South America-focused Nexa Resources (NYSE: NEXA) expanded the resource at its Aripuanã zinc and copper mine in Mato Grosso state, Brazil by enough to extend the operation’s life by three years.
Nexa, one of the five largest metallic zinc producers globally, added 8.3 million tonnes of probable mineral reserves after more than 34,000 metres of infill drilling last year, the company said in a filing to the NYSE on Thursday. It increases the mine’s life to 14 years.
The underground mine, about 2,000 km northwest of the capital Brasilia, is currently ramping up and expected to hit full plant capacity in the second half of this year, Nexa said. Average annual production is forecast at 70,000 tonnes of zinc, 24,000 tonnes of lead, 4,000 tonnes of copper, 1.8 million oz. of silver and 14,500 oz. of gold.
Aripuanã consists of three main mineralized zones – Arex, Link and Ambrex. Additional targets include Massaranduba, Boroca and Mocoto to the southeast and Babaçu and Arpa to the northwest.
Ignacio Rosado, CEO of Nexa Resources, said the increase in Aripuanã’s reserves and its mine life extension reinforces Nexa’s belief that it will be a long-life mine.
“In 2023, we plan to continue to advance with our drill program in Babaçu and at the Link and Ambrex mineralization gap,” Rosado said in a news release. “We expect to expand the Babaçu deposit to the northwest, potentially further increasing mineral resources.”
Aripuanã’s proven and probable mineral reserves are estimated at 30.1 million tonnes grading at 3.4% zinc, 1.3% lead, 0.2% copper, 32.1 grams silver per tonne and 0.23 grams gold. Contained metal is estimated at 1 million tonnes zinc, 377,700 tonnes lead, 50,400 tonnes copper, 3.1 million oz. silver and 220,000 oz. gold.
It’s a 38% increase from 21.8 million tonnes grading at 3.6% zinc, 1.4% lead, 0.2% copper, 33.5 grams silver per tonne and 0.30 grams gold as of the end of 2021, Nexa said.
The company plans 15,600 metres of diamond drilling this year, including 4,400 meters to extend the Babaçu deposit and to test the mineralization gap between Link and Ambrex. An additional 11,200 meters of infill drilling is aimed at reclassifying mineral resources at Babaçu to mineral reserves and potentially to further expand the life of the mine.
Babaçu assay results received this year and not included in the resources update show high-grade massive stratabound mineralization, the company said. Hole BRAPD000151 cut 11.7 metres grading 8.7% zinc, 4% lead, 0.1% copper, 118.9 grams silver per tonne and 0.2 grams gold.
Nexa owns and operates six underground mines — three in the central Andes of Peru, two in Brazil’s state of Minas Gerais, and Aripuanã in Mato Grosso.