Metals are elements that occur naturally in the rock, the ground and water. Of the just over 100 known elements, no less than 80 are metals and a further six so-called half metals. Everywhere on earth metals are bound in minerals. A metal is defined as an element with metallic properties, such as high metallic shine, high electrical and thermal conductivity. It is also ductile and malleable. Aluminium and iron are two of the four most commonly found elements in the crust of the earth.
Metals are included in many of the everyday products and applications that we use every day. They are also a necessary component for the manufacturing of most other materials and products that we need today. In constructions metals are often chosen for their, high strength, good malleability, durability and long useful life. For some purposes metals are used because they conduct heat and electricity well. Furthermore, many metals, for example iron, zinc, copper and chromium, fulfil necessary functions in all living organisms. Thus they are essential in small or moderate amounts.
Metals in the steel production processes
Steel which is made up of iron and different alloys is the world's most widely used metallic material with a market demand of about 1.5 billion tons a year. In order to obtain the right composition and properties in the steel, many other metals are used as alloying elements. This means that the steel industry uses metals such as chromium, nickel and molybdenum. Metals are not consumed during use and can usually be recycled again and again. Recycled metals still retain their original properties. Steel is the world’s most recycled material.
The residues of different metals can accompany the airborne emissions or water discharges arising from the production processes. Consequently, both process gas and process water undergo different cleaning stages where the metals are taken in hand before purified gas and water is released into the recipients (water, air, ground). Metals can often be recovered from the dust emissions and sludge in waste purification units.
The metals industry works together with environmental researchers to better understand the effects of metals on the environment, and to improve the decision-making basis for public authorities. Previously, assessments were often focused on the total contents of metals in e.g. water samples, sediment samples and soil samples. Now it is known that the effects of metals largely depend both on their amount and form, with bioavailability being a key parameter. A major difference between metals and other polluting substances is that metals occur naturally in the different recipients; it is thus not possible to phase them out entirely.
Industry trade groups and companies within the steel and metals industry work to improve information through the collaboration called ITF Metal Information. The purpose is to disseminate factual information on metals and their effects on the environment.
Read more about the collaboration, MITF Metal Information
The all-important issues concerning metals that affect the steel industry are very largely connected with the existing water, product and chemical legislation. This may, for example, relate to how certain metals become "priority substances" under the EU’s Water Framework Directive (Priority substances list no. 2455/2001/EC) thereby having environmental quality standards assigned. It may also relate to registration of raw materials according to the REACH Regulation and the possibility that the hazard classification of metals might be revised according to the CLP Regulation (classification, labelling and packaging of substances and mixtures (EC) No 1272/2008)
- Assessment of the environmental impact of metals must take account of potential exposure and the bioavailability of the metals. The risk of health and environmental effects from human and environmental exposure of metals and substances from a product must be considered.
- Environmental and health risk assessment of steel must take into account potential exposure and the bioavailability of the components in the steel. The properties of the mixture of components in steel often differ from the sum of properties of each included separate substance. Stainless steel is one example of this difference.
- Environmental quality requirements for metals, for example environmental quality standards, must be based on relevant risk assessments and bioavailability, and take account of local conditions.
- Demands for emission reductions shall be motivated by the environmental benefits that arise.