in 90 min and the saturated adsorption capacity is 196.4 mg/g.It is indicated that the prepared 4A molecular sieve exhibits good adsorption performance,which provides the theoretical and experimental foundation for the high value-added utilization of CGFS.