Kennecott Corp., which operates the Bingham Canyon open-pit copper mine in Salt Lake County, and Molycorp Inc., Los Angeles, have reached agreement in principle to form a joint venture to own and operate Molycorp's Washington, Pa., molybdenum roasting and processing facilities.

Each party will own 50 percent of the facilities, subject to satisfactory due diligence results and successful completion of an operating performance test by mid-1991.Roasting operations at the Washington plant will begin next January with concentrate supplied by Molycorp's Questa Mine and Kennecott's Bingham Canyon mine.

Molycorp explores for, mines, processes and markets non-energy minerals including lanthanides, molybdenum and niobium while Kennecott explores for and produces base and precious metals in the U.S., Canada, Mexico and Papua New Guinea.