Published: October 16, 2019

Tapojärvi Oy received an international innovation award at the Global Slag Conference in Germany on Friday. The award was granted for research on a slag-based geopolymer.

Tapojärvi has an ongoing a Cleantech project aimed at developing slag-based geopolymer products as well as designing, implementing and monitoring test structures.

The geopolymer surface structure is a dense, water- and oxygen-proof structure that can be used to cover the sulphidic waste rock piles of mines. In Finland, HDPE film has typically been used for this purpose.

“We are testing the functionality of the geopolymer under real conditions in Kittilä, where we built a test structure in September 2018. The performance of the test structure will be monitored at least until the end of 2022. Some of the surface of the test structure will also be covered with soil”, says Juha Koskinen, Development Manager at Tapojärvi Oy.

In addition to developing the utilisation of steel industry side streams, the ten-member research and development unit of Tapojärvi focuses on increasing the material efficiency and recycling rate of electrical and electronic waste as well as the paper and mining industries.

The development team is tasked with creating new products and services, considering sustainable and efficient approaches as well as responding to the development needs of customers.

“We are currently working on 16 different projects aimed at reducing the burden on nature and the use of virgin raw materials”, says Tapojärvi Oy’s Chief Commercial Officer Henri Pilventö.



• A cement-like material developed from stainless steel slag that can be used in concrete-like structures

• The main raw material of the geopolymer is the slag type 0/1 mm, which is created when highly alkaline slag cools down

• Due to its characteristics, this type of slag in question is one of the most difficult to valorise, and it is globally stored and landfilled

• The geopolymer is much cheaper and more environmentally friendly than traditional cement

• A pilot on the usage has been conducted in Kittilä, and so far the results have been excellent

• Small carbon footprint