ABSTRACT
To meet sustainability targets and move towards a circular economy, the recovery of precious metals from processed urban mine liquors for production is an absolute necessity. Recovery processes are employed to obtain metals of high purity for further applications, depending upon concentration of leach liquors, availability of cheap electric power, and other economic considerations. This chapter reviews the feasibility of precious metal recovery from cyanide, halide, thiosulphate, thiourea-based leach liquors by precipitation, adsorption, nano- accumulation, and electrowinning. The fundamental principles and the effects of impurity metals on the recovery process are highlighted for each approach. Bio-mediated recovery of precious metals from various secondary liquors by biosorption are also discussed. The metal-binding ability of various biomaterials for precious metals, including algae, fungi, bacteria, and yeast as well as certain biopolymers and bio-waste materials is discussed.
