The invention relates to the fields of sensible-heat utilization of metallurgical high-temperature
slag and efficient comprehensive utilization of resources, and provides a thermal-state
slag online modification device. Through the device, high-quality modified
slag can be prepared by use of the
sensible heat of slag. The device comprises a top plug, a modification furnace body, a primary wind gap, a secondary wind gap, a third wind gap, a
cyclone hearth, a stirring
paddle, a partition wall, a slope
pool bottom, a slag
discharge hole, an iron liquid
discharge hole, a
scrap iron separation wall, a
flue, a
handle, a pressure relief hole, a
combustion observation hole, an ignition burner, a modification chamber observation hole, a concurrent heating burner, a slag
discharge chamber observation hole, a liquid flow hole, a charging hole, a sampling hole, a modification chamber, a
scrap iron separation chamber, a slag discharge chamber and a
cyclone furnace body. The high-quality modified slag after the treatment by the device can be directly applied to the fields such as building materials and industries; the
metal iron can be recycled from the iron-containing slag. The device is simple to operate, low in operation cost and wide in application range, and has relatively good application prospect and economic value.