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FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



centration of the valuable sea salts. A few 

 projects depended on adsorption or biochemical 

 conceiitration as exemplified by the production of 

 soda, potash, and iodine from seaweeds. Of the 

 other likely methods of recovery, precipitation bj^ 

 a specific reagent had been demonstrated in the 

 commercial production of magnesia bj' liming sea 

 water and in the experimental removal of bro- 

 mine as the insoluble tribromoaniline. The latter 

 process was developed in 1924 by the Ethyl Gaso- 

 line Corporation and carried to large scale experi- 

 mental work in the floatmg chemical laboratory, 

 the S. S. Ethyl (Stine 1929). Separation by ion 

 exchange processes or by selective volatUization 

 of the material sought had not j^et been commer- 

 cially exploited. 



In 1933, a sharp increase in the demand for 

 ethylene dibromide as a constituent of gasoline 

 anti-knock could not be readily met by increasing 

 the output of bromine plants using subterranean 

 brines. Based on experimental work done in 

 anticipation of this need, a plant was constructed 

 by the Ethyl-Dow Chemical Company on the 

 Atlantic coast at Kure Beach, North Carolina, to 

 remove bromine directly from sea water without 

 the prior concentration which had been necessary 

 for the earlier commercial recoveries. The sig- 

 nificant feature of this operation was that the 

 small amount of bromine was removed as a gas 

 from the relatively large volume of water; past 

 efforts had largely been directed toward removal 

 of large amounts of water as vapor from the 

 relatively small amounts of dissolved salts. 



The original Kure Beach plant was designed to 

 extract 6 million pounds of bromine per year for 

 the production of ethjdene dibromide. Through 

 minor additions and process improvements the 

 capacity was increased to nearly 9 million pounds 

 per year. In 1937 the capacity of the plant was 

 doubled, and in 1938, increased again, reaching an 

 output of approximately 40 million pounds per 

 year. 



In 1940 a further increase in bromine require- 

 ments led to the erection of a plant at Freeport, 

 Texas, to recover bromine from the waters of the 

 Gulf of Mexico. This plant had an initial capacity 

 of about 30 million pounds of bromine per year; 

 a second imit of equal output was built in 1943. 



Another milestone in the recovery of minerals 

 from sea water was passed in 1941 when at Free- 

 port, Texas, the first magnesium metal was pro- 



duced from water of the Gulf of Mexico by the 

 Dow Chemical Company. Although the pre- 

 cipitation of magnesium hydroxide from sea 

 water bitterns and brines and the method of 

 making magnesium metal from magnesiimi chlo- 

 ride were both well known prior to 1941, it was 

 not until then that these methods were revised and 

 integrated to give an economically feasible process 

 for making metallic magnesium from sea water. 

 The success of the first 18 mUlion pounds per 

 year magnesium plant was shown by the erection 

 of another plant of equal size 1 year later. 



In 1942, a 72 million pounds per year magnesium 

 metal-from-sea-water plant was built by the 

 United States Government at Velasco, Texas, as 

 a part of the program planned to meet emergency 

 war-time needs. The plant was designed and run 

 by the Dow Magnesium Corporation. It operated 

 at or above rated capacity for the duration of the 

 war. That sea water represented no handicap as 

 a source of raw material for the newly developed 

 magnesium process was demonstrated by compar- 

 ative costs published by the Defense Plant Corpo- 

 ration, after cessation of hostilities (Klagsbrunn 

 1945). The Velasco plant of the Dow Magnesium 

 Corporation bettered by nearly 30 percent the 

 lowest cost achieved by other government plants 

 using more concentrated magnesium sources. 



Unfortunately, both this government-owned 

 magnesium project at Velasco and the privately 

 owned bromine plant at Kiu-e Beach were among 

 the war casualties when wartime production 

 capacity encountered reduced peacetime demands. 

 However, economic survival was largely in favor 

 of the sea-water processes. Since World War II 

 the entire United States production of virgin 

 magnesium and an estimated four-fifths of the 

 bromine have been derived from sea water. 



The processes which have been successfully 

 used for bromine production at Kure Beach, 

 North Carolina, and Freeport, Texas, and for 

 magnesium at Freeport and Velasco, Texas, are 

 chemically very simple. They have been de- 

 scribed in detail in articles by vStewart (1934), 

 KLrkpatrick (1941), Schambra (1945), and others 

 but are worthy of brief review. 



There are two bromine extraction processes. 

 Both can achieve recoveries of bromine from sea 

 water approaching 90 percent. The first, called 

 the "alkaline process," is the one which was used 

 for the initial phases of the Kure Beach develop- 



