Provides green growth for both cement, concrete, plants, and business

At the top of Eramet Norway's agenda are emission cuts and the reuse of by-products. Two years ago, the idea of using the by-product silicomanganese slag, SiGS (Silica Greenstone), was introduced. It has proven to have value in both agriculture and the construction industry as a greener alternative.

Each year, Eramet Norway produces approximately 300,000 tons of SiGS, a by-product from the production of silicomanganese. By crushing SiGS into smaller fractions, it can be utilized for various purposes, including as a raw material in cement, concrete, soil improvement agents, and as a base layer for road construction.

Reducing Greenhouse Gas Emissions

-We are incorporating the material into a circular economy. We have a clear philosophy to improve in the areas of climate, energy, environment, and circular economy, says Leif Hunsbedt of Eramet Norway Kvinesdal.

Increased utilization of this valuable by-product can indeed reduce greenhouse gas emissions and preserve biodiversity.

Value in Multiple Areas

After participating in the Spin-out project by Gunnar Kulia (Eyde Cluster) and Magne Dåstøl from Styrhuset, Hunsbedt realized that SiGS could have value in several areas, in a circular economy approach.

-This aligned well with our ambition to improve in circular economy. Magne Dåstøl is incredibly knowledgeable in this area. He can also take much of the credit for the development of microsilica, which he worked on during his 40 years at Elkem. He was enthusiastic and eager about this, says Hunsbedt.

-The starting point was to take a closer look at the slag’s physical and chemical properties. These pointed towards potential uses in cement/concrete and soil improvement, says Dåstøl.

Based on this, contact was made with some research institutions, both domestically and abroad, followed by laboratory tests. These tests consistently showed quite positive results.

Reducing the Carbon Footprint by 180,000 Tons of CO2

SiGS, or Green stone, as they call the by-product at Eramet, can replace cement or be used as part of a mixture. This significantly reduces CO2 emissions, and SINTEF is involved in parts of the project. Cement production is one of the largest man-made sources of CO2 emissions globally. By using the SiGS produced by Eramet Norway, the carbon footprint could be reduced by 180,000 tons of CO2 annually, according to Hunsbedt.

-This is important for cement producers, who also face challenges in sourcing raw materials, he says.

Better Plant Growth

Greenstone has also been shown to have a positive effect on plant growth. As a result, the product can be used in agriculture, entering an entirely new market.

-We are working to increase the value creation of SiGS through new applications and a new market. In the long run, we hope this will also contribute positively to the balance sheet, says Hunsbedt.

In addition to SINTEF, the University of Agder and the Research Council of Norway are also involved in the Greenstone project.

Needs Large-Scale Verification

Dåstøl emphasizes that there is still a long way to go from laboratories and greenhouses to the market. The trials must be verified on a large scale, potential limitations such as standards and environmental requirements must be met and overcome, the products must be tailored to customer requirements and logistics—and not least, profitable business models must be developed. However, at present, many indicators are positive.

-And I would like to add that, from my perspective, I have experienced support and enthusiasm from the company’s side that I have rarely seen in Norwegian industry. This may be one of the most important factors for continued success. To quote an old Chinese proverb: ‘When the winds of change blow, some seek shelter. But others build windmills! concludes Dåstøl.