MAGNESIUM COMPOUNDS AND MISCELLANEOUS SALINES 1507
 Recently a large deposit of brine about three times as rich in magnesium
salts as that used by the Dow Chemical Co. at its Midland (Mich.) plant has
been discovered near Ludington, Mich. It is planned to use magnesium chloride
extracted from this brine for the annual production of 72,000 tons of magnesium
metal, most of which will be manufactured by the Dow Chemical Co.
 The magnesium chloride obtained as a byproduct of the production of potassium
sulfate by the Union Potash & Chemical Co., Carlsbad, N. Mex., subsidiary
of the International Minerals & Chemical Co., is also to be used as a
source of magnesium metal. Anhydrous magnesium chloride will be shipped to
Austin, Tex., for conversion into metal. Additional metal will be produced
at this plant from dolomite as raw material.
Production of magnesium chloride from other sources, notably dolomite and
magnesium sfficates, is expanding rapidly. Of the huge quantity of magnesium
chloride needed for magnesium-metal production, over 200,000 tons will be
derived from dolomite and additional quantities may be obtained from olivrne
and serpentine. The chapter on Magnesium in this volume contains further
details concern-. ing these developments.
 Production of magnesium sulfate from natural brines increased substantially
during 1941. Production was reported in Michigan, Texas, and Washington,
with one plant in each State. The recovery of Epsom salts from Epso Lake
in north central Washington by the C. A. Kearney Co. of Tonasket, Wash.,
ha~ been discussed in Mining Worl4,~July 1941 (pp. 29—31).
 Naturally occurring brines rich in magnesium sulfate found west of the Pecos
River in Eddy County, southeastern New Mexico, were described by Lang." These
brines average 382 grams per liter solids content, of which 44 pezpent is
magnesium sulfate, 39 percent sodium sulfate, 10 percent magnesium chloride,
4 percent potassium sulfate, 2 p~rcent magnesium borate, and 1 percent magnesium
carbonate. Interest was expressed in utilization of these brines as a source
of raw material for magnesium-metal production.
 Considerable expansion of the magnesium sulfate plant near Sylva, N. C.,
is contemplated, although. no action was taken during 1941. This plant produces
Epsom salts by the digestion of olivine with sulfuric acid, followed by leaching,
purification, and crystallization of the magnesium sulfate so produced.
 Methods for preparing magnesium sulfate by treatment of magnesium hydroxide
and gypsum with CO2 12 and by calcination of a mixture of serpentine and
iron pyrites'3 have been described, The first of these methods is carried
out in an aqueous medium always containing some magnesium hydroxide rather
than in a solution saturated with carbon dioxide. In the other method, only
about one-third of the magnesium present in the serpentine may be recovered
as magnesium sulfate.
' 1 Lang, Walter B., New Source for Sodium Sulfate in New Mexico: Bull. Am.
Assoc. PetroL (leoL, vol.
25, No.1, lanuary 1941,~pp. 152-160.
"Farnsworth, Wm. H., and Martin, Clair B., Magnesium Sulfate from Magnesium
Carbonate and CaIcj~im Sulfate: U. S. Patent 2,231,327, February 11, 1941.
"Brandenburg, Heilmuth B., Serpentine as a Source of Magnesia: Mm. iour.
(Phoenix, Aria,), vol. 24, No. 10,1940, pp. 2-3.