The metallurgy sector is essential in our society, especially thanks to the non-ferrous metals that are used in various industries. With global environmental awareness, metal recycling has become a major challenge to preserve our natural resources and limit the loss of these valuable materials. We will see in this article how the recycling of non-ferrous metals works and what are the main steps in this process.
Before we go into recycling, it is essential to understand what non-ferrous metals are. The latter are, as their name suggests, metals that contain little or no iron (less than 50%), unlike ferrous metals. The non-ferrous metals group is large and includes many elements such as aluminum, copper, zinc, lead, nickel, tin, titanium or gold and silver.
In general, the non-ferrous metals have certain physical properties that make them particularly interesting for various industrial applications. For example, they often have a good resistance to corrosion and high temperatures, high electrical or thermal conductivity, as well as an appreciable lightness. These qualities explain why these metals are widely used in the sectors of electronics, aeronautics, construction or automotive.
: All types of metals are recyclable. Non-ferrous metals can be recycled individually with minimal risk of degradation compared to ferrous metals. They also retain their chemical properties during the process. It is important to recycle these metals because they are not readily available. Another reason for recycling is that the process reduces waste and protects the environment. To do this, it saves energy when extracting from natural sources and reduces the gas emissions that would occur during the extraction process.
The first step in non-ferrous metal recycling is to collect metal waste from various sources, such as end-of-life vehicles, electronic equipment, packaging or industrial scrap. This collection may be carried out by specialized companies, municipalities or individuals.
Once collected, the waste is transported to sorting centres , where it will be separated according to its composition. Some non-ferrous metals, such as aluminium or copper, can be easily identified by their specific physical properties, while others require further analysis. This is done using techniques such as X-ray fluorescence spectroscopy, which provides an accurate spectrum of the elements in a metal sample.
In this step, non-ferrous materials are prepared for recycling. This mainly includes operations involving the grinding, cutting or dismantling of metal-containing equipment and structures. The aim is to facilitate the subsequent separation of different components before processing and to reduce the size of the parts in order to optimize the efficiency of the following process.
Refining is a set of techniques to extract and purify non-ferrous metals from collected waste. The methods used depend largely on the nature of the metal to be treated and its concentration in the material. The processes commonly used include:
- The pyrometallurgy: This technique consists of heating metal waste to cause melting metals and their separation from other elements. The molten metals can then be recovered, solidified and purified according to their respective melting points.
- Hydrometallurgy: This process involves the use of chemical reactions to extract non-ferrous metals dissolved in aqueous solutions, usually after a leaching step. The metals are then precipitated, filtered and purified by appropriate methods.
- Electrometallurgy: This method uses the principle of electrolysis to separate different metals in a liquid bath, based on their respective electrical potentials.
Once the non-ferrous metals are extracted and purified, they can be transformed into ingots or billets that will be used to manufacture new products. This may involve processes such as casting, extrusion or forging. Recycled materials can thus be used to create new items or replace worn out components in various industries, contributing to the reduction of natural resource consumption and the environmental impact of industrial production.
Despite the many benefits of NFF recycling, there are some limitations to this practice. Thus, the recovery of certain metals can be complex and costly due to their low concentration in finished products or the use of specific alloys that are difficult to separate. In addition, although the overall recycling rate is increasing, there is still much to be done to optimize the collection and processing of these materials.
However, the prospects for non-ferrous metal recycling are promising, thanks in particular to advances technological that improve identification techniques, selection and purification of materials, as well as the eco-design of products to facilitate their dismantling and end-of-life processing. At the same time, environmental policies aimed at encouraging the recovery of metal waste and reducing our ecological footprint also contribute to the sustainable development of this sector.
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