IGO Interactive Annual Report 2020

Mineral Resources & Ore Reserves IGO publicly reports Exploration Results, Mineral Resource and Ore Reserve estimates in accordance with the ASX listing rules and the requirements and guidelines of the 2012 edition of the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves – the JORC Code. IGO last reported its annual Mineral Resource and Ore Reserve estimates to the ASX on an end of calendar year 2019 (CY19) and the estimates will be next updated and reported at the end of CY20. At the end of CY19, 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 (TGM). The complete JORC Code reports relating to the CY19 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 CY19 Mineral Resource and Ore Reserve Statement dated 30 January 2020. Listings of the respective estimates for the end of CY18 and end of CY19 are tabulated below for IGO’s total interests in Nova and TGM operations. The JORC Code Competent Persons Statement for IGO’s end of CY19 estimates are included on page 31 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. On operating mines, IGO additionally ensures that the estimation precision is reviewed regularly through a reconciliation comparing the Mineral Resource and Ore Reserve forecasts to actual mine and process production results. 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. NOVA OPERATION — MINERAL RESOURCES Source JORC Code Class 2018 2019 Mass Nickel Copper Cobalt Mass Nickel Copper Cobalt (Mt) (%) (kt) (%) (kt) (%) (kt) (Mt) (%) (kt) (%) (kt) (%) (kt) Underground Measured 12.5 2.10 261 0.80 104 0.07 9 10.9 2.07 226 0.83 90 0.07 7 Indicated 0.6 1.00 6 0.40 2 0.04 <1 0.6 0.96 6 0.44 3 0.04 <1 Inferred <0.1 1.90 1 0.70 <1 0.06 <1 <0.1 1.90 1 0.70 <1 0.06 <1 Subtotal 13.2 2 .00 268 0.80 106 0.07 9 11.5 2 .00 232 0.80 93 0.07 8 Stockpiles Measured 0.1 2.10 1 0.90 1 0.08 <1 0.1 1.88 1 0.80 1 0.06 <1 Total Measured 12.6 2.10 263 0.80 104 0.07 9 11.0 2.07 227 0.83 91 0.07 8 Indicated 0.6 1.00 6 0.40 2 0.04 <1 0.6 0.96 6 0.44 3 0.04 <1 Inferred <0.1 1.90 1 0.70 <1 0.06 <1 <0.1 1.90 1 0.70 <1 0.06 <1 Total 13.2 2 .00 270 0.80 107 0.07 9 11.6 2 .00 234 0.80 94 0.07 8 TABLE 3 — 31 December 2018 and 31 December 2019 NOVA OPERATION IGO TOTAL IGO TOTAL — MINERAL RESOURCES Calendar Year Ending Mining Operation Mass (Mt) Grades estimates In situ metal estimates Ni Cu Co Au Ni Cu Co Au (%) (%) (%) (g/t) (kt) (kt) (kt) (koz) 2018 Nova Operation (100%) 13.2 2.0 0.8 0.07 - 270 107 9 - Tropicana Gold Mine (30%) 40.9 - - - 1.76 - - - 2,310 Total 54.1 Grades are not additive 270 107 9 2,310 2019 Nova Operation (100%) 11.6 2.0 0.8 0.07 - 234 94 8 - Tropicana Gold Mine (30%) 38.6 - - - 1.70 - - - 2,106 Total 50.2 Grades are not additive 234 94 8 2,106 CY19/CY18 Nova Operation (100%) 88% 101% 100% 100% - 87% 88% 89% - Tropicana Gold Mine (30%) 94% - - - 97% - - - 91% CY19/CY18 93% Grades are not additive 87% 88% 89% 91% TABLE 1 — 31 December 2018 and 31 December 2019 TABLE 2 — 31 December 2018 and 31 December 2019 IGO TOTAL — ORE RESERVES Calendar Year Ending Mining Operation Mass (Mt) Grades estimates In situ metal estimates Ni Cu Co Au Ni Cu Co Au (%) (%) (%) (g/t) (kt) (kt) (kt) (koz) 2018 Nova Operation (100%) 11.5 1.90 0.76 0.06 - 219 87 7 - Tropicana Gold Mine (30%) 19.7 - - - 1.77 - - - 1,122 Total 31.1 Grades are not additive 219 87 7 1,122 2019 Nova Operation (100%) 9.5 1.85 0.78 0.07 - 177 74 6 - Tropicana Gold Mine (30%) 16.9 - - - 1.67 - - - 909 Total 26.4 Grades are not additive 177 74 6 909 CY19/CY18 Nova Operation (100%) 83% 97% 103% 117% - 81% 85% 86% - (relative) Tropicana Gold Mine (30%) 86% - - - 94% - - - 81% CY19/CY18 85% Grades are not additive 81% 85% 86% 81% 28 — IGO ANNUAL REPORT 2020 IGO ANNUAL REPORT 2020— 29