Leaching Processes

Abstract

When solid materials are exposed to a liquid, some constituents will dissolve to a greater or lesser extent. The degree of dissolution of individual constituents by the contacting liquid leads to a leachate/percolate or extract composition that can be of interest for different purposes [1], such as the extraction of metals from solid waste through a suitable leachant. Leaching is a step in hydro- and electrometallurgical processes and has been also employed for the recovery of metals from waste of electrical and electronic equipment (WEEE). The process may be preceded by a mechanical pretreatment of the waste (see Chap. 6 ) and followed by purification and metal recovery from the solution (see Chaps. 8 and 9 ). This chapter will discuss the different leaching solutions and conditions for WEEE processing.