A new resource estimate for Venturex Resources Ltd.'s Sulphur Springs deposit, part of the larger Sulphur Springs property in Western Australia, resulted in 40% of inferred resources being upgraded to the indicated category, with a 7% increase in the indicated copper grade for supergene mineralization.
Indicated and inferred resources now total 13.8 million tonnes grading 1.5% copper, 3.8% zinc and 18 g/t of silver, according to a March 21 statement.
The company noted that 60% of inferred supergene resources were upgraded to the higher-confidence category.
Indicated resources include 300,000 tonnes of supergene mineralization grading 4.5% copper, 0.6% zinc and 27 g/t of silver, while inferred resources include 300,000 tonnes of supergene mineralization grading 2.8% copper, 1.5% zinc and 17 g/t of silver.
The updated estimate uses a 0.4% copper cutoff and incorporates data from infill drilling completed in 2017. The drill program confirmed high-grade supergene mineralization in the western portion of the deposit and increased exploration potential on the western margins.
Venturex Resources is planning an exploration program in the second quarter focused on testing extensions to resources. The company is also finalizing an environmental review document to submit in April; a decision is anticipated in the third quarter.
A value engineering study completed in early 2017 on the Sulphur Springs project estimated a pretax net present value of A$338 million, at a discount rate of 8%, with an internal rate of return of 52%.