Indium could be the saviour of Cornish mining

MEI's Jon Wills with John Webster in the mine

I have reported a couple of times of developments taking place at the old South Crofty tin mine in Cornwall (see last posting of 10 May 2010), now operated by Western United Mines.
South Crofty was Europe's last working tin mine, closing 13 years ago, and in my last report was on the brink of reopening as a polymetallic mine, working orebodies containing copper, zinc, silver, lithium, gold and indium, as well as tin. Copper prices in particular have risen so dramatically recently that theft of the metal has become a real problem.

However, the development has had problems recently, which led to the lay-off of 16 of its 60 workers, but now hopes to employ up to 400 staff within two years.

When I spoke to ex-Camborne School of Mines (CSM) student John Webster, the chief operating officer, in November at Process Mineralogy '10, he indicated that the next stage in feasibility would be a thorough mineralogical analysis of the ore. Dr. Robin Shail, a geologist at CSM, suggested that they should look for indium, and up to 1000g per tonne was found in some assays, the average being about 100g per tonne. John estimates that they will mine between 250,000 to 400,000 tonnes per year in the first phase.

Until now significant amounts of indium have been found only in China, Canada and parts of continental Europe. It is an important ingredient in the manufacture of touch-screen technology and a small amount is used to make every liquid crystal display screen, including laptops, digital clocks and GPS receivers.

The rapid growth in the touch-screen market has forced indium prices up dramatically in the past ten years, peaking at about $800 (about £500) a kilogram, about the same as silver. It is about £550/kg at the moment.

The local member of Parliament is quoted as saying “This is an exciting time. It may be too early to call it a modern-day gold rush, but let’s hope it’s an indium rush. Demand for this element keeps growing. This would be a state of the art facility and help resurrect mining in Cornwall.”