JPS5938585A - Method of reutilizing exhaust gas from metallurgical furnace - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for reusing exhaust gas from a metallurgical furnace, for example, in which exhaust gas discharged from a lead concentrate sintering furnace is used as combustion gas for fuel.

Lead sheath, which is the raw material for lead smelting, contains approximately 60% lead and approximately 60% sulfur.
This lead concentrate is sintered in a sintering furnace to form lead lump ore containing lead oxide as a main component, and then sent to the next process.

Therefore, the exhaust gas discharged from the lead concentrate sintering furnace contains sulfur dioxide gas (802), and its concentration is 3 to 4 tv.
Reach oLchi. For this reason, conventionally, as shown in Fig. 1, in order to remove the sulfur dioxide gas in the exhaust gas from the sintering furnace 1, the exhaust gas was sent to an electrostatic precipitator 2 to remove dust, and then the sulfuric acid production plan Then, it is removed by oxidizing it to sulfuric acid using a catalytic oxidation method or the like. However, the generation temperature of the exhaust gas from the sintering furnace 1 is approximately ≠00℃.
Because the temperature is relatively low, unburned organic matter and
For example, hydrocarbons caused by lead concentrate flotation agents are included,
The sulfuric acid produced in the sulfuric acid production plant 3 is contaminated with the organic matter, resulting in black colored sulfuric acid. For this reason, decolorization treatment using hydrogen peroxide, potassium permanganate, or the like is required in order to obtain the product sulfuric acid, which poses a problem of increasing the production cost of the by-product sulfuric acid.

A similar problem has also been pointed out regarding TJF gas in fluidized incubation furnaces for copper concentrate.

This invention has been made in view of the above-mentioned 4F circumstances, and provides a method for reusing metallurgical furnace exhaust gas, which can prevent the generation of colored sulfuric acid and can effectively utilize the heat contained in the exhaust gas. The purpose is to

Hereinafter, the present invention will be described in detail with reference to the drawings. .

FIG. 2 shows an embodiment of the method of utilizing metallurgical furnace exhaust gas according to the present invention, and reference numeral 11 in the figure is a lead concentrate sintering furnace.

The exhaust gas discharged from this sintering furnace 11 is collected by an electrostatic precipitator 12.
The waste is sent to the factory, where it is cleaned of dust. The exhaust gas leaving the electrostatic precipitator 12 has a temperature of 2jO to 300°C and contains sulfur dioxide gas of 3 to ≠
Since the temperature at which the sintering furnace 11 is generated is as low as ≠00° C., it contains unburned particulate hydrocarbons as described above. After this exhaust gas is mixed with air and oxygen-enriched air with an oxygen concentration of 10%, it is sent to the reverberatory furnace 13 for iron smelting, which is installed in the same factory as the lead concentrate sintering furnace J1, where it is combusted. It is considered to be a commercial gas.

At this time, air and oxygen-enriched air are mixed so that the oxygen concentration in the exhaust gas after adding air and oxygen-enriched air is between l♂ and koovoL, and the temperature is 750°C or higher. The lid is adjusted. The mixed exhaust gas introduced into the reverberatory furnace 13 as combustion air is used as combustion air for fuel such as coal, but the temperature inside the reverberatory furnace 13 is
, 20[theta] to 130O<0>C, which is a high temperature, so that the unburned particulate hydrocarbons contained in the exhaust gas are completely combusted. The exhaust gas from the copper smelting reverberatory furnace 13 is
Contains sulfur dioxide gas from 3 to 50%, and its temperature is /20
It is about 0-/300°C. After heat is recovered from this exhaust gas in a waste heat boiler (not shown), dust is removed by an electrostatic precipitator, and the exhaust gas is sent to a sulfuric acid production plant 14vc, where sulfur dioxide gas is recovered as sulfuric acid by a catalytic oxidation method or the like.

According to such an exhaust gas reuse method, unburned hydrocarbons in the exhaust gas from the lead ore sintering furnace 11 are transferred to the copper smelting reverberatory furnace 13.
The sulfuric acid manufacturing plant 1
The cytogas sent to step 4 does not contain any hydrocarbons, so that the obtained sulfuric acid is free from coloration, and is clean and does not require further decolorization treatment.

Further, since the temperature of the exhaust gas introduced into the reverberatory furnace 13 as combustion air is about /jO'c, preheating is unnecessary and energy consumption is reduced. Furthermore, the exhaust gas discharged from the conventional copper bath reverberatory furnace 13 also contains sulfur dioxide gas at a considerable bacterial concentration, and a sulfur production plant may be installed to process and recover this gas, but this method This eliminates the need for a sulfuric acid production plant with either 11 systems of lead concentrate sintering furnaces or 13 systems of copper smelting reverberatory furnaces.

In the above embodiments, a lead concentrate sintering furnace is used as the metallurgical furnace, but the present invention is not limited to this, and the exhaust gas from the furnace, such as a fluidized roasting furnace for copper concentrate, is sulfur dioxide gas. Any type of metallurgical furnace may be used as long as it contains unburned hydrocarbons, has a generation temperature of 1,000°C or less, and contains unburned hydrocarbons. In addition, although a 13Vc reverberation furnace for copper smelting was introduced as a fuel combustion gas, the present invention is not limited to this, but is not limited to this, but the furnace has a furnace temperature of 100θ°C or more, such as a steelmaking blast furnace, at a temperature at which the unburned hydrocarbons are completely combusted. It may also be a boiler, internal combustion engine, etc. In particular, it is preferable that the metallurgical furnace and a furnace or the like that utilizes the exhaust gas from the metallurgical furnace are installed in the same factory, as this improves the utilization efficiency.

As explained above, the method for reusing metallurgical furnace exhaust gas of the present invention is such that the metallurgical furnace exhaust gas is discharged from the metallurgical furnace and its generation temperature is /00
Air or oxygen-containing gas is mixed with exhaust gas containing unburned hydrocarbons and sulfur dioxide gas at temperatures below 0°C, and this is used as combustion air for fuel, so sulfur dioxide gas is converted into sulfuric acid from this exhaust gas. When recovering, clean sulfuric acid is obtained instead of the black colored sulfuric acid that is conventional.
The decolorization process becomes unstable, and the production cost of by-product sulfuric acid can be reduced. Also, use it as a gas for combustion of fuel, /jO~2
Since it is heated to about 00''C, there is no need for preheating and energy consumption is reduced.

[Brief explanation of the drawing]

Figure 7 is a system diagram showing a conventional metallurgical furnace exhaust gas treatment method;
FIG. 2 is a system diagram showing one embodiment of the method for reusing the metallurgical furnace exhaust gas of this company. 11...Lead concentrate sintering furnace 13...Copper smelting reverberatory furnace 14...Sulfuric acid! R construction plant applicant Mitsubishi Kanagawa Corporation

Claims (1)

[Claims] If the generation temperature discharged from a metallurgical furnace such as a lead CI ore sintering furnace or a fluidized incubation furnace for copper concentrate is 100°C or less,
1. A method for reusing metallurgical furnace exhaust gas, which comprises mixing flue gas containing acid gas with gas or oxygen-containing gas, and using this as a combustion gas for fuel.