B2Gold (BTO.TO, BTG) late on Thursday released results of a technical report for the company's Back River Gold District in Nunavut that includes an updated life of mine plan for the Goose project based on a new mineral reserve estimate.

The Back River Gold District consists of 11 mineral claims along an 80-kilometer belt. Construction and development is on schedule for first gold pour in the second quarter, followed by ramp-up to commercial production in the third quarter. The company reiterated the previously announced total construction and mine development cash expenditure estimate of $1.54 billion for the project.

Indicated mineral resource estimate at the Goose project is around 3.6 million ounces of gold, or 15.5 million tonnes grading 7.16 grams per tonne gold. The gold grade is a 16% improvement from the gold grade in the last published technical report by the prior owner. Inferred mineral resource estimate is around 2.4 million ounces of gold, or 10.1 million tonnes grading 7.54 g/t gold. The gold grade is a 14% improvement versus the prior report.

The open pit and underground gold mine has an initial mineral reserve mine life of about 9 years, with mineral reserve life of mine production of about 2.3 million ounces of gold. The weighted average all-in sustaining cost of about US$1,360 per ounce from 2027 through 2031 is a better representation of long-term project potential, the company said. Projected AISC is about US$1,547 per gold ounce over the mineral reserve life of mine.

The mineral reserve estimate that forms the basis for the Goose project mineral reserve life of mine includes a probable mineral reserve estimate of 11.3 million tonnes grading 6.82 g/t gold for a total of 2.5 million ounces of gold.

B2Gold's share price at last look lost 2.2% to US$3.10 in U.S. pre-market trading on Friday.