Application of flotation on the recovery/removal of heavy metals in secondary resources: A comprehensive review.

[Display omitted] • Activation of the depressed minerals in cyanide tailing by several activators. • Comprehensive consideration to the reasonable flotation condition for the recovery of the valuable metals from some solid wastes. • Recovery of heavy metals from the secondary resources by the combination of flotation and other techniques. • Several challenges and opportunities faced in recycling heavy metals using flotation technology. Due to the stringent environmental regulations requiring proper disposal of the wastes, recycling/removing heavy metals from solid wastes and wastewater has attracted the worldwide attention. Flotation tends to be one of the promising techniques that have enjoyed widespread use because of its high yield, low cost, and ease of operation. This article provided an overview of the present application status of flotation in the recovery/removal of heavy metals from secondary resources such as tailings, waste printed circuit boards, slags, lithium-ion batteries, leach residue and wastewaters. The study was focused on the reagent regimes and physicochemical & electrochemical mechanism of flotation, in particular, the application of single and hybrid process was reviewed. Finally, the paper has pointed out challenges and future perspectives of the flotation application in metal recovery from secondary resources. Hence, this work aims to promote the development of flotation technology to recover heavy metals from secondary resources. [ABSTRACT FROM AUTHOR]