Antimony

Antimony is a chemical element with symbol Sb and atomic number 51. It is one of the oldest elements in usage with the Ancient Egyptians having used it for make-up (kohl for the dramatic eye effects). An artifact, said to be part of a vase, made of antimony dating to about 3000 BC was found at Telloh, Chaldea (part of present-day Iraq), and a copper object plated with antimony dating between 2500 BC and 2200 BC has been found in Egypt. The ancient Romans called it stibium, hence its chemical symbol Sb. A lustrous gray metalloid, it is found in nature mainly as the sulfide mineral stibnite (Sb2S3). As mentioned, Antimony compounds have been known since ancient times and but metallic antimony was also known, being erroneously identified as lead. It was established to be an element around the 17th century. The first European description of a procedure for isolating antimony is in the book De la pirotechnia of 1540 by Vannoccio Biringuccio. However pure antimony was well known to Jābir ibn Hayyān as far back as the 8th century. The first natural occurrence of pure antimony in the Earth's crust was described by the Swedish scientist and local mine district engineer Anton von Swab in 1783; the type-sample was collected from the Sala Silver Mine in the Bergslagen mining district of Sala, Västmanland, Sweden.

The abundance of antimony in the Earth's crust is estimated at 0.2 to 0.5 parts per million, comparable to thallium at 0.5 parts per million and silver at 0.07 ppm. Even though Sb is not abundant, it is found in over 100 mineral species. Antimony is sometimes found natively, but more frequently it is found in the sulfide stibnite (Sb2S3) which is the predominant ore mineral. 

The largest applications for metallic antimony are as alloying material for lead and tin and for lead antimony plates in lead-acid batteries. Alloying lead and tin with antimony improves the properties of the alloys which are used in solders, bullets and plain bearings. Antimony compounds are prominent additives for chlorine- and bromine-containing fire retardants found in many commercial and domestic products. An emerging application is the use of antimony in microelectronics. The principle use of antimony is in flame retardants as antimony trioxide (ATO), which accounts for 72% of its primary antimony consumption in Europe, in China this figure is estimated to be 50% and in the US nearer 60%. Antimony trioxide is most commonly used as a synergist to improve the performance of other flame retardants such as aluminium hydroxide, magnesium hydroxide and halogenated compounds. This enhanced performance minimises the amount of flame retardant required. Antimony trioxide is used in this way in many products including plastics, textiles, rubber, adhesives and plastic covers for aircrafts and automobiles. The second most common use of antimony alloy is as a hardener for lead electrodes in lead acid batteries. This use is in decline as the antimony content of typical automotive battery alloys has declined by weight to 1.6%, having been 7% in the past, hence the use of antimony in batteries will reduce further as calcium, aluminium and tin alloys are expected to replace it over time. Interestingly the latest application of Sb (the flame retardant aspect) allows virtually no recycling. 

The Chinese have dominated global Antimony production since the mid-1800s with the possession of some of the most prolific mines in the world and a vast network of refineries (both major and "backyard"). In particular China's place as the largest producer of antimony and its compounds was due to the Xikuangshan Mine in Hunan. However all "good" things must come to an end and the Chinese have staged crackdowns on the more polluting small-scale operators and this has changed not only the Chinese industry but the world Antimony outlook. The leading firm of specialty metals consultants, Roskill, have estimated that in primary production, in 2010, China held a 76.75% share of world's supply with 120,462 tonnes (90,000 tonnes of reported and 30,464 tonnes of un-reported production), followed by Russia (4.14% share, 6,500 tonnes of production), Myanmar (3.76% share, 5,897 tonnes), Canada (3.61% share, 5,660 tonnes), Tajikistan (3.42% share, 5,370 tonnes) and Bolivia (3.17% share, 4,980 tonnes). Roskill also estimated that secondary production globally in 2010 was 39,540 tonnes. The preceding chart shows that recent years have seen a rather strong drop-off in production. Reported production of antimony in China fell in 2010 and is unlikely to increase in the coming years, according to Roskill's report. No significant antimony deposits in China have been developed for about ten years, and the remaining economic reserves are being rapidly depleted. This would appear to be a 'sunset" moment for the era of Chinese dominance of this metal. 

The fall in production, not unsurprisingly, resulted in a surge in prices of Sb to over $17,000 per ton in 2010. The price then dropped back to $12,000 per tonne in 2011 before rebounding to around $14,000 per tonne. Antimony is out there with Tungsten in having a similarly resilient trend. Both, it might be noted, have a similar dynamic of dramatic over-exploitation by the Chinese combined with long term predatory pricing. 

The universe of Antimony plays is dominated by the Chinese. The most impressive thing about the Twinkling Star mine is that it was found in the 1500s and has been producing constantly since the 1850s. We would also note that the Beaver Brook mine in Newfoundland was bought by the Chinese and closed down in 2012.