Processing Tests, Adjusted Cost Models and the Economies of Reprocessing Copper Mine Tailings in Chile

Abstract

To increase resource efficiency, mining residues–especially tailings–have come into the focus of research, companies, and politics. Tailings still contain varying amounts of unextracted elements of value and minerals that were not of economic interest during production. As for primary mineral deposits, only a small share of tailings offers the possibility for an economic reprocessing. To minimize exploration expenditure, a stepwise process is followed during exploration, to estimate the likelihood of a project to become a mine or in this case a reprocessing facility. During this process, costs are continuously estimated at least in an order of magnitude. Reprocessing flowsheets for copper mine tailings in Chile were developed and costs and revenues of possible products from reprocessing were examined for a rough economic assessment. Standard cost models with capex and opex for flotation, leaching, and magnetic separation were adopted to the needs of tailings reprocessing. A copper tailing (around 2 M t) that also contains magnetite was chosen as a case study. A combination of magnetic separation and leaching gave the best economic results for copper and magnetite. The adopted cost models showed positive results at this early stage of investigation (semi-technical scale processing tests).

Progress in bioleaching: part B, applications of microbial processes by the minerals industries

“…Also, trace metals such as indium have been targeted (Martin et al 2015 ). Economic considerations for reprocessing of mine tailings are rare but are a prerequisite for application (Araya et al 2021 ; Drobe et al 2021 ).…”

Past, Present, and Future of Copper Mine Tailings Governance in Chile (1905–2022): A Review in One of the Leading Mining Countries in the World

“…Therefore, considering recent studies on old tailings storage facilities, it is possible to say that the deposited tailings material still contains around 0.3 wt.% Cu in some tailings storage facilities. Considering the current high prices of copper, together with the fact that the tailings material is already crushed and ground (representing 30% of the operating costs of mining), it can be considered as a potential georesource material [ 59 ] and is currently being studied worldwide for its potential exploitation [ 1 ]. Therefore, the reprocessing of many old mine tailings storage facilities may be a first-choice option for the remediation of an old mine site, providing a new opportunity for mining companies to relocate tailings material, reprocess it, and deposit it in an environmentally friendly way [ 1 ].…”

New Insights Into Recovery of Copper and Gold from Old Flotation Tailings from Bor, Serbia

“…Efficient processing of tailings, i.e., mine waste, is crucial to eliminate environmental risks often connected with tailings ponds. Tailings also represent a valuable source of secondary raw materials, which has been earlier neglected as an opportunity, but now seen globally .as potentially exploitable and cost saving raw material sources, since they consist of already mined and comminuted minerals [1][2][3][4][5].…”