Brine rejection that drains from the newly formed ice is replaced by a weak flow of relatively fresh water, from the liquid region below it. The new water partially freezes within the pores of the ice, increasing the solidity of the ice. As sea ice ages and thickens, the initial salinity of the ice decreases due to the rejection of brine over time [Fig. 2]. While the sea ice ages, desalinization occurs to such a degree that some multiyear ice has a salinity of less than 1 PSU. This occurs in three different ways: Brine rejection occurs in the sea ice packs
Brine mining magnesium from the bitterns left after salt precipitation. The Dow Chemical Company began producing magnesium on a small scale in 1916, from deep subsurface brine in the Michigan Basin. In 1933, Dow began using an ion exchange process to concentrate the magnesium in its brine. In 1941, prompted by the need for magnesium for aircraft during World War II, Dow started a large plant at Freeport, Texas, to extract magnesium from the sea. A number of other plants to extract magnesium from brine were built in the US, including one near the Freeport plant at Velasco. At the end of