| According to the leaching toxicity of chromium in AOD, influence of slagcomponents and cooling rate on the crystalization of high melting point mineral phaseand leaching characteristics of chromium in slag has been investigated. The resultsprovide a foundation for illustrating the impact rule of minerallogical phase on chromiumleaching from AOD slag, and theoretical basis for eco-risk accessment of toxic element intoxic solid waste.It has been shown that the slag components and cooling rate has significantinfluence on the crystalization of high melting point phase. When AOD slag has beenkeep constant temperature at1600℃for1hour, the main mineral phase of remeltingslag after quick-cooling is augite and diopside. Cooling rate has significantly effect onmineralogical composition and their content of the remelting slag. When the content ofCr2O3, Al2O3, Fe2O3has been varied, the type and content of pyroxene in the remeltingslag could be changed.It was shown that the cooling rate has significant influence on chromium from theremelting slag when the Al2O3content has been changed. Chromium content in leachateincreased with the increasing of cooling rate because chromium leaching could beaccelerated by Al2O3. Compared with the original slag, the leaching ratio of chromiumfrom the slag with2%and3%Al2O3after slow-cooling process increased by49.9%and114.3%, respectively, while those from air-cooling process increased by36.3%and116.9%, respectively. The cooling rate has weak influence on chromium leaching fromthe remelting slag after the Fe2O3content has been changed. It show that Fe2O3couldinhibit chromium leaching from the remelting slag. Compared with the original slag, theleaching ratio of chromium from the slag with2%and3%Fe2O3after slow-coolingprocess decreased by40.5%and42.9%, respectively, while those from air-coolingprocess decreased by44.1%and45.1%, respectively. |
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