The invention relates to a high-quality steel
slag aggregate as well as a preparation method and application thereof, the method is a graded
carbonization process and comprises the following steps: (1) primary
carbonization and reduction: taking
molten steel slag at 1300-1500 DEG C as a
raw material, continuously introducing
industrial waste gas into a hot and stuffy tank in a water spraying and cooling process, carbonizing for 8-14 hours, and reducing for 2-4 hours; meanwhile,
ferric oxide in the steel
slag is reduced into iron elementary substance and ferroferric
oxide, and first-grade carbonized steel slag is obtained; the volume ratio of CO2 in the
industrial waste gas is 20%-30%, and the volume ratio of CO in the
industrial waste gas is 30%-60%; (2) secondary
carbonization: selecting the primary carbonized steel slag below 10mm in the step (1) as aggregate, placing the aggregate in a closed container, spraying the steel slag aggregate according to a preset spraying amount, maintaining the pressure in the closed container to be 0.3-0.5 Mpa, continuously introducing the same industrial
waste gas into the closed container for secondary carbonization, and enabling the content of
free calcium oxide in the steel slag aggregate to be lower than 3%; and carrying out
magnetic separation to obtain high-quality steel slag aggregate after secondary carbonization. According to the method, the high-quality steel slag aggregate meeting related technical requirements can be prepared within 24 hours and is used for preparing
asphalt concrete.