Using results from ongoing exploration, Ero yesterday released a resource update and the updated LOM plan, which outlined a six-year operation producing a total of about 227,000 ounces of gold at an average all-in sustaining cost of US$720/oz.

Ero said there was a 78% increase in contained gold in the probable reserves, comprising 862,134t grading 8.83g/t for 244,650oz.

Gold in the indicated resource increased by 55% and by 37% plus a 13% increase in grade in the inferred category, to 573,772t at 10.55g/t for 194,556oz.

"In a very short period of time, NX Gold has grown from a mine with no reserves in front of it … to a low-cost, highly profitable six-year operation featuring an actionable road-map to further grow production and extend mine-life through conversion of our newly defined high-grade inferred mineral resource," president and CEO David Strang said.

"We expect to ramp-up drilling efforts to encompass eight drill rigs by year-end operating on both near-mine and regional programmes throughout the extensive land package controlled by NX Gold."

The company recently increased its forecast exploration spend at NX for 2020 from US$2-$3 million, to $3-$5 million.

It also revised NX's 2020 production guidance earlier this month from 38,000-40,000oz to 36,000-37,000oz, due to difficult ground conditions in the upper panel of the Santo Antonio Vein.

Ero had reported a quarterly record in adjusted EBITDA for the September quarter of US$62.5 million, a $20.1 million improvement on the previous quarter.

Its flagship asset is the Vale do Curaca copper mine in the Bahia state, which produced 10,961t of copper in the September quarter at record quarterly C1 cash costs of 63c/lb.

Ero shares (TSX: ERO) are trading near the top of a one-year range, closing up 4.3% yesterday to C$22.47 to capitalise it at $1.9 billion (US$1.4 billion).