Study the effects of P2O5 mineralization additives on cement clinker quality at low calcination temperature 1300oC and 1400oC

Abstract

In this study, the cement clinker was mixed with P₂O₅ mineralization additives with the rate of 1.0% and 2.0% (compared to the content of cement clinker without P₂O₅ mineralization additives which was called the control sample) and then this mixture was calcined at temperatures of 1300^oC and 1400^oC by gas furnace. The mechanical properties of the prepared cement samples were determined: density and free lime content of clinker; normal consistency and setting time of cement paste; soundness and compressive strength of hardened cement paste. The results showed that, the cement samples mixed with P₂O₅ mineralization additives had free lime content (1.36-1.91%) which was lower than the control sample (1.39-2.34%). The setting time significantly reduced compared with that of the control sample. The soundness of cement samples mixed with P₂O₅ reache 0.55-1.2 mm in accordance with TCVN 4031:1985 and it was smaller than that of the control sample. The compressive strength of hardened cement paste sample which mixed with P₂O₅ of 1.0% (at the age of 28 days) reached 25.23 N/mm² at 1300^oC (the control sample reached 24.32 N/mm²) and reached 28.6 N/mm² at 1400^oC (the control sample reached 27.00 N/mm²). The study showed that, The using of P₂O₅ mineralization additives with appropriate content will bring to the improved quality of the cement clinker.