Aurubis AG: Largest modernization at the Bulgarian site in 30 years successfully completed

Aurubis AG: Largest modernization at the Bulgarian site in 30 years successfully completed

• Investments of around €115 million delivered on schedule and within budget
• Major project involving 120 individual measures completed, securing long-term operational excellence
• Planned maintenance shutdown cycle extended from two to three years

Hamburg/Pirdop/Zlatitsa, July 21, 2025 — Aurubis , a leading global provider of non-ferrous metals and one of the largest copper recyclers worldwide, has wrapped up the largest scheduled maintenance shutdown at its Bulgarian plant in three decades on schedule. Following this achievement, all facilities at the site have resumed full operations. Over approximately two months, 120 coordinated projects were executed on schedule and within budget. The nearly €115 million investment helps secure the Bulgarian plant’s strong operational performance for the foreseeable future.

Thanks to major investments in advanced plant technology along with numerous digitalization and automation initiatives during past shutdowns, Aurubis has achieved a substantially higher level of efficiency and stability in production. Building on this stable foundation, the company is set to extend the interval between future planned maintenance shutdowns from two to three years.

"Successfully completing such a large-scale project in just around two months is a clear testament to our capabilities — Aurubis can execute complex projects safely and reliably. This is a strategic investment in the long-term viability of the site, which is a vital pillar in the Group," said Tim Kurth, COO Custom Smelting and Products and Executive Director Aurubis Bulgaria. "Our site in Bulgaria has earned recognition for maintaining peak plant availability in the past. We have now laid the groundwork to uphold that standard — while also extending the time between maintenance cycles."

A maintenance shutdown of this magnitude is a major logistical and technical project — planning for the latest shutdown began back in 2023. In addition to the Aurubis Bulgaria team, around 2,000 people from 12 countries representing partner companies, suppliers and service providers were involved. As in regular operations, work safety and health protection were given the highest priority.

Ensuring future viability through state-of-the-art technology

A key focus of the project was the complete renovation of the flash smelter — the core unit of the copper smelter. Originally commissioned in the late 1980s, it has a throughput capacity of approximately 1.5 million tons of copper concentrate.

300 tons of steel walls, cooling units, and 15 km of copper pipes were replaced as part of the overhaul. The new furnace lining incorporates over 1,500 tons of refractory bricks equivalent to the brickwork of around 40 single-family homes. The proven smelting technology was upgraded with state-of-the-art components designed to ensure maximum availability.

In addition, two electrostatic precipitators with a total weight of 900 tons were replaced to improve environmental performance at the Bulgarian site. A modular pre-assembly concept minimized the duration of the planned maintenance shutdown, and a 750-ton crawler crane, assembled and dismantled on site, was used for the replacement. 

The third core element was the most extensive modernization of sulfuric acid production since the early 2000s. A new converter was installed, and six heat exchangers were replaced — equipment with a combined weight exceeding 1,000 tons. Sulfuric acid is an important earnings driver in copper production.

"Together with local partners, our team carried out this demanding project with the highest level of professionalism and delivered successful results in every respect," Tim Kurth emphasized. "We would like to thank everyone involved in making this achievement possible. It’s very rewarding to see our dedication to the highest occupational safety standards pay off."

Further implementation of the "Investment for Progress. Bulgaria 2027" program

Maintenance is a central component of the "Investment for Progress. Bulgaria 2027" investment program. In addition to the maintenance shutdown, the four-year plan includes increasing tankhouse capacity by 50% to 340,000 tons per year, expanding the solar parks for the company's captive power supply (a comprehensive energy efficiency package), and targeted investments in optimizing slag and water treatment systems. Through this program, Aurubis is actively advancing decarbonization and strengthening its global smelting network.

Aurubis — Metals for Progress

Aurubis AG is a leading global provider of non-ferrous metals and one of the largest copper recyclers worldwide. The company processes complex metal concentrates, scrap metals, organic and inorganic metal-bearing recycling materials, and industrial residues into metals of the highest quality. Aurubis produces more than 1 million tons of copper cathodes annually, and from them a variety of products such as wire rod, continuous cast shapes, profiles, and flat rolled products made of copper and copper alloys. Aurubis produces a number of other metals as well, including precious metals, selenium, lead, nickel, tin and zinc. The portfolio also includes additional products such as sulfuric acid and iron silicate.

Sustainability is a fundamental part of the Aurubis strategy. “ Aurubis responsibly transforms raw materials into value” — following this maxim, the company integrates sustainable conduct and business activities into the corporate culture. This involves a careful approach to natural resources, responsible social and ecological conduct in everyday business, and sensible, healthy growth.

Aurubis has around 7,000 employees, production sites in Europe and the US, and an extensive distribution network around the world.

Aurubis shares are part of the Prime Standard Segment of the German Stock Exchange and are listed in the MDAX, the Global Challenges Index (GCX), and the STOXX Europe 600.

More information at www.aurubis.com