Largely because of environmental restraints, the USA now supplements domestic production with imports of refined metal rather than concentrates. There are signs that Japan and Germany are beginning to follow this policy. Substantial investment in new low-emission lead refining plants is occurring as part of this restructuring. Copper and lead markets are characterised by extensive recycling of scrap metals. These markets are therefore less dependent on rises and falls in mine production.
Commodity trends Long-term copper prices closely follow economic activity in metals manufacturing.
Long-term lead and zinc prices are more volatile. Trade in base metals was characterised by weak demand because of the recession in manufacturing in Europe and to a lesser extent in Japan. This stock overhang had a strong downward influence on prices and has led to mine closures in recent times. However, improvements in world economic growth have flowed through to the metals industry, with signs of strengthening base metal prices in 1994. Copper prices have risen significantly over the past year and inventories have begun to deplete.