Recovery of copper from PVC multiwire cable waste by steam gasification.
Screened multiwire, PVC insulated tinned copper cable was gasified with steam at high temperature (HTSG) under atmospheric pressure for recovery of cooper. Gases from the process were additionally equilibrated at 850°C on the bed of calcined clay granules and more than 98% of C+H content in the cable was transformed to non-condensing species. Granules prepared from local clay were generally resistant for chlorination, there was also almost no deposition of metals, Cu and Sn, on the catalytic bed. It was found that 28% of chlorine reacted to form CaCl2, 71% was retained in aqueous condensate and only 0.6% was absorbed in alkaline scrubber. More than 99% of calcium existed in the process solid residue as a mixture of calcium chloride and calcium oxide/hydroxide. PVC and other hydrocarbon constituents were completely removed from the cable sample. Copper was preserved in original form and volatilization of copper species appeared insignificant. Tin was alloying with copper and its volatilization was less than 1%. Fractionation and speciation of metals, chlorine and calcium were discussed on the basis of equilibrium model calculated with HSC Chemistry software. High temperature steam gasification prevents direct use of the air and steam/water is in the process simultaneously gaseous carrier and reagent, which may be recycled together with hydrocarbon condensates.
Wrocław University of Technology, Faculty of Chemistry, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland. Electronic address: monika.zablocka-malicka@pwr.edu.pl.
Monika
M
Zabłocka-Malicka
Wrocław University of Technology, Faculty of Chemistry, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland.
Piotr
P
Rutkowski
Wrocław University of Technology, Faculty of Environmental Engineering, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland.
Włodzimierz
W
Szczepaniak
D003300:Copper / Q000032:analysis*; D006358:Hot Temperature; D011143:Polyvinyl Chloride / Q000737:chemistry*; D059027:Recycling / Q000379:methods*; D013227:Steam; D014835:Volatilization; D018505:Waste Management / Q000379:methods*
D013227:Steam; D003300:Copper; D011143:Polyvinyl Chloride
Copper; PVC; Recycling; Steam gasification; Waste cable