Local Opinion: Hucksters and hype at Hudbay

Several things threaten Green Valley’s future allure: Hudbay’s mining aspirations on the east side of the Santa Cruz valley is high on the list.

What kind of company focuses their advertising and press releases on their investors rather than on their neighbors, whose water they waste and land they despoil? Why, apparently, that would be Hudbay Minerals, owners of Rosemont Copper and the newly much-touted Copper World project. Here are some public quotes from Hudbay:

On an Aug. 9 investor call, Hudbay CEO Peter Kukielski “stressed the benefits from the company’s standpoint, of doing a mine on private land versus public land, due to lesser amount of government oversight and control.” Note that Rosemont has been put on a court hold due to a flawed National Environmental Policy Act (NEPA) assessment. Then why has Hudbay filed mining claims on thousands of acres of public lands in the Copper World vicinity? Presumably to “copper their bets”!

Some hype:

“Copper World is a very, very, very compelling alternative (to Rosemont) or a very, very compelling add-on,” Kukielski said. Note that Copper World, as presently claimed, is but a fifth the size of Rosemont!

“Copper World is one of the top copper discoveries in the past decade” (in the world!). Note that this completely disregards international copper projects that are in current development, and that are an order of magnitude larger than Copper World. What is true is that mining these small Copper World deposits would still devastate and despoil the surrounding rivers and underlying aquifers.

Some facts:

Hudbay has released copper assays of 70 of their recent drill holes on the west side of the Santa Ritas. There are some highly copper-rich zones identified. Of course, when you start a drill hole on “green” rock outcrop, the next few dozens of feet of core is generally going to look pretty good. And if the visually “barren” core zones are not then assayed, they won’t dilute the reported copper content. Given this, the “average” copper content of the assayed core from the five identified deposits called Copper World is 0.5%; this is likely an overestimate. A large open pit copper mine, like the Rosemont project, can make money with an average grade of 0.5%. It’s very unlikely the small “quarry” operations like Copper World can.

But here’s the absolutely key fact that Hudbay has “disclosed,” but has not highlighted. And it is massively damaging to our water and air. They emphasize that lots of the copper lies near the surface, so it is cheaper to mine. One corollary of this is that the ore is likely a mixture of sulfide and oxide-based copper. In fact, in their assays, half of the copper is in oxide form. This copper cannot be concentrated using conventional flotation circuits, as used at the other porphyry copper mines in Green Valley. Instead, oxide-copper is extracted by an acid-leaching process called “heap-leach.” Finely ground ore is piled on the ground and sulfuric acid is pumped through it, copper dissolves into the acid and the retrieved acid is then processed for the copper.

There is no environmentally safe way to do this, without piling the rock on an impermeable geo-membrane. And this is expensive, making low-grade deposits like Copper World unprofitable. In the 2011 draft environmental impact statement for Rosemont, a heap-leach process was proposed for some of the ore – this was quickly dropped, when challenged by the federal agency leading the NEPA process. Hudbay knows all of this full well, but does not even hint at it in their recently accepted Arizona Mine Plan of Reclamation.

Nor do they mention that this acid-leaching process also dissolves lead minerals; where does this lead go? Ultimately into your drinking water! What is Hudbay really up to?