Decomposition of the ISA-card under steam for valorized polymetallic raw material

Abstract

The complete 3Com TokenLink Velocity ISA 16/4 3C319 waste card was gasified under steam at atmospheric pressure in the allothermal process by heating up to 900 °C. The product was easily partitioned according to size and magnetic properties into 5 fractions. Each fraction was analyzed for content of metals by classical chemical route (aqua regia/ICP-OES). With exception of bulky steel parts, these fractions were also investigated by XRD and SEM-EDS methods It was found that there were no bromides in the solid product of gasification. Aqueous condensates, collected in six periods, were individually analyzed for content of bromine and potentially volatile metals (Sn, Zn, and Pb). The composition of tars and oils from condensates and proportions between contents of detected species were also evaluated (GC–MS). Condensation of the excess of steam appeared efficient in the cleaning of the gas from tars, oils, and HBr − final form of bromine. Results of the experiment were discussed and supplemented by the thermodynamic assessment of oxygen potential of the system as well as speciation and volatilization of metals and bromine. Finally, the process was shortly discussed in terms of zero-emissions + zero-waste model as well as the valorization of the waste due to transformation into metal-mineral resource enriched in valuable metals.