Three Forks talc mill

The Three Forks talc mill, part of a Rio Tinto divestiture that became final Monday, is seen Tuesday. It and a sister mill at Sappington, as well as the Yellowstone Mine south of Ennis, are part of the Luzenac Group that Rio Tinto sold to the French mining conglomerate Imerys for $340 million.

Andy Malby

Rio Tinto, the mining behemoth that for the last several years has owned the Luzenac Group, which operates two talc mills in the Gallatin Valley, announced Monday it has completed the sale of the group to the French firm Imerys.

The $340 million sale, which has been pending since February, closed Monday, Aug. 1, according to corporate announcements from Rio Tinto and Imerys. It affects all U.S.-based Luzenac operations, as well as the group’s holdings in Europe, Australia and Asia.

The sale is not expected to have an immediate impact on local operations, but the new owner’s specific plans for the Three Forks and Sappington mills and the Yellowstone Mine south of Ennis remained unknown at press time Monday.

Pat Downey, chief of Montana operations for Luzenac in Three Forks, said he was not authorized to speak with the press, and efforts to reach Imerys’ public relations office were unsuccessful.

The Montana operation employs about 140 people, including 30 at the Yellowstone mine and 110 between the two mills. The mine produces roughly 300,000 tons of talc ore annually, which is hauled to the mills, pulverized, packaged and shipped to customers worldwide. Talc is used in polymers, paints, ceramics, paper and other products.

Paris-based Imerys bills itself as “the world leader in adding value to minerals.” It maintains industrial-minerals operations at 245 sites in 47 countries, according to the statement issued Monday morning, and employs 16,000 people worldwide. Its North American operations are based in Roswell, Ga.

The Luzenac Group employs about 1,000 people at 20 worldwide locations, including the Montana operations.

The Three Forks mill is planning its annual Community Day open house from 10 a.m. to 2 p.m. Saturday.