Non-ferrous metal recycling
The recycling of non-ferrous metals applies to waste collected from private individuals as well as from professionals, thanks to a recycling channel that is entirely dedicated to them. This recycling avoids waste, the extraction of new raw materials and allows the eternal reuse of these non-ferrous metals. After collection, non-ferrous metals are taken to a processing centre where they are sorted before they can be recycled.
Non-ferrous metals include aluminium, copper, lead, zinc, nickel, titanium, cobalt, chrome and precious metals. They can be recycled indefinitely without losing any of their properties.
The benefits of recycling non-ferrous metals
The use of non-ferrous metals is increasing over the years. It is estimated that world primary aluminium production averages around 24 million tonnes per year, of which Australia is the largest producer. With the increase in metal production in general and the decrease in precious resources needed to produce them, it is more important than ever to find ways to increase the value of scrap metal reuse.
While plastic packaging is difficult to recycle due to its disparate nature, recycling metals is easier. As ferrous and non-ferrous components can be separated using magnets and then separated from other materials by an eddy current machine, recycling is more efficient.
The recovery of non-ferrous metals for recycling has both environmental and economic benefits. The process can :
- reduce pollution ;
- preserve our natural resources from mining;
- reduce greenhouse gases
- reduce water pollution
- Save energy;
- reduce landfill of metal waste
- strengthen environmental protection with the recycling of used scrap metal;
- create jobs...
Non-ferrous metal recycling in figures
According to official figures, in 2013 in France, 1.8 million tonnes of non-ferrous metals were collected by 1,060 recycling companies. With 4,576 million euros, the purchase and processing of non-ferrous metals is the largest contributor to the turnover of the recycling industries.
Of the estimated 700 million tonnes of aluminium produced since commercial manufacture began in the 1880s, around 75% of this is still used today as a secondary raw material.
One tonne of recycled aluminium saves up to 8 tonnes of bauxite, 14,000 kWh of energy, 40 barrels (6,300 litres) of oil and 7.6 cubic metres of landfill.
Recycling one aluminium can saves enough energy to power a 100-watt light bulb for almost four hours.
A used aluminium can is recycled and returned to the grocery shop in 60 days.
For every can made from virgin ore, the same amount of energy used will produce 20 recycled cans.
The aluminium can is the most recycled container in the world, accounting for over 63% of all recycled cans worldwide.
The average car contains up to 10 kilos of zinc in its galvanised bodywork that can be recycled back into parts of the same quality.
The recycling of :
- aluminium uses 95% less energy than producing aluminium from raw materials;
- copper saves up to 85% of the energy used in primary production;
- zinc uses 76% less energy than primary production;
- tin requires 99% less energy than original production.
- 50% of the lead produced and used worldwide each year has already been used in other products. Today, about 80% of lead is used in acid batteries, all of which are recoverable and recyclable.
Global tin production is 350,000 tonnes, of which 50,000 tonnes is from scrap metal and other secondary sources.
What non-ferrous metals are recycled
Produced from bauxite, aluminium is a clay mineral found only in the form of a compound called alumina, a hard material composed of aluminium combined with oxygen. To release the aluminium, the alumina must be stripped of its oxygen and dissolved in a molten salt in a reduction plant, after which a powerful electric current is passed through the liquid to separate the aluminium from the oxygen.
This process uses large amounts of energy. Recycling aluminium requires much less energy than producing aluminium (only 5%) and produces only 5% of the CO2 emissions of primary production, while reducing the amount of waste sent to landfill. Furthermore, aluminium can be recycled indefinitely, as reprocessing does not damage its structure.
Other non-ferrous metals, often present in smaller quantities, can also be recycled. These metals, including nickel, copper, silver, gold, lead and brass, are widely used in specific industries, such as electronics and technology, as well as in everyday objects.
The non-ferrous metal recycling process
The process of recycling non-ferrous metals starts with their collection from professionals and private individuals.
Non-ferrous metals are collected from various industries, with a large proportion coming from the automotive industry and from ELV (End of Life Vehicle) dismantling centres. Demolition sites are another important source. Non-ferrous metals from private individuals are recovered from waste collection centres and collections of bulky items.
Recyclable materials come from the production of processing industries and end-of-life domestic products: WEEE (Waste Electrical and Electronic Equipment), ELVs, batteries, accumulators, cans and various objects (Nespresso capsules, kitchen utensils, medicine plates, etc.). They also come from industrial and commercial equipment including stainless steel, aluminium and lead.
Bottom ash from incineration plants that treat municipal waste is also used.
Shredding of waste
Shredders break up the collection with a system of rotating blades and hammers distributed around an axis.
For large and heavy scrap metal, but also for lighter scrap metal - cladding, elements from demolition, roofing elements or household appliances - shears make it possible to reduce the volumes so that they can then be pressed.
Once shredded, the waste is sorted. This involves extracting the steel using its magnetic properties. Installations consisting of overbands circulate the waste for an initial sorting that separates the ferrous metals from the non-ferrous metals, thanks to a system of magnets.
The non-ferrous metals must then be separated from the other materials using eddy current machines.
The different metals are melted in large furnaces. Each metal has its own specially designed furnace according to its properties. The furnaces are equipped with fuel-efficient regenerative burners to reduce the amount of energy used and the environmental impact. They are also equipped with jet agitators that ensure uniform temperature and composition, promoting the circulation of the metal in the furnaces. The stirring process ensures the highest quality end product.
In the molten state, the metals are purified by eddy current electrolysis before being poured into different moulds, depending on the metal, and cooled.
In order to be transported to the industries that will reuse them, the scrap metal must be conditioned so that it can be handled and occupy the smallest possible space. It therefore goes through compactors that increase its density by pressing it into bundles called bricks or bales.
Waste management: what happens to recycled non-ferrous metals
Non-ferrous metals are recycled with little or no loss of their original physical properties. They are such versatile materials that the possible applications for each metal and their combinations are endless.
Aluminium recycling is extremely useful, as the metal is often reused for the same application for which it was originally manufactured. By being reused, aluminium becomes a raw material again and its life cycle is eternal.
Its strength, flexibility and lightness make it ideal for :
- building and construction: window frames, building structures, roofs, etc. ;
- transport: planes, trains, boats, cars, trucks, bicycles, motorbikes, wheelchairs, etc. ;
- Packaging: cans, tins, foil, etc. ;
- electricity: since 1945, aluminium has replaced copper in high-voltage lines;
- cooking and tableware.
After silver, copper has the best electrical conductivity of all the elements. It is also a very good thermal conductor and is easily alloyed with other metals such as lead, tin and zinc for foundry applications to produce, among others, water transmission products such as valves.
It is also used in other common applications:
- Electrical: cables, circuits, switches and solenoids;
- Piping: plumbing fittings, refrigeration, air conditioning and water supply systems;
- roofing and insulation;
- Household items: kitchen utensils, door handles and cutlery.
Most recycled lead is used in batteries, but there are other applications for this metal, including car batteries (electrode plates) and X-ray protection.
Zinc is used for coins, but also for galvanising to protect iron and steel from corrosion, for batteries (anode component) and to create brass by alloying with copper.
Besides precious metals, tin is one of the most expensive non-ferrous metals. Therefore, recycling from secondary materials is very important:
- creation of tinplate for the manufacture of cans ;
- automotive production: it increases the strength of the engine block, piston rings and clutch discs;
- makes springs stronger;
- glassmaking: tin oxide layers on glass surfaces make them stronger.
We hope that this article has helped you to broaden your knowledge of non-ferrous recycling. The Raoul LENOIR company remains at your disposal for your ferrous and non-ferrous recycling projects.
Publié le : 15/03/2022