1976 - Boliden-Norzink Hg removal system installed
1995 - New larger star coolers installed to reduce gas temperature from previous 30-35ºC to 20ºC.  Cooling sea water temperature: 4-10ºC.  Lower temperature to improve Hg removal by lowering Hg vapour pressure in Boliden-Norzink Hg removal system.  Lead star coolers were selected over stainless steel heat exchangers because sea water is used for cooling and lead inhibits growth of organisms.  Engineering by Hugo Petersen.   Fabricated by Apparatebau Goslar.
- Product Hg reduced from 0.4-0.8 ppm to < 0.3 ppm
- New WESP installed
  - Particle: <1 mg/Nm³ @ 60,000 Nm³/h
  - Acid Mist: <15 mg/Nm³
  - Boliden Etitube WESP: 91 tubes, 150 mm dia., 5 m long
  - Material: 254 SMO 

 

Photo Courtesy of Jarles Vines

The zinc plant Boliden Odda was established in 1924. The plant is situated on a peninsula, approximately 4 kilometers north of Odda. The main products are zinc and aluminum fluoride. Currently the annual capacity is 160,000 and 40,000 tonnes respectively, and the plant is one of the world's most cost-efficient zinc producers. In addition Boliden Odda also produces sulphuric acid.
The zinc plant was modernized during 2003 and 2004, a EUR 88 million investment.
Boliden Odda has its own ice-free port, which is used for receiving zinc concentrates and other raw materials and for shipping refined zinc and aluminum fluoride powder.
More than 90 percent of the zinc produced at the Boliden Odda plant is exported, mainly to Scandinavia, the UK and other European countries. The aluminum fluoride powder is mainly sold to Norwegian aluminum smelters. 

October 16, 2024 - Swedish mining company Boliden has pushed back the opening date of its Odda zinc smelter capacity additions due to delays at the roasting facility. The ramp-up to the new production level will now occur at the end of the first quarter of 2025 (Q1 2025), increasing the cost of the project by €100m ($110m).  In 2021, Boliden decided to invest in its Odda zinc smelter with the aim of increasing annual production capacity from 200,000 to 350,000 tonnes. Upgrades included improvements to electricity supply and quay infrastructure, a new roasting facility, a new sulphuric acid plant, expansion and modernisation of the leaching and purification plant, a new tankhouse and expansion of the foundry.  The start of expanded operations was due in the Q4 2024, but the issues at the roasting facility have resulted in the delay.  According to Boliden, the investments at Odda are expected to generate an additional €150m in annual earnings before interest, taxes, depreciation and amortization (EBITDA), based on Boliden’s long-term prices and market conditions.  Mikael Staffas, president and CEO of Boliden, said: “The cost increase is mainly due to the extra time and additional fixed costs incurred” during the ongoing renovation of the roasting facility.  Zinc is primarily used in the galvanising process, which protects iron and steel from rusting. It is important in construction as it extends the life of steel. In recent years zinc has become associated with the energy transition as it can be used to make zinc-ion batteries. Zinc-ion batteries are more thermally stable than lithium-ion batteries, minimising potential fire risks across the battery supply chain.  According to Mining Technology’s parent company, GlobalData, global zinc production is expected to grow by 2% in 2024. China, Peru, Australia, India and the US were the world’s top five producers of zinc in 2023, accounting for 66.2% of global production.  "Boliden delays opening of new capacity at Odda zinc smelter" was originally created and published by Mining Technology, a GlobalData owned brand.

2001 - Rio Tinto and Boliden have completed the sale of the Norzink zinc smelter in Norway to Outokumpu for US$180 million cash.  Rio Tinto and Boliden each owned 50% of Norzink.