Rock salt forms the most common and practical source of supply. It is found in all parts of the world and reasonably near the surface. The deposit is said to be what is left of ancient salt seas. In the United States the largest deposits of salt are found in the states of Michigan, New York, Ohio, Utah, Louisiana, Kansas, Texas and California. The above-mentioned states are the largest producers of salt in this country.
Salt Heaters and Filters
One of the largest sources of salt supply in Europe is at Wielizka in Poland. This deposit of salt is said to be the largest in the world, the bed of salt rock being 500 miles long, 20 miles wide and 1,200 feet thick. Some of the salt mines in Poland are so extensive that it is said some of the miners spend all of their lives in them, never coming to the surface of the earth.
Most of the deposits of salt rock contain impurities which need to be removed before the salt is fit for use commercially; however, some deposits show a very pure salt rock and when ground up this rock salt is suitable for table use. In general, however, the salt made from crude salt rock is only fit for the crudest commercial uses. The most common impurity is gypsum and it is necessary to remove this gypsum before the salt can be considered pure.
Photo by Brown Bros.
Salt Beds Near Salt Lake City
These extensive salt beds about eighteen miles from Salt Lake City are part of the deposit left when Lake Bonneville dwindled to Great Salt Lake.