February 1944 Popular Science
[Table of Contents]
Wax nostalgic about and learn from the history of early
electronics. See articles from
Popular
Science, published 1872-2021. All copyrights hereby acknowledged.
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If this "War Metals from
Sand" article had appeared in a contemporary magazine instead of a 1944 issue of
Popular Science, I might think it was referring to all the
semiconductors being made from silicon --- sand. However, the story reported on
the mining and processing of sand, monazite sand in particular. At the time, it
was the only known commercial source for thorium. Other rare earth metals are
also separated from the "sand," including cerium, lanthanum, and erbium. The
outbreak of World War II forced the primary source for monazite sand to be
changed from India to coastal CONUS locations like Florida, the Carolinas, and
Oregon. In fact, by the end of the war, the U.S. produced the vast majority of
its raw materials, which contributed to the country establishing itself as a
major global economic force in addition to being a military force. Sadly, we are
way too dependent on offshore sources for both raw materials and manufacturing
for some of our most vital products, including medicine and semiconductors. It
doesn't have to be this way, but scumbag politicians, bureaucrats, and industry
leaders (many of whom are foreigners) make far too much money to allow any other
system.
War Metals from Sand
![Monazite Sand, produced by the disintegration of granite rocks - RF Cafe](images/war-metals-sand-popular-science-february-1944-1_small.jpg)
Monazite Sand, produced by the disintegration of granite rocks, gives us rare-earth
metals and thorium. Close-up below shows how the brittle resinous grains vary from
honey-yellow to brown. In peacetime, much of it went into mildew-proofing fabrics
(middle photo, below) and making "flints" for cigarette lighters. War uses are in
electrodes for search-lights, filaments for radio.
Welding goggles, searchlights, incandescent lamps, radio tubes - these are only
a few of the wartime necessities that are improved by the use of little-known elements
found in monazite sand. Produced in dune and beach deposits by the weathering of
granite rocks, this sand was once used chiefly in making Welsbach mantles for gas
lighting; now it is vital as the only commercial source of the "rare-earth" metals
and of the metal thorium.
Cerium, most abundant of the rare-earth metals, is mixed with carbon to make
cores of arc-light electrodes for searchlights, film projectors, and therapeutic
lamps. In England, it is alloyed with aluminum to produce a strong, lightweight
metal for airplane castings. Cerium acetate makes textiles mildewproof. Other salts
have medicinal uses. Salts of lanthanum and erbium, members of the rare-earth group,
go into beauty preparations.
Welding-goggle lenses made with praseodymium and neodymium cut off useless visible
rays and harmful ultraviolet rays to protect workers' eyes.
Thorium, also obtained from monazite sand, finds important use in radio tubes.
Filaments containing a trace of this metal operate at lower temperatures than filaments
of pure tungsten, prolonging the life of the tube. Both thorium and cerium salts
are used as catalysts in chemistry.
Before the war, 75 percent of our supply of monazite sand came from India. With
that source cut off, most of our importation is now from Brazil. If necessary, however,
we can get all we need by working deposits in the Carolinas, Florida, and Idaho.
Posted November 3, 2023
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