Slag washing desulphurization method for molten iron utilizing residue thermal-state steel slag

Abstract

The invention discloses a slag washing desulphurization method for molten iron utilizing residue thermal-state steel slag, and specifically relates to a slag washing desulphurization method for the molten iron by pouring the residue thermal-state steel slag of continuous casting into an empty hot-metal ladle when the molten iron is added. The method comprises pouring the residue thermal-state steel slag in a ladle into the empty hot-metal ladle by transport equipment such as a crane and the like, or by intermediate containers when the molten iron is added; carrying out slag washing desulphurization for the molten iron utilizing an impact of the molten iron; and then carrying out gas stirring or mechanical stirring for the molten iron followed by a slag removal operation. The method is advantaged by recycling thermal energy of the residue thermal-state steel slag, replacing molten iron desulphurizers or effectively reducing the consumption of the iron desulphurizers, shortening the desulphurization time of the molten iron, recycling the residue steel, improving the metal yield, realizing direct heat recovery of the residue thermal-state steel slag, simplifying the treatment process of the steel slag, and reducing the production cost of the steel.

Description

technical field [0001] The invention belongs to the technical field of steelmaking production, molten iron pretreatment, and waste steel slag treatment, and relates to a method for slag-eluting sulfur from molten iron by using the hot steel slag injected. Background technique [0002] In the production process of steelmaking and continuous casting, after the molten steel is refined, it is transported to the continuous casting machine for pouring. When the molten steel in the ladle is basically emptied, the nozzle of the ladle should be closed to prevent the slag in the ladle from entering the continuous casting tundish. Then affect the cleanliness of molten steel and the quality of steel. At this time, a certain amount of hot steel slag remains in the ladle. The conventional steel slag recovery process is to pour the steel slag into the slag tank and transport it to the steel slag treatment plant. After a series of treatments, it can be reused. Conventional steel slag recov...

AI Technical Summary

Problems solved by technology

[0003] 1) The steel slag transported to the steel slag treatment plant is not only time-consuming and labor-intensive, but also very expensive;

[0004] 2) The remaining steel and slag are poured into the ladle, and the temperature is as high as about 1400°C, and its heat is not fully utilized;

[0005] 3) The remaining steel slag in the ladle contains about 5-10% (volume) metal, which has not been directly recycled;

[0006] 4) Ladle injection residue has high alkalinity and CaO content, and its residual desulfurization capacity has not been effectively utilized;

[0012] The disadvantages of the above four steel slag recovery technologies are: as the number of steel slag cycles increases, unfavorable factors appear. When the remaining steel slag is recycled for more than 3 times, the amount of slag in the ladle increases and the amount of slag is too much. The CaO content decreases and the sulfur capacity decreases, so it is no longer suitable for refining, and the slag operation must be carried out at this time

The disadvantages of these technologies are: large investment in equipment, large consumption of desulfurizer, high processing cost, long processing time, and large heat loss