A Bird’s Eye View of Chino and Tyrone Mines
Copper Mining at Grant County Copper Mines
Sulfuric acid leaching operations are used to process low-grade copper ore at the Chino and Tyrone mines. A sulfuric acid solution drips through the many stockpiles around the mines, leaching out the copper and other metals as the acid solution makes its way down through the unlined stockpiles. This resulting Pregnant Leach Solution (PLS) is collected at the toe of the stockpiles where it is then pumped to the Solvent Extraction/Electrowinning (SX/EW) plant for further processing. During the solvent extraction (SX) phase of the process, the PLS is mixed with an extractant to strip the copper from the solution. The electrowinning process plates the copper onto a metallic copper cathode by applying an electric current to the solution, resulting in a cathode that is 99.99% copper. Seen every day being transported on Grant County’s highways, the copper cathodes are shipped out for further manufacturing into copper pipe, wire and other products. The PLS that is captured is returned back into the leaching process.
The photos below show a few of the many PLS ponds located around the Chino and Tyrone mines.
A BIRD’S EYE VIEW OF MINING RECLAMATION
GRIP Mining Photo Essay 2nd Installment
As a follow-up to our last aerial photo-essay of PLS ponds at the Chino and Tyrone mines, we’re sharing more images from our collection, available at www. gilaresources.info. This time we’re highlighting the progress made in reclaiming tailings piles at Freeport-McMoRan’s Tyrone mine.
By winning strong reclamation and financial assurance requirements, GRIP helped create a viable financial incentive for Phelps-Dodge and its new owner, Freeport-McMoRan, to reclaim inactive mine areas sooner rather than later. With copper prices soaring, the company cut its taxes and reduced long-term environmental liabilities by employing dozens of workers to get several years ahead of schedule on reclamation. Some of the units being reclaimed have been inactive since the early 1990’s, sending dust into the air and killing birds that happened to land in acidic pond water.
Reclamation is very close to completion at the Tyrone tailings ponds and stockpiles no longer in use. Recontouring, covering, and much of the seeding of vegetation seeding of is now done. Most of the work, which requires huge machinery and creates many additional jobs, will come to a close at the end of this year. Some of the equipment purchased for this mammoth project is being moved to Chino for reclamation work that has begun on the older, retired tailings ponds. This work can be observed from Highway 180 southeast of Hurley. GRIP will continue to participate with the state Environment Department and the Mining and Minerals Division in inspections of these clean-up operations in order to ensure compliance with approved reclamation plans before Freeport- McMoRan is released from associated financial assurance requirements.