In situ kinetics and flocs conformation studies of kaolinite flocculated by Chi-g-CPAM  

作　　者：Ruijing Xu Wenjie Zou Bo Rao Wei Zhao Ting Wang Zhijun Zhang 

机构地区：[1]State Key Laboratory of High-Efficient Mining and Safety of Metal Mines of Ministry of Education,University of Science and Technology Beijing,Beijing 100083,China [2]School of Civil and Resources Engineering,University of Science and Technology Beijing,Beijing 100083,China [3]School of Chemical and Environmental Engineering,China University of Mining and Technology,Beijing 100083,China

出　　处：《International Journal of Minerals,Metallurgy and Materials》2023年第5期813-823,共11页矿物冶金与材料学报（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(No.51604019);the State Key Laboratory of Water Resource Protection and Utilization in Coal Mining,China(No.GJNY-20-113-12);the Foundation of State Key Laboratory of Mineral Processing of China(No.BGRIMMKJSKL-2020-11)。

摘　　要：This study presents a comparative study of the flocculation behavior of kaolinite induced by chitosan-graft-poly(acrylamide-dimethyl diallyl ammonium chloride)(Chi-g-CPAM) and a commercial cationic polyacrylamide(CPAM).The flocculation behaviour was characterised in terms of both flocculation kinetics and the corresponding morphology changes during flocculation.Both Chi-g-CPAM and CPAM were grafted from silica wafers by means of atom transfer radical polymerization(ATRP).The quartz crystal microbalance with dissipation(QCM-D) tests were conducted.The equilibrium time flocculated by Chi-g-CPAM was found to be 0.46 times as that of CPAM,together with a larger total mass of kaolinite layer.The flocculation behaviour by Chi-g-CPAM can be well captured by a pseudo-first-order model.In contrast,the presence of CPAM leads to a more complex kinetics.A relatively larger fitting slope(0.4663) was obtained at the initial stage but the fitting slope droped to 0.2026 after 800 min,indicating a densification process caused by CPAM.The flocculation kinetics of CPAM can be captured by the Elovich model for the inital stage but the combination of pseudo-first-order and pseudo-second-order models for the latter stages,which can be attributed to the long chain of CPAM.With a dosage of 75 g/t,the settling test with Chi-g-CPAM exhibits the same turbidity in the supernatant but a smaller layer thickness of the settlement compared to CPAM.The study enables a better understanding of the flocculation behavior and contributes to the development of efficient flocculants in mineral processing and tailings treatment.

关 键 词：Chi-g-CPAM flocculation QCM-D KINETICS CONFORMATION 

分 类 号：O313[理学—一般力学与力学基础]