碱水热处理粉煤灰及其吸附性能探究

Study on alkali hydrothermal treatment of fly ash and its adsorption properties

粉煤灰具有多孔结构,而且其价格低廉、来源广泛,可以作为廉价的吸附材料。经过改性的粉煤灰闭合的孔结构打开,活性升高,通过水热法可以在粉煤灰中生成沸石,使粉煤灰具有更好的吸附性能。用不同浓度的氢氧化钠溶液通过碱水热法处理粉煤灰,探究粉煤灰碱处理后的物相变化和微观形貌,发现粉煤灰与4 mol/L的NaOH溶液按固液比为1:2混合后,再经过120℃水热处理24 h后粉煤灰颗粒表面有八面沸石生成,且在Cr(Ⅵ)初始质量浓度为10 mg/L时,粉煤灰投加量为0.1 g/L条件下,对Cr(Ⅵ)的去除率可达到62%。

Fly ash has porous structure,low price and wide source.It can be used as cheap adsorption material.After modification,the closed pore structure of fly ash is opened and the activity is increased.Zeolite can be generated in fly ash by hydrothermal method,so that fly ash has better adsorption performance.Fly ash was treated with different concentrations of sodium hydroxide solution by alkaline hydrothermal method,and the phase changes and micro morphology of fly ash after alkaline treatment were studied.It was found that after mixing fly ash with 4 mol/L NaOH solution at a solid-liquid ratio of 1:2,octahedral zeolite was formed on the surface of fly ash particles after hydrothermal treatment at 120 ℃ for 24 hours,and the initial mass concentration of Cr(Ⅵ) was 10 mg/L.When the dosage of fly ash is 0.1 g/L,the removal rate of Cr(Ⅵ) can reach 62%.