Densification and improvement of slaking resistance of calcia clinker by addition of ZrO2

CaO clinker was sintered from CaCO3 powder (with purity of more than 98%) at 1300-1600degreesC by the addition of ZrO2 to 1% (molar ratio). ZrO2 reacted with CaO to form CaZrO3 at all temperatures. The formed CaZrO3 was mainly located between CaO grains when the sample was sintered at a lower temperature (1300degreesC), whereas it was mainly located within CaO grains when the sample was sintered at higher temperatures (above 1400degreesC). The growth of CaO grains was inhibited by the addition of ZrO2, resulting in poor densification when the sample was sintered at a lower temperature (1300degreesC). When the sintering temperature Was raised, grain growth and densification were promoted and the relative density of the clinker reached a maximum at 1500degreesC. The slaking test showed a better slaking resistance when the clinker was sintered at 1400-1600degreesC by the addition of ZrO2.