The Mineral Reserve and New Materials

The mineral reserve of our planet is being gradually exhausted. Where once we used crude machines to pick minerals almost from the earth's sur­face, today we use dynamic and massive machines to extract these miner­als.

Industry depends heavily on some 80 minerals, including a number which, like aluminium and iron, are in relatively plentiful supply. True, a few countries will soon exhaust their domestic supplies of such materials, but there is enough elsewhere to go round, without the risk of cartelized cutbacks on production and supply.

A small number of minerals, however, qualify as strategic commodities. That is, they are critically important to industry, while being in relatively short supply. Chromium, for example, does more than put a shine on bumpers; it also contributes to irreplaceable alloys used in tool steel and in jet engines. Manganese is essential for high-grade steels. Platinum is used for catalytic converters, which are at the heart of many auto-emission control systems, and for advanced communications equipment. Cobalt is crucial for high-strength, high-temperature alloys used in aero­space.

Minerals are an integral part of diplomacy. Each country tries to ensure access to those minerals which affect its vital national interests, especially defence. Strategically important minerals are vulnerable to interruptions of supply, often for political reasons. Lacking indigenous supplies, many Western countries have been building up stockpiles of such miner­als as manganese, chromium, cobalt and platinum. One unintended effect of stockpiles is to even out the sharp fluctuations in mineral prices. Substitution and recycling can also be strategic options, boosting supply.

Recycling has become a vitally important process. Almost half the iron needed for steel-making now comes from scrap and nearly a third of the aluminium. Recycling can bring major energy savings. For example, the energy required to produce one tonne of secondary aluminium from scrap is only 5% of the energy used to extract and process primary metal from ore. Scrap is now a vital source of supply for metals. Recycling plays an important role in environmental protection, because we can get rid of metal scrap without spoiling the surroundings.

Another way of mineral wealth preservation is substitution. Metals that are easy to substitute include antimony, cadmium, selenium, tellurium, and tin. Tin has been losing out to glass, plastics, steel, and alumini­um in the can-making and packaging industries: aluminium now accounts for over 90% of all US drinks cans. But substitution is no panacea: platinum is an unrivalled catalyst and stainless steel depends on chromi­um.

In recent years the ability to model new materials on computer has opened whole new vistas of materials development, providing a theoreti­cal basis for what has traditionally been an empirical science. This work is based on the crystalline structure of all metals and most other solid mate­rials.

The characteristics of a given era are often fundamentally affected by the most advanced type of material available. Thus we have such eras as the Stone Age, the Bronze Age, the Iron Age, and the Steel Age. Based on advancing materials technology, the ages of history have changed. Yet even in the advanced scientific era, materials development has until recently remained primarily an empirical process.

Today, the end of the Steel Age and the end of empirical materials sci­ence appear to be at hand. We are now on the threshold of an age expect­ed to be dominated by exotic new materials, created in our scientific lab­oratories and featuring made-to-order chemical and physical properties. The searches for new materials are very promising and will help our plan­et to survive.