AlCircle: Please tell us about the functionalities of your technologies used for recovering aluminium scrap. Do they aid in reducing carbon emissions?

Mr Carmelo Maria Brocato:  Since the day of its foundation – sometime in 1998 – Engitec Technologies has dedicated its research to technologies related to the circular economy applied to the nonferrous industry. After 25 years after its inception, Engitec is a well-established international global Supplier of high-tech technology and equipment dedicated to the sustainable recycling of various waste from the metallurgical and iron and steel industry, aimed at the recovery of all the components of value they contain.

I'm sure our readers are familiar with the way of saying, "it is not possible to unscramble scrambled eggs"…. Well, Engitec has denied this assumption with its CX® Plants intended for the total recovery of the lead and the other components that make up the lead/acid batteries.

The Engitec CX® Plants installed on five continents recover around 30% of the world's secondary lead.

AlCircle: What is the STE process? How is it used for the treatment of aluminium salt slag?

Mr Carmelo Maria Brocato: Likewise, in the steel or lead industries, the greenest technology is based on the usage of secondary metal. It is well-known that the energy spent for getting 1ton of aluminium using scrap as raw material is some 95% lesser than the energy required for producing 1tonne starting from mineral. In fact, according to the most accurate statistics available, about 1/3 of global aluminium production comes from the reclamation of aluminium scraps.

For such reason, Aluminium scrap, in general, is somehow considered “the bank of energy”, which includes more than forty (40) different typologies, as per the classification of the Institute of Scrap Recycling Industries (ISRI).

Just to name some of them:

• Sheets and Foils
• Used Beverage Cans [UBCs]
• Wires and Cables
• Pistons and Motors Castings
• Extruded Profiles
• Borings and Turnings
• Dross, Skimming and Similar

All materials pass through the phases of sorting, crushing, drying, de-coating, baling etc., in order to be suitable for the smelting and alloying operations. In many cases, the smelting occurs under a layer of salt (NaCl/KCl) to prevent oxidation. The resulting slag represents a waste by-product that must undergo a dedicated recovery system.

The Engitec proprietary technology for the secondary aluminium industry is the STE process for treating aluminium salt slag. The process is suitable for large or small productions and can be installed directly at the aluminium recyclers’ site.

The STE process allows the recovery of residual aluminium and salt fractions, which are re-used in the smelting process. The fine clean oxides in the slag are recovered for use in other industrial applications such as cement manufacturing.

All polluting gases generated during the aluminium salt slag leaching are combusted, and the heat generated is used for water evaporation and salt crystallization. No liquid effluents are released from the plant, and the gaseous emissions are kept within regulatory limits.

AlCircle: What R&D are you currently pursuing on technologies for aluminium recycling and sustainability?

Mr Carmelo Maria Brocato: Engitec Technologies has its own Research Center (ERC) equipped with the most advanced laboratory instruments and benefits from the collaboration of several specialized engineers employed full-time.

A conspicuous part of Engitec's profits is devoted to research which is carried out in the ERC (Engitec Research Center). Talking about the salt slag, each secondary producer has its furnaces type and production methodologies. Therefore, the composition of slag is expected to differ from producer to producer.

When there is a project, therefore, as a first step, Engitec requires the prospective Client to dispatch a sample of the slags that are then processed in the lab for analyzing the composition.

During the past 20 years, Engitec has delivered STE Plants for the treatment of salt slag both in Italy and in North America.

AlCircle: Do you use renewable energy for recycling processes to achieve Green Aluminium?

Mr Carmelo Maria Brocato: Engitec supplies tailor-made plants designed and manufactured in Italy using renewable and classic energy. The user of Engitec plants will have or will not have access to renewable energy for feeding the plant according to their energy strategy. Therefore, we cannot determine which type of energy will be feeding the Engitec plants.

Anyway, since we are talking, I would like to share a few considerations about the concept of renewable energy.

Worldwide we can say that 30% of the energy consumed comes from renewable sources while 70% is from fossil fuels. Unfortunately, renewable energies are not always available, so a thermoelectric power backup is always needed.

The real energy transition towards green will occur when it is possible to implement the transition towards clean nuclear power.

AlCircle: How can technologies help the aluminium industry in achieving sustainability?

Mr Carmelo Maria Brocato: As we have said, aluminium could be considered the bank of energy. Over the years, this bank has been fed millions of tonnes of aluminium products for which an EOL (End of Life) of 20/25 years has been considered.

I believe that the sustainability of aluminium goes through several stages, but the milestones of the agenda could be:

• Maximizing the use of aluminium scrap (bank of energy)
• The development of primary smelting technologies with higher efficiency
• Last but not least is the transition towards nuclear energy. This one will undoubtedly make the difference provided we have sufficient water.