Aurubis completes modernization of its Bulgarian operations

Aurubis AG, headquartered in Hamburg, Germany, has concluded the largest scheduled maintenance shutdown at its Bulgarian plant in three decades, with all facilities at the site resuming full operation.

The company says that over approximately two months, 120 coordinated projects were executed on schedule and within budget, involving a total investment of approximately 115 million euros, or $135 million.

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With its investments in advanced plant technology and numerous digitalization and automation initiatives during past shutdowns, Aurubis says it has achieved a substantially higher level of efficiency and stability in production at the site and can 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,” says Tim Kurth, chief operating officer, Custom Smelting and Products, and executive director of Aurubis Bulgaria. “This is a strategic investment in the long-term viability of the site, which is a vital pillar in the group. 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 key focus of the project was the complete renovation of the flash smelter—the core of the copper smelter, Aurubis says. Originally commissioned in the late 1980s, it has a throughput capacity of approximately 1.5 million tons of copper concentrate.

Three hundred tons of steel walls, cooling units and 15 kilometers (more than 49,000 feet) of copper pipes were replaced as part of the overhaul. The new furnace lining incorporates more than 1,500 tons of refractory bricks, which Aurubis says is equivalent to the brickwork of around 40 single-family homes. The company’s smelting technology was upgraded with modern 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 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, a key earnings driver, since the early 2000s, the company says, involving the installation of a new converter and the replacement of six heat exchangers.

Maintenance is central to the "Investment for Progress. Bulgaria 2027" investment program, Aurubis says. In addition to the maintenance shutdown, the four-year plan includes increasing tankhouse capacity by 50 percent to 340,000 tons per year, expanding the solar parks for the company's captive power supply and targeted investments in optimizing slag and water treatment systems.