Did you know that nearly 75% of all aluminum ever produced is still in use today?1
That’s because aluminum is infinitely recyclable. Unlike paper and plastics, which have limited recyclability, aluminum can be remade without losing its inherent properties.
This matters because although aluminum is the most abundant metal on Earth (making up 8.1% of the planet’s crust2), it is locked in minerals such as bauxite. And the typical smelting process for producing commercially usable aluminum metal is carbon intensive.
Through ELYSIS™ (a joint venture with Alcoa) and investments in hydropower plants, Rio Tinto is rapidly transforming the aluminum smelting process. Aluminum production in North America already uses clean, renewable power and through ELYSIS, Rio Tinto is introducing a breakthrough smelting technology with no carbon output from the electrolysis process.
However, aluminum recycling already makes a critical impact in the world’s race to net zero. Rio Tinto’s joint venture with Matalco, helps us meet the growing demand from manufacturers for low-carbon aluminum materials by providing recycling solutions.
If you’re purchasing aluminum for your manufacturing process, it’s important to understand how borates contribute to the recycling process.
Borates in aluminum production
Lightweight, strong, and durable, aluminum is used in applications from household products to automobiles, aircraft, and energy production. But perhaps it’s greatest value is that it is one of the most recyclable materials we have.
Because the aluminum recycling process has a lower carbon footprint than conventional primary aluminum smelting, seeking responsibly produced recycled aluminum is part of many organizations’ playbooks. For example, recycled aluminum products by Matalco are produced with one eighth the carbon footprint3 of most primary aluminum products.
However, recycled aluminum still requires exacting quality controls to ensure high-performing end products. Just as in primary aluminum production, borates are key to recovering aluminum from scrap. Adding borates removes oxides and other impurities from scrap and mixed alloys to ensure high-quality aluminum billets, slabs, and other products.
Borates provide multifunctional benefits in metal recycling:
- Borates act as a cover flux during the melting process. They help to purify aluminum by combining with metallic oxides and impurities. Then, they bind those impurities and form a slag that rises to the surface of the crucible and can be skimmed off.
- An anhydrous borate (such as Dehybor®) easily forms a liquid flux that actually helps dissolve oxides, silica, and other non-metallic impurities
- A cleaner melt helps maintain the quality required for thin sheets and other precision aluminum products
- In addition to acting as a flux, borates serve as a grain refiner and hardening agent, improving the mechanical properties and surface finish of the aluminum
- Because borates enable metals to melt at lower temperatures, the melting process requires less energy
Selecting the right borate concentration, purity, and particle size makes the difference between high-quality recycled aluminum and an inconsistent product prone to cracking or pitting.
Transparency is key in your borates supplier
Consistent quality in your materials means a more predictable end product. That’s why evaluating your suppliers’ processes matters.
Borates are an important part of that evaluation. Inconsistent or insufficient borate concentration in a formulation can result in less metal recovery, increased scaling and slag, higher levels of impurities, and a poorer overall aluminum product.
For manufacturers, that can mean costly specification variations in processes and products.
U.S. Borax is known worldwide for the quality and consistency of our refined borates. Our products undergo a comprehensive quality testing process to ensure they deliver high borate concentration and uniform particle size. And, they are backed by robust traceability and support documentation.
When you’re seeking a trusted borates partner for your processes that involve aluminum, tap into the expertise of our technical support team.
References
1 Aluminum’s Sustainability. c2021. The Aluminum Association. https://www.aluminum.org/sustainability
2 Periodic Table: Aluminium. c2024. Royal Society of Chemistry. https://www.rsc.org/periodic-table/element/13/aluminium
3 Low Carbon Leaders. c2021. Matalco. https://www.matalco.com/low-carbon-leaders-local/
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