The silver content is extracted through flotation and filtration, and is refined to a silver concentrate, which is then processed by our own smelter or is sold on to external customers.
“This new process is of great importance for Boliden Kokkola since it will improve both profitability and raw material efficiency. Silver concentrate will now be one of Boliden Kokkola’s most valuable by-products”, says Jarmo Herronen, General Manager at Boliden Kokkola.
Second largest zinc plant in Europe
With its annual production capacity of 315,000 tonnes per year Boliden Kokkola is the second largest zinc plant in Europe.
The zinc plant in Kokkola began operations in 1969 and its main products are pure zinc and zinc alloys. Since 2010 the smelter has also produced sulphuric acid.
The majority of the zinc concentrate used by the plant comes from Boliden’s own mines in Sweden, Ireland and Finland, but concentrates are also purchased from other mining companies in Europe, North America and Peru.
About 85 per cent of production is exported. The most important market areas are Northern and Central Europe.
Boliden Kokkola is committed to continuously and systematically improving its operations. As a result, the company is today one of the most modern zinc smelters in the world.
The latest link in this chain of development is a silver recovery plant being built next to the zinc smelter. With this new process stage, silver contained in the zinc raw material can be recovered as silver concentrate, which is a valuable product. The recovery of silver in Kokkola has begun in 2014.
The zinc plant is the largest private employer in Kokkola, with more than 500 employees.