JP2003253348A - Process for operating hot-air drying furnace - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a process for operating a hot-air drying furnace which can prevent the generation of sulfur dioxide gas or other SOx by preventing excessive heating in the hot-air drying furnace in a drying step for drying sulfide mineral concentrate charged as a raw material. <P>SOLUTION: A high-temperature gas 4 obtained from a hot-air generator 3 is fed to the hot-air drying furnace 6 together with the sulfide mineral concentrate 5, and the obtained dried sulfide mineral concentrate 9 is fed to a flash furnace (not shown). Waste nitrogen generated in oxygen production plants for flash smelting is fed to the hot-air generator 3. Alternatively, the waste nitrogen is fed to the hot-air generator 3 to cool its furnace casing and heated therein to become the high-temperature gas 4. Preferably, the furnace pressure inside the hot-air drying furnace 6 is controlled through the amount of waste nitrogen introduced into the hot-air generator 3. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot-air drying furnace operating method for hot-air drying a sulphide concentrate, and more particularly, when supplying the sulphide concentrate as a raw material for a flash smelting furnace used in non-ferrous metal melting and smelting. Relates to the operation method of the hot air drying furnace.

[0002]

2. Description of the Related Art When a flash furnace is used in the melting and smelting of non-ferrous metals (smelting furnace smelting), the sulfide concentrate as a charging material is hot-air dried with high-temperature gas (drying step), and is automatically mixed with oxygen. Supply to the melting furnace. Oxygen required in the flash furnace was produced from, for example, air in an oxygen production plant, and unnecessary waste nitrogen (oxygen plant waste nitrogen) was released into the atmosphere.

Conventionally, a high temperature gas for drying a sulfide concentrate, which is a charging raw material of a flash smelting furnace, is supplied from a hot air generating furnace.
The furnace body of the hot-air generating furnace is equipped with a furnace body cooling pipe, the furnace body is cooled by applying air to be introduced, and after the temperature is raised by heat exchange, the air introduced into the furnace is heated by a heavy oil burner. And make hot gas.

In this flash smelting and refining process, in the drying step for drying the sulfide concentrate as a raw material, combustion of the sulfide concentrate occurs due to excessive heating in the hot-air drying furnace and an increase in the amount of free air. Furthermore, inside the electric dust collector after the drying process, the sulfide concentrate burns due to ignition to the sulfide concentrate.
Sulfur dioxide gas can be generated. Furthermore, in the drying step,
If the dry exhaust gas containing sulfur dioxide gas is released into the atmosphere as it is, it will lead to environmental pollution. Therefore, it was necessary to prevent the generation of sulfur dioxide gas due to the combustion of the sulfide concentrate.

[0005]

In order to solve the above-mentioned problems, the method of the present invention prevents excessive heating in a hot-air drying furnace in a drying step of drying a sulfide concentrate as a charging raw material, It is an object of the present invention to provide a hot-air drying furnace operating method capable of preventing the generation of SOx including sulfur gas.

[0006]

The hot-air drying furnace operating method of the present invention is to supply the high-temperature gas obtained in the hot-air generating furnace to the hot-air drying furnace together with the sulphide concentrate so that the obtained dry sulphide concentrate can be produced automatically. Supply to the melting furnace. Waste nitrogen generated in an oxygen manufacturing plant for flash smelting is supplied to the hot air generating furnace.

[0007] At this time, the waste nitrogen is supplied so as to cool the furnace body of the hot air generating furnace, is heated by heat exchange, and is heated in the hot air generating furnace to become the high temperature gas.

It is desirable to control the furnace pressure of the hot air drying furnace by the amount of the waste nitrogen introduced into the hot air generating furnace.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the hot air drying furnace operating method of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic view showing an embodiment of a process according to the hot air drying furnace operating method of the present invention.

Waste nitrogen discharged from an oxygen manufacturing plant (oxygen plant waste nitrogen) or a mixed gas 1 of the oxygen plant waste nitrogen and air is introduced into a hot air generating furnace 3 by a blower 2 and inside the hot air generating furnace 3. It is heated with a heavy oil burner. At this time, the introduced oxygen plant waste nitrogen or the mixed gas 1 of the oxygen plant waste nitrogen and air flows inside the furnace body cooling pipe provided in the furnace body so as to cool the furnace body of the hot air generating furnace 3. After passing through the path indicated by the arrow and heating up by heat exchange,
It is introduced into the hot air generating furnace 3. In the case of a mixed gas of waste nitrogen and air, the waste nitrogen content is preferably 70% by volume or more.

The high-temperature gas 4 obtained by heating in the hot-air generating furnace 3 is exhaust gas from a steam heater (not shown) and water content of about 10
% Sulfurized concentrate 5 is introduced into a hot air drying furnace 6, passes through a pulverizing mill 7, and a sulphide concentrate collector 8 has a water content of about 0.3.
% To dryness and is collected as dry sulphide concentrate 9. The collected dried sulfide concentrate 9 is charged into a flash furnace.

When the internal pressure of the hot air drying furnace 6 fluctuates, the internal pressure of the hot air drying furnace 6 is kept constant by controlling the amount of the oxygen plant waste nitrogen 1 introduced. This makes it possible to suppress the amount of free air that is introduced into the hot air drying furnace 6 and promotes the combustion of the sulfide concentrate.

The dry exhaust gas from the sulphide concentrate collector 8 is
The exhaust fan 10 sends the dust to the electrostatic precipitator 11 and the bag filter 12 to completely remove the sulfide concentrate in the dry exhaust gas, and then discharges it from the chimney 13 to the atmosphere.

With the hot-air drying furnace operating method of the present invention, the oxygen concentration in the hot-air drying furnace is lower than in the conventional case where only heated air is used for hot-air drying. Therefore, the generation of sulfur dioxide gas can be suppressed. In addition, when the internal pressure of the hot air drying furnace fluctuates, the amount of waste nitrogen introduced in the oxygen plant is controlled to keep the internal pressure of the hot air drying furnace constant so that the combustion of the sulfide concentrate into the hot air drying furnace is promoted. It is possible to suppress the amount of free air. As for the introduction route of the oxygen plant waste nitrogen, the furnace body cooling pipe provided in the hot air generating furnace is used as in the conventional case.

FIG. 2 shows the relationship between the furnace pressure of the hot air drying furnace and the SOx concentration of the dry exhaust gas.

As shown in FIG. 2, when the internal pressure of the hot air drying oven decreases, the SOx concentration in the dry exhaust gas rises. Therefore, when the internal pressure of the hot air drying oven fluctuates, it is possible to suppress the increase of the amount of free air into the hot air drying oven by controlling the introduction amount of the oxygen plant waste nitrogen and keeping the internal pressure of the oven constant. , SOx concentration can be prevented from increasing.

FIG. 3 shows the SOx concentration in the dried exhaust gas before and after carrying out the hot-air drying furnace operating method of the present invention, with a regulated value of 1
It is shown as 00.

It was possible to reduce the SOx concentration to about half of that before the implementation, and it was confirmed that the method of the present invention is an effective means for environmental pollution countermeasures.

[0020]

EFFECTS OF THE INVENTION According to the method of the present invention, excessive heating in a hot air drying furnace is prevented in a drying step for drying a sulfide concentrate as a charging raw material, and SOx such as sulfur dioxide gas is prevented from being generated. It has become possible to provide a hot air drying oven operating method capable of performing the above.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an example of a process according to the method of the present invention.

FIG. 2 is a graph showing a relationship between a furnace pressure of a hot air drying furnace and a SOx concentration of dry exhaust gas according to the method of the present invention.

FIG. 3 is a graph showing SOx concentration in dry exhaust gas before and after carrying out the hot air drying furnace operating method of the present invention.

[Explanation of symbols]

1 Oxygen plant waste nitrogen 2 blower 3 hot air generator 4 hot gas 5 Sulfide concentrate 6 hot air drying oven 7 crusher 8 Sulfide concentrate collector 9 Dry sulfide concentrate 10 blower 11 Electric dust collector 12 Bug filter 13 chimney

Continued front page    (72) Inventor Shuji Endo             145-1 Shinchi Oto, Funaya, Saijo City, Ehime Prefecture Sumitomo             Metal mining Co., Ltd. (72) Inventor Mitsuo Kudo             145-1 Shinchi Oto, Funaya, Saijo City, Ehime Prefecture Sumitomo             Metal mining Co., Ltd. F-term (reference) 4K001 AA09 AA19 BA06 CA09 DA03                       GA04 GB09 GB12                 4K063 AA02 BA03 CA01 CA02 GA03                       GA11

Claims (3)

[Claims] 1. A hot-air drying furnace operating method in which high-temperature gas obtained in a hot-air generating furnace is supplied to a hot-air drying furnace together with a sulfide concentrate, and the obtained dried sulfide concentrate is supplied to a flash smelting furnace. A method for operating a hot-air drying furnace, characterized in that waste nitrogen generated in an oxygen manufacturing plant is supplied to the furnace. 2. The waste nitrogen is supplied so as to cool the furnace body of the hot air generating furnace, and becomes the high temperature gas by being heated in the hot air generating furnace. Hot air drying oven operating method. 3. The hot-air drying furnace operating method according to claim 1, wherein the internal pressure of the hot-air drying furnace is controlled by the amount of the waste nitrogen introduced into the hot-air generating furnace.