Aurubis Bulgaria supports sustainable development of the construction sector with innovative materials

Dr. Manolova, there seems to be a paradigm shift in the perception of raw materials and their role in the energy transition. What is your take on this, what is the role of companies like Aurubis in building a sustainable future?

Aurubis is a Group-level producer of over 20 different metals, with a primary focus on copper. The metals we produce are the foundation for the energy and mobility transformation on the one hand and digitalization on the other. In this context, Aurubis is a key enabler of innovation and decarbonization.

There is a high demand for copper, the key metal we produce. According to market research, this demand is growing by about 2% to 3% per year. To meet this growing demand, Aurubis is investing heavily to supply more copper to Europe and beyond. In Bulgaria, we have launched a significant program that will be implemented over the next four years, with a total investment of BGN 800 million.

Our strategy aims not only to meet the growing demand for copper, but also to modernize, digitalize and increase the energy efficiency of our production processes, thus reducing our impact on the environment. The metallurgical industry, including our operations, is a huge consumer of energy. Therefore, we are focusing on several key areas of investment. One of the main areas is regular shutdowns for renovation, starting with our furnaces in 2025. In addition, we are modernizing our wastewater treatment plant to meet the highest standards of water treatment and cleaning, and we are also working on projects related to slag processing. These projects aim to increase the percentage of copper extracted while reducing the environmental impact of the thermal processes used to cool the slag. In addition, we are modernizing our transport infrastructure, equipping it with new, environmentally friendly rail cars to transport concentrate from Burgas to Pirdop. We are also committed to modernizing our facilities, including the highest efficiency engines and lighting at our plant.

Overall, our strategy continues to prioritize investment in our core business, increasing efficiency and effectiveness in various aspects of the production process. The Aurubis Group aims to define the highest standards and become the most sustainable steel mill network not only in Europe but in the world.

While industrial companies are indeed responsible for a significant share of emissions, they are also at the forefront of transforming production processes and sustainable innovation. Are public initiatives keeping up with these advances, or is there a need to catch up?

Very good question. The company’s sustainability efforts depend on its scale and specific goals. At Aurubis Bulgaria, we are deeply committed not only to sustainable production, but also to the well-being of the region where we operate and the people living there. We strive to make our employees and local communities feel that they are part of a company that truly cares about living standards. We focus on implementing the most efficient and appropriate technologies in our operations. This goes beyond just following ISO 9001 standards and continuous improvement processes; we prioritize sustainability from both a cost and environmental perspective. Reducing CO2 emissions is a key goal, in line with Europe’s green strategy.

One of our key projects is generating our own electricity. We have started work on internal solar parks, which will reach 41 MWp in 2026. The first one is already operational, the second and third are under construction and the fourth is scheduled to start operating at the end of this year. The Group’s goal is to achieve carbon neutrality by 2050. In addition, we are exploring opportunities for hydro and wind energy projects. We are convinced that these efforts will significantly contribute to our sustainability goals.

You have already mentioned some aspects of the recently presented new investment program in Bulgaria. Can you share some details with us?

Yes, our decarbonisation efforts are a significant part of a long-term programme. This is just the beginning and several key projects have been included in this initial phase. One of the key projects is the expansion of our tank farm for refined copper, which is our key product. By expanding our production capacity, we intend to increase our copper cathode production by 50%. We currently produce copper in two stages: anodes and cathodes. Until now, we have only been able to convert a fraction of our input into cathodes. With this new investment, we will be able to refine the entire 340,000 tonnes per year on site. This expansion is a key part of our investment programme.

Another significant project is the modernization of wastewater treatment processes. Copper concentrates, our main raw material, now contain more diverse metals, which requires more thorough cleaning processes, which ultimately affects wastewater treatment.

In addition, we are working on a slag treatment and cleaning project. The aim of this project is to extract valuable materials in an environmentally friendly way, which will further reduce our environmental footprint. These activities are essential to our overall strategy to improve the sustainability and efficiency of our operations.

Speaking about sustainable innovation, Aurubis Bulgaria has certified one of its main by-products, fine iron silicates, as a construction product for use in concrete and mortar. Tell us a little more about it and its practical application.

In recent years, we have carried out extensive R&D activities to understand the properties of fine iron silicates, the secondary material we produce. Aurubis mainly produces three materials: copper, sulfuric acid, which is our largest product by volume, at around 1.35 million tons, and iron silicate, of which we produce around 800,000 tons in Bulgaria. In comparison, our copper production is 340,000 tons, which highlights the significant volume of fine iron silicates we generate.

Given the significant amounts of iron silicate fines, we started by thoroughly investigating their properties and identifying potential applications that could provide additional benefits. Once these applications were identified, we sought certification one by one. We then sought approval for the reclassification of iron silicate fines from waste to by-products, a process that involved multiple ministries in Bulgaria and was completed in 2021. This reclassification was a key milestone for expanding our market.

Applications for fine iron silicates include their use in concrete, mortar and the production of ceramic bricks. After obtaining the initial certification, we continued to have annual external audits and required our customers to certify their final products, as our material serves as a raw material in their production processes. Various certification bodies approved these applications and our customers were very pleased with the results.

The benefits of using iron silicates are numerous. Technically, they improve the mechanical and radiological properties of the final products. Economically, they reduce the need for sand and cement in the production of concrete and mortar, which directly reduces CO2 emissions in a sustainable way. Cement production is a significant source of pollution, and reducing its consumption helps to mitigate its environmental impact. Fine iron silicates, due to their high iron content, also serve as an alternative fuel, particularly beneficial for high-temperature processes such as cement and ceramics production. This helps reduce the consumption of traditional fuels and supports decarbonisation efforts in these industries.

In addition, we are investigating additional applications, such as the incorporation of fine iron silicates into asphalt mixtures for road construction, which traditionally rely largely on natural materials. We are working to align Bulgarian standards with proven applications in Europe. In addition, fine iron silicates can be used as a substitute in cement production and, although their certification in Bulgaria takes some time, they have received a European Technical Assessment Certificate. This opens the door to the production of more sustainable concrete, the most widely used material by volume in the world.

We are now closing the loop on the circular use of fine iron silicates by incorporating them into our new investment projects as a key component of the concrete composition. The first such project is almost complete: new photovoltaic parks are located on historic ponds made of this material, and the foundations of the parks are made of it.