Big Kennecott upgrade — Rio Tinto plans new facility for molybdenum

COPPERTON — The sight of silvery molybdenum slipping over the sides of a floatation chamber has become a lot more attractive to Kennecott Utah Copper in the last couple of years.

It's become so financially attractive, in fact, that the company's parent, Rio Tinto, announced plans Tuesday to invest $270 million into building a new facility that will process the metal to higher grades that aren't currently possible at the mine. The project will increase the mine's production of molybdenum by 15 percent, and since Kennecott currently produces 30 million pounds of the metal each year — worth $33 a pound — molybdenum stands to bring Rio Tinto a pretty big profit.

"What we plan to do is process and sell any molybdenum the mine produces every year," said Doug Stauffer, project manager over the recently approved Molybdenum Autoclave Process project. "If the mine produces it, we're going to process it and the resulting material we will sell. And we believe there will certainly be markets for that well into the future."

Kennecott currently processes its molybdenum — separates it, pounds it into powder, washes it and roasts it dry — then packages the product into 4,000-pound bags that are hauled to Belgium and Mexico for further processing. Once the company builds its MAP project near the existing Kennecott smelter in Salt Lake County, the molybdenum won't be shipped abroad anymore. The product will be processed in-state, and the mine will produce a higher chemical-grade material that can be used in oil refineries to remove sulfur from fossil fuels.

When the project is completed in 2010, Kennecott will also start recovering and selling rhenium, which is a rare metal used in the production of jet engine turbines. The metal allows jet engines to be smaller, hotter, faster and more fuel-efficient.

Stauffer estimates the mine will produce 9,000 pounds of rhenium annually to satisfy about 9 percent of the world's overall demand of about 100,000 pounds a year.

The worldwide demand for molybdenum is 400 million pounds, but that need is growing as developing countries have an increased need for metal products used for construction.

"Molybdenum is used in stainless steels, tool steels, cast irons and high-temperature superalloys," said Siva Guruswamy, professor of metallurgy in the University of Utah's Department of Metallurgical Engineering. "This segment of the market has dramatically increased over the last few years due to demand for steel in China, India, Brazil and other rapidly developing nations."