Tungsten was successfully extracted from the brines of Searles Lake, California. By the U.S. Department of the Interior, Bureau of Mines. Pilot-scale operation was initiated in July 1979 at the westend facility of the Kerr-McGee Chemical Corp. at Trona, California. The extractive method is based on a novel ion exchange resin. The objectives met during pilot testing included proving operational viability during seasonal changes in brine properties, concentrating the tungsten to enable concluding tungsten recovery research, supplying escalation data necessary for commercialization, and confirming earlier small-scale laboratory work. The demonstration unit typically removed 92 percent of the tungsten from alkaline brine using qrf (8-hydroxyquinoline-resorcinol-formaldehyde) resin beads produced by the Bureau. A "merry-go-round" system was employed whereby two 12-inch-diameter resin beds were loaded in series while a third bed was eluted. Testing was concluded after treating over 500,000 gallons of brine. Tungsten, isolated in the primary ion exchange system, was reconcentrated in a secondary ion exchange system. Several tungsten products were produced from tungsten-rich solutions.