浮选脱碳粉煤灰砂浆性能试验研究  

Study on the performance of flotation decarburized fly ash mortar

作　　者：毕雯惠 朱亚光[1] 徐培蓁[1] 陈超 王新波 BI Wenhui;ZHU Yaguang;XU Peizhen;CHEN Chao;WANG Xinbo(School of Civil Engineering,Qingdao University of Technology,Qingdao 266525,China;Qingdao Construction Engineering Management Service Center,Qingdao 266000,China)

机构地区：[1]青岛理工大学土木工程学院,青岛266525 [2]青岛市建筑工程管理服务中心,青岛266000

出　　处：《青岛理工大学学报》2023年第2期1-8,86,共9页Journal of Qingdao University of Technology

基　　金：国家自然科学基金资助项目(51878365)。

摘　　要：粉煤灰的高含碳量是限制其作为矿物掺合料使用的主要原因,浮选法能有效降低粉煤灰含碳量。通过正交试验对浮选因素进行探究,确定最优浮选工艺,并将浮选前后粉煤灰作为掺合料用于砂浆中,比较其对所制备砂浆的强度、流动度及干燥收缩性的影响,对砂浆孔结构进行分析。结果表明:粉煤灰的最优浮选工艺采用仲辛醇用量1000 g/t,矿浆浓度150 g/L,0号柴油用量1600 g/t,浮选时间12 min,充气量0.20 m^(3)/h,矿浆与药剂作用时间3 min,得到粉煤灰的烧失量为1.55%。浮选后粉煤灰更能改善砂浆的性能,对砂浆孔结构细化效果更好。当掺量为20%时,较基准砂浆的56 d抗压强度提高8.68%,抗折强度提高13.64%;掺量为40%时,较浮选前砂浆的流动度提升5.66%,56 d的干缩率降低6.61%,无害孔(<20 nm)比例增加30.37%。The high carbon content of fly ash is the main reason that limits its use as mineral admixture,and the flotation method can effectively reduce the carbon content of fly ash.Through orthogonal test,the flotation factors were explored in this study to determine the optimal flotation process,and then fly ash was used as mineral admixture in mortar before and after flotation.The influence of fly ash on strength,fluidity and drying shrinkage of mortar before and after flotation was compared,and the pore structure of mortar was analyzed.The results show that the optimal flotation process of fly ash is as follows:the dosage of sec-octanol is 1000 g/t,the concentration of mortar is 150 g/L,the dosage of No.0 diesel fuel is 1600 g/t,the flotation time is 12 min,the aeration rate is 0.20 m^(3)/h,and the reaction time of mortar and reagent is 3 min.The fly ash with a loss of 1.55%can be obtained.The fly ash after flotation can improve the properties of mortar and refine the pore structure of mortar.When the content is 20%,the 56 d compressive strength increases by 8.68%and the flexural strength increases by 13.64%compared with the reference mortar;when the content is 40%,the fluidity of mortar increases by 5.66%,the dry shrinkage rate decreases by 6.61%at 56 d,and the proportion of harmless pores(<20 nm)increases by 30.37%compared with that before flotation.

关 键 词：粉煤灰 浮选工艺 掺合料 砂浆性能 孔结构 

分 类 号：TU528[建筑科学—建筑技术科学]