Metals in a sustainable society

By Dr Peter Cutler, Nickel Institute

Metals have played a major role ever since the bronze and iron ages. They remain as vital today.

Our food production, energy production, water distribution, buildings, transport systems, infrastructure and communications systems would not exist without metals. They have an equally vital role in providing solutions to the sustainability challenges which society faces.

Many metals are well-known and recognised: aluminium beverage cans and aircraft; copper water pipes and electrical cables; steel building frames and car bodies; gold and silver jewellery. Other metals are less well known and yet have thousands of uses – nickel, for example. It is found throughout our daily lives, usually alloyed with other metals. It is an important constituent of much of the stainless steel used in food and beverage production, and for practical and aesthetic building components; it is in the hottest parts of aircraft engines; it is used throughout chemical plants and the energy industries; it is in coins; it makes possible the production of CDs and DVDs; it is in rechargeable batteries; and it is at the heart of printing textiles.

Right from the bronze and iron ages, when they gave cutting edges which were sharper and lasted longer, metals have enabled innovation. In recent times, we have seen the miniaturisation of computers and mobile phones. This has occurred through improved electronic components, and rechargeable nickel-cadmium and nickel metal hydride (NiMH) batteries. That same NiMH battery technology is used in the hybrid vehicles being developed to combat climate change. Today’s highly efficient aircraft engines would not have been possible without the development of high-strength nickel alloys able to operate for thousands of hours at high temperatures.

Sustainability is the big challenge facing the world today: we have to do more with less and with a smaller footprint. That means improving efficiency and that in turn comes through innovation. Nickel-containing materials are often at the forefront. We find nickel-containing stainless steels playing key roles in sustainable construction because they can extend service life and eliminate premature material replacement. They have been an important part of desalination plants for several years. The iron 36 percent nickel alloy is used in liquid natural gas installations and transport. The uniquely low thermal expansion coefficient simplifies the engineering design of equipment to operate at -182 ºC. The same alloy enabled colour television tubes to produce high quality pictures. After its discovery over one hundred years ago, the alloy’s first application was to enhance the timekeeping of mechanical clocks.

One aspect of metals that is often overlooked is that most are already highly recycled - copper, aluminium, lead, steel, stainless steel etc. Much less energy and raw material inputs are needed to use recycled metals. Together with its high value, this has helped stainless steel to be one of the world’s most recycled materials today. And as new uses of metals are found, new recycling mechanisms are established – for example, for electronics and rechargeable batteries.

Although they are natural elements, metals may have properties that present a human health or environmental hazard. The same is true, of course, of very many substances that we use in our daily life (e.g. petrol, cleaning products, garden pesticides). But just because there is a hazard, it does not mean that there should be an automatic ban on use. We all deal with dozens of hazards every day of our lives. What really counts is if the product or its application may cause a potential risk to human health or the environment, and how we manage that risk. The strength of many alloys – including stainless steels – is that they are specifically designed to be corrosion resistant and durable, and therefore safe to use.

Metals and alloys will remain essential in providing innovative solutions to the problems of moving towards a more sustainable society.