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Through further processing and the use of innovative technology, we turn waste into value-creating products.

A circular approach 

Boliden has created value from residual products for a number of years. Further processing and advanced technologies enable us to get the most out of our smelters’ processes. By investing in innovative solutions, we can extract the maximum amount of metal possible from the raw material, while also reducing the amount of waste that needs to go to landfills.  

Further processing 

A circular approach creates value from residual products, whether they come from our own operations or other industries. This means that we can now offer a wide range of by-products. These, in turn, fulfill important functions in society. Our by-products come primarily from the Rönnskär and Harjavalta smelters. At Rönnskär we extract copper sulfate, zinc clinker, and iron sand from slag from copper production. At Harjavalta we extract copper sulfate and copper telluride. These are just a few examples of the further processing of materials at our smelters. 

Copper sulfate

Copper sulfate takes the form of blue crystals that are formed when sulfuric acid reacts with copper. We sell copper sulfate as a reagent to the mining industry and are ourselves a major user of the product.

Zinc clinker

Zinc clinker is a yellowish powder and a slag product from our copper production. We sell this to other smelters that can then extract zinc from the powder.

Copper telluride

Copper telluride is a black powder that can be used as an alloying element in the steel industry and in rubber production.

Iron sand

One of our contributions to the circular economy is iron sand.
A by-product with very good ground insulation and drainage properties.

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Selenium is a black powder used in medicine, for soil improvement, paint manufacturing, coloring and decolorizing glass, and in the steel industry.

Crude nickel sulfate

Boliden also produces crude nickel sulfate, which is a greenish-yellow powder and an important by-product of copper production.

PGM concentrates

PGM or Platinum Group Metals is a collective term for palladium, platinum, rhodium, iridium, ruthenium, and osmium. PGM are used for catalytic converters in the automotive industry but also in the jewelry and electronics industries.

Links and documents


Peter Johansson
Manager Sales Iron Silicates

[email protected]
+46 (0) 70 602 3126

Get in touch


Boliden Head Office

Boliden Group
Klarabergsviadukten 90
P.O. Box 44, SE-101 20 Stockholm 
Tel: + 46 8 610 15 00
Fax: + 46 8 654 80 90