Copper miner Hudbay sees the Copper World discovery, in Arizona, as “very interesting, either alternative or add-on” to the adjacent Rosemont project, which continues to be in legal limbo.
The company made the high-grade copper sulphide discovery earlier this year on wholly patented mining claims about 7 km off its Rosemont project. Four deposits have been identified with copper mineralisation that contains higher grades, closer to the surface than Rosemont.
The intersections included 134 m of 1.38% copper and 75 m of 0.7% copper starting at surface, underscoring the high-grade and shallow nature of the copper mineralisation.
“We are going to push Copper World forward very hard,” CEO Peter Kukielski said this week, stating that the timeline for the project indicated the value that Hudbay placed on the deposit.
An inferred resource would be published by the end of the year, and a preliminary economic assessment was expected early next year, he stated.
The expanded 2021 exploration programme at Copper World was well-advanced with 25 900 m of drilling completed in the first half of the year and four drill rigs currently turning at site.
The company will publish an update once most assays have been received for the holes drilled during the first half of 2021.
Senior VP and COO Cashel Meagher said that the lower strip ratio of Copper World, compared with Rosemont, would present a positive set of economics and a compelling case to move forward.
While advancing technical studies for Copper World, Hudbay was also evaluating several targets identified through geophysical surveys on its extensive regional land package, Kukielski added.
The drill programme was initiated in 2020 to confirm historical drilling in this past-producing copper region formerly known as Helvetia. After receiving encouraging initial results, the company launched a larger drill programme in early 2021.
The Copper World region has a rich history of mining from 1874 to 1969, during which time more than 20 small underground mines produced a total of about 440 000 t at an average copper grade of 4.42%.
Kukielski stressed that Hudbay remained committed to advancing Rosemont through the appeals process.
In production, the Rosemont project will be one of the largest copper mines in the US, with an expected mine life of 19 years.
In July 2019, the US District Court for Arizona issued a ruling that vacated the final record of decision (RoD) issued by the US Forest Service. As a result, work on Rosemont was suspended. The judge essentially ruled that the decision to issue the final RoD was based on an incorrect interpretation of mining claims.
Hudbay has appealed the ruling and believes that the court misinterpreted federal mining laws and Forest Service regulations as they applied to Rosemont.