Geopolymers and Geomaterial Based Binding and Adsorbent Materials
In the Green Mining, energy efficiency and emissions (CLEEN) and zero-waste discussion, the use of geopolymers is an emerging trend. They can be used for the utilization of mining and process industry waste materials into useful products such as concrete (green concrete), fire-proof panels, mine fills, traffic areas, soil stabilization, water purification materials and heavy metal encapsulation. Geopolymer research is constantly increasing internationally.
The aim of the project is to be at the forefront of developing new types of green concrete, binding and adsorbent materials.
Geopolymerization is a synthesis in which aluminosilicate materials react in the presence of alkaline activator to form inorganic polymer. Examples of aluminosilicate materials include many industrial by-products such as fly ash, microsilica and blast furnace slag. Also metakaolin, the calcinated form of clay mineral kaolinite, can be utilized as a raw material. The formed geopolymers are structurally and chemically durable. In the manufacture of such products, materials containing kaolin and usually aluminum silicate, as well as waste products, are crucial.
Environmental protection is constantly becoming more important. Geopolymers made with metakaolin can be used to bind hazardous heavy metals and to encapsulate radioactive waste. Furthermore, this method is believed to be competitive in terms of manufacturing since geopolymers can even form at room temperature.
The focuses of product development are:
The application and optimization of binding materials based on geopolymer in the concrete industry.
Minerals, industrial by-products and geopolymers as an adsorbent material for water treatment.
Soil stabilization; support structures in mines (shotcreting), mine water management, mine fills, and mine access roads
The project will study and process mineral deposits within Kainuu region and by-products from the mining industry, power plants and other industrial processes. The aim of the project is to support the Kainuu region expertise and to develop new production methods and product concepts to ensure that the region’s companies will have the best possible opportunity to organize efficient technological solutions and cost-effective production.
The project will be implemented in cooperation with Kajaani University of Applied Sciences, Cemis Oulu, Kainuun Etu Oy and industrial project partners: Stora Enso Oyj Oulu, Kainuun Voima Oy, Consolis Technology Ab, Aquaminerals Finland Oy, Rudus Oy, Oulu Water Alliance Ltd, Ekokymppi, Pielisen Betoni Oy, Juuan Dolomiittikalkki Oy, and Suomen Valugrilli Oy.
Geopolymerization provides new applications by transforming otherwise unexploited waste materials (e.g. ashes and slags) into useful products. A significant opportunity to decrease carbon emissions exists by partially or totally replacing ordinary Portland cement with geopolymer cements based on raw materials such as metakaolinite and other pozzolanic materials (e.g. modified fly ash). Therefore, geopolymer products will advance the cement industry’s attempts to decrease its carbon footprint. CO2 emissions could decrease to a level as low as 1/10 compared to the traditional cement production.
In addition, polymers based on fly ash adsorb different types of cations, anions and complex ions in water solutions and their efficiency in water purification has been successfully tested in previous research projects.
The project will develop manufacturing technology resulting in:
The widespread replacement of Portland cement with geopolymer cement in various types of construction products such as concretes and mortars.
The use of by-products of the energy, mining and paper industry as soil-stabilizers and mine fills.
Sulfate and ammonium adsorbents including minerals, industrial by-products and geopolymers and a survey to examine whether geopolymers and other materials can be used to remove other toxic substances including organic compounds from landfill leachate. The project will further develop water purification granulation technology.
An encapsulation method for binding and stabilizing radioactive and heavy metal substances from mines and nuclear power plants into an insoluble structure.
The project will assess the quality of attained products from both a technical and environmental point of view.
The targets and beneficiaries of product development comprise:
Construction sector with regard to new, green concretes, mine fill products, and soil stabilizers.
The use of ashes, slags and industrial minor flows in new products.
Removal of heavy metals from waste and circulation water in the mining industry.
Increasing material efficiency in mining industry concentration processes.
The foundation and base materials for refuse tips and basins.
New products for more efficient and environmentally friendly community water processing.
New active materials such as multistage adsorbents for the encapsulation of heavy metals and radioactive substances.
The project creates uses for the region’s mineral deposits and power plant ashes, which once refined will have extensive local and global markets.