OZ Minerals Limited announced an update on the Prominent Hill Expansion Study released on November 16, 2020 shows installation of a vertical hoisting shaft to replace truck haulage (Study Update) is technically and economically feasible. The Study Update is based on a conservative interim case (Interim Case) containing only a third of the total Prominent Hill Inferred Resource of 59 million tonnes outside the current life of mine plan. OZ Minerals will now invest $47 million to progress the study. The largest portion of the investment will be directed towards further infill drilling to potentially convert Inferred Resources to Reserves to inform a final investment decision expected in mid-2021. Over the past decade, Prominent Hill has seen a positive conversion of Inferred Mineral Resources to Indicated Mineral Resources (or better) with a conversion rate of greater than 1:1 on a contained metal basis. The Study Update confirms the installation of a 1,360 metre, 7.5 metre diameter vertical shaft at Prominent Hill is technically and economically feasible with capital investment consistent across the interim and strengthened cases. The robustness of the investment into the shaft was tested by examining the feasibility of mining the existing Ore Reserves with a production target based on approximately 6 Mtpa from 2025 comprising less than 30% Inferred Mineral Resource. The Interim Case shows that converting to a vertical shaft would lower the operational risks of mining at depth and be NPV and cashflow positive over the current truck haulage mining operation. The economics thus far support continued investment in the expansion study to undertake further infill drilling to increase mine life and inform a final investment decision. The Study Update shows a shaft haulage expansion would require capital cost of approximately $450 million (not expected to materially increase if there is conversion of Inferred Resources to Reserves to expand the scale of the Study) to be spent over four years from 2021 and potential for: improved safety and productivity as mining conditions become deeper and hotter enabling access to more of the total Inferred Mineral Resource; lower site operating costs by between $10 and $15 per tonne; seamless conversion to vertical shaft haulage from 2025; potential to extend mine life upon further conversion of Mineral Resources to Reserves consolidating Prominent Hill as a low-cost, long-life open stoping mine; improved greenhouse gas emissions intensity by progressively shifting to an electrified shaft and underground fleet; the existing processing plant to accommodate the new throughput rates without major modification; and access to exploration beyond the Resource limits to provide further growth potential.