Recovery of metals and energy from pyrolyzed electronic scrap

Abstract

This thesis is directed at developing a process ow sheet for the recovery of valuable metals and energy from pyrolyzed electronic scrap in an economic and environmentally acceptable manner. In order to accomplish this objective the chemistry fundamentals for an extremely complex system must be explored and understood. An initial low temperature pyrolysis was investigated by our research group, which provides the basis for the pretreatment step (Shuey, 2006). Pretreatment sequesters the halides via salt formation from sodium bicarbonate while volatilizing o the organic fraction. It was found that trona is equally eective as sodium bicarbonate at sequestration of the halides. Initial processing results in four primary constituents: carbon char, mixed metals, silica bers/ceramics, and sodium salts. This project critically analyzed selected ow sheets based on laboratory experiments, which provided the supporting data. Initial separation of the dierent constituents was evaluated using traditional mineral processing techniques, such as physical separation. The subsequent processing study treated the concentrate to produce a marketable metal product via pyrometallurgical processing.