Cambior Inc. - substantial increase in mining reserves at La Granja.

MONTREAL, Quebec--(BUSINESS WIRE)--Sept. 21, 1995--Cambior Inc. is announcing a substantial increase in mining reserves at the La Granja copper project in Peru.

Proven and probable mining reserves have been increased to nearly 600 million tonnes at 0.73 percent Cu representing 9.7 billion lbs of copper in situ.

The following table details the change in mining reserves from March 1994 to September 1995. -0-

                             September 1995
                           Proven and Probable

Mining Reserves (tonnes)  596 million at 0.73 percent Cu
Waste Ore Ratio                  1.43:1
Cut-Off Grade                 0.5 percent Cu

                                March 1994
                           Probable and Possible

Mining Reserves (tonnes)  175 million at 0.84 percent Cu
Waste Ore Ratio                  1.5:1
Cut-Off Grade                0.5 percent Cu

This reserve update is based on a hundred additional holes, for a total of 36,000 meters, which have been drilled at the La Granja project since Cambior's involvement in the project began in 1994. ~

Strategic Impact

Louis P. Gignac, President and Chief Executive Officer stated, "We are very pleased with the results of this advanced exploration program as the mining reserves have more than tripled since our involvement began in 1994. The investment to date of US $14 million has increased the value of the project.

Furthermore, the development of this project has helped us establish an important presence in Peru with a number of other promising exploration projects. The prefeasibility study, expected by the beginning of 1996, will further determine the full value and potential of the project. Based on the results of this study, Cambior will determine the strategy that will best enhance long-term shareholders' value relative to this project."

Background

The La Granja project is located about 650 kilometers north of Lima, Peru. By road, the project is 217 kilometers east of Chiclayo, on the east flank of the Northwestern Cordillera of the Andes at an altitude of 2,000 to 2,700 meters above sea level.

The La Granja deposit is a highly altered intrusive formation of late Tertiary age and is comprised of two zones. The most important zone, the primary zone, contains the copper mineral chalcopyrite. The secondary zone contains copper sulfide minerals that might be recovered by lixiviation. Some areas are still open laterally as well as at depth which could lead to further increases in the mining reserves.

In 1994, Cambior secured an option to acquire 100 percent of the La Granja project from the state-owned mining corporation, Minero Peru S.A. and can exercise this option by funding US $25 million in exploration and development over five years and preparing a feasibility study. In May 1995 a payment of US $2 million was made to Minero Peru for the second year option payment. The third option payment of US $4 million will be due in May 1996.

In the first half of 1995, expenditures on the La Granja project amounted to US $6 million. As of June 30, 1995, Cambior had invested US $14 million on the La Granja project.

Development Program

The current program for the second half of this year, includes 14,000 meters of drilling (40 holes) to better define the boundary of the deposit. These holes will complete the 200m x 200m pattern and infill certain sectors on a tighter grid of 100m x 100m. Ongoing metallurgical testwork confirmed that flotation recoveries for copper should be in the order of 90 percent and that copper concentrates would be in the 30-32 percent range.

The prefeasibility study is expected to be completed by the beginning of 1996 and the full feasibility study should be completed during the following year. Subsequent to the confirmation of the feasibility study and arrangement of financing, construction could begin in 1997 with commercial production anticipated in 1999.

According to a preliminary mine plan, some 70 million tonnes grading 1 percent copper could be mined with a waste/ore ratio of 1.31:1 in the first five years of commercial production. These preliminary results indicate an average annual production of 275 million lbs of copper.

Cambior is a major gold producer with operating and exploration activities in North and South America. Cambior's shares and warrants are listed on the Montreal and Toronto stock exchanges and on the American Stock Exchange (AMEX) in the United States under the symbols CBJ and CBJ.WTA.

CONTACT: Cambior Inc., Montreal

Henry A. Roy, 514/878-1484

Robert LaValliere, 514/878-1282

Victoria Putnam, 514/878-3166