Hot steel slag cracking method

Abstract

The present invention relates to an incandescent steel slag cracking method, including: directly pouring the incandescent steel slag in a steel slag cracking furnace, spraying water for thermal stewing cracking, cooling drying discharge and steam heat energy recovery. The invention is characterized in that the incandescent steel slag from the steel plant no longer needs a dedicated storage yard for stacking cooling, namely, the incandescent steel slag can be directly poured in the steel slag cracking furnace for thermal stewing cracking; fork-lift truck and excavator are nor required in the whole process form self-loading furnace to discharging from furnace; the steel wall material of the cracking furnace has stable working conditions, and is free from man-made mechanical damages, so thatits service life will be more than 5 years; sensible heat of the incandescent steel slag can be stably and efficiently recovered, and the whole process can realize PLC automated control; the system investment is approximately 50% of the existing technology, operating cost is 60% of the pot stewing technology, the metal recovery rate is improved 10% or more, water from the furnace cinder is less than 5%; a 500,000 tons / year steel slag processing line recovers steel slag residual heat equivalent to 10,000 tons of standard coal thermal value.

Description

【Technical field】 [0001] The invention relates to a metallurgical slag treatment method, in particular to a hot steel slag cracking method. 【Background technique】 [0002] The steelmaking process is actually a slag-making process. my country's crude steel production capacity has reached 600 million tons per year, and about 200kg of steel slag can be produced for each ton of steel produced. The temperature of the hot steel slag discharged from the steelmaking furnace is between 1300 ° C and 1550 ° C But in liquid state, not only about 5% metallic iron is wrapped in the hot slag, but also the sensible heat of each ton of hot steel slag is not less than the calorific value of 60kg standard coal. The annual production of 600 million tons of steel means that more than 100 million tons of steel slag will be produced, of which about 5 million tons / year of metallic iron needs to be recycled, and the calorific value of 6 million tons / year of standard coal needs to be utilized. [000...

AI Technical Summary

Problems solved by technology

[0005] One is: it is necessary to pour the hot slag (above 1000°C) from the slag pot of the steelmaking workshop into the open field and cool it down to a medium temperature (300-800°C) naturally, and then put it into the stew pot by a forklift for stewing, that is Hot slag cannot be stewed. Although some technologies can stew high-temperature liquid slag, the operation is very complicated and the production efficiency is extremely low;

[0006] The second is: the hot stewing process of steel slag in the stewing tank is a periodic operation. One cycle includes four processes of forklift filling, atomization and spraying water heating, static cooling, and excavator hook material out of the tank. It takes about 12 hours, which will inevitably lead to too many stewing pots (usually more than 4), and forklifts and excavators will turn over the small stewing pots, which is not conducive to safe production and increases the loading capacity. Energy consumption during material handling;

[0007] The third is: the material layer in the stewing tank is too thick (usually more than 4 meters), and when the water is sprayed from the upper part of the material layer to the surface of the hot steel slag, it will instantly gasify and overflow the stewing tank. The layer penetrates into the lower part of the material layer, and there are dead angles in the stewing tank, resulting in too long heating time and poor uniformity of stewed slag;

[0008] The fourth is: the bottom of the stew tank is easy to collect water, and it is very easy to explode when it is filled with hot steel slag, resulting in casualties or property losses. Frequently damaged under the action of various factors;

[0009] Five is: the waste heat of hot steel slag cannot be recycled, but is lost in the atmosphere with steam;

[0010] The sixth is: due to the large number of stewing tanks, the need for a forklift for loading, the need for an excavator for discharging, and the short life of the stewing tank, the system investment is too large, the operating cost is high, and there are many safety hazards

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