Green-tech testing

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Mining giant opts for sustainable technology that enables metal extraction in the Atacama desert without the use of nitrogen oxide.

New green technology based on natural materials to recover nitrogen oxide emissions is now being tested for use in copper extraction in Chile’s Atacama desert. The technology, developed by Austria’s Krajete and perfected in collaboration with Audi, was recently discovered by technology scouts from one of the world’s largest mining groups. The group focuses on the recovery of nitrogen oxides (NOx) produced during copper mining and their further use for valuable materials. Krajete’s zeolite-based process seems to offer the optimal solution here and will now be tested in a first test plant.

The extraction of copper from mineral ores is accompanied by the emission of large quantities of NOx. These are still often released into the atmosphere, but increased environmental sensitivity and legal requirements have now led to a rethink in the industry. The realisation that these exhaust gases can be turned into valuable raw materials if they are intelligently recovered is accelerating this reorientation and making companies look for innovative, sustainable ways.

Strong bond

Krajete has found such a path in recent years. The company, which specialises in the development of sustainable solutions for gas extraction and purification, optimises natural processes for use in industry. For example, it succeeded in developing a zeolite-based way to remove NOx from emission gases. Together with the German Audi, this technology has been optimised for use on internal combustion engines in recent years.

“In fact, our process is so flexible to use,” explains Dr Alexander Krajete, CEO, “that we can adapt it to other – even large-scale industrial – requirements with little effort.” And this is exactly what is now planned together with one of the world’s top 10 mining companies. This company mines large quantities of copper in the Chilean Atacama desert – a process that releases large quantities of NOx. The company wants to reduce these quantities.

Valuable change

“But that’s not all,” Krajete reveals: “We specialise in converting problematic emissions into valuable raw materials. Our process therefore not only allows NOx to be filtered out of gas emissions, but also the recovery and concentration of these raw materials, which can then serve as a starting point for other valuable materials such as nitric acid.” The principle of the technology is the physical binding of NOx to a specially prepared zeolite matrix. From this, the gases filtered out can then be recovered cheaply and easily in concentrated form. “And the best thing about it,” says Krajete, “is that the zeolite survives this process completely undamaged and can be used again. It’s a sustainable principle that turns waste gases into valuable materials.”

The simplicity and sustainability of the process also convinced the mining company’s technology scouts. They looked at a significant number of companies for solutions for sustainable recovery of the NOx emitted during copper extraction – and finally found what they were looking for with Krajete and its company motto “On behalf of nature”.

If the process proves successful in this setting, gigantic plants are already being discussed for NOx recovery in copper production. Structures measuring 14km2 could be erected that would serve solely to recover the NOx. But there is still a long way to go and the immediate plan is to test the Krajete process in the laboratory with real exhaust gases from copper production.

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