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BIA-Brukerstyrt innovasjonsarena

Geopolymer Concrete Based on Mining Residues

Alternative title: Geopolymer sement basert på gruveavfall

Awarded: NOK 6.8 mill.

Concrete is the most widely used construction material in the world. Concrete consists of cement and aggregates (stone and gravel), where the cement acts as the binder that glues the aggregates together and ensures the concrete’s high compressive strength. However, a challenge is that Portland cement, which is the type of cement normally used as binder, emits significant amounts of CO2 during production. In fact, Portland cement production is responsible for 6-8 % of all anthropogenic CO2 emissions worldwide. Consequently, there is a need to find alternative binder materials for concrete that have considerably lower CO2 emissions than Portland cement. Saferock is developing a new type of concrete completely without Portland cement. The binder in Saferock’s concrete is an alkali-activated cement, sometimes called “geopolymer”, where mine tailings and other industrial waste materials are used as precursors to make the binder. This results in an 80 % reduced CO2 footprint compared to Portland cement. In this project, Saferock has collaborated with the mining company Titania to use tailings from their mine to make cement-free concrete. Key persons from Titania have contributed with valuable information on for example mineralogy of the tailings, and the cooperation has been fruitful throughout the project period. By using mine tailings from Titania to make concrete, their need for landfills will be considerably reduced. Moreover, this also paves the way for potential future collaborations with other mining companies elsewhere in Norway, where tailings from other mines can be used to make binder for concrete instead of being deposited at landfills. Saferock has also collaborated with the University of Stavanger in this project, for example by having a common Post.Doc., and in addition wrote two Master students in concrete technology their thesis about Saferocks concrete based upon experiments they performed in Saferock’s laboratories. This IPN-project has been crucial for Saferock’s ongoing product development, which so far has focused on “simple” concrete products such as paving stones, slabs, and screed. The outcome of this project is that Saferock is now very close to introduce its first concrete product into the marked.

In this project, Saferock is developing a new type of sustainable concrete without Portland cement. As concrete is the most widely used construction material in the world, and production of Portland cement is one of the main causes of anthropogenic CO2 emissions, there is a need to develop new concrete products without Portland cement. Therefore, future use of a new concrete completely without Portland, such as Saferock’s new concrete, will have a conservable positive impact on the environment. Moreover, the binder material in Saferock’s concrete is based upon mine tailings, i.e., residue from mining activities, where this surplus residue is normally disposed of in landfills, causing various environmental challenges. Due to the current and future high activity level in the mining industry, the amounts of such surplus tailings to be deposited is expected to increase considerable. Consequently, Saferock’s new concrete may contribute to reducing the need for landfills and thus have another major positive impact on the environment. In addition to these future environmental impacts, this IPN-project has been crucial for Saferock as a small start-up company. The project has resulted in product developments of concrete without Portland cement, and the outcome of the project is that Saferock is now very close to introduce its first product into the marked. For Saferock, this project has been a success.

Concrete is the main construction material used on earth. Ordinary Portland Cement (OPC), representing as € 620 bn/year business, works as the glue that binds the aggregates in concrete together. However, the industry is facing challenges as OPC production is responsible for 6-8% of all human-made global carbon emissions, more than 3 billion tons CO2/year. The production also consumes a large amount of natural limestone and releases SO2, SO3 and NOx that can cause acid rain. Adding to the challenge, the price of fly ash, a key ingredient in mixed cements, is also increasing due to coal power plants being shut down in Europe. SafeRock is developing unique rock-based geopolymer binders, providing more than 80% reduction of the CO2 footprint compared to OPC due to no calcination, and offering favorable mechanical properties. The project will optimize SafeRock’s mix design by broadening the choice of binders, hardeners and additives, cater to handling and upscaling challenges in relation to production, storage, and loading/offloading, and initiate an effort to create value from a circular economy involving mining residues. The core team of SafeRock has very high competencies in geopolymeric materials, regulations and practical building experience. Industry players along the value chain have joined the team on the road to market. UiS is a natural R&D partner providing expertise, infrastructure and validation of results. The ultimate ambition is for the technology to be suitable for widespread international use in the building and construction industry. Market entry is planned based on using the material as screed (“avrettningsmasse”) and in other non-structural applications. Taking advantage also of developments in the areas of materials science, processing engineering, structural engineering, infrastructure systems, and market perspectives, the innovation has the potential to be a breakthrough in sustainable building materials.

Funding scheme:

BIA-Brukerstyrt innovasjonsarena