2021 Annual Report

Mineral Resources & Ore Reserves IGO publicly reports its Exploration Results, Mineral Resource and Ore Reserve estimates in accordance with the Australian Securities Exchange (ASX) listing rules and the requirements and guidelines of the prevailing JORC Code (2012 edition of the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves). IGO last reported its annual Mineral Resource and Ore Reserve estimates to the ASX as at 31 December 2020. The next update and reporting of estimates will be as at the end of 2021. At the end of 2020, IGO reported Mineral Resources and Ore Reserves from IGO’s 100%-owned Nova Operation base metal (nickel-copper-cobalt) mine, and IGO’s 30% interest in the Tropicana Gold Mine (Tropicana). IGO divested its 30% interest in Tropicana at the end of May in FY21 and as such, is not reporting estimates or results for Tropicana for the end of FY21. The complete JORC Code reports relating to the end of 2020 estimates, including JORC Code Table 1 checklists, which detail the material assumptions and technical parameters for each estimate, can be found at www.igo.com.au under the menu ‘Our Business – Mineral Resources and Ore Reserves’ and also the ASX release 2020 Mineral Resource and Ore Reserve Statement dated 17 March 2021. Listings of the respective estimates for the end of 2019 and end of 2020 are tabulated below for IGO’s Nova Operation. The JORC Code Competent Persons Statement for IGO’s end of 2020 estimates are included on page 27 of this Annual Report. IGO’s public reporting governance for estimates and results includes several assurance measures. Firstly, IGO ensures that the Competent Persons responsible for public reporting: • Are current members of a professional organisation that is recognised in the JORC Code framework • Have sufficient mining industry experience that is relevant to the style of mineralisation and reporting activity, to be considered a Competent Person as defined in the JORC Code • Have provided IGO with a written sign-off on the results and estimates that are reported, stating that the report agrees with supporting documentation regarding the results or estimates prepared by each Competent Person; and • Have prepared supporting documentation for results and estimates to a level consistent with standard industry practices – including the JORC Code Table 1 Checklists for any results and/or estimates reported. IGO also ensures that any publicly reported results and/or estimates are prepared using accepted industry methods and using IGO’s corporate guidance for metal prices and foreign exchange rates. At its operating mines, IGO additionally ensures that the estimation precision is reviewed regularly through comparing the Mineral Resource and Ore Reserve forecasts to actual mine and process production results. The reconciliation of these inputs and outputs is then used for future Ore Reserve updates. Estimates and results are also peer reviewed internally by IGO’s senior technical staff before being presented to IGO’s Board for approval and subsequent ASX reporting. Market sensitive or production critical estimates may also be audited by suitably qualified external consultants to ensure the precision and correctness of the reported information. Operations Nova Operation —Mineral Resources Source JORC Code Class 2019 2020 Mass Nickel Copper Cobalt Mass Nickel Copper Cobalt (Mt) (%) (kt) (%) (kt) (%) (kt) (Mt) (%) (kt) (%) (kt) (%) (kt) Underground Measured 10.9 2.07 226 0.83 90 0.07 7 10.4 1.88 196 0.76 78 0.06 6 Indicated 0.6 0.96 6 0.44 3 0.04 <1 1.3 0.81 10 0.37 5 0.03 <1 Inferred <0.1 1.88 <1 0.69 <1 0.06 <1 0.1 1.26 <1 0.47 <1 0.04 <1 Subtotal 11.5 2.01 232 0.81 93 0.07 8 11.8 1.76 207 0.71 84 0.06 7 Stockpiles Measured 0.1 1.88 <1 0.79 <1 0.06 <1 <0.1 1.62 <1 0.65 <1 0.06 <1 Total Measured 11.0 2.07 227 0.83 91 0.07 7 10.4 1.88 196 0.75 79 0.06 6 Indicated 0.6 0.96 6 0.44 3 0.04 <1 1.3 0.81 10 0.37 5 0.03 <1 Inferred <0.1 1.88 <1 0.69 <1 0.06 <1 0.1 1.26 <1 0.47 <1 0.04 <1 Total 11.6 2.01 234 0.81 94 0.07 8 11.8 1.76 208 0.71 84 0.06 7 TABLE 1 — 31 DECEMBER 2019 AND 31 DECEMBER 2020 Nova Operation — Ore Reserves Source JORC Code Class 2019 2020 Mass Nickel Copper Cobalt Mass Nickel Copper Cobalt (Mt) (%) (kt) (%) (kt) (%) (kt) (Mt) (%) (kt) (%) (kt) (%) (kt) Underground Proved 9.2 1.86 172 0.78 72 0.07 6 8.7 1.83 159 0.78 67 0.07 6 Probable 0.2 1.49 3 0.58 1 0.05 <1 0.3 1.41 4 0.58 2 0.05 <1 Subtotal 9.5 1.85 176 0.78 74 0.07 6 9.0 1.82 163 0.77 69 0.07 6 Stockpiles Proved 0.1 1.88 1 0.79 1 0.06 <1 <0.1 1.62 1 0.65 <1 0.06 <1 Total Proved 9.3 1.86 174 0.78 73 0.07 6 8.7 1.83 160 0.78 68 0.07 6 Probable 0.2 1.49 3 0.58 1 0.05 <1 0.3 1.41 4 0.58 1 0.05 <1 Total 9.5 1.85 176 0.78 74 0.07 6 9.0 1.82 163 0.77 69 0.07 6 TABLE 2 — 31 DECEMBER 2019 AND 31 DECEMBER 2020 26 — IGO ANNUAL REPORT 2021