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

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Acid Plant Database   October 29, 2019

Owner Boliden Harjavalta Oy

Boliden-Logo.gif (2761 bytes)

Location Suurteollisuuspuisto Industrial Park
Background Formerly
- Outokumpu Oy

1944 - Copper factory moved from Imatra to Harjavalta
1945 - Start of the Outokumpu copper factory
1947 - Start up of the Kemira sulphuric acid plant
2004 - Boliden Harjavalta Oy founded

Website www.boliden.se
Plant Harjavalta Smelter
R5 R6 R7 R8?
Coordinates* 61º 19' 4" N, 22º 6' 57" E (site) 61° 19' 15" N, 22° 7' 21" E 61° 19' 12" N, 22° 7' 27.5" E -
Type of Plant Liquid SO2 Plant Metallurgical Metallurgical Metallurgical
Gas Source

- Outotec (Outokumpu) Flash Furnace and Pierce-Smith Converters

- Outotec Flash Furnace Direct Outokumpu Nickel (DON) Process

Flash Furnace Gas (Combined): 27.5% SO2, 0.6% SO3, 7.6% O2, 54.9% N2, 5.7% H2O, 4.4% CO2
Copper Converter Gas: 7.7% SO2, 0.04% SO3, 13.3% O2, 77.9% N2, 1.0% H2O, 0.1% CO2

Plant Capacity

4500 MTPA(1)

Inlet GCL: 75,000 Nm3/h to gas cleaning

500 MTPD(1)

Inlet GCL: 45,000 Nm3/h
Inlet Converter: 69,400 Nm3/h, 8.5-13.5% SO2

1230 MTPD(1)

Inlet GCL: 126,000 Nm3/h
Inlet Converter: 194,000 Nm3/h, 6.8-12% SO2

2240 MTPD
149,000 Nm3/h @14% SO2
SA/DA - DA DA 3/2 DA
99.96% conversion
Emissions - SO2: 1.6 kg/MT
>1000 mg/Nm3 (daily average)
SO2: 0.7 kg/MT 100 ppm SO2
Status Operating Operating Operating Operating
Year Built - 1984 1995 2019
Technology - MECS MECS Outotec
Contractors - - - -
Remarks Hg removal process (Thiosulphate) on flash smelting gas stream only - Autothermal: 7.5%SO2 @75,000 Nm3/h

Total Heat Recovery: 50 MW(1)

  - Modular NOx removal System
Converter Dia.: 10.9 m
3 internal HX
Energy recovery from contact section (25 t/h steam @38 barG
Hot water from strong acid system
Pictures -
 Boliden-Harjavalta-2.jpg (300305 bytes)    Boliden-Harjavalta-PFD.JPG (38047 bytes)
General Boliden Harjavalta comprises two plants – the smelter in Harjavalta, which produces anode copper, and the refinery in Pori, where copper anodes are refined into copper cathodes. At the Harjavalta smelter Boliden Harjavalta also carries out nickel smelting on a tolling basis. The cities Harjavalta and Pori are situated on the western coast of Finland and are at some 30 kilometers' distance from each other. The number of personnel is approximately 415.
The company has a long and creditable tradition starting from the first copper smelter, established in eastern Finland in 1936. It was transferred to Harjavalta during the final stages of the World War II. Today's most used metal recovery method, the flash smelting method, was developed at Harjavalta and implemented in 1949. The copper refinery in Pori has been operating since 1941.
The Harjavalta copper smelter has the nominal annual capacity of 160,000 tonnes of copper. Most of the copper produced is cast into copper anodes for further refining into pure copper cathodes. Sulphur is recovered and sold as sulphuric products.
The nickel smelter of Boliden Harjavalta, operating on a tolling basis, produces nickel matte for customer needs.
The copper anodes are transported by train from Harjavalta to the copper refinery in Pori to be refined into cathodes. The nominal annual capacity of the copper refinery is 125,000 tonnes. Besides copper cathodes, the copper refinery produces e.g. gold and silver.

Best Available Technology (BAT) is a concept and principal used for technology that minimises the environmental impact from production processes and other installations. For many years, the Nordic countries have applied environmental permit procedures based on these principles. The word technology in the BAT principal has a broad interpretation. The word not only includes the technology used, but also the way in which a plant is constructed, designed, built, maintained, operated and decommissioned. The purpose is to prevent emissions by using the most effective technological solutions.“In the environmental permit for the new sulphuric acid plant, operations at the future factory are compared with the EU’s reference BAT documents (BREFs) that describe the best available technology for various industrial sectors. Boliden’s new sulphuric acid plant meets and in certain respects even surpasses the reference points in the BREFs,” project manager Timo Suutari explains.Thanks to the latest technology and improved process management, emissions will not increase despite the fact that production capacity in the future plant will be greater. In particular, the diffuse emissions that can occur during disruptions decrease when the new technologies are put to use. Even noise propagation to local residential areas is reduced.The emission limit for gases from the existing sulphuric acid plant is 680 mg/Nm3 as a daily average, while the corresponding emission limit for the new sulphuric acid plant is 425 mg/Nm3. Using the latest technology, gas concentrations are anticipated to be well below the emission limit. This buffer is necessary despite careful maintenance, as the life cycle of this investment is more than 30 years.The new plant is expected to reduce sulphur dioxide emissions by 20-25 percent. Even the diffuse emissions that can occur during disruptions decrease when the new technologies are put to use.“Sulphuric acid plants tend to be bottlenecks at smelting plants. When the smelter is running at full capacity, the sulphuric acid plants are pushed to the limit, which increases the risk of diffuse emissions. When the washing section at the new plant is completed, emission handling will also be improved, since the sulphuric acid plant can then handle approximately 30 percent larger gas volumes,” says Esa Peuraniemi, Development Manager. When it’s in operation, the new sulphuric acid plant’s cooling water volume will also be reduced by 40 per cent thanks to more effective recycling of waste heat when heat is partially recovered from steam instead of conventional cooling via a heat exchanger. At the same time, the discharge of metals to water will drop by around 10 per cent.

Sulphuric Acid Plant History
1947: Sulphuric Acid Plant #1, 1st unit commissioned
1949: Sulphuric Acid Plant #2, 2nd unit commissioned
1959: Sulphuric Acid Plant #3 commissioned
1970: Sulphuric Acid Plant #4 commissioned
1974: Sulphuric Acid Plant #5 commissioned
1984: Sulphuric Acid Plant #6 commissioned
1995: Sulphuric Acid Plant #7 started
2018: Sulphuric Acid Plant #8 commissioned (Phase 1)
2019: Sulphuric Acid Plant #8 commissioned (Phase 2)
References Kuivala, A., Poijärvi, J. and Virtamen, H., "Expansion of Outokumpu Copper Production|, Copper 95-Cobre 95 International Conference, Volume III - Electrorefining and Hydrometallurgy of Copper, pp. 59-69.

Proposal for Deletion of Hot Spot No. 7: Outokumpu Harjavalta Metals Oy, Harjavalta Plant, March 7, 2003

 Veneranta, T., Peuraniemi, E.J., Latostenmaa, P. and Järvi, J., "Review of Boliden Harjavakta Copper Smelter", Copper 2019, Vancouver, Canada.

News February 14, 2018 - Boliden has decided to expand the Kevitsa copper-nickel mine and Harjavalta copper-nickel smelter. In total, EUR 125 m will be invested until 2020.  "A few years ago we decided to invest in the copper production at Harjavalta and revise our nickel strategy. The Kevitsa copper-nickel mine was acquired in 2016 and is now Harjavalta's most important concentrate supplier. Today's investment decision should be viewed as part of the development of Boliden's overall operations in Finland," says Lennart Evrell, President & CEO.  Boliden invests EUR 80 m in increasing production at Kevitsa from 7.5 to 9.5 Mtonnes per year from 2021. The investment includes a new autogenous mill and peripheral equipment, and a new mill building. The investments will be commenced in 2018 and full production will be achieved in the first quarter of 2021.  "Now that the integration of Kevitsa has been completed, it's time to take the next step. We have substantial Mineral Resources and high grades, but the concentrator's grinding capacity is limiting production. Today's decision is an important step towards maximising the value of Kevitsa," says Mikael Staffas, President Boliden Mines.  Boliden invests EUR 45 m in Harjavalta and Pori in order to increase copper cathode production from 135,000 tonnes to 170,000 tonnes per year. The investments addresses bottlenecks at the Harjavalta smelter as well as an expansion of the Pori copper refinery. Boliden expects to achieve the new capacity in Q1 2020. The copper cathode refining capacity is below that of anode production, and approximately 15,000 tonnes of anode copper is currently being sold externally. Today's investment will enable Harjavalta to refine all of its anode copper in-house.  "Today's decision increases copper production and is part of a combined investment programme between 2017 and 2019 of over EUR 200 m. The investments in a new sulphuric acid plant and modernization of furnaces is ongoing", says Kerstin Konradsson, President Boliden Smelters. 


April 1, 2016 - Outotec Oyj has agreed with the Sweden-based mining and smelting company Boliden on the main design and delivery of proprietary equipment for a sulfuric acid plant to be built in connection with the Harjavalta nickel and copper smelter in Finland. The order has been booked in Outotec’s 2016 first quarter order intake, the value is not disclosed.  The Boliden Harjavalta plant is one of the largest nickel-copper smelters in Europe. The new gas-cleaning and sulfuric-acid-plant solutions designed by Outotec will process off-gas from the smelters into high-grade industrial sulfuric acid. The plant will meet all of the current and planned European environmental requirements through innovative gas cleaning, production of sulfuric acid and highly efficient heat recovery system. In order to recover as much energy as possible, the heat recovery system uses the surplus heat of the SO2 converter and turns it into high-pressure steam. The surplus heat from the drying and absorption section of the acid plant is converted into hot water and then supplied to the adjacent power plant for further use.  The first construction phase of the sulfuric acid plant is expected to be operational in May-June 2018.


December 17, 2015 - Boliden continues to develop its copper-nickel operations as it invests in improved environmental performance and operational efficiency at its Harjavalta smelter. The smelter operates two acid plants that produce sulphuric acid and liquid sulphur dioxide from smelter off-gases formed in the copper and nickel smelting processes. Boliden has decided to invest in a new and more efficient acid plant, using best available technology. The investment program that will run from 2016 to 2019 consists of two parts, the first and now decided part amounts to €65 million. The total investment is estimated at €90 million.

“This investment improves our technical infrastructure, which is fundamental for our long-term competitive position,” said Timo Rautalahti, general manager Boliden Harjavalta. “Continuity of the site together with the improved environmental performance is important for our local community, too.”

With the new plant in operation, the efficiency and environmental performance of Boliden Harjavalta will improve in several areas. SO2 emissions will be reduced by 20%-25 % and cooling water by 40%, as heat is recovered, resulting in higher energy efficiency. In addition, minor bottlenecks will open, especially on the copper line, and make future expansion projects possible on both the copper and nickel line.

January 30, 2009
- The prevailing weak market situation is causing Boliden to implement a reduction in copper metal production at its smelters in Sweden and Finland in the first quarter.  "This is an extreme situation that affects the whole industry, and it is hard to predict how the market is going to develop. The demand for copper and the by-product sulphuric acid is weak," says Svante Nilsson, SVP for Business Area Market.  The reduction, which will be implemented with immediate effect, will see copper metal production cut by approximately 17,000 tonnes in the first quarter of 2009.

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