Advanced Technology and Manufacturing Institute (ATAMI)

A new technique is developed to recover elemental tellurium (Te) from cadmium telluride (CdTe) which is abundantly available in photovoltaic semiconductor waste. The method is based on microchannel fluid flow with the use of a supported liquid membrane (SLM) between the donor (feed) and acceptor (strip) channels. A predictive theoretical model is also developed based on diffusional transport. A comparison of the measured data with the theoretical predictions shows excellent agreement both in magnitudes and trends of dependency on the varied parameters. Areas for further required research in the development of the technique are identified. The experiments were carried out in a three phase microchannel reactor with 0.5mm square channels. The flow geometry consisted of two counter-flowing hydrochloric acid streams of differing acidity, separated by a membrane saturated with the organic extractant methyl isobutyl ketone (MIBK). Separation funnel experiments were also conducted to characterize the extraction of Te in hydrochloric acid with MIBK. In the microreactor experiments, the Te mass transferred between the two streams was measured for two channel lengths, three feed volume flow rates, and two feed phase inlet CdTe concentrations.