Cables and wires, which are essential parts of equipment for the transmission of both information and electricity, contain valuable materials including copper (Cu) and aluminum (Al). This experimental work evaluates t...Cables and wires, which are essential parts of equipment for the transmission of both information and electricity, contain valuable materials including copper (Cu) and aluminum (Al). This experimental work evaluates the use of mechanical processing (grinding and sieving), followed by spouted bed elutriation, for separation of the valuable materials (steel-coated copper, copper, and aluminum) present in waste coaxial and internet cables. A recovery efficiency of approximately 90% was achieved for the steel-coated copper in coaxial cables. For in ternet cables, the copper recovery efficiency was approximately 87%. These findings dem on strate that it is possible to separate, recover, and recycle the valuable materials (metals) present in waste cables using simple, low-cost, and efficient mechanical processing followed by spouted bed elutriation.展开更多
Wax obtained from the pyrolysis of polyethylene waste can contain inorganic contaminants and must be purified before application.We evaluated different filter aids(perlite,sand,and rice husk ash)for the filtration of ...Wax obtained from the pyrolysis of polyethylene waste can contain inorganic contaminants and must be purified before application.We evaluated different filter aids(perlite,sand,and rice husk ash)for the filtration of a crude wax and a pyrolysis wax through a filter medium that was coated with nylon 6 nanofibers to improve filtration efficiency.We first examined the performance of the filter aids in improving crude wax filtration,with the filtration time,temperature,and pressure held constant at 1 h,170℃,and 2.5 bar,respectively.Oily wax was then produced by pyrolysis of high-density polyethylene(HDPE)waste in the temperature range 425-475℃.The best filter aid was perlite,which had a filtrate production rate of 5.47×10^(-5)m^(3)/h.The highest oily wax yield(87.8%)was achieved at a pyrolysis temperature of 425℃.The assembly comprising the filter medium coated with nylon 6 nanofibers plus perlite as a filter aid was most suitable for removing impurities from the oily wax generated by the HDPE pyrolysis as it achieved a purification efficiency of 99.9%.展开更多
文摘Cables and wires, which are essential parts of equipment for the transmission of both information and electricity, contain valuable materials including copper (Cu) and aluminum (Al). This experimental work evaluates the use of mechanical processing (grinding and sieving), followed by spouted bed elutriation, for separation of the valuable materials (steel-coated copper, copper, and aluminum) present in waste coaxial and internet cables. A recovery efficiency of approximately 90% was achieved for the steel-coated copper in coaxial cables. For in ternet cables, the copper recovery efficiency was approximately 87%. These findings dem on strate that it is possible to separate, recover, and recycle the valuable materials (metals) present in waste cables using simple, low-cost, and efficient mechanical processing followed by spouted bed elutriation.
基金The authors are grateful for the financial support provided by CAPES(Brazilian Agency for Improvement of Graduate Personnel),CNPq(National Council of Scientific and Technological Develop-ment),FAPERGS(Foundation for Research Support of the State of Rio Grande do Sul),and SDECT(Department of Economic Develop-ment,Science and Technology of the State of Rio Grande do Sul).
文摘Wax obtained from the pyrolysis of polyethylene waste can contain inorganic contaminants and must be purified before application.We evaluated different filter aids(perlite,sand,and rice husk ash)for the filtration of a crude wax and a pyrolysis wax through a filter medium that was coated with nylon 6 nanofibers to improve filtration efficiency.We first examined the performance of the filter aids in improving crude wax filtration,with the filtration time,temperature,and pressure held constant at 1 h,170℃,and 2.5 bar,respectively.Oily wax was then produced by pyrolysis of high-density polyethylene(HDPE)waste in the temperature range 425-475℃.The best filter aid was perlite,which had a filtrate production rate of 5.47×10^(-5)m^(3)/h.The highest oily wax yield(87.8%)was achieved at a pyrolysis temperature of 425℃.The assembly comprising the filter medium coated with nylon 6 nanofibers plus perlite as a filter aid was most suitable for removing impurities from the oily wax generated by the HDPE pyrolysis as it achieved a purification efficiency of 99.9%.
