Collaboration between Centro Rottami, Indinvest LT and TOMRA Recycling boosts aluminium recycling

Aluminium is a precious material which, when recycled, maintains its surface characteristics. A 100% recyclable resource that can and must be enhanced, the recycled alloy saves 95% of the energy that would be required to produce primary aluminium from bauxite – with the associated reduction in CO2 emissions.

Italy ranks first in Europe for recycled aluminium production, achieving 70% recovery and far exceeding the objectives set by the European Union (50% by 2025). In the Italian province of Latina, a scrap recycler, Centro Rottami, supplies a nearby foundry run by Indinvest LT, with recycled aluminium to produce an 85% recycled content billet.

Founded in 1985, Centro Rottami of Cisterna di Latina, Italy, has been working with aluminium scrap for 10 years. Gennaro Del Prete, Technical Director at the plant, comments: “We started out as a scrap iron shredder then five years ago we decided to specialise in aluminium refining, a move which has been possible thanks to TOMRA’s technologies.”

The plant processes around 1,500 tonnes of aluminium and 1,000 tonnes of ferrous scrap each month. The infeed aluminium mainly comes from old window profiles which contain some contaminants such as plastics and rubber, as well as other metal materials like copper, brass, zinc and steel, all of which must be separated to produce pure aluminium fractions.

The company, which has been working with TOMRA for twelve years, currently has three TOMRA FINDER and three TOMRA X-TRACT sensor-based sorters. Once the infeed material is shredded and pre-sorted using both magnets and eddy current separators, the material follows two lines. The material dropped by the eddy current separator is processed by a TOMRA FINDER unit, which recovers metals such as stainless steel. Advanced technologies such as SUPPIX® and Z-TECT enable the TOMRA FINDER to detect metal objects with ultra-precision, delivering exceptional purity levels for greater saleability of the recovered end fractions.

The three TOMRA X-TRACT units simultaneously purify the aluminium ejected by the eddy current separator. Thanks to advanced X-ray transmission technology, X-TRACT detects the remaining contaminants and sorts them by their respective atomic density. In doing so, shredded aluminium is freed from heavy metals such as copper, brass and cast aluminium with outstanding precision and reliability, while using very little energy and increasing production capacity.

Gennaro Del Prete adds: “In 2019, we purchased two more TOMRA X-TRACT units because the aluminium market demands ever-increasing quantity and quality. We then combined the three machines into a single line, subdividing the material to be screened for further sorting to achieve the highest quality recovered aluminium from the shredding process. This move was also made to take advantage of synergies with Indinvest, an aluminium smelter whose plant is adjacent to ours.”

Gennaro Del Prete explains the collaboration with Indinvest: “Being able to guarantee a constantly high purity aluminium is essential to establishing trust with foundries. Thanks to TOMRA, we have achieved the highest possible quality alloy materials which meet the quality requirements for the production of new aluminium profiles.”

From post-consumer scrap to green billet at Indinvest

Indinvest LT is a leader in the production and extrusion of aluminium profiles. Located next to Centro Rottami’s plant, Indinvest has its own integrated billet foundry with five extrusion lines and a total production capacity for extruded profiles of 60,000 tonnes per annum.

Ezio Porreca, Casthouse Manager for Indivest LT, comments: “For around five years, Indinvest has been buying post-consumer scrap from Centro Rottami. Thanks to Centro Rottami’s use of the TOMRA X-TRACT units, we’ve been able to significantly increase the use of post-consumer material in the melting furnaces from around 20% scrap to around 40 to 50%. This has not only allowed us to reduce our use of primary material, but has also led to energy and gas savings of 5%, which is significant given our production volumes.”

Indinvest LT produces alloys that meet certain specifications and has developed its own melt recipes to create these alloys by using on a mixture of three materials: primary aluminium, post-production scrap from its own plant and the post-consumer scrap supplied by Centro Rottami. This mix provides the reference alloy for the production of the billets. The higher the quality of the scrap, the less raw material used.

Ezio Porreca continues: “By using cleaner recycled aluminium our production has increased significantly. If not properly cleaned, recycled aluminium can still contain some contaminants such as paint, plastic and other material, which, in turn, form slag in the furnace. Using the clean material from TOMRA, we have far fewer pollutants and don’t need to clean the furnace as frequently. Cleaning the furnace involves opening the door and dropping the temperature from 1100 degrees to 800 to 900 degrees. Getting it back to 1100 degrees requires time, gas and electricity.”

Roberto Antichi, President of Indinvest LT, says: “For us, the concept of collaboration is very important. We started this project together and thanks to our synergiesw and can clearly see that it has paid off.”

It’s a collaboration that has led to the production of a far superior and ‘greener’ aluminium product, as Roberto Antichi explains: “Two years ago, we created a billet called Creal, containing 85% post-consumer aluminium with mechanical and, above all, surface results comparable to those of primary aluminium created by aluminium manufacturers from bauxite.”

Indinvest was able to achieve this incredible result thanks to the capabilities of TOMRA’s technology. Without this technoliogy, the recycled aluminium content could have been as low as 35-40%.

Roberto Antichi continues: “Recent years have shown us that our recycled aluminium is well received by the market and is increasingly in demand. Especially now, with the 2030 Paris Agreement mandating a reduction in CO2 consumption, all customers are pushing for the production of profiles with recycled material.” 

Aluminium: a growing market 

Gennaro Del Prete of Centro Rottami concludes: “One of the few positive notes of recent years is the growth in demand for recycled aluminium.  Thanks to the wide availability of recycled material and thanks to aluminium’s mechanical properties (flexible, resistant, etc.), it will be the material of the future alongside wood and glass. That’s why we have staked everything on recycled aluminium. Many companies approach us because they know the technologies we use, and they know they can rely on us for a recycled product of the highest quality. We already resell our aluminium to companies working in the two primary sectors that use this material: automotive and construction. But in the future we’ll also be exploring other markets as well. We have the best team and equipment!”

 

A video of this case study is available at https://video.tomra.com/aluminum-sorting-centro-rottami