Large barrel furnaces increased capacity at Greybull in 1964, then Lovell in 1969, then at the new Thermopolis plant in 1980. All were updated to process bentonite for the steel industry. Rail cars full of bentonite left the Wyo-Ben mills regularly to feed an expanding steel industry in the United States. They later shipped – across the Great Lakes – to Canada. By super-heating this semi-crude bentonite, it could now be combined with iron-ore fines to make hardened, marble-sized pellets that could be easily transported. For more than twenty-five years, Wyo-Ben cornered this market, gradually expanding into the Far East and Europe.