Slagstock European project confirms the use of steel slags as a feasible storage material for the thermo-solar industry

The IK4-AZTERLAN Metallurgical Research Centre has participated in this outstanding project within the 7th SOLAR-ERA.NET European framework programme, along with an important international consortium led by CIC Energigune.

 

Steel slags are one of the most voluminous industrial wastes. Only in the European Union 6.5 million tonnes are yearly generated and in the Basque Country, where the steel industry is one of the most entrenched activities, about 300,000 t are yearly deposited in landfill.

To improve slag recovery rates, the Slagstock “Low-cost sustainable Thermal Energy Storage Systems Made of recycled Steel Industry Waste” Project consortium has focused its research on different ways to transform this waste for an innovative field of application of high added value: the storage of thermal energy for the solar concentration industry through the compact bed thermocline.

To achieve this, the organizations and companies involved in the project have had to cope with important challenges such as the transformation and synthesis of the new slag based thermal energy storage materials, the conceptual design and the construction of a pilot system of storage for its testing, as well as the development and the technical characterization of the materials, taking into consideration the properties that lead the thermo-physical behaviour of such systems.

IK4-AZTERLAN Metallurgy Research Centre has developed within the project different steel slag transformation processes, using the slag from the steel company ARCELORMITTAL. The Technology Centre has also participated in the characterization of these materials in terms of the most important chemical, mechanical and thermophysical properties involved in heat loading and unloading operations that ensure their suitability and viability for the application pursued.

After 4 years of intensive research work, the Slagstock project has come to an end with a satisfactory evaluation of the solution developed, considering that the steel slags are a valid source that meets the properties and qualities required, compared to the main thermal storage materials nowadays used.

The European project Slagstock has been financed by the Spanish Ministry of Economy and Competitiveness through the 7th European Framework Programme SOLAR-ERA.NET. Led by the CIC ENERGIGUNE, it also has had the participation of the University of Nuremberg FRIEDRICH ALEXANDER, IK4-AZTERLAN and PAUL SCHERRER INSTITUTE research centres, along with the companies ARCELORMITTAL, NOVARGI and SAS TELLUS CERAM.

 

 

Different kinds of shapes (pebbles) of the heat collector material, resulting from the different transformation processes applied to the steel slags.