MINERAL RESERVES & RESOURCES | Vale do Curaçá

Mineral Reserves Notes:

1. Effective Date of August 1, 2018.
2. Mineral Reserves included within stated Mineral Resources. All figures have been rounded to reflect the relative accuracy of the estimates. Summed amounts may not add due to rounding.
3. The Mineral Reserve estimates are prepared in accordance with the CIM Definition Standards on Mineral Resources and Mineral Reserves, and the CIM Estimation of Mineral Resources and Mineral Reserves Best Practice Guidelines, using geostatistical and/or classical methods, plus economic and mining parameters appropriate for the deposit. Mineral Reserves are based on a long-term copper price of US$2.75 per pound (“lb”), and a USD:BRL foreign exchange rate of 3.20. Mineral Reserves are the economic portion of the Measured and Indicated Mineral Resources. Mineral Reserve estimates include mining dilution at zero grade. Mining dilution and recovery factors vary for specific reserve sources and are influenced by factors such as deposit type, deposit shape, stope orientation and selected mining method.
4. The Mineral Reserve estimate was calculated by Rubens Mendonҫa, MAusIMM, an independent qualified person, in accordance with the standards set out in CSA, NI 43-101 and generally accepted CIM “Estimation of Mineral Resource and Mineral Reserves Best Practices” guidelines.

Mineral Resources Notes:

1. Effective Date of  July 1, 2018 for the Pilar and Surubim Mines, May 31, 2018 for the Vermelhos Mine, Vermelhos West and R22W
2. Presented Mineral Resources inclusive of Mineral Reserves. All figures have been rounded to reflect the relative accuracy of the estimates. Summed amounts may not add due to rounding.
3. Cut-off value of 0.68% copper for underground resources and 0.18% copper for open pit resources based on 2015 operating costs (last full year of operation).
4. Mineral Resources estimated by ordinary kriging inside 5m by 5m by 5m blocks. Please refer to Ero’s Vale do Curaçá Technical Report for additional details.
5. The Mineral Resource estimate was calculated by Porfírio Cabaleiro Rodriquez, MAIG, Fábio Valério Câmara Xavier, MAIG and Bernardo Horta de Cerqueira Viana, MAIG, all independent qualified persons, in accordance with the standards set out in CSA, NI 43-101 and generally accepted CIM “Estimation of Mineral Resource and Mineral Reserves Best Practices” guidelines.

Please refer to the Vale do Curaçá Technical Report, dated October 17, 2017, with an effective date of August 1, 2018 for additional technical information related to the Mineral Reserve and Mineral Resource estimates.