JPS62280315A - Melt reduction method - Google Patents

Abstract

PURPOSE:To efficiently recover the heat generated by secondary combustion into a metal bath by burning a carbonaceous material in a slag layer so that ore is reduced by melting and further splashing the metal to the secondary combustion zone where the formed gaseous CO is burned by gaseous O2. CONSTITUTION:The carbonaceous material and ore are blown together with the gaseous O2 from a top blowing lance 2 into the slag layer 4 in the furnace 1 of a converter type of a melt reduction furnace. The above-mentioned carbonaceous material is burned to reduce the ore by melting and to form the metal bath 3. The gaseous O2 is blown from the position at the height of the slag layer 4 of the furnace wall through tuyeres 5 for secondary combustion into the slag layer 4 and the gaseous CO formed by the combustion is secondarily burned in the slag layer 4 in the above-mentioned melt reduction method. The gas is further blown from the position at the height of the metal bath 3 of the furnace wall through tuyeres 6 into the metal bath 3 for forming splashes. The splashes of the metal formed in such a manner are splashed to the above- mentioned secondary combustion zone, by which the sensible heat of the secondary combustion is directly absorbed therein and is recovered into the metal bath 3.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Industrial Field of Application] This invention, for example, involves blowing carbon material, ore, and 02 gas into a slag layer in a furnace, and then blowing the carbon material into the slag layer. Reduce the ore while burning it internally? This paper relates to the 8 fusion reduction method, particularly to improving the recovery efficiency of secondary combustion heat recovered into a metal bath.

[Prior art] As a conventional melt reduction method, carbonaceous material, ore, and 02 gas are blown into a furnace, and the ore is directly reduced while burning the carbonaceous material, and 02 gas is further blown into the furnace. C that occurs
Prior to filing this application, we had proposed a smelting reduction method in which O gas is subjected to secondary combustion and the heat generated by this secondary combustion is used to reduce ore.

[Problems to be solved by the invention] In the conventional smelting reduction method as described above, by increasing the secondary combustion ratio (ratio of Co2+ 820 to 120 C, 0+ co, + J+ inside the furnace), The problem is that the flow rate of the HF gas discharged into the metal bath becomes faster and the heat transfer time of the exhaust gas becomes shorter, making it difficult to efficiently transfer sensible heat from secondary combustion to the metal bath, as shown in Figure 2. was there.

This invention was made to solve these problems, and aims to provide a smelting reduction method that can efficiently transfer the sensible heat of secondary combustion to a metal bath.

[Means for Solving the Problems] The smelting reduction method according to the present invention involves blowing carbonaceous materials, ore, and 02 gas into a slag layer in a furnace, and burning the carbonaceous materials within the slag layer. In the smelting reduction method for reducing ore, 0.2
Gas is blown into the metal bath from the height of the metal bath on the furnace wall to cause secondary combustion of CO gas generated by combustion of the carbonaceous material in the slag layer. It is characterized by a metal splash being thrown into the combustion zone.

[Operation] In this invention, gas is blown into the metal bath from the height of the metal bath on the furnace wall, and the metal splash is thrown into the secondary combustion zone, so that the sensible heat of the secondary combustion is directly transferred to the metal. He is captured and collected in a metal bath.

[Example] '! Figure FS1 is an explanatory diagram of a melting reduction furnace for carrying out the present invention. In the figure, (1) is a converter type furnace, (2)
) is the top blowing lance inserted into this furnace, (3) is the metal bath formed at the bottom of this furnace, (4) is the slag layer formed on this metal bath (3), (5) tuyere for secondary combustion formed at the height of the slag layer (4) on the furnace wall, (6)
(7) is the tuyere for splash formation formed at the height of the metal bath (3) in the lower part of the furnace wall, and (7) is the height of the slag layer (4) on the furnace wall, which is higher than the secondary combustion tuyere (5). (8) is the tap hole formed at the height of the metal bath (3) in the lower part of the furnace wall, and (9) is the bottom blowing tuyere.

In the smelting reduction furnace configured as described above, carbonaceous materials, ore, and O2 gas are blown into the slag layer (4) in the furnace (1) from the top blowing lance (2), and the carbonaceous materials are blown into the slag layer (4). (4
) The ore is melted and reduced while being burned in the slag layer (
4) Secondary combustion within the tuyeres (6) for splash formation
Gas is blown into the secondary combustion zone to send a splash of metal into the secondary combustion zone. Sensible heat from secondary combustion is directly absorbed by the metal splash and transferred to the metal (3) bath.
Sensible heat from secondary combustion is efficiently recovered into the metal bath (3). That is, 0.0 of the present invention. As shown in FIG. 2, it can be seen that the heat transfer efficiency with respect to the D ratio is improved compared to the conventional method.

[Effects of the Invention] As explained above, the present invention has a 0.0-. The CO gas generated by the carbon fuel is blown into the slag layer, and the blown gas is used to cause secondary combustion in the slag layer, and metal splash is thrown into the secondary combustion zone, so the sensible heat of the secondary combustion is reduced. is directly captured by the metal splash and transmitted to the metal bath, thus having the effect that the sensible heat of secondary combustion is efficiently recovered to the metal bath.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a melting reduction furnace for implementing the present invention, and FIG. 2 is a graph showing the relationship between OD, ratio, and heat transfer efficiency. In the figure, (1) is the furnace, (2) is the top blowing lance, and (3) is the furnace.
) is the metal bath, (4) is the slag layer, (5)! i is a tuyere for secondary combustion, (6) is a tuyere for splash formation, (7) is a slag discharge port, (8) is a tap hole, and (9) is a bottom blowing tuyere. Agent Patent Attorney Tadashi Sato Year 1 Subaru Ki (%) Man Son

Claims (1)

[Claims] In the smelting reduction method, in which carbonaceous material, ore, and O_2 gas are blown into the slag layer in the furnace, and the ore is reduced while burning the carbonaceous material within the slag layer, this O_2 gas is blown into the slag layer, and the CO gas generated by combustion of the carbonaceous material in the slag layer is secondary combusted by the blown O_2 gas, and the gas is injected into the metal bath from the height of the metal bath on the furnace wall. A smelting reduction method characterized by blowing metal into the secondary combustion zone.