Discovery and Underground Mining of Large Deposits: Essential Training to Ensure Copper Supply

Editor’s note: The aim of the Geology and Mining series is to introduce early career professionals and students to various aspects of mineral exploration, development, and mining in order to share the experiences and insight of each author on the myriad of topics involved with the mineral industry and the ways in which geoscientists contribute to each. Abstract A supply shortfall of at least 6 million tonnes (Mt) Cu is expected by 2031—with total demand now forecast to increase from 25 Mt in 2023 to >36 Mt, and possibly to a suggested 50 Mt by 2050—given the present trend in demand. The deficit can be partially filled by increased mine production, expanding currently installed mine production capacity, and increasing Cu recycling. However, satisfying demand in 2050 as the demand-to-mining supply gap increases will require the accelerated discovery of at least five large Cu deposits—individually producing >0.5 to >1.0 Mt/yr Cu—and their related mine development, by 2030. These five deposit discoveries are required to replace mines scheduled to close in the 2050s, given the >20 years needed to take a deposit from discovery to mine production. The two largest sources of Cu supply, porphyry and sediment-hosted Cu deposits, can potentially fill the gap if enough discoveries are made; however, there is no evidence that this is about to occur. Future porphyry Cu discoveries are expected to be mined underground, mostly by a caving method. The demand increase is occurring at a time when the capital intensity of porphyry Cu mine development has almost doubled since 2006. We predict that the only solution to the future Cu demand-supply challenge for society and the mining industry in the short to medium term rests with simple demand-supply economics and a substantially increased Cu price. Copper substitution by other materials and recycling could potentially benefit from a significantly increased price; however, the major advantage will be conferred on deposits amenable to open-pit mining that are undeveloped because of price-dependent, failed feasibility studies. The challenge of possibly doubling Cu supply by ca. 2050 through developing mines on large Cu deposits—both discovered and undiscovered, in an unprecedented number and in a shorter period—will require a major increase in the number of competent mining industry personnel. This comes at a time when the industry faces an aging workforce, leading to a critical skills gap compounded by a chronic shortage of students graduating in the sciences and engineering with mining-related university degrees. There is an acute shortage of experienced professionals in cave mining, and the substantial number of open-pit mining professionals who are predicted to retire by 2030 will need to be replaced. On-the-job training of geoscientists and engineers after graduation, delivered by experienced practitioners through university-accredited professional development programs, is suggested as the solution.