In order to obtain better carbonation effect, extraction behavior of slag batch is necessary to study. Relevant parameters like selective extraction yield were originally discussed. The relationship between selective ...In order to obtain better carbonation effect, extraction behavior of slag batch is necessary to study. Relevant parameters like selective extraction yield were originally discussed. The relationship between selective extraction yield and conversion ratio was systemically focused on. The results show that alkaline earth metal conversion ratio is changed with leaching time and NH4CI concentration by first order exponential, and the maximum conversion for calcium keeps about 68% at 120 min in 0.4 mol/L NH4C1 solution, while leaching temperature and particle size have a linear effect on conversion ratio. Selective extraction yield of calcium is more than 93%, and the value of Mg is less than 5%. Apparent layer bands of silicon and calcium appear in the surface area through morphology detection of slag after leaching, and the case for 38-75 μm slag batch is more obvious than 75 150 μm slag and slag with larger particle size when leaching in 0.4 mol/L NH4Cl solution for 90 rain at 60 ℃.展开更多
The influences of different alkaline conditions on the kinds and morphologies of steel slag＇s hydration products, Ca（OH）2 con- tent of hydration products, pore stiucture of hardened paste, non-evaporable water cont...The influences of different alkaline conditions on the kinds and morphologies of steel slag＇s hydration products, Ca（OH）2 con- tent of hydration products, pore stiucture of hardened paste, non-evaporable water content of hydration products, and strength of steel slag mortar were investigated by changing the initial alkalinity of the hydration condition of steel slag. The results showed that increasing the initial alkalinity of hydration condition can promote the early hydration of steel slag＇s active com- ponents （e,g., C2S, C3S, and C12A7）, but it has little influence on their late-age hydration degree. The hydration degree of non-active components （e.g., RO phase and Fe304） of steel slag is very low even under strong alkaline condition with pH value of 13.8. The excitation effect of alkaline condition on the early hydration of steel slag is more obvious with the increase of pH value, but the kinds of steel slag＇s hydration products are not influenced by changing the alkaline condition. The amount of steel slag＇s hydration products is limited, so the strength of alkali-activated steel slag mortar is very low though the strong al- kaline condition significantly promotes the early hydration of steel slag. Steel slag is not an ideal raw material for alka- li-activated cementitious material.展开更多
基金Acknowledgements This study was financially supported by National Natural Science Foundation of China （No. 21346011） and the Key Project of Natural Science foundation Research Plan of Shaanxi Province （No. 2013JZ014）.
基金This study was financially supported by National Natural Science Foundation of China （No. 2t346011）, the Key Project of Natural Science foundation Research Plan of Shaanxi Province （No. 2013JZ014）, and Building Materials Branch, State Key Laboratory of Architecture Science and Technology in West China （No. K09129）.
基金Project(2006BAE03A07)supported by National Key Technology Research and Development Program of 11th Five-year Plan of China
文摘In order to obtain better carbonation effect, extraction behavior of slag batch is necessary to study. Relevant parameters like selective extraction yield were originally discussed. The relationship between selective extraction yield and conversion ratio was systemically focused on. The results show that alkaline earth metal conversion ratio is changed with leaching time and NH4CI concentration by first order exponential, and the maximum conversion for calcium keeps about 68% at 120 min in 0.4 mol/L NH4C1 solution, while leaching temperature and particle size have a linear effect on conversion ratio. Selective extraction yield of calcium is more than 93%, and the value of Mg is less than 5%. Apparent layer bands of silicon and calcium appear in the surface area through morphology detection of slag after leaching, and the case for 38-75 μm slag batch is more obvious than 75 150 μm slag and slag with larger particle size when leaching in 0.4 mol/L NH4Cl solution for 90 rain at 60 ℃.
基金supported by the National Natural Science Foundation of China (Grant No. 51108245)the National Basic Research Program of China ("973" Project) (Grant No. 2009CB623106)
文摘The influences of different alkaline conditions on the kinds and morphologies of steel slag＇s hydration products, Ca（OH）2 con- tent of hydration products, pore stiucture of hardened paste, non-evaporable water content of hydration products, and strength of steel slag mortar were investigated by changing the initial alkalinity of the hydration condition of steel slag. The results showed that increasing the initial alkalinity of hydration condition can promote the early hydration of steel slag＇s active com- ponents （e,g., C2S, C3S, and C12A7）, but it has little influence on their late-age hydration degree. The hydration degree of non-active components （e.g., RO phase and Fe304） of steel slag is very low even under strong alkaline condition with pH value of 13.8. The excitation effect of alkaline condition on the early hydration of steel slag is more obvious with the increase of pH value, but the kinds of steel slag＇s hydration products are not influenced by changing the alkaline condition. The amount of steel slag＇s hydration products is limited, so the strength of alkali-activated steel slag mortar is very low though the strong al- kaline condition significantly promotes the early hydration of steel slag. Steel slag is not an ideal raw material for alka- li-activated cementitious material.
