Lead, Zinc and their minor elements: enablers of a circular economy

In their own right, both lead and zinc are crucial everyday metals playing their well-known roles in our society. Increasingly, they are linked in concert with the other base metals, copper, nickel and cobalt, which together form the crucial carrier metals for a sustainable society – the Web of Metals (WoM). This paper examines the special and crucial role both lead and zinc have in acting as enablers in any recycling efforts as they carry and release important and vital minor elements. Through examination of the rising needs for such carriers, this paper examines the approach and technologies which need to be considered by any producer of lead or zinc. Attention is paid to the limits and extent of this carrier role in the typical processing of materials. Examples of specialised technology and flow sheet needs are presented with consideration given to a “whole of chain” or systems-integrated metal production (SIMP) approach as a cornerstone of a circular economy. Also outlined are the challenges facing not only producers, but legislators who need to consider the balance between providing our societal needs with baseline technology infrastructure requirements for valuable metals extraction. A number of conclusions after each section summarize the message of this paper, which states simply that not only is the criticality of metals important but the criticality of the infrastructure (Infrastructure Criticality) that can recover metals from complex mixtures. Lead and zinc are metals at the heart of a Circular Economy, therefore key enablers of the Internet-of-Things (IoT).