Environmental protection at Hamburg

While considerable improvements were made by installing filters in the chimneys in the early 1990s, additional improvements are more difficult to achieve these days.

Since 2000, dust emissions at the site have been reduced, both specific (-67 g/t of copper output per year) and absolute (-32 t per year). The voluntary emission reduction agreements entered into with the city of Hamburg have always been fufilled.

Our plants already operate using the best available abatement techniques. But a low level of emissions remains, mainly influenced by fugitive emissions. In many cases, appropriate reduction systems are not proven or available on the market with the required efficiency. Despite these challenges, Aurubis plans to continue further reducing especially fugitive dust emissions in the future with tailor-made solutions, for example efficient and demand-controlled suctioning and filtering of building ventilation air at roof openings or utilizing newly developed filter media.

We will invest € 100 million in measures to further reduce emissions in the primary smelter at the Hamburg site.These measures include optimized source extraction, a newly installed procedure for processing intermediates, and the use of state-of-the-art suctioning and filter technology to trap residual dust emissions. After our plans are fully implemented, we will reduce fugitive emissions from the primary smelter by more than 70 %. All of this contributes to our sustainability strategy and makes the location fit for future in the long term.

Due to optimizations in the plant’s internal sewage treatment facility, metal emissions to water have decreased by about 30 % per ton of copper output and by more approximately 30 % in absolute terms since 2000, taking into account the normal range of fluctuation. Additional improvements are planned, such as increasing dwell times and enhancing precipitation of the metals.

By using raw materials and energy sparingly, we are acting responsibly towards future generations. From a long-term perspective, the specific energy consumption at the Hamburg production site has been significantly reduced in recent decades, by 45 % compared to 1990.

The more measures that have been implemented in energy efficiency in the past, the more challenging a further optimization is. Moreover, because there are limits to reducing energy consumption and emissions, the improvements being achieved today within the plant boundaries are only marginal compared to previous years. This is despite the same or higher levels of investment, which were already high to begin with. For example, complex recycling raw materials with relatively low metal contents and complex ore concentrates require more energy to be processed. As a result, we focus not only on further increasing efficiency but also on solutions that save energy and thus prevent CO2 outside of our plant – such as the Industrial Heat project in Hamburg with a total reduction potential of up to 140,000 t CO2/a. Furthermore, we are increasingly considering measures to replace fossil fuels with alternatives, for example by commissioning the 10 MW power-to-steam plant. Assuming that 100 % of the power supply comes from renewable energies, this plant alone could cut about 4,000 t of CO2 annually. The reduction of greenhouse gas emissions is taking a higher priority in investment decisions as well.

1. Reduction of fugitive emissions in primary copper production

• All measures can reduce fugitive emissions from primary copper production by 70 % when fully implemented. The first phase of implementation is successfully implemented. The second phase is in the preparation stage.
• Gradual completion 2020 - 2024

2. Further reduction of fugitive emissions in secondary copper production

• Optimization of phase separation and reduction of exposed bulk stocks
• Completed by the end of 2023

1. Further decoupling of industrial and non-fossil fuel waste heat, up to an additional 38 MW from sulfuric acid production lines 2 and 3, and feeding it into the existing urban transmission grid.

• This second stage of the Industrial Heat project started in 2018 can additionally save more than 100,000 t/a of CO2
• Prospective target: 2024

2. Reduction of CO2 emissions through various measures:

• Natural gas reduction in the anode casting machine and channel area and at the center lance of the flash smelter furnace.
• Replacement of several units in the acid facilities
• Reduction of compressed air losses in secondary copper production
• Implemented during 2023

1. Further reduction of the amount of wastewater in acid production.

• In addition to the already implemented reduction of the cooling water demand through the decoupling of industrial heat, a further optimization of the cooling processes is planned. In the process, the discharge volume of the existing cooling towers is to be reduced by 500,000 m³/a, fulfilling the necessary conditioning requirement of the cooling circuits.
• Commissioning by 2024

2. Reduction of metal emissions

• Reduction of metal loads by various optimizations in control systems
• Implemented in 2023

The aim of maintaining our green spaces is to keep them as close to nature as possible. The use of chemical pesticides such as herbicides or insecticides is deliberately avoided. Due to the limited areas available for near-natural use, the possibility of constructing vertical gardens or green roofs is taken into account in the construction plans.

To attract bird species that have special requirements for nesting sites – e.g., in high, exposed locations – we have successfully provided a nesting site for peregrine falcons on one of our smokestacks for several years. Aurubis is a member of the Hamburg initiative UnternehmensNatur, a network and idea platform.

Reduction of fugitive emissions in the primary copper production sector: Step-by-step implementation of measures to further reduce fugitive dust emissions from primary copper production. The project includes efficiency improvements in existing capture systems close to the source, aided by measures to optimize the hall circulation conditions. An additional part is the installation of new aggregates for the low-emission treatment of internal intermediate products. In addition, the gradual installation of a purely demand-driven collection and cleaning system for residual fugitive emissions at the roof is an important part of the innovative design. The roof suction is designed to be extended in steps. A high level of energy efficiency is achieved through the control concept, which is adapted to the actual demand at any given time. The overall measure is expected to reduce fugitive emissions from primary copper production by about 70 %, which would result in an exemplary, clean operation even on a global scale. The project started in 2020. Gradual implementation, first step to be completed in 2022 Investment: €100 million. The second phase is in the preparation stage.

Electrode steam boiler: The 10 MW electrode boiler generates steam from electricity, particularly at times of surplus electricity from renewable sources. This contributes to grid stabilization within the framework of secondary power control. During the operating phases of the electrode steam boiler, process steam conventionally generated with natural gas can be substituted. This results in an annual CO2 savings potential of 4,000 t/a.

Replacement of old wet gas cleaning in the concentrate drying drum of the primary smelter RWO by a modern dry filter installation • Reduction in accident risk due to improved ergonomics • 75 % reduction in dust emissions • 85 % reduction in SO2 emissions

Commissioning of a steam turbine to generate electricity. The previously unused pressure stage between 60 and 20 bar is made usable with the help of a superheater. This reduces about 5,000 t of CO2 per year.

Commissioning of a modern, steam-heated anode slime press including a sliding off-gas hood to collect all of the thermally induced emissions above the press.

Replacement of the old lead refinery. Approx. 50 % reduction in fugitive emissions due to improved processes with a ventilation concept. Construction costs of roughly € 20 million.

Construction of a storage hall including an enclosed, suctioned crusher for pollutant-laden bulk material in Plant North. Material is now transported via a fully closed system.

Construction of a new filter installation to continue reducing fugitive emissions in the converter area.

Commissioning of two washing towers to remove fluorides and other water-soluble components from the off-gas. The gas flows through the towers from below in a countercurrent to the washing water.

New off-gas collection system for anode furnace and casting machine reduces emissions in the area by more than 70 %. Investment of more than € 7 million.

Enclosure and suctioning of Peirce-Smith converter in the Plant North primary smelter to collect and treat SO2-bearing off-gases from charging processes within the converter hall (house-in-house concept).