Environmental protection at Pirdop

SO2 emissions per ton of copper output have been reduced by 95 % since 2000.

Dust emissions per ton of copper output have been reduced by 99.7 % since 2000.

Key factors in the reduction of dust and SO2 emissions include:

• a number of modernizations in both lines of the Sulfuric Acid Plant (2001–2014)
• the replacement of the heavy oil dryer with a steam dryer (2001–2002)
• the first (conventional) off-gas cleaning system for secondary hood off-gases (2007)
• the new additional (Sulfacid) off-gas cleaning system for secondary hood off-gases (2016)
• the new facility for cooling converter slag in pots (2020)

The specific metal emissions to water per ton of copper output have been reduced by 97 % since 2000.

Key factors in the reduction of metal emissions to water include:

• the commissioning of the second and third stages of the treatment plant for industrial wastewater (2005-2006)
• the modernization of the wastewater system for acidic wastewater (2006-2008)
• the modernization of the wastewater systems for domestic sewage (2010-2011) and rainwater (2012-2013)
• the commissioning of the rainwater treatment plant (2014)
• the commissioning of a sand bed filter unit in the industrial wastewater treatment plant (2020)

Due to a new process of the planned upgrade of the wastewater treatment plant at Pirdop site, the amount of sludges for landfilling (generated during production processes in Pirdop) and the chemical consumption will be reduced. This will extend useful lifetime of the landfill for the sludges. Furthermore, the upgrade will increase the WWTP treatment volume capacity for a most efficient wastewater treatment. The project is in detailed engineering phase with implementation activities foreseen for mid-2023.

The specific CO2 emissions per ton of copper output have been reduced by 36 % since 2000.

Key factors in the reduction of CO2 emissions include the following projects (examples):

• change of fuel burners in the anode furnaces to increase efficiency
• installation of a steam turbine to produce electricity from waste heat
• changes in process control to optimize electricity consumption

​​​​​​​The planned gasification of the Pirdop plant, with construction starting in Q1 2024, will enable Aurubis Bulgaria to continuously reduce CO2 emissions further.

Degree of implementation/date/next steps:

• Constructing a new facility for cooling converter slag in pots.

  • Building permit received in Feb 2018
  • Commissioned in Q1 2020

Status:

• Done

• Extension of the project to further optimize the flash smelter furnace slag cooling process until Q3 2025 

Degree of implementation/date/next steps

• Installing a new sand bed filter unit in the industrial wastewater treatment plant 

• Building permit by October 2018

• Commissioned in 2020  

Status:

• Done

Degree of implementation/date/next steps

• Investigation of optimization possibilities finished
• Implementation done during the large-scale facility overhaul (Q2 2019)

Status:

• Done 
• Existing bag filters modified and additional filter boxes installed

Next steps:

• Building permit received 
• Landfill area renatured

Status:

• Finished in Q3 2021

Degree of implementation:

• Signed agreement with CEZ ESCO Bulgaria for the construction of the photovoltaic power plant (10 MW) on a territory of historical remediated landfill
• Detailed engineering for solar park number two and three finished

Status:

• Done. The solar power plant was installed in 2021
• Construction start in Q1 2024 for solar park number two and three

Solar farm: In July 2020, the contract was signed with CEZ ESCO Bulgaria EOOD, a company of the CEZ Group. The Aurubis-1 photovoltaic system at the Pirdop site optimizes the smelter’s external energy consumption by 11,000 MWh annually. The electricity generated is equivalent to the annual requirements of 3,500 households or a city with a population of 14,000. Compared with the use of coal-generated power, this will reduce CO2 emissions by 15,000 t per year – and over 225,000 t for the planned period of operation.

Converter slag cooling optimization: A new facility for cooling converter slag in pots was commissioned in early 2020. This project will be extended in the coming years in order to also optimize the flash smelter furnace slag cooling process.

Industrial wastewater treatment plant modification: A new sand bed filter unit was installed in order to reduce the discharge of undissolved substances into bodies of water.

Expansion of fayalite landfill: The first stage of the fayalite landfill expansion was completed and commissioned in May 2018.

The objective of the project is to build an extension to the existing fayalite landfill that will consist of two cells with a total capacity of approximately 19.8 million tons. The cells are surrounded by soil that is protected by an insulating layer and equipped with a drainage system. Each cell will be built in eight separate stages up to the height of the existing fayalite landfill.

Special terminal for handling and storing sulfuric acid at the Port of Burgas: A new terminal for handling and storing sulfuric acid was officially inaugurated at the Port of Burgas on the Black Sea. The entire storage capacity is 50,000 tons of sulfuric acid.

Both projects (the terminal for sulfuric acid and the warehouse for copper raw materials) were implemented in cooperation with the largest private port operator in Bulgaria – BMF Port Burgas.

Warehouse for copper raw materials in the Port of Burgas: A new warehouse for copper raw materials opened at BMF Port Burgas in May 2017. The warehouse has a storage capacity of 65,000 tons of copper concentrates and covers an area of 6,000 m2. The focus of this project is on improving environmental performance when it comes to protecting the air. The new facilities enable the transport and storage of copper concentrates in closed rooms. In the process, bulk material is handled without losses. The current equipment uses the best available techniques (BAT).

Seveso permit issued: In August 2017, Aurubis Bulgaria successfully received the Seveso permit pursuant to Directive 2012/18/EU (Seveso-III).

Closure of the third sludge landfill: Similar to the first and second sludge landfills, the third sludge landfill for sludge from wastewater and off-gas treatment was successfully closed according to plan and in conformity with all applicable environmental requirements (especially Directive 1999/31/EC). The closed landfill will now be monitored for at least the next 30 years to ensure that all restoration work was successful.

Construction of the fourth sludge landfill: The fourth special landfill for sludge from wastewater and off-gas treatment was constructed and commissioned in full conformity with all relevant environmental requirements (in particular Directive 1999/31/EC).

New additional treatment plant for secondary hood off-gases (Sulfacid): The new gas cleaning system (Sulfacid) was constructed and commissioned in full conformity with the best available techniques (BAT). The project makes a notable contribution to environmental protection. It uses a modern process, a technology called Sulfacid, that is unique for Bulgaria and for the entire copper smelting industry.

Opening of a rainwater treatment plant: Aurubis invested a total of € 6.3 million in the treatment plant for rainwater and drainage water. The building phase extended over a year and comprised the construction of the facility with a capacity of 250 m³/h and containment basins for accumulated wastewater. To decrease emissions to water sustainably, this plant cleans the rain and drainage water from the premises, which cover a surface of 4 km². The plant conforms to the best available techniques (BAT).

Use of waste materials and introduction of a new product in the portfolio: At the end of 2012, EU subsidies to Aurubis Bulgaria were approved for a project to recycle waste materials and to introduce a new product (fayalite/fine-grained iron silicate) to the portfolio. The project was financed by the EU Regional Development Fund as part of the program “Development of the Competitiveness of the Bulgarian Economy” (2007-2013) together with the Bulgarian government. The 50 % financial support is contractually guaranteed and is related to the regional development program category “Investments in Green Industries.” Among other things, the project includes the purchasing and commissioning of new equipment for copper scrap processing and a filter press for drying fayalite, which opens up additional possibilities for using this by-product.

Investment program “Aurubis Bulgaria 2014”: The project, which had a capital expenditure volume of € 44.2 million, included environmental protection measures amounting to € 26 million. The objective of the program was to improve the environmental balance of the smelting operations, in addition to process improvements. These improvements included the expansion of the filter capacity for the concentrate drying facility, the replacement of the concentrate burner, the expansion of the smelting furnace’s cooling equipment, and the modification and increase of the waste heat boiler’s heat exchange capacity. The construction of the new additional treatment plant for secondary hood off-gases was a considerable contribution the project made to environmental protection.

Reopening of the renovated Flotation Plant for slag: In addition to increasing the slag processing capacity, the copper recovery rate increased, which further improved the site’s resource efficiency. The best available techniques are used in the facility.

Opening of new Tankhouse: The new Tankhouse operates with fully automatic equipment and uses state-of-the-art technology pursuant to the ISA 2000 standard (Australia). The process is monitored and controlled by an automatic management system (DCS 7). The total costs for building the Tankhouse amounted to € 82 million, making it the largest industrial investment in Bulgaria at that time.

Construction of the third sludge landfill: The third landfill for sludge from wastewater and off-gas treatment was built and commissioned. The highest safety standards to protect the soil, surface water, and groundwater were fulfilled here as well (especially Directive 1999/31/EC).

First conventional treatment system for secondary hood off-gases: In 2008, the first conventional treatment system for secondary hood off-gases was officially commissioned in full conformity with the best available techniques (BAT). The system notably reduces emissions of fine dust and sulfur dioxide. The total investment for the project amounted to € 14 million and was financed by Aurubis.

Certification of the environmental management system in accordance with ISO 14001: In March 2006, the environmental management system at the Pirdop site was successfully certified by an external auditor in accordance with the ISO 14001 standard for the first time.

Opening of the second and third stages of the treatment plant for industrial wastewater: In 2005, the second and third stages of the treatment plant for industrial wastewater were commissioned. They use a modern technology that was developed to treat industrial wastewater in a three-stage process and that guarantees adherence to the limits for water emissions.

Upgrade of Sulfuric Acid Plant: The sulfur dioxide-rich gases that form during copper concentrate smelting in the flash smelter and at the converters are cleaned, dried, and converted into sulfuric acid in the Sulfuric Acid Plant. The facility consists of two identical units that produce concentrated sulfuric acid fully automatically. This is both used internally and sold for external use.

Implementation of the Directive concerning integrated pollution prevention and control (IPPC Directive): In June 2005, the plant’s environmental protection measures were recognized with a permit pursuant to the European IPPC Directive concerning integrated pollution prevention and control.

Construction of the second sludge landfill: The second landfill built especially for sludge from wastewater and off-gas treatment also fulfills all environmental requirements and the highest safety standards to protect the soil and groundwater (especially pursuant to Directive 1999/31/EC).

Belgian environmental protection prize: The successful completion of the environmental remediation program in Pirdop was distinguished with the 2003/2004 Belgian environmental protection prize in the category “International Cooperation for Sustainable Development.”

Construction of a fayalite landfill: A landfill was built to store fayalite, which accumulates in the flotation process. The landfill fulfills all environmental protection requirements. The first and second expansions of the landfill were completed in 2009 and 2015, respectively.

Environmental remediation program: The “Georgi Damyanov” smelter was operated as a state-owned company from 1958 to 1997. Due to inadequate investments in environmental protection by the Bulgarian government, there were considerable environmental impacts in the region during this time. The company was privatized in 1997 and managed by the Belgian Union Minière Group from that point. The privatization agreement included a remediation program amounting to US$ 25 million, among other things. Within the scope of this program, defunct facilities were torn down, building rubble was appropriately disposed of, and landfill areas (the sludge settling pond known as the “Blue Lagoon,” the fayalite landfill, the slag landfill) and contaminated soil were rehabilitated. In the course of the remediation program, the first stage of the treatment plant for industrial wastewater and the first landfill for sludge from wastewater and off-gas treatment were built and commissioned in 1999.