Introduction - Metals and Society: An Introduction to Economic Geology - page 2

18

Price ($US/tonne(/100)
Production (x 100000 tonnes/yr)
Grade (%)

16

14

12

10

8

6

4

2

0

1900 1920 1940 1960 1980 2000

Year

Fig. 1.1 Evolution in the price and production of copper over the past 120 years (statistics from
the United States Geological Survey 2010 , Mineral Resources Program. http://minerals.usgs.gov/
products/index.html )

￿ Improvements in technology . The main reason why the price of copper has

dropped steadily is improvement in the efficiency of the mining and refining
industry, a chain of operations that starts with the search for new deposits,
continues through the mining of these deposits and ends with the extraction of
the metal from the mined ore. At the turn of the last century it was only possible
to mine deposits with high grades that were close to the surface and close to
industrial centres. Exceptions were a few unusually large and unusually rich
deposits in more remote areas. Improvements in mining and extraction
technologies have changed all this. Today's copper mines are enormous
operations - vast open-pits that extract hundreds of thousands of tons of ore
per day. Through the advantages of scale and the utilisation of modern
techniques, it is possible now to mine ore with as little as 0.5% Cu. And with
the economy of scale and improvement of technology has come a decrease in the
cost of mining, an increase in supply, and a century-long drop in the price of the
metal.

Now let us consider in detail the trends illustrated in Fig. 1.1 . The decrease in
copper price in the 1930s, and the corresponding decrease in copper production
coincided with the Great Depression. Economies throughout the world collapsed,
demand for copper plummeted and this had immediate repercussions on the price.
The opposite has happened in the past 5 years. The economic miracles in China and
to a lesser extent in India have boosted the industrial and societal demands of two
billion people. To construct the cell phones, cooking pans and power stations that