Characterisation and Techno-Economics of a Process to Recover Value from E-waste Materials

Abstract

Printed circuit boards, collected from Bangladesh, were melted to determine the proportion of metal, ceramic and volatile components. The concentration and amount of valuable elements in the e-waste were calculated from the analysis of the metal and ceramic phases. This information was used to design a simple three-stage process to recover the valuable components. The stages included smelting, electrorefining of a copper rich anode and melting of anode slimes and reduction of a tin rich slag. In this process, copper would be recovered as a high purity cathode, silver and gold recovered as a precious metal bullion from the processed anode slimes and tin recovered from the reduction of tin rich slag. A flowsheet simulation of this process was used to estimate the size of unit operations and process streams. Capital costs of the process situated in Bangladesh were estimated based on the equipment required and included capital on-costs. Operating costs were estimated from power, labour and consumables required as well as operating factors such as maintenance and administration. Cash inputs to the process were estimated from the value of product streams. The preliminary financial viability of the process was estimated, and net present value and internal rate of return are determined.