Selecting chemicals for separation of ABS and HIPS in WEEE by froth flotation
Utimura, Solange Kazue; Chaves, Arthur Pinto; Tenório, Jorge Alberto Soares; Espinosa, Denise Crocce Romano
The feasibility of using common chemicals to separate plastics from waste electrical and electronic equipment (WEEE) by froth flotation is investigated. Plastic waste is one of the WEEE polluters and a separation is necessary to recycle it. The most common plastics in electronic industries are acrylonitrile-butadiene-styrene (ABS) and high impact polystyrene (HIPS). These plastics are difficult to separate due to the similar specific weights and to both being repellent to water. Froth flotation allows for separating particles by the differences in their surface characteristics by selective wetting agents. The common chemicals are ethanol and acetic acid to depress the plastics. The process with 20% weight of ethanol was able to produce a recovery concentrate of HIPS with 98% and ABS with 96%. The process with 40% weight of acetic acid produces a recovery concentrate of HIPS with 96% and ABS with 83%.
1 Baldé, C. P., Forti, V., Gray, V., Kuehr, R., & Stegmann, P. (2017). The global E-waste monitor 2017: quantities, flows, and resources. Vienna: UNU, ITU, ISWA.
2 Suresh, S. S., Bonda, S., Mohanty, S., & Nayak, S. K. (2018). A review on computer waste with its special insight to toxic elements, segregation and recycling techniques. Process Safety and Environmental Protection, 116, 477-493. http://dx.doi.org/10.1016/j.psep.2018.03.003.
3 Guo, C., Zou, Q., Wang, J., Wang, H., Chen, S., & Zhong, Y. (2018). Application of surface modification using sodium hypochlorite for helping flotation separation of acrylonitrile-butadiene-styrene and polystyrene plastics of WEEE. Waste Management (New York, N.Y.), 82, 167-176. http://dx.doi.org/10.1016/j.wasman.2018.10.031. PMid:30509579.
4 Wang, H., Wang, J., Zou, Q., Liu, W., Wang, C., & Huang, W. (2018). Surface treatment using potassium ferrate for separation of polycarbonate and polystyrene waste plastics by froth flotation. Applied Surface, 448, 219-229. http://dx.doi.org/10.1016/j.apsusc.2018.04.091.
5 Negari, M. S., Ostad Movahed, S., & Ahmadpour, A. (2018). Separation of polyvinylchloride (PVC), polystyrene (PS) and polyethylene terephthalate (PET) granules using various chemical agentes by flotation technique. Separation and Publication Technology, 194, 368-376. http://dx.doi.org/10.1016/j.seppur.2017.11.062.
6 Thakur, S., Verma, A., Sharma, B., Chaudhary, J., Tamulevicius, S., & Thakur, V. K. (2018). Recent developments in recycling of polystyrene based plastics. Green and Sustainable Chemistry, 13, 32-38. http://dx.doi.org/10.1016/j.cogsc.2018.03.011.
7 Braga, P. F. A., Chaves, A. P., Luz, A. B., & França, S. C. A. (2014). The use of dextrin in purification by flotation of molybdenite concentrates. International Journal of Mineral Processing, 127, 23-27. http://dx.doi.org/10.1016/j.minpro.2013.12.007.
8 Wang, J., Wang, H., Wang, C., Zhang, L., Wang, T., & Zheng, L. (2017). A novel process for separation of hazardous poly(vinyl chloride) from mixed plastic wastes by froth flotation. Waste Management (New York, N.Y.), 69, 59-65. http://dx.doi.org/10.1016/j.wasman.2017.07.049. PMid:28801216.
9 Thanh Truc, N. T., & Lee, B.-K. (2017). Selective separation of ABS/PC containing BFRs from ABSs mixture of WEEE by developing hydrophilicity with ZnO coating under microwave treatment. Journal of Hazardous Materials, 329, 84-91. http://dx.doi.org/10.1016/j.jhazmat.2017.01.027. PMid:28126573.
10 Pita, F., & Castilho, A. (2017). Separation of plastics by froth flotation. The role of size, shape and density of the particles. Waste Management (New York, N.Y.), 60, 91-99. http://dx.doi.org/10.1016/j.wasman.2016.07.041. PMid:27478025.
11 Chen, S., Zhang, Y., Guo, C., Zhong, Y., Wang, K., & Wang, H. (2019). Separation of polyvinyl chloride from waste plastic mixture by froth flotation after surface modification with sodium persulfate. Journal of Cleaner Production, 218, 167-172. http://dx.doi.org/10.1016/j.jclepro.2019.01.280.
12 Truc, N. T. T., & Lee, B. K. (2017). Combining ZnO/microwave treatment for changing wettability of WEEE styrene plastics (ABS and HIPS) and their selective separation by froth flotation. Applied Surface, 420, 746-752. http://dx.doi.org/10.1016/j.apsusc.2017.04.075.