OCR Text |
Show 107 bischofite, either from the Lake brine as it approaches the bittern stage, or from leach solutions from the leaching of carnallite. These highly concentrated magnesium chloride brines may be marketable themselves to some extent. Bischofite is consumed directly in a small segment of the market, but it is more useful as a raw material for other magnesium products. Bischofite can be easily converted to magnesium oxide for refractory brick products with hydrochloric acid as a by- product. Dehydrating bischof- ite is complicated and costly. Dow Chemical Company reduces its water content from 53 percent to about 25 percent to produce a feed material for the electrolytic cells for producing magnesium metal. N. L. Industries' Magnesium Project has expended considerable effort to develop a process for dehydrating bischofite to make magnesium with chlorine gas as a byproduct and is currently producing limited amounts of magnesium from the Great Salt Lake. Great Salt Lake Minerals and Chemicals Corporation initially planned to produce 500,000 tons of magnesium chloride, but their contract for this produce was cancelled in 1971. The magnesium chloride plant is now nearly complete, but is in a standby status. N. L. Industries has an integrated plant expected to produce electrically 45,000 tons per year of magnesium metal plus chlorine gas from Great Salt Lake brines. The plant was to commence production in 1971, but by 1974 was producing only at about 30 percent of capacity due to normal problems and damage to their pond system by high water in 1973. They use South Arm brines but own lands which would allow construction of a canal to use North Arm brines. The quality of brine used for magnesium production depends on both the general chemical composition and on the concentration of magnesium in |