When European cultures came to the New World, they continued to make soda ash, using the ancient process of burning plant materials. In the late 1700s a French scientist named LaBlanc invented a method for manufacturing soda ash using salt, limestone and coal. Belgian scientists Ernest and Alfred Solvay created a more efficient method in the 1860s using ammonia instead of salt. This is the method that is still used today in creating synthetic soda ash.

Trona was discovered in Sweetwater County in 1938 during oil and gas explorations. The first mine shaft was excavated in 1946 and commercial production of soda ash began in 1948. Up until that time all soda ash in the United States was produced synthetically using the LaBlanc and Solvay methods.

Since that initial discovery five mines and processing plants have been opened. These companies produce over 15 million tons of trona and over 8 million tons of soda ash each year as well as being the major employer in both Sweetwater and Uinta counties.

New uses are being found for soda ash, particularly in the areas of environmental protection. Soda ash is used to clean smoke stack emissions which, if left untreated, would cause acid rain.

Geology
Trona is a rare mineral found in only a few locations worldwide. There are deposits in Africa, China, Turkey, Mexico and the Green River Basin of Wyoming. Sweetwater County is the only site where trona is commercially mined.

Where did trona come from? About fifty million years ago the Green River Basin and surrounding areas were covered by a 20,000 square mile land-locked lake. As the climate changed over thousands of years the water evaporated, leaving behind several beds of a mineral mixture called trona wedged between layers of sandstone and shale. There are an estimated 100 billion tons of trona in the basin, enough to meet the world’s needs for another 2000 years. These deposits cover about 1,000 square miles and vary in depth from 800 to 3500 feet below the surface. Actual mining occurs at a depth of 800 to 1600 feet in beds that are eight to ten feet thick.

What is Trona and Soda Ash?
Trona is a naturally occurring mineral that is chemically known as sodium sesquicarbonate. Trona is the raw material from which the chemical soda ash (sodium carbonate) is refined. Soda ash in turn is used to make glass, paper, laundry detergents and many other products. It is also used in the manufacture of other chemicals including sodium bicarbonate (baking soda) and sodium phosphates (detergents).

Over 90% of the soda ash produced in the United States and about 25% of the world’s supply is natural soda ash from Sweetwater County.

Trona Capital of the World
In recognition of the importance of the trona/soda ash industry to the economy of the State of Wyoming, on November 3, 1989 Sweetwater County was proclaimed as Trona Capital of the World by Governor Mike Sullivan.

Reprinted from Sweetwater County Historical Museum brochure.