Interfacial interactions between plastic particles in plastics flotation.
Plastics flotation used for recycling of plastic wastes receives increasing attention for its industrial application. In order to study the mechanism of plastics flotation, the interfacial interactions between plastic particles in flotation system were investigated through calculation of Lifshitz-van der Waals (LW) function, Lewis acid-base (AB) Gibbs function, and the extended Derjaguin-Landau-Verwey-Overbeek potential energy profiles. The results showed that van der Waals force between plastic particles is attraction force in flotation system. The large hydrophobic attraction, caused by the AB Gibbs function, is the dominant interparticle force. Wetting agents present significant effects on the interfacial interactions between plastic particles. It is found that adsorption of wetting agents promotes dispersion of plastic particles and decreases the floatability. Pneumatic flotation may improve the recovery and purity of separated plastics through selective adsorption of wetting agents on plastic surface. The relationships between hydrophobic attraction and surface properties were also examined. It is revealed that there exists a three-order polynomial relationship between the AB Gibbs function and Lewis base component. Our finding provides some insights into mechanism of plastics flotation.
School of Chemistry and Chemical Engineering, Key Laboratory of Resource Chemistry of Nonferrous Metals, Ministry of Education, Central South University, Changsha, Hunan 410083, China. Electronic address: zilangwang@126.com.
Chong-qing
CQ
Wang
School of Chemistry and Chemical Engineering, Key Laboratory of Resource Chemistry of Nonferrous Metals, Ministry of Education, Central South University, Changsha, Hunan 410083, China. Electronic address: huiwang1968@163.com.
Hui
H
Wang
School of Minerals Processing and Bioengineering, Central South University, Changsha, Hunan 410083, China. Electronic address: guguohua@126.com.
Guo-hua
GH
Gu
School of Chemistry and Chemical Engineering, Key Laboratory of Resource Chemistry of Nonferrous Metals, Ministry of Education, Central South University, Changsha, Hunan 410083, China. Electronic address: fu_jiangang@126.com.
Jian-gang
JG
Fu
School of Minerals Processing and Bioengineering, Central South University, Changsha, Hunan 410083, China. Electronic address: linqingquan1988@126.com.
Qing-quan
QQ
Lin
School of Chemistry and Chemical Engineering, Key Laboratory of Resource Chemistry of Nonferrous Metals, Ministry of Education, Central South University, Changsha, Hunan 410083, China. Electronic address: liuyounian@csu.edu.cn.
You-nian
YN
Liu
D057927:Hydrophobic and Hydrophilic Interactions; D008962:Models, Theoretical; D052638:Particulate Matter / Q000737:chemistry*; D010969:Plastics / Q000737:chemistry*; D012037:Refuse Disposal; D014874:Water Pollutants, Chemical / Q000737:chemistry*
D052638:Particulate Matter; D010969:Plastics; D014874:Water Pollutants, Chemical
Hydrophobic attraction; Interfacial interactions; Plastics flotation; Surface energy