Through laboratory test, the relationships among change of compactibility, liquid/plastic limit, free swell, swell ratio without load, california bearing ratio (CBR) and soakage (after being soaked in water), and mix-...Through laboratory test, the relationships among change of compactibility, liquid/plastic limit, free swell, swell ratio without load, california bearing ratio (CBR) and soakage (after being soaked in water), and mix-ratio of quick lime and time were studied. The results show that optimum water content, plastic limit and CBR of high liquid limit clay improved by quick lime increase with the increase of mix-ratio of quick lime, while the maximum dry density, liquid limit, plasticity index, soakage (after being immersed in water), free swell, and swell ratio without load decrease with the increase of mix-ratio of quick lime. Plastic limit of high liquid clay improved by quick lime gradually increases with time, while the liquid limit, plasticity index, free swell and swell ratio without load gradually decrease with time. When the mix-ratio of quick lime exceeds 2%, after 14 d, swell ratio without load of the improved clay is zero, its free swell is about 30% of that of untreated soil, and its plasticity index is less than 26 for sub-grade material, satisfying the requirement by 'Specifications for Design of Highway Subgrade'.展开更多
Lime, which is a frequently used activating agent of fly ash (FA), has two main states: slaked lime and quick lime. We studied the effects of slaked lime and quick lime on activating FA, and discussed their kinetics. ...Lime, which is a frequently used activating agent of fly ash (FA), has two main states: slaked lime and quick lime. We studied the effects of slaked lime and quick lime on activating FA, and discussed their kinetics. The results show that slaked lime is more beneficial for activating FA than quick lime given the condition of equivalent CaO amount. The use of slaked lime has superiority in technology and economy on activating FA. Theoretical analysis revealed that the kinetic constant of the activation reaction using slaked lime is higher than using quick lime, credited to the better volume stability and fineness, and smaller water demand of slaked lime.展开更多
The hydration of quick lime and the sulfation of hydrated lime were carried out for verification of relationship between the reactivity of quick lime and the properties of hydrated lime as a sorbent. The effect of rea...The hydration of quick lime and the sulfation of hydrated lime were carried out for verification of relationship between the reactivity of quick lime and the properties of hydrated lime as a sorbent. The effect of reactivity of quick lime was investigated with the change of calcination temperature and time. Results obtained showed that the temperature rise during the hydration of quick limes varied from 31 to 69℃ with the variation of calcination temperature and time. The specific surface area and the sulfation ability of hydrated lime prepared by hydration of quick lime showed a proportional relationship with the reactivity of quick lime. The hydrated lime which was prepared by hydration of quick lime calcined at 1100℃ had the highest reactivity and showed 41.53 m^2/g of the specific surface area, 0.16 cm^3/g of the pore volume and 87% of the removal efficiency for SO2 removal,展开更多
The urgent need to mitigate climate change impacts and achieve net zero emissions has led to extensive research on carbon dioxide(CO_(2))-capture technologies.This study focuses on the kinetics of CO_(2)capture using ...The urgent need to mitigate climate change impacts and achieve net zero emissions has led to extensive research on carbon dioxide(CO_(2))-capture technologies.This study focuses on the kinetics of CO_(2)capture using solid adsorbents specifically through thermal gravimetric analysis(TGA).The research explores the principles behind TGA and its application in analyzing adsorbent performance and the significance of kinetics in optimizing CO_(2)-capture processes.Solid adsorbents have gained significant attention due to their potential for efficient and cost-effective CO_(2)capture.Therefore,three different types of adsorbents,namely calcium-,tin-,and zirconium-based ones(quicklime:CaO,potassium stannate:K_(2)SnO_(3),and sodium zirconate:Na_(2)ZrO_(3)),in adsorbing high-temperature carbon dioxide were investigated;their quality and performance by various factors such as price,stability,non-toxicity,and efficiency are different.The diffusion models and geometrical contraction models were the best-fitted models to explain the kinetic of these solid adsorbents for high-temperature CO_(2)sorption;it means the morphology is important for solid adsorbent performance.The minimum energy needed to start a reaction for K_(2)SnO_(3),Na_(2)ZrO_(3),and CaO,is 73.55,84.33,and 86.23 kJ·mol^(-1),respectively;with the lowest value being for potassium stannate.The high-temperature CO_(2)adsorption performance of various solid adsorbents in regard with the rate of reaction followed the order of K_(2)SnO_(3)>CaO>>Na_(2)ZrO_(3),based on experiments and kinetic studies.展开更多
文摘Through laboratory test, the relationships among change of compactibility, liquid/plastic limit, free swell, swell ratio without load, california bearing ratio (CBR) and soakage (after being soaked in water), and mix-ratio of quick lime and time were studied. The results show that optimum water content, plastic limit and CBR of high liquid limit clay improved by quick lime increase with the increase of mix-ratio of quick lime, while the maximum dry density, liquid limit, plasticity index, soakage (after being immersed in water), free swell, and swell ratio without load decrease with the increase of mix-ratio of quick lime. Plastic limit of high liquid clay improved by quick lime gradually increases with time, while the liquid limit, plasticity index, free swell and swell ratio without load gradually decrease with time. When the mix-ratio of quick lime exceeds 2%, after 14 d, swell ratio without load of the improved clay is zero, its free swell is about 30% of that of untreated soil, and its plasticity index is less than 26 for sub-grade material, satisfying the requirement by 'Specifications for Design of Highway Subgrade'.
基金Funded by Natural Science Foundation of China under the grant No. 50672137
文摘Lime, which is a frequently used activating agent of fly ash (FA), has two main states: slaked lime and quick lime. We studied the effects of slaked lime and quick lime on activating FA, and discussed their kinetics. The results show that slaked lime is more beneficial for activating FA than quick lime given the condition of equivalent CaO amount. The use of slaked lime has superiority in technology and economy on activating FA. Theoretical analysis revealed that the kinetic constant of the activation reaction using slaked lime is higher than using quick lime, credited to the better volume stability and fineness, and smaller water demand of slaked lime.
基金supported by grants-in-aid for the National Research Laboratory Program from MOST/KOSEF (No. R0A-2003-000-10320)partially supported by grants-in-aid for the National Core Research Center Program from MOST/KOSEF (No. R15-2006-022-01001-0)
文摘The hydration of quick lime and the sulfation of hydrated lime were carried out for verification of relationship between the reactivity of quick lime and the properties of hydrated lime as a sorbent. The effect of reactivity of quick lime was investigated with the change of calcination temperature and time. Results obtained showed that the temperature rise during the hydration of quick limes varied from 31 to 69℃ with the variation of calcination temperature and time. The specific surface area and the sulfation ability of hydrated lime prepared by hydration of quick lime showed a proportional relationship with the reactivity of quick lime. The hydrated lime which was prepared by hydration of quick lime calcined at 1100℃ had the highest reactivity and showed 41.53 m^2/g of the specific surface area, 0.16 cm^3/g of the pore volume and 87% of the removal efficiency for SO2 removal,
文摘The urgent need to mitigate climate change impacts and achieve net zero emissions has led to extensive research on carbon dioxide(CO_(2))-capture technologies.This study focuses on the kinetics of CO_(2)capture using solid adsorbents specifically through thermal gravimetric analysis(TGA).The research explores the principles behind TGA and its application in analyzing adsorbent performance and the significance of kinetics in optimizing CO_(2)-capture processes.Solid adsorbents have gained significant attention due to their potential for efficient and cost-effective CO_(2)capture.Therefore,three different types of adsorbents,namely calcium-,tin-,and zirconium-based ones(quicklime:CaO,potassium stannate:K_(2)SnO_(3),and sodium zirconate:Na_(2)ZrO_(3)),in adsorbing high-temperature carbon dioxide were investigated;their quality and performance by various factors such as price,stability,non-toxicity,and efficiency are different.The diffusion models and geometrical contraction models were the best-fitted models to explain the kinetic of these solid adsorbents for high-temperature CO_(2)sorption;it means the morphology is important for solid adsorbent performance.The minimum energy needed to start a reaction for K_(2)SnO_(3),Na_(2)ZrO_(3),and CaO,is 73.55,84.33,and 86.23 kJ·mol^(-1),respectively;with the lowest value being for potassium stannate.The high-temperature CO_(2)adsorption performance of various solid adsorbents in regard with the rate of reaction followed the order of K_(2)SnO_(3)>CaO>>Na_(2)ZrO_(3),based on experiments and kinetic studies.
