Method for recycling CO2 separated from converter steel-making gas for top blowing and bottom blowing

Abstract

The invention discloses a method for recycling CO2 separated from converter steel-making gas for top blowing and bottom blowing and belongs to the fields of ferrous metallurgy, energy conservation and environment protection. In the invention, the CO2 in the converter steel-making gas is separated and recycled after being cooled and dedusted; the recovery is 100 to 15,000Nm<3> / h; and the concentration of CO in the converter gas is improved by 5 to 20 percent at the same time. The CO2 serves as a gas source for the top blowing and the bottom blowing of a top and bottom combined blown converter. A chemical absorption separation method is adopted to separate the CO2; steam added with rich liquid is generated by using the residual heat of the converter gas; and almost no additional energy is consumed in the process for separating the carbon dioxide. 1 to 30 percent of the CO2 and 99 to 70 percent of O2 are blown from the top part; pure CO2 or a mixture of the CO2 and N2 or Ar or O2 or gas and the like is adopted in the whole process of the bottom blowing; and the amount of the CO2 is 100 to 3,000Nm<3> / h. The method is applicable to a steel-making process for a 30 to 350 ton converter. By adopting the method, for each ton of steel, 1 to 20 m3 of CO2 emission is reduced synthetically; the soot amount is reduced by 1 to 30 percent; and the content of the CO in the gas is improved to more than 2 to 15 percent.

Description

technical field [0001] The invention belongs to the fields of iron and steel metallurgy, energy saving and environmental protection, and in particular relates to separating and recovering CO2 gas in the converter gas, and then directly injecting the CO2 gas into the converter for use in the converter top-blowing or bottom-blowing steelmaking process. Background technique [0002] In the converter steelmaking process, 60-120m of gas can be recovered for every 1 ton of steel produced 3 , the gas contains 50-80% CO, CO 2 10-20%, conventional CO 2 As the exhaust gas is emitted with CO, it has no effect. How to use CO effectively 2 Metallurgical function and improve the quality of gas, CO 2 After separation from CO, using CO 2 Metallurgical functions such as decarburization, dephosphorization, blowing and dust removal, and as a stirring gas source for the converter instead of a bottom blowing gas source, etc. Realize CO 2 recycling. At the same time, after the gas is sep...

AI Technical Summary

Problems solved by technology

[0002] In the converter steelmaking process, 60-120m of gas can be recovered for every 1 ton of steel produced 3 , the gas contains 50-80% CO, CO 2 10-20%, conventional CO 2 Emitted as exhaust with CO, has no effect

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