Aluminum (Al) dross is a hazardous waste from the secondary smelting of aluminium industries, and safe disposal of this waste is a big challenge to these industries. Dumping of this waste is an environmental hazard to plants, animals, and even human beings. This study is aimed at improving the mechanical properties of polypropylene (PP) by adding Al dross in 2–50？wt% for particle sizes 53？μm and 150？μm. PP-Al-dross composite samples were cast, and ultimate tensile strength (UTS), impact resistance (IR), water absorption (WA), and density (D) tests were carried out. The results obtained show that UTS improved by 68% (at 15？wt% Al-dross addition), D increased by 54% (at 50？wt% Al-dross addition), and WA by 500% (at 8？wt% Al-dross addition) over the convectional PP. The impact resistance of the composite was found to be the same (68？J) with that of conventional PP at 15？wt% Al dross. 1. Introduction Aluminum (Al) drosses (white and black) are residues from primary and secondary aluminum production formed on the surface of molten Al that is exposed to furnace atmosphere during fusion processing. The dross is usually a mixture of free Al metal and nonmetallic substances such as aluminium oxide, nitride, and carbide; salts; metal oxides [1]. Disposal and recycling of dross is a worldwide problem. Majority of dross is disposed of in landfill sites, which is likely to result in leaking of toxic metal ions into the ground water causing serious pollution problems. In addition to this, when aluminium dross comes in contact with water it emits harmful gases such as NH3, CH4, PH3, H2, and H2S [2]. When the dross particles are allowed to escape into the atmosphere, inhalation can cause health problems such as Alzheimer’s disease, silicosis, and bronchitis. The challenge posed by aluminium dross to the environment has continued to engage the attention of researchers over the years. Efforts are geared towards putting this otherwise hazardous waste to productive use. For example, it has been used as reinforcement for aluminium-matrix [3], as raw material for refractories [4], and as additive in cement production [5]. It has also been used in the synthesis of adsorbent and catalytic materials such as alumina and zeolites [6–13]. Polypropylene (PP) is a commodity polymer that has found wide range of applications in the packaging, textile, automobile, and furniture industries because of its good processbility, recyclability and low cost [14–16]. It has limited use as engineering thermoplastic due to its low strength, low modulus, and high notch sensitivity. To address this
References
[1]
O. Manfredi, W. Wuth, and I. Bohlinger, “Characterizing the physical and chemical properties of aluminum dross,” JOM, vol. 49, no. 11, pp. 48–51, 1997.
[2]
T. W. Unger and M. Beckmann, “Salt slag processing for recycling, light metals,” in TMS Annual Meeting, E. R. Cutshall, Ed., pp. 1159–1162, San Diego, Calif, USA, 1992.
[3]
V. M. Kevorkijan, “The quality of aluminum dross particles and cost-effective reinforcement for structural aluminum-based composites,” Composites Science and Technology, vol. 59, no. 11, pp. 1745–1751, 1999.
[4]
H. N. Yoshimura, A. P. Abreu, A. L. Molisani, A. C. de Camargo, J. C. S. Portela, and N. E. Narita, “Evaluation of aluminum dross waste as raw material for refractories,” Ceramics International, vol. 34, no. 3, pp. 581–591, 2008.
[5]
R. Kikuchi, “Recycling of municipal solid waste for cement production: pilot-scale test for transforming incineration ash of solid waste into cement clinker,” Resources, Conservation and Recycling, vol. 31, no. 2, pp. 137–147, 2001.
[6]
S. J. Yoo, H. S. Yoon, H. D. Jang et al., “Synthesis of aluminum isopropoxide from aluminum dross,” Korean Journal of Chemical Engineering, vol. 23, no. 4, pp. 683–687, 2006.
[7]
B. Dash, B. R. Das, B. C. Tripathy, I. N. Bhattacharya, and S. C. Das, “Acid dissolution of alumina from waste aluminium dross,” Hydrometallurgy, vol. 92, no. 1-2, pp. 48–53, 2008.
[8]
B. R. Das, B. Dash, B. C. Tripathy, I. N. Bhattacharya, and S. C. Das, “Production of η-alumina from waste aluminium dross,” Minerals Engineering, vol. 20, no. 3, pp. 252–258, 2007.
[9]
B. Lucheva, T. Tsonev, and R. Petkov, “Non-waste aluminium dross recycling,” Journal of the University of Chemical Technology and Metallurgy, vol. 40, no. 4, pp. 335–338, 2005.
[10]
N. Murayama, K. Arimura, N. Okajima, and J. Shibata, “Effect of structure-directing agent on AlPO4-n synthesis from aluminum dross,” International Journal of Mineral Processing, vol. 93, no. 2, pp. 110–114, 2009.
[11]
N. Murayama, N. Okajima, S. Yamaoka, H. Yamamoto, and J. Shibata, “Hydrothermal synthesis of AlPO4-5 type zeolitic materials by using aluminum dross as a raw material,” Journal of the European Ceramic Society, vol. 26, no. 4-5, pp. 459–462, 2006.
[12]
J. Kim, K. Biswas, K.-W. Jhon, S.-Y. Jeong, and W.-S. Ahn, “Synthesis of AlPO4-5 and CrAPO-5 using aluminum dross,” Journal of Hazardous Materials, vol. 169, no. 1-3, pp. 919–925, 2009.
[13]
M. Fang, H. Du, W. Xu, X. Meng, and W. Pang, “Microwave preparation of molecular sieve AlPO4-5 with nanometer sizes,” Microporous Materials, vol. 9, no. 1-2, pp. 59–61, 1997.
[14]
J. Z. Liang, “Toughening and reinforcing in rigid inorganic particulate filled poly(propylene): a review,” Journal of Applied Polymer Science, vol. 83, no. 7, pp. 1547–1555, 2002.
[15]
S. M. Zebarjad, R. Bagheri, A. Lazzeri, and S. Serajzadeh, “Fracture behaviour of isotactic polypropylene under static loading condition,” Materials and Design, vol. 24, no. 2, pp. 105–109, 2003.
[16]
B. Alcock, N. O. Cabrera, N. M. Barkoula, J. Loos, and T. Peijs, “The mechanical properties of unidirectional all-polypropylene composites,” Composites Part A, vol. 37, no. 5, pp. 716–726, 2006.
[17]
K. Yang, Q. Yang, G. Li, Y. Zhang, and P. Zhang, “Mechanical properties and morphologies of polypropylene/single-filler or hybrid-filler calcium carbonate composites,” Polymer Engineering and Science, vol. 47, no. 2, pp. 95–102, 2007.
[18]
J. Cho, M. S. Joshi, and C. T. Sun, “Effect of inclusion size on mechanical properties of polymeric composites with micro and nano particles,” Composites Science and Technology, vol. 66, no. 13, pp. 1941–1952, 2006.
[19]
Y. W. Leong, M. B. Abu Bakar, Z. A. M. Ishak, A. Ariffin, and B. Pukanszky, “Comparison of the mechanical properties and interfacial interactions between talc, kaolin, and calcium carbonate filled polypropylene composites,” Journal of Applied Polymer Science, vol. 91, no. 5, pp. 3315–3326, 2004.
[20]
Y. Zheng, Z. Shen, C. Cai, S. Ma, and Y. Xing, “The reuse of nonmetals recycled from waste printed circuit boards as reinforcing fillers in the polypropylene composites,” Journal of Hazardous Materials, vol. 163, no. 2-3, pp. 600–606, 2009.
[21]
H. S. Yang, H. J. Kim, J. Son, H. J. Park, B. J. Lee, and T. S. Hwang, “Rice-husk flour filled polypropylene composites; mechanical and morphological study,” Composite Structures, vol. 63, no. 3-4, pp. 305–312, 2004.
[22]
H. D. Rozman, G. B. Peng, and Z. A. M. Ishak, “The effect of compounding techniques on the mechanical properties of oil palm empty fruit bunch-polypropylene composites,” Journal of Applied Polymer Science, vol. 70, no. 13, pp. 2647–2655, 1998.
[23]
T. T. L. Doan, S. L. Gao, and E. M？der, “Jute/polypropylene composites I. Effect of matrix modification,” Composites Science and Technology, vol. 66, no. 7-8, pp. 952–963, 2006.
[24]
T. Inoue and T. Suzuki, “Selective cross linking reaction in polymer blends-the effects of the cross linking of dispersed EPDM in particles on the impact behaviour of PP/EPDM blends,” Journal of Applied Polymer, vol. 56, no. 9, pp. 1113–1125, 1995.
