By carbothermal reduction of Mg O with black carbon as reduction agent at a high temperature,Mg O was deposited on the surface of Mg O- Ca O clinker（ as coating） to improve the clinker ＇s hydration resistance. In t...By carbothermal reduction of Mg O with black carbon as reduction agent at a high temperature,Mg O was deposited on the surface of Mg O- Ca O clinker（ as coating） to improve the clinker ＇s hydration resistance. In the paper,effect of deposition temperature and holding time on the hydration resistance of the treated Mg O-Ca O,the deposition mechanism and Mg O coating kinetics were investigated with hydration resistance test,X-ray diffractometry（ XRD） and scanning electronic microscope（ SEM）. Results showed Mg O coating grew in a2D mode on the surface of Mg O- Ca O particles; the Mg O coating improved the hydration resistance of the coated Mg O- Ca O clinker,and the coated clinker would become stronger when coated at higher deposition temperature and longer holding time. The measurements also found that Mg O deposition process varied with the deposition temperature： it was mainly a chemical-controlled process at temperatures between 1 400- 1 500 ℃,with an apparent activation energy（ AAE） of 97. 8kJ·mol^（-1）; it would change into a diffusion-controlled process when the temperature rising to 1 500- 1 600 ℃,with apparent activation energy of 19. 2kJ·mol^（-1）.展开更多
基金supported by The Industrial Research Project of Shaanxi Province , China under Grant No. 2012k07-07
文摘By carbothermal reduction of Mg O with black carbon as reduction agent at a high temperature,Mg O was deposited on the surface of Mg O- Ca O clinker（ as coating） to improve the clinker ＇s hydration resistance. In the paper,effect of deposition temperature and holding time on the hydration resistance of the treated Mg O-Ca O,the deposition mechanism and Mg O coating kinetics were investigated with hydration resistance test,X-ray diffractometry（ XRD） and scanning electronic microscope（ SEM）. Results showed Mg O coating grew in a2D mode on the surface of Mg O- Ca O particles; the Mg O coating improved the hydration resistance of the coated Mg O- Ca O clinker,and the coated clinker would become stronger when coated at higher deposition temperature and longer holding time. The measurements also found that Mg O deposition process varied with the deposition temperature： it was mainly a chemical-controlled process at temperatures between 1 400- 1 500 ℃,with an apparent activation energy（ AAE） of 97. 8kJ·mol^（-1）; it would change into a diffusion-controlled process when the temperature rising to 1 500- 1 600 ℃,with apparent activation energy of 19. 2kJ·mol^（-1）.
