| TECHNOLOGY |
But in the 1940s, "W" later acquired by "F" developed a method based on trona, an ore found around Green River, Wyo., that contains soda ash and sodium bicarbonate. The trona route took off, and by 1986 the last U.S. Solvay process plant had shut down. Today, the U.S. supplies more than one-third of the world's soda ash needs--about 36 million tons per year--almost all from plants in Green River. Although Green River is 175 miles from Parachute, the two mineral deposits are thought to be relics of the same ancient saline lake.
Making soda ash from trona is cheaper than making it synthetically, but still challenging. Trona must be pulled from the ground with labor-intensive hard-rock mining techniques. The ore contains other minerals, and separating them is a complex process involving high-temperature calcining and several sorting and purifying steps. Waste is placed in evaporation ponds as large as 1,400 acres. Indeed, Co.'s executives thought their trona solution mining advances in the 1980s would revolutionize the soda ash industry, rendering traditional mining obsolete. "It took us more than 15 years, and a change in the concept, to get it right," Today, about 700,000 tons of Co.'s 4 million-plus tons of soda ash capacity is solution-based.
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