Introduction - Metals and Society: An Introduction to Economic Geology - page 4

increased steadily over the past two decades, initially during a period of falling
prices, and more recently during a period when the price of copper has tripled. In
the first period, exploitation of stockpiles, the introduction of new improved mining
and extraction techniques, and the opening of new large high-production mines,
particularly in South America and Oceania, made this possible. Throughout
the 1990s many mines were running at a loss: the cost of production was greater
than the value of the metal extracted from the mine. Then from 2005 onwards, as
the copper price increased, mines that had been loss-making operations suddenly
started making money. Improvements in technology, which made it possible to
mine and refine the ore more efficiently, aiding the return to profitability. Other
deposits that had been explored and evaluated by mineral exploration companies
but had been put aside because they were not viable at low copper prices suddenly
became viable. Nothing had happened to the deposit: it still contained the same
grade of copper and the same total amount of copper, and its location both
geographically and geologically also had not changed. But a deposit that in the
year 1998 was of little economic interest had became potentially highly profitable
in 2010. These ideas lead us to examine several notions and definitions that are
fundamental to economic geology.

Box 1.1 Consider the Following Statements and Discuss What They Tell
Us About Economic Geology and the Mining Industry, as Perceived
by the General Public
1. In the 1990s a Japanese scientist developed a new type of catalytic
converter in which manganese replaced platinum. Why is this discovery
important?
2. English ecologists have proposed that a new tax should be applied to “rare”
metals such as silver,

lead and copper. What do you think of this

suggestion?
3. A journalist recently suggested that war might break out over the last drops
of petrol. Is this suggestion reasonable and realistic?

Response

Consider the first statement. Why would it be important if manganese could
be used in the place of platinum in the catalytic converters that are fitted to
every new car? The answer lies in the price of the two metals. In February
2008, platinum (Pt) sold for about

100 per gram and manganese (Mn) for 10

€

cents per gram ( 10,000 per ton), a 1000-fold difference in price. If Mn could

replace Pt, catalytic converters would be much cheaper. Currently the cost of
the metal makes up about half the cost of the converter, so if Mn replaced Pt,
the cost would be cut by almost half. (Unfortunately the process does not
work and Pt continues to be a highly sought-after metal). This discussion
(continued)

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