By Tony Davis
Arizona Daily Star
That’s due to changes in the technologies and production levels it now plans for the Rosemont Mine southeast of Tucson.
But the company’s statements, made in its latest letter to the U.S. Forest Service, have drawn skepticism from critics.
On truck traffic, a table included in the letter from Rosemont Copper Vice President Kathy Arnold predicts the total number of daily mine truck shipments will drop from 78 to 69.
One reason is that 81 weekly shipments of copper cathodes and sulfuric acid will no longer be made because the company is no longer going to produce copper cathodes through heap leaching.
She also credits the reduction in shipments to the fact that the copper concentrates produced at the mine now will have a higher grade compared with earlier estimates.
The table shows the total amount of copper concentrate shipped declining from 484,700 to 439,000 tons per year, although it also shows the number of daily concentrate truckloads would rise from 46 to 50.
Rosemont backs off water-use statement/Arizona Daily Star