| Summary: | 碩士 === 國立成功大學 === 環境工程學系碩博士班 === 97 === Based on previous studies, calcium-based ashes and slags have the potential to absorb CO2. In this study, the degree of aging of natural aged and rapid carbonation BOF slag were compared on their physical and chemical characteristics, including the conversion rate of total calcium, pH, ANC/BNC, and pH dependence behavior leaching test. Results show that the BOF slag with calcium content over 20% has the potential to absorb CO2. The calcium conversion rate of 6 months natural aged BOF slag were about 15%. Rapid carbonation of BOF slag at temperature of 100℃, moisture content of 90% and 10% partial pressure of carbon dioxide under the reaction for 24 hours, the conversion rate of BOF slag is up to 18%.
According to the follow-up grinding analysis and SEM analysis, it was discovered that BOF slag carbonation reaction occurred on the surface with calcium oxide as the main reaction species. And BOF slag was confirmed by the leaching test which the surface layer of calcium carbonate reduces the effects of dissolution. In addition, the BOF slag conversion degree of 8 hours carbonation has similar results with that of 6 months natural aged.
The rapid carbonation BOF slag although lower pH values from 12.5 to about 11, but did not increase the leaching of heavy metals concentration. BOF slag after a 24-hour rapid carbonation absorbs the amount of CO2 up to 0.035g of CO2/g of BOF Slag. This shows rapid carbonation has the ability of CO2 absorption at the same time achieved the goal of BOF slag stabilization, which enhances the value of BOF slag follow-up reuse.
|
|---|
