Plastics floatability: effect of saponin and sodium lignosulfonate as wetting agents
Pita, Fernando; Castilho, Ana
Abstract
Froth flotation is the most common process in mineral processing. For the separation of plastic mixtures by flotation, the use of appropriate wetting agents is mandatory. The floatability of six post-consumer plastics was studied at different concentrations of the wetting agents, saponin and sodium lignosulfonate. Also, the influence of size and shape of the particles were analyzed. Contact angle and floatability of the six plastics decreased with increasing wetting agents concentration. The order of floatability is similar to the order of the contact angles values. However, the influence of the wetting agents in the plastics floatability is more pronounced than in the contact angle. Floatability decreased with the increase of particle density, particle size and spherical shape. For fine particles floatability is fundamentally conditioned by the contact angle, while for coarse particles floatability is fundamentally conditioned by the particles weight.
Keywords
References
1 PlasticsEurope. (2018). Plastics - the facts 2017: an analysis of european plastics production, demand and waste data. Brussels. Retrieved in 2018 June 15, from http://www.plasticseurope.org/en/resources/publications/plastics-facts-2017
2 Shent, H., Pugh, R. J., & Forssberg, E. (1999). A review of plastics recycling and the flotation of plastics. Resources, Conservation and Recycling, 25(2), 85-109. http://dx.doi.org/10.1016/S0921-3449(98)00017-2.
3 Fraunholcz, N. (2004). Separation of waste plastics by froth flotation, review, part I. Minerals Engineering, 17(2), 261-268. http://dx.doi.org/10.1016/j.mineng.2003.10.028.
4 Wang, C. Q., Wang, H., Fu, J. G., & Liu, Y. N. (2015a). Flotation separation of waste plastics for recycling - A review. Waste Management, 41, 28-38. http://dx.doi.org/10.1016/j.wasman.2015.03.027. PMid:25869841.
5 Singh, N., Hui, D., Singh, R., Ahuja, I. P. S., Feo, L., & Fraternali, F. (2017). Recycling of plastic solid waste: a state of art review and future applications. Composites. Part B, Engineering, 115, 409-422. http://dx.doi.org/10.1016/j.compositesb.2016.09.013.
6 Shibata, J., Matsumoto, S., Yamamoto, H., Kusaka, E., & Pradip, P. (1996). Flotation separation of plastics using selective depressants. International Journal of Mineral Processing, 48(3-4), 127-134. http://dx.doi.org/10.1016/S0301-7516(96)00021-X.
7 Marques, G. A., & Tenório, J. A. S. (2000). Use of froth flotation to separate PVC/PET mixtures. Waste Management (New York, N.Y.), 20(4), 265-269. http://dx.doi.org/10.1016/S0956-053X(99)00333-5.
8 Shen, H., Forssberg, E., & Pugh, R. J. (2002). Selective flotation separation of plastics by chemical conditioning with methyl cellulose. Resources, Conservation and Recycling, 35(4), 229-241. http://dx.doi.org/10.1016/S0921-3449(02)00003-4.
9 Alter, H. (2005). The recovery of plastics from waste with reference to froth flotation. Resources, Conservation and Recycling, 43(2), 119-132. http://dx.doi.org/10.1016/j.resconrec.2004.05.003.
10 Takoungsakdakun, T., & Pongstabodee, S. (2007). Separation of mixed post-consumer PET-POM-PVC plastic waste using selective flotation. Separation and Purification Technology, 54(2), 248-252. http://dx.doi.org/10.1016/j.seppur.2006.09.011.
11 Kangal, M. O. (2010). Selective flotation technique for separation of PET and HDPE used in drinking water bottles. Mineral Processing and Extractive Metallurgy Review, 31(4), 214-223. http://dx.doi.org/10.1080/08827508.2010.483362.
12 Carvalho, M. T., Ferreira, C., Santos, L. R., & Paiva, M. C. (2012). Optimization of froth flotation procedure for poly (ethylene terephthalate) recycling industry. Polymer Engineering and Science, 52(1), 157-164. http://dx.doi.org/10.1002/pen.22058.
13 Wang, H., Chen, X. L., Bai, Y., Guo, C., & Zhang, L. (2012). Application of dissolved air flotation on separation of waste plastics ABS and PS. Waste Management, 32(7), 1297-1305. http://dx.doi.org/10.1016/j.wasman.2012.03.021. PMid:22503154.
14 Yenial, U., Kangal, O., & Güney, A. (2013). Selective flotation of PVC using gelatin and lignin alkali. Waste Management & Research, 31(6), 613-617. http://dx.doi.org/10.1177/0734242X13476748. PMid:23439876.
15 Saisinchai, S. (2014). Separation of PVC from PET/PVC mixtures using flotation by calcium lignosulfonate depressant. Engineering Journal, 18(1), 45-53. http://dx.doi.org/10.4186/ej.2014.18.1.45.
16 Güney, A., Özdilek, C., Kangal, O., & Burat, F. (2015). Flotation characterization of PET and PVC in the presence of different plasticizers. Separation and Purification Technology, 151, 47-56. http://dx.doi.org/10.1016/j.seppur.2015.07.027.
17 Negari, M. S., Movahed, S. O., & Ahmadpour, A. (2018). Separation of polyvinylchloride (PVC), polystyrene (PS) and polyethylene terephthalate (PET) granules using various chemical agents by flotation technique. Separation and Purification Technology, 194, 368-376. http://dx.doi.org/10.1016/j.seppur.2017.11.062.
18 Pascoe, R. D., & Hou, Y. Y. (1999). Investigation of the importance of particle shape and surface wettability on the separation of plastics in a LARCOMEDS separator. Minerals Engineering, 12(4), 423-431. http://dx.doi.org/10.1016/S0892-6875(99)00022-9.
19 Shen, H., Forssberg, E., & Pugh, R. J. (2001). Selective flotation separation of plastics by particle control. Resources, Conservation and Recycling, 33(1), 37-50. http://dx.doi.org/10.1016/S0921-3449(01)00056-8.
20 Burat, F., Güney, A., & Kangal, M. O. (2009). Selective separation of virgin and post-consumer polymers (PET and PVC) by flotation method. Waste Management, 29(6), 1807-1813. http://dx.doi.org/10.1016/j.wasman.2008.12.018. PMid:19155169.
21 Wang, C. Q., Wang, H., & Liu, Y. N. (2015). Separation of polyethylene terephthalate from municipal waste plastics by froth flotation for recycling industry. Waste Management, 35, 42-47. http://dx.doi.org/10.1016/j.wasman.2014.09.025. PMid:25449606.
22 Pita, F., & Castilho, A. (2017). Separation of plastics by froth flotation. The role of size, shape and density of the particles. Waste Management, 60, 91-99. http://dx.doi.org/10.1016/j.wasman.2016.07.041. PMid:27478025.
23 Schulz, N. F. (1970). Separation efficiency. In Transactions of The 247º SME (pp. 81-87). Englewood: AIME.
24 Basarová, P., Bartovská, L., Korínek, K., & Horn, D. (2005). The influence of flotation agent concentration on the wettability and flotability of polystyrene. Journal of Colloid and Interface Science, 286(1), 333-338. http://dx.doi.org/10.1016/j.jcis.2005.01.016. PMid:15848435.
25 Ma, N. (2008). Direct force measurements between surfaces coated with hydrophobic polymers in aqueous solutions and the separation of mixed plastics by flotation (Master's dissertation). Faculty of the Virginia, Blacksburg, Virginia.
26 Pongstabodee, S., Kunachitpimol, B., & Damronglerd, S. (2008). Combination of three-stage sink-float method and selective flotation technique for separation of mixed post-consumer plastic waste. Waste Management, 28(3), 475-483. http://dx.doi.org/10.1016/j.wasman.2007.03.005. PMid:17493796.
27 Abbasi, A., Salarirad, M. M., & Ghasemi, I. (2010). Selective Separation of PVC from PET/PVC Mixture Using Floatation by Tannic Acid Depressant. Iranian Polymer Journal, 19(7), 483-489.
28 Wang, H., Wang, C. Q., Fu, J. G., & Gu, G. H. (2014). Flotability and flotation separation of polymer materials modulated by wetting agents. Waste Management, 34(2), 309-315. http://dx.doi.org/10.1016/j.wasman.2013.11.007. PMid:24355830.
29 Florido, P. L., & Torem, M. L. (2001). Selective flotation of polyvinyl chloride (PVC/polyethylene terephthalate (PET) mixtures. In Proceedings oh The VI Southern Hemisphere Meeting on Mineral Technology (pp. 708-713). Rio de Janeiro: Corbã Editora Artes Gráficas.
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