Recovery of Ni, Mo, Co from the copper slag processed by flotation at Aurubis slag flotation plant

Abstract

This work was focused on recovery metals such as Co, Ni and Mo from slags that have been treated previously by flotation. At the very beginning a characterization of the material showed how the metals of interest occur in the slag, giving an initial indication on how to orient the research. Then, a series of treatments options were executed and their processing variables studied. Two processing routes were suggested, both aiming to suggest a process which valorize the valuable metals, minimize waste production and at the same time can be economically feasible. The double Sulphation- Leaching route proposed forms a selective process that allows to separate iron in advance and obtain acceptable recoveries for Cu, Ni and Co. In a very first economic analysis it looks as a feasible and promising option. The second suggested processing method is a two stages Sulphation process coupled with a carbothermic reduction of the solid residue coming from the second stage leaching. This process reduces overall waste generation by yielding 4 different products that are possibly marketable in different industries. These proposals are in line with the circular economy concept, which is on the agenda of modern industrialized society.