Composition design and pilot study of an advanced energy-saving and low-carbon rankinite clinker

In order to save energy and reduce greenhouse gas emission, a new type of clinker with a self-pulverization ability was successfully designed, which mainly consisted of rankinite (3CaO·2SiO2 or C3S2) and auxiliary γ-dicalcium silicate (γ-2CaO·SiO2 or γ-C2S). Furthermore, a pilot study was also carried out in a Φ 0.8 × 10 m rotary kiln. The cement was prepared by grinding the clinker to control the target particle size, and then it was hardened by carbonation. The suitable composition range of the clinker was 53–55% CaO, 38–41% SiO2 and 4–9% Al2O3. The optimum clinkerization temperature range was 1260–1320 °C. The powder clinker had a BET surface area of 365.3 m2/kg. After being carbonated with CO2 for 7 d, the flexural and compressive strengths of cement mortar reached 13.5 MPa and 57.4 MPa, respectively. The weight percentage of CO2 in the 3-day carbonated specimen could be as high as 18.9%. The overall results well demonstrate that the developed new-type clinker is both energy-saving and greenhouse gas reducing, thereby holding great promise for applications in construction industries.