煤矸石两步除铁合成低铁杂质4A沸石

Synthesis of 4A zeolites with less Fe impurity from gangue after two removaliron stages

为了得到低铁杂质、高白度的4A沸石,首先将煤矸石用盐酸和硫酸的混合酸溶液酸浸,同时添加不同络合剂络合除铁,对比除铁率找到除铁效果较好的络合剂;再以除铁率为指标,以络合剂的量、反应温度、反应时间为因素,建立3因素、3水平正交实验,找到优化的第一步除铁条件;然后研究不同的络合剂添加量在水热合成阶段对除铁效果的影响,找到优化的第二步除铁条件;最后将两步优化的除铁工艺进行整合,得到低铁杂质、高白度的产物。研究主要通过XRD、TEM、SEM、白度、钙交换能力等手段对产物进行了表征,结果表明经过整合的两步除铁过程,产物为含铁杂质较少的高白度4A沸石。

In order to obtain 4A zeolites with less Fe impurity and higher whiteness, firstly, the coal-gangue was acid-leached by mixed acid solution of hydrochloric acid and sulphuric acid, and Fe impurity was erased through complexing reaction, then the proper complexing agent which has higher ability to erase the Fe impurity was found through comparison ; secondly, the optimized experiment conditions which were used for the first stage of removaliron were found by building the three fac- tors and three levels orthogonality experiments which researched the amount of complexing agent, reaction temperature, and reaction time,with the removaliron rate as the evaluation criteria;thirdly,the optimized conditions which were used for the second stage of removaliron were found by studying the effect of the removaliron results which were caused by different amounts of eomplexing agents in the hydrothermal synthesis stage;finally, all the two optimized conditions were integrated together and the products with less Fe impurity and higher whiteness were obtained.The products were characterized by XRD, TEM, SEM, Whiteness, and Ca2＋ exchange capacity and the results showed that the products were 4A zeolites with less Fe impurity and higher whiteness after the integrated two steps removaliron process,