Great Salt Lake

GREAT SALT LAKE (EN: Great Salt Lake; RU: Большое соленое озеро) is the salty lake within the north-western part of the Utah state, within the USA, which is containing the industrial concentrations of the salts within the brines. It is situated among the western spurs of the Rocky Mountains, near the Salt Lake City. The altitude of the level of the water surface is +1280 metres. It is the remaining basin of the ancient Lake Bonneville. The lake is closed without the water runoff, the most significant tributaries (the Baer, Uiber, Jordan rivers) flow down from the adjacent Wasatch Ridge at the east. The area of the lake changes from 2500 to 6000 square kilometres, depending on the quantity of the atmospheric precipitation and, respectively, on the altitude of the level of the lake. The average depth is 4.5-7.5 metres, the deepest is 13-15 metres. The climate of the region is arid. The usage of the brines from the lake has been started during the 1916 with the purpose of the obtainment of the Na, Mg, Br, B, Li salts. Since the 1968, there has been mastered the industrial production of the K and Na sulfates, Mg, Na, Li, Br chlorides.

The basin of the lake is stretched from the south-east to the north-west conformably with the general strike of the structural elements of the Rocky Mountains; it represents by itself the deep graben, which is bounded by the blocks of the two parallel horsts, and is complicated by the two submerged transverse horsts; it is filled with the thick stratum of the Quaternary depositions. The brines of the lake belong to the magnesium chloride type, with the relatively high content of sulfates. Since the 1959, the lake is divided by the railway embankment into the two parts, the water exchange between which is limited. The surface water runoff proceeds into the southern part from the Baer, Jordan, and Uiber rivers, thus the northern part plays the role of the evaporative basin. The salinity of the brine within it reaches 334-345 grams per litre. The southern part is the feeding basin; up to the depth of 6-7 metres, the brines have the salinity of 130-150 grams per litre, and yet deeper, of 240-280 grams per litre. The chemical composition is constant since the 1936. The quantity of the salts, which are arriving into the lake, is approximately 2 million tonnes. The underground water runoff by volume is smaller by several times, but there arrive with it by 60 times more salts. The total reserves of the salts within the brine of the lake are approximately 6 billion tonnes, including (million tonnes): 200 of K2SO4, 450 of Na2SO4, 530 of MgCl2, 3800 of NaCl. The reserves increase themselves at the expense of the inflow of the salts by the waters of the surface and underground water runoff.

The extraction of the brines is performed by the pumping them from the northern part of the lake into the evaporative ponds, within which the brines move themselves as the gravity induced flow. At the expense of the natural evaporation, and of the increasing of the concentration of the brine, there proceeds first the deposition of halite, and at the final stage, the deposition of the mixture of the potassium and magnesium salts (kainite and carnallite), which are the raw materials for the obtainment of K2SO4 and Na2SO4, MgCl2, LiCl, BrCl. The extraction of the brines, and their further processing, are performed by the "Great Salt Lake Minerals and Chemical Corp." ("GSL") firm. The enterprise for the production of lithium and bromine belongs to the "Lithium Corp. of America". The productivity of the enterprises of the "GSL" firm (1980), the beneficiation plant of which is situated on the eastern shore of the lake (near the Ogden city), is 10 million tonnes of the salts within the basin system. During the processing of the salts, there are produced 240 thousand tonnes of K2SO4 (51-53% of K2O), 150 thousand tonnes of Na2S04, 600 thousand tonnes of MgCl2. There are available the productive capacities for the production of 5 million tonnes of NaCl, however, because of the absence of demand, there is issued only 1-2% of this quantity. The productive capacities ensure the issue of approximately 50% of K2SO4, which is produced within the USA. During the 1979, there have been performed the trials on the flotation of schoenite.