Gasification furnace charge level lowering shutdown method of European smelting furnace

Abstract

The method comprises the following steps: controlling the temperature of molten iron to be 1500-1530 DEG C and the average [Si] to be 2.5-3% 3 days before blowing out the furnace, and adding 200-300kg of fluorite to each batch of materials in full coke smelting 2 days before blowing out the furnace; the manganese content of the molten iron is controlled to be 1-1.5%, the content of MnO in the slag is 1-1.5%, and the content of CaF2 in the slag is 2-3%; the furnace charge structure of the shaft furnace is matched with the fuel of the gasification furnace, the fuel ratio is adjusted to be 200-450 kg / t, the material column of the shaft furnace is 80% of pellets and 20% of granular steel during stockline descending, the furnace temperature is increased to 1500 DEG C or above 24 hours before stockline descending of the shaft furnace, and the large coke ratio is 200 kg / t; the large coke ratio is increased to 450 kg / t before a stockline is lowered, coal injection full-coke smelting is stopped, the furnace temperature is increased to 1550 DEG C or above, and the coke ratio is 980 kg / t or above when the last furnace of iron is subjected to full-coke smelting before damping down; in the process of lowering the charge level of the shaft furnace, the top gas flow is controlled to be 15000-200000 Nm < 3 > / h, the total oxygen amount of the tuyere of the gasification furnace is 36000-42000 Nm < 3 > / h after the shaft furnace is emptied, 100 tons of coke is added into the gasification furnace twice through a coal line, and the lowest tuyere oxygen is controlled to be 12000-16000 Nm < 3 > / h.

Description

technical field [0001] The invention relates to the field of non-blast furnace metallurgy, in particular to a method for shutting down a gasifier at the lowering surface of a gasifier of an Ouye furnace. Background technique [0002] In order to solve the problems of large investment and heavy pollution in the traditional blast furnace ironmaking method, since the 1970s, a COREX furnace ironmaking method, namely the smelting reduction ironmaking method, has been developed in the world. This ironmaking method directly uses lump coal and a small amount of low-strength coke into the furnace to generate heat for smelting molten iron and reducing gas. At present, there are five sets of COREX devices in production in the world as follows: the first C2000COREX furnace in Pohang Plant in South Korea, two C2000COREX furnaces in JINDAL Plant in India, one C2000COREX furnace + direct reduction shaft furnace in SALDANHA Plant in South Africa, and Baowu in China Group Bayi Steel Ouye Fu...

AI Technical Summary

Problems solved by technology

In the process of emptying the material line, the following technical problems need to be solved: (1) As the material line is getting deeper and deeper, the top temperature of the Ouye furnace shaft furnace and the gasifier is likely to exceed the design top temperature, causing damage to the furnace top equipment; ( 2) Since the water cannot be vaporized in time at the top of the furnace, part of the water droplets will fall and contact the molten furnace slag and iron, causing detonation; (3) If the gasifier is in the process of lowering the material line, the material layer will It is getting thinner and thinner, because it is an all-oxygen blast, it is easy to increase the O2 content in the gas, and it is generally required that the O2 content in the gas is not more than 1.5%

Generally, the gasifier can only be lowered to the material line position of the material level LIR04623. The material level LIR04623 is 7.7m away from the tuyere.

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