Fines extracted from porphyry and dolomitic limestone aggregates production: MgO as fluxing agent for a sustainable Portland clinker production

• Porphyry fines could replace fly ash in a Portland clinker meal.
• MgO could have a positive mineralogical influence on Portland clinker production.
• MgO in combination with alkali and SO3 has fluxing activities.
• The fluxing effect promotes the alite formation.
• A decrease of the liquid formation temperature is noticeable by the fluxing effect.
• Finetuning of MgO (wt%) up to 2.0–2.5 wt% in Portland clinker could be recommended.

This paper aims to examine the use of fines and sludge generated out of the production of porphyry and dolomitic limestone as an alternative raw material for Portland clinker kilns with enumeration of possible limitations. The possibility to generate a raw material with a stable compositional variation was investigated and simulations were carried out to maximise their use in clinker kilns. Furthermore, experimental clinkers were produced with dosages that were esteemed as realistic by the numerical simulations. The final clinkers were fully analysed and evaluated on possible mineralogical influences.