Background and objectives of the project
Aim of the project is to control the colour of different calcined clays varying the process atmosphere and research the associated effects on the emissions and mineral composition as well as the stability of newly formed minerals, as well as their potential influence on the durability of clay-containing cements.
Clays with different Fe-bearing minerals (hematite, magnetite, siderite, limonite, pyrite / marcasite, jarosite) and organic contents, partially prepared in different feed grain sizes, are going to be calcined and cooled down under changing redox conditions. Emissions, colour, mineral content and reactivity will be analysed. Additionally, stability of specific new mineral phases and their influence on colour and durability (rust, inner sulphate attack, late ettringite formation, etc.) are tested by storage in moist environment. Finally first upgrade tests are planned in an application laboratory of a plant manufacturer.
