BASE METALS — Cambior anticipates green light for Carlota project — Company spends five years and US$52 million preparing for production

After considerable delays, Montreal-based Cambior (CBJ-T) expects to receive environmental permits for its Carlota copper project in east-Central Arizona.

The company has spent five years and US$52 million preparing the open-pit deposit for production. All that is required before production can proceed is the final environmental impact statement (EIS), though one last appeal period is also expected. The Environmental Protection Agency expects to release the EIS by mid-June, to be followed by an immediate appeal period.

Gerald Veillette, president of subsidiary Carlota Copper, says the appeal is likely, given the opposition the project has faced over the past several years. If the appeal can be addressed quickly, construction, which is expected to last 13 months, could begin by October, with production conceivably commencing by the end of 1998.

The company acquired the property in August 1991 from Westmont Mining, and immediately began development drilling. Along with infill drilling and metallurgical test work, Cambior began collecting data for environmental baseline studies. A plan of operations was submitted in February 1992 and updated in January 1993, at which point the permitting process began in earnest.

Delays lengthened that process. American Rivers, a national environmental group, argued that Pinto Creek, an intermittent stream which runs through the Carlota deposit, was one of the most endangered rivers in the country. The group fears that operations at Carlota will pollute the river. As a precaution, Cambior plans to build a 1-Mile-long channel to divert waterflow away from the creek bed.

Environmental groups were also concerned about the archeological work being conducted on the property. In April 1996, opponents sought a temporary restraining order to halt that work, but courts decided against both this injunction and an emergency injunction filed later on. More than 40 prehistoric and historic sites have been located on the property, and Cambior has spent US$2 million on archeological studies there.

In 1996, the U.S. Fish and Wildlife Service studied the effects the operations are expected to have on local flora and fauna, including the hedgehog cactus and the lesser longnosed bat. The agency concluded that the proposed mine would likely not jeopardize the existence of those species.

The process of meeting the requirements for further development, as outlined in the National Environmental Policy Act (NEPA), has been lengthy.

Nonetheless, Cambior has picked up many permits along the way. The company already holds a state water quality certification, and has received a letter from the Arizona Department of Environmental Quality approving the issuance of the aquifer protection permit. Numerous hearings and review periods have addressed such issues as air quality, bio-diversity, socio-economics and land use.

However, these and other obstacles on the road to production have not deterred Cambior. With a renewed vigor, the company is determined to complete the permitting process. Carlota will become an increasingly important operation for Cambior, and its entry into production will enhance the company’s presence in the copper sector.

.SA first for Cambior

In 1996, Cambior produced 18.3 million lb. of the red metal from two polymetallic mines in Quebec. Both the Bouchard-Hbert mine, near Rouyn-Noranda, and the Gonzague Langlois mine, near Lebel-sur-Quvillon, host gold, silver and zinc, as well as copper. The Gonzague Langlois mine, however, was shut down last December owing to low zinc prices and the need to revise certain mining methods. Proceeds from copper production represented only 4% of the company’s total revenue in 1996.

The Carlota operation is a first in many respects. To begin with, it is the company’s first copper mine.

Carlota will be the first entirely new mine to be built in the state in 25 years. Other mining projects built since the early 1970s have revolved around the development of satellite orebodies or expansions of existing operations.

It will also be Cambior’s first foray into solvent extraction-electrowinning (SX-EW) technology, and the first mine in Arizona to employ solely that technique. (Other mines in the state use a combination of SX-EW and other extraction methods.)

“The state agencies in charge of the permitting have been hard on us,” explains Viellette. “It’s the first time they’ve had to permit a brand-New mine using NEPA standards. Everything had to be done by the book. But, we will have quite a showcase operation once it is finally constructed.” The mine is expected to crank out 66 million lb. copper per year — three times the amount the company produced last year.

Carlota is in the heart of Arizona’s copper country, 6 miles west of the town of Miami and adjacent to the Pinto Valley operation of BHP. The Carlota project contains 106 million tons of oxide reserves grading 0.45% copper, sufficient for a mine life of 20 years. The proposed open-pit operation will produce 24 million tons of material per year.

The heap-leach operation is expected to produce 33,000 tons of copper per year at a cash cost of less than 50 cents per lb.

The company expects to invest US$100 million in Carlota through preproduction, which will give the local economy a much-Needed shot in the arm. Conditions in nearby Globe and Superior have been depressed since a mining operation in Superior ceased several years ago. The new mine will bring 300 new jobs to the area.

Carlota’s mineralization is associated with supergene enrichment of oxide copper minerals above the water table. The mineralization comes from three main deposits: Carlota-Cactus, Eder North and Eder South. The principal minerals include chrysocolla, malachite and azurite. Chalcocite, a leachable copper sulphide, has been found in those deposits, though only in drill core.

The copper is believed to have been leached by surface waters from the uplifted Pinto Valley deposit, a few miles to the northeast, and precipitated as coatings and fracture fillings within breccia units.

The general geology of the Globe-Miami area consists of Laramide-Aged copper-bearing granitic rocks intruding into Precambrian metasediments and granitic rocks.

Meanwhile, Cambior is developing two other large copper properties in South America: El Pachn in Argentina and La Granja in Peru. Production at each is expected to exceed that of Carlota.