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Sulphuric Acid on the WebTM Technical Manual DKL Engineering, Inc.

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Acid Plant Database   September 3, 2019

Owner Aurubis Bulgaria

Aurubis-Logo.jpg (18984 bytes)
Cumerio-Logo.gif (3568 bytes)


BG - 2070


- Georgi Damyanov Copper Combine
- MDK Copper Smelter and Refinery
1997 - Acquired by Umicore (Union Minere)
2005 - Umicore Copper demerged from Umicore Group to form Cumerio 
2009 -
Cumerio Med JSCo.

Website www.aurubis.com

Pirdop Smelter

Plant No. 1 Plant No. 2

42° 43' 8" N, 24° 9' 30" E

42° 43' 10" N, 24° 9' 26" E
Type of Plant Metallurgical Metallurgical
Gas Source

Outotec (Outokumpu) Flash Furnace
Peirce-Smith Converters

Outotec (Outokumpu) Flash Furnace
Peirce-Smith Converters

Plant Capacity 1940 MTPD
66,600 to 160,000 Nm3/h, 7.4 to 11.3% SO
1940 MTPD
120,000 to 160,000 Nm3/h, 7.4 to 11.3% SO
SA/DA 3/1 DA, 2.6 kg SO2/MT 3/1 DA, 99.80% conversion
Emissions - SO2: 0.032%
SO3/Acid Mist: < 40 mg/Nm3
Status Operating Operating
Year Built 1981 1987
Technology - -
Contractor -

Civil Works - Geotechmin ood

Remarks 1997 - 780 MTPD, 120,000 Nm3/h, 4-6.3% SO2, 4 SA, 98.5% conversion
2002 - Plant revamped by Outotec
        - single to double absorption
        - revamp wet gas cleaning section
        - sodium silcate addition system
        - revamp WESP's
1997 - 1050 MTPD, 120,000 Nm3/h, 7-9% SO2
2003 - Plant revamp by Outotec
        - 150,000 Nm
3/h, 7 to 9% SO2
        - new 1st washing tower
        - new drying tower
        - new blower
        - revamp converter
        - replace electric preheater with diesel fired
2007 - new intermediate and final absorbers
In order to increase plant productivity and its environmental performance several sub projects were executed in the sulphuric acid plant.
- Improvement of cooling system by implementation of control circuits and revamping of existing cooling towers
- Cooling/Quench Towers
- Installation of one additional WESP per line for ensuring of acid quality
Converter/Drying/Absorber - Installation of additional cooling capacity in drying and absorption section by rearrangement of existing equipment and installation of new coolers.
Replacement of ducts for ensuring new required volumes
Pictures       Cumerio - Pirdop 4.jpg (47853 bytes)  Cumerio - Pirdop 5.jpg (54314 bytes)  Cumerio - Pirdop 6.jpg (47385 bytes)  Cumerio - Pirdop 7.jpg (40762 bytes)  Cumerio-Pirdop-8.jpg (59583 bytes)  Aurubis-Pirdop-9.jpg (25124 bytes)

Civil Construction Photos Geotechmin ood
General Cumerio Med in Pirdop transforms concentrates with 25 -35 % copper content into anodes (99% Cu). The annual smelting capacity is around 240,000 tons. Part of the anodes is transported by train to the Cumerio plant in Olen, Belgium as feed for the electrolytic refinery. Cumerio Med also produces 60,000 tons of copper cathodes for the regional markets.
References Kirilov, D., Obereich, Th., Shulekov, G. and Nedelchev, N., "Aurubis Bulgaria 2014", Copper 2016, Kobe, Japan.
Geotechmin ood
News September 3 - Hamburg-based copper producer Aurubis said that the concentrate throughput of its Bulgarian plant, located in the town of Pirdop, fell by an annual 19% to 849,000 tonnes in the first nine months of its 2018/2019 financial year, started October 1, 2018.  "Apart from unplanned shutdowns in Q1 2018/19, a planned maintenance shutdown carried out at our Pirdop site in May/June 2019 negatively impacted concentrate throughput," Aurubis said in an interim financial statement last month.  Cathode output at the Pirdop plant decreased by 7% year-on-year to 157,000 t, while sulfuric acid production dropped 21% to 824,000 t. in the first three quarters of the company's 2018/2019 fiscal year.  In the third quarter of Aurubis' 2018/2019 fiscal year, concentrate throughput at Pirdop dropped 37% on the year to 217,000 t, cathode output fell 16% to 47,000 t, while sulfuric acid production was 35% lower at 217,000 t.  The average copper price throughout the first nine months of Aurubis' 2018/2019 financial year was $6,167 (5,636 euro) per tonne, 10% lower year-on-year.

August 15, 2017
- Hamburg-based copper producer Aurubis said the copper concentrate throughput of its Bulgarian smelter more than doubled to 335,000 tonnes in the third quarter of its 2016/2017 fiscal year. In the nine months started October 1, 2016 the copper concentrate throughput of the Pirdop smelter in Bulgaria rose by an annual 37% to 986,000 tonnes, Aurubis said in an interim financial report. Sulfuric acid output at Pirdop rose 39% on the year to 1,020,000 tonnes during the first nine months of the company’s 2016/2017 fiscal year. In the April-June period alone, sulfuric acid output rose to 356,000 tonnes from 117,000 tonnes in the like period of last year. Cathode output at Aurubis’ Bulgarian smelter increased by an annual 8% in the October-June period to 172,000 tonnes. In the third fiscal quarter alone, cathode output rose 27% year-on-year to 57,000 tonnes. The Pirdop smelter is located 80 kilometres east of Sofia.

May 15, 2017
- Hamburg-based copper producer Aurubis said on Monday the copper concentrate throughput of its Bulgarian smelter rose 7% year-on-year to 651,000 tonnes in the first six months of its 2016/2017 fiscal year started October 1, 2016.  In the second fiscal quarter alone, the copper concentrate throughput of the Pirdop smelter in Bulgaria rose by an annual 7% to 324,000 tonnes, Aurubis said in an interim financial report.  Sulfuric acid output at Pirdop rose 8% on the year to 664,000 tonnes during the first half of the company’s 2016/2017 fiscal year. In January-March period alone, sulfuric acid output rose 7% to 329,000 tonnes.  Cathode output at Aurubis’ Bulgarian smelter edged up by an annual 1% in the October-March period but dropped by 2% year-on-year in the January-March period.

February 11, 2016
- In November 2015 the Competition Protection Commission issued a statement of objection against Aurubis Bulgaria AD and Aurubis AG. Based on its preliminary findings, the commission accused Aurubis of abuse of its dominant position in the Bulgarian market for the production and sale of sulphuric acid. The commission accused Aurubis of selling the acid at unjustifiably high prices and thereby discriminating against its Bulgarian customers in favour of international clients.  The commission began its investigation in 2013 following a claim brought by Agropolychim AD against Aurubis for abusing its dominant position as a sulphuric acid producer, and against Aurubis and KCM AD (Plovdiv) – a leading producer of non-ferrous and precious metals in Southeast Europe and the Black Sea Region – for concerted practices aimed at sharing the markets for the sale of sulphuric acid.  At the beginning of the investigation the commission conducted a dawn raid at Aurubis' offices in Pirdop. During the raid, the commission seized electronic, digital and forensic evidence from computer hard drives. Aurubis objected that copies of certain emails between the company and its external lawyers should not be reviewed by the commission as relevant evidence because they were subject to legal privilege. Thus, the commission had no right to request non-confidential versions of the emails to be submitted. Nevertheless, the commission issued a ruling by which, among other things, it accepted that the emails were business secrets and Aurubis was obliged to provide the commission with non-confidential versions in order to assess whether they were privileged. Aurubis objected to the ruling before the Supreme Administrative Court.  The appeal was considered impermissible because it was brought against an act of the commission, which alone could not be appealed before the court. According to the court, the commission's ruling, that certain information provided by the parties to the investigation did not qualify as a business secret, could be appealed separately. However, the court concluded that the commission's assessment of whether the evidence was relevant to the investigation and whether it was privileged could be appealed as part of the commission's final decision only.  The investigation is in its second phase. Aurubis can oppose the statement of objection and propose commitments, and has the right to be heard by the commission in an open hearing session. No time limit is envisaged for completion of the investigation.


November 20, 2015 - A Linden Comansa 21LC290 tower crane is being used to construct two chimneys at a sulphuric acid plant in Bulgaria.  The crane, which was delivered by Linden Comansa's Bulgarian dealer Bulgarcom, will be used by the Aurubis Group at its plant near Pirdop.  Aurubis is one of the leading global copper manufacturers but also produces sulphuric acid as a bi-product.  The company is constructing outgoing gas cleaning facilities at the plant, as part of a €44.2m project launched in 2011 to improve productivity and environmental performance. To assist construction of the towers, which comprise a fibre-glass pipe with a supporting steel structure, Bulgarcom erected the 18t 21LC290 crane in April with an initial freestanding height of 63.1m and a jib length of 40m.  As the towers gained height, the crane was tied to the steel structure with a bracing at 49m. Bulgarcom then used a Linden Comansa J2-10 cage to climb the crane to a height of 101.6m.  In July another tie-frame was added at 88m and the crane climbed again, to a final height under hook of 134.6m. In October the crane was disassembled and erected elsewhere at the plant to build the second, 120m-high chimney.

December 21, 2011 - Jacobs Engineering Group Inc. announced Tuesday that its Chemetics unit in Pickering, Ontario, Canada, was awarded a design and fabrication contract by Aurubis Bulgaria AD for two proprietary designed sulfuric acid coolers to be installed in its acid plant in Pirdop, Bulgaria.  The work involves the design and fabrication of sulfuric acid coolers. Jacobs worked with Aurubis engineering staff to develop a solution that would allow optimal performance in both distinctly different operating modes.

June 21, 2011 - Aurubis, the largest copper producer in Europe, announced its new investment programme for environmental protection and increasing productivity - "Aurubis Bulgaria 2014".  The project was launched with a symbolic groundbreaking ceremony by Prime Minister of the Republic of Bulgaria Boyko Borisov and the Deputy Prime Minister and Minister of Finance Simeon Dyankov, Minister of Transport Ivaylo Moskovski and His Excellency Matthias Höpfner, German ambassador together with the hosts Peter Willbrandt, Member of the Executive Board of Aurubis AG and Nicolas Treand, Executive Director of Aurubis Bulgaria, in the presence of local and national authorities, diplomats, metallurgy business representatives, the NGO sector etc.  "By providing the funds for this new project, Aurubis Group has put its confidence in the potential of the plant of Aurubis Bulgaria. We are very satisfied with the performance in the last years and we would like to make a step further to rank this plant in the first five smelters worldwide. We are as well confident of the sustainable value of our investment and appreciate the support of the Bulgarian government", states Mr. Peter Willbrandt, Member of the Executive Board of Aurubis AG.  The total investment of the project is EUR 44.2 million and 60% of this amount involves measures for environmental protection with a total capital expenditure of more than EUR 26 million.  The scope of the project, which will be implemented in the next three years, consists of two main focuses - productivity increase and improvement of the environmental performance in the plant to meet also future EU regulations. The main goal is together with productivity improvements in new systems to maintain the best parameters and complete control in terms of gases and SO2 emissions. One of the main activities in the new project,  is construction of an additional gas treatment plant, through which will be further contained and treated exhaust all processes gases that will provide a final consistent solution in this area.  Concrete measures in both directions are:  the expansion element includes installation of additional equipment, improvement of the performance and reliability of the existing production facilities, continuous improvement and optimisation of the production processes; the environmental part includes installation of an additional off-gas treatment plant, capturing of additional sources, changing the internal processes and implementation of best practices in operation.  "At Aurubis Bulgaria requirements and standards are in full compliance with the national and European legislation, because we are following the best available techniques for environmental protection. The new project will put focus on further reduction of emissions. We also stay active social position, which is in the name of protection and the well-being of our employees and the local citizens. I thank to our Board and share holders for the confidence they show to our Bulgarian site." stated Nicolas Treand, Executive Director of Aurubis Bulgaria.  After the privatisation of the copper production site near Pirdop, over € 400 million has been invested in modernising the processes and improving environmental performance. The most significant implemented projects in this area are a secondary gas cleaning system (2008), the construction of a new refinery (2008) and expansion of the slag flotation plant (2010).

December 16, 2008 - Norddeutsche Affinerie AG and Cumerio nv/sa now wish to present the combination to the outside world. The new enlarged company will be called Aurubis. „The name represents all that unites us and makes us strong, our common passion for copper“, said Chief Executive Officer, Dr Bernd Drouven, today in Hamburg.   „Aurubis“ is derived from Latin and means „red gold“. „The name puts in a nutshell what copper symbolizes for us and our customers – a metal of extraordinary value. It is the oldest metal in the world and has always been the cornerstone for progress and civilization. This holds true even today: mobile phones, computers, electricity – nothing would function without copper. This special meaning makes us work with passion on our product. To us, copper not only glitters like gold, it is just as valuable“, continued Drouven.  Norddeutsche Affinerie AG’s well-known logo, the blue triangle, will not be changed. It has a long tradition and originally showed three metallurgical tools. It has been modernised several times in the course of the company’s 142 year history.  The official renaming under German commercial law will not take place until after the official resolution is passed at the Annual General Meeting on 26 February 2009. Until then the shares will also still be listed as Norddeutsche Affinerie AG.  The CEO assured that the new name will express the greater international importance of the company. At the same time it is also a commitment to the employees and the current production sites.

MTPD - Metric Tonne per Day           STPD - Short Ton per Day
MTPA - Metric Tonne per Annum      STPA - Short Ton per Annum
SA - Single Absorption
DA - Double Absorption

* Coordinates can be used to locate plant on Google Earth