粉煤灰制备高分子絮凝剂研究进展

Research progress in the preparation of polymer flocculants from fly ash

总结了粉煤灰在酸碱体系中主要元素溶出行为。粉煤灰在酸性体系中主要浸出铝铁元素且铁元素浸出率远高于铝元素;在碱性体系中主要溶出硅铝元素且硅元素溶出率远高于铝元素。硅铝以非晶相状态存在,单独酸浸、碱溶对硅铝提取率较低,采用高温助熔结合酸浸、碱溶工艺可使硅铝断键提高元素提取率。对粉煤灰合成絮凝剂的种类进行归纳,根据粉煤灰制备絮凝剂的化学组分将其分为无机高分子絮凝剂和无机-有机杂化高分子絮凝剂,其中无机高分子絮凝剂按其阴离子系列所含酸根的数量和种类,分为一元酸、二元酸及多元酸系列,阴离子酸根以硅酸根、硫酸根、氯离子及磷酸根为主。对粉煤灰合成絮凝剂的发展及亟待解决的问题进行展望。

The dissolution behavior of the main elements of fly ash in acid-base systems.Fly ash mainly leaches aluminum-iron elements in the acid system,and the leaching rate of iron is much higher than that of aluminum.Under alkaline conditions,silicon-aluminum elements are mainly dissolved,and the leaching rate of silicon elements is much higher than that of aluminum elements.Silicon aluminum exists in the amorphous phase state,and the extraction rate of silicon aluminum is low by acid leaching and alkali solution alone,and the use of high temperature melting combined with acid leaching and alkaline solution process can make silicon aluminum bond break and improve the element extraction rate.The types of fly ash synthetic flocculants are summarized,and they are divided into inorganic polymer flocculants and inorganic-organic hybrid polymer flocculants according to the chemical components of fly ash to prepare flocculants,among which inorganic polymer flocculants are divided into monoacids,diacids and polyacids according to the number and types of acids contained in their anion series,and anionic acids are mainly silicate,sulfate,chloride ion and phosphate.The development of fly ash synthetic flocculants and the problems to be solved urgently are prospected.