About the blog: What Things Are Made Of


The United States relies on imports for dozens of commodities in everyday use. Often enough, that reliance is 100%. In this book I aim to provide awareness of the hidden geology and mineralogy behind common things, and to develop an appreciation for the global resource distribution that underpins our society. While concerns about oil import reliance are in the news every day, our needs for other minerals are comparable and are typically unknown even to technologically aware Americans.

Monday, November 23, 2015

Mineral Monday: Stibnite

by Richard Gibson

Stibnite, antimony sulfide, is the main source of the element antimony. The United States has no primary mine production of antimony, although some is recovered in smelters and through recycling of antimony-bearing lead products, but even with that the U.S. is dependent on imports for 84% of its antimony.

So what? Antimony is used by every American every day. The main use world wide is in flame retardants for things as diverse as children’s toys to automobile seat covers. Antimony compounds essentially suck the oxygen out of a fire, helping inhibit its spread.

Lead is alloyed with antimony to make it a little stronger, more corrosion resistant, and to reduce shrinkage when it solidifies. Lead-acid batteries in cars typically use antimonial lead, and ammunition (bullets) and solder are also lead-antimony alloys. These metal mixtures are the second-largest use of antimony.

Volumetrically smaller but still important uses include antimony as a clarifier for TV screens, as a semiconductor compound in electronics, and as pigment in some paints and enamels.

China is by far the world’s leading producer of antimony, with about 90% of the total, and much of it comes from the Xikuanshan Mine in Hunan Province, the source of the specimen in the photo here. Three-quarters of U.S. antimony imports come from China. U.S. consumption amounts to about 22,000 tons every year, valued at more than $200 million.

See also this article. 

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