Cyprus Bagdad Copper Company
Eureka, AZ, U.S.

Cyprus Bagdad Copper Expansion

The Client selected Fluor, in a joint venture with Holmes and Narver, for the engineering, procurement, and construction of expanded copper concentrating facilities at the Cyprus Bagdad Copper Company operation in western Arizona. The $240 million expansion project boosted mine production from 6,000 tons of copper ore a day, to 40,000 tons daily, a 700 percent increase in the mine's capacity.

The ambitious capital project was completed in three years, with Fluor contributing more than 370,000 hours to engineering, procurement, and overall joint-venture management.

Fluor brought the project on line and under budget in September 1977, four months ahead of schedule.

Client's Challenge

The mine's history dates back more than a century. The original claims were discovered in 1882. The huge open-pit is in the Eureka mining district, located 65 miles west of Prescott. This arid, semi-desert is a region of hot, dry winds and 115 degree temperatures. Test drilling showed more than 303 million tons of copper-ore reserves lay within easy access.

Cyprus Bagdad initiated new environmental programs on this expansion. Electric trucks, dust control, and revegetation programs have prevented blighting of this desert region. Construction of a new tailings pond that recycles reclaimed water back to the mill not only saves water, it contributes to the overall efficiency of the operation.

The Client, in conjunction with the University of Arizona, in Tucson, pioneered revegetation techniques to remove signs of former mining operations. In a region that receives less than 10 inches of rainfall a year, on mine tailings devoid of nutrients, Cyprus agronomists developed a new strain of grass to enhance an ambitious revegetation program. Cyprus experimented with over 5,000 different species of barley to develop a new strain of grass to grow in the sandy, high silica tailings.


Fluor's Solution

Fluor's involvement in the expansion began in 1973. Cyprus Mines Corporation had merged with Bagdad Copper to form Cyprus Bagdad Copper Company. Fluor was called in to conduct a feasibility study to determine if expansion of the existing mill would be advisable.

Fluor was responsible for engineering and procurement of stockpile reclaiming, the design of the mill with a new type of grinding circuit, and overall management of the joint venture.

Ore from the pit is trucked to the primary crusher, and then carried on a 6,500-foot long overland conveying system to the radial stacker. The ore is belt-fed to the autogenous ball / cone crusher circuits and then moves to a potation circuit.

A molybdenum disulfide plant is on line and produces 2,000,000 ponds of the metal-hardening by-product per year. The extraction of the moly concentrates offsets the volatility in the copper market.


In Arizona's Eureka mining district, Fluor's expansion project raised Cyprus Bagdad's copper ore production 700 percent.

The 40,000-ton-per-day copper concentrator was completed in late 1977 for Cyprus Bagdad Copper Company. The expansion increased local employment to 750 personnel.