KR100305393B1 - A substitute for fine coal in copper smelting by CDQ dust - Google Patents

Abstract

The present invention is not easy to manufacture conventional, and to solve the waste end of expensive coal dust, and is used as a fuel used in the continuous copper smelting process to replace the pulverized coal generated as coke-cooled by-product during the coke manufacturing process of steel mills, Although the chemical composition of pulverized coal is almost the same, the effect is to use good coke cooling dust.

Description

A substitute for fine coal in copper smelting by CDQ dust}

The present invention relates to pulverized coal substitutes for using pulverized coal used as fuel during copper smelting by using coke cooling dust generated as a coke cooling by-product during steelmaking coke production process.

Currently, anthracite coal is used as a fuel in continuous copper smelting facilities introduced and installed for the purpose of manufacturing a mat from copper ore to smelting copper, and the anthracite coal is used as a fuel for copper smelting. In order to maintain a constant particle size, the bulk anthracite coal is used to make pulverized coal through a cumbersome crushing and grinding process.

In the case of continuous copper smelting, the condition of pulverized coal injected for the purpose of creating good heat transfer by combustion on the surface of molten metal is very demanding. The particle size distribution should be 60% or more in 1mm or less and 90% or more in 3mm or less. The content should be 10% or less, the constituents must be 35% or more volatile, and the unit calorific value should be maintained at 5,000Kcal / Kg or more.

The pulverized coal currently used in continuous copper smelting is composed of approximately 5.7% moisture, 15% ash, 45% volatiles, and 38% fixed carbon. It can be seen that (H) 5%, oxygen (O) 9%, nitrogen (N) 2%, sulfur (S) about 1%.

As mentioned above, although it is necessary to maintain a constant particle size in order to use it as fuel for continuous copper smelting, pulverized coal, which is currently used in Korea only as a fuel for continuous copper smelting, is about 15,000 tons / year, is a hammer crusher and a hammer. Despite the difficult granularity control processes such as milling, crushing, and sieving processes using mills, the particle size is not uniform and may contain particles larger than 5mm. In many cases, the slag is formed to have a closed end where the volume thereof increases, and a closed end where the clogging phenomenon of slag adheres to the furnace wall is generated.

Accordingly, an object of the present invention is to solve the waste end of expensive pulverized coal, which is not easy to manufacture, and is used as a coke cooling by-product during the coke-making process of steelworks as a fuel used in a continuous copper smelting process to replace the pulverized coal. In addition, the same chemical composition as that of the conventional pulverized coal, but the effect is to use an excellent coke cooling dust.

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

Currently, the amount of coke-cooled dust generated from the coke manufacturing process in steel mills reaches 54,000 tons per year. However, due to the lack of research on utilization and physical properties, it is used only for the use of simple charcoal.

Therefore, while the present inventors are studying the use of dust generated as coke-cooled by-products during steelmaking coke production process, the coke-cooled dust has a similar particle size to that of pulverized coal conventionally used as fuel for continuous copper smelting. Therefore, it was conceived that it can be used as a fuel for continuous copper smelting of good quality without being crushed and crushed.

On the other hand, in the coke manufacturing process required in the steelmaking process, there is a cooling process to cool rapidly to prevent coke oxidation after the coke is manufactured, it is divided into the case of using water and the use of liquid nitrogen for the cooling, these two methods are cooling Most often used simultaneously in the process.

However, when water is used and liquid nitrogen is used, the sludge-type powder generated after the cooling process has a completely different property, and the coke powder generated by the cooling method using liquid nitrogen has an even particle size distribution. Since the components are almost the same as the pulverized coal used as fuel in continuous copper smelting, there is no problem in replacing the conventional pulverized coal.

On the other hand, in the case of water cooling, there is a lot of moisture and the particle distribution is very uneven, so in order to recycle it as fuel during continuous copper smelting, only the dust of 0.5 mm or less is selected through the drying process, the pulverization and the sieving process, thereby replacing the conventional coal dust .

That is, the components of the coke-cooled dust are composed of 0.35 to 0.8% moisture, 10.5 to 12.3% ash, 0.85 to 1.1% volatile matter, and 86.3 to 87.8% fixed carbon. ) Composed of 73%, hydrogen (H) 5%, oxygen (O) 9%, nitrogen (N) 2%, and sulfur (S) 1%. It can be seen that the components are almost identical, and the particle size distribution is very fine with an average of about 0.30 mm.

Table 1 shows the main collection locations, particle size distribution, and water content of the coke cooling dust generated by the coke cooling by-products are as follows.

Table 1

As such, the particle size distribution of the coke-cooled dust is in the range of 0.21 to 0.47 mm, relatively constant and fine, and the water content is low, thereby reducing the phenomenon that the fuel particles are not completely burned and floated in the smelting furnace.

In addition, as a result of comparing the calories of the conventional pulverized coal and coke-cooled dust, the conventional pulverized coal is 6,580 Kcal / Kg, while the calorie of the coke-cooled dust generates 6,927 Kcal / Kg. When used as a large amount of fixed carbon it can have a higher effect in terms of unit calories as a heating source.

In addition, the coke-cooled dust is less ash, so the amount of the slag is reduced to reduce the amount of slag and may prevent the clogging phenomenon that the slag is attached to the furnace wall during the smelting process.

Moreover, coke cooling dust has 0.52% of sulfur (S) and 1.19% of nitrogen (N), which are the main causes of NO _x and SO _{x, which} are the main sources of air pollution. By reducing sulfur (S) to Cu) it has the effect of improving the quality of the copper.

When described in detail by the following examples.

Example 1

The coke water-cooled dust was dried in a furnace at 200 ° C. for 10 hours, pulverized with a rod mill, and sieved to obtain a mat less than 0.5 m.

The temperature and mat quality are shown in Table 2.

[Table 2]

In the above table, it can be seen that the conventional co-controlling method of coke and melt temperature in a non-quantitative manner at the time of inputting pulverized coal and continuous coke cooling dust in the continuous copper smelting process is almost the same.

Example 2

The case where no pulverized coal and coke cooling dust was added at the time of continuous copper smelting process, and the case where the fine pulverized coal was added, the case where coke cooling dust and water cooling dust obtained at each place of Table 1 were added were same as Example 1 After the experiment under the conditions, the experimental results and the operation factors are shown in Table 3.

Table 3

As described above, there was no significant difference in the quality of the mat during the injection of fine coal and the addition of coke cooling dust. Especially, the clogging phenomenon due to slag formation was significantly reduced during the injection of coke cooling dust. .

The present invention can simplify the copper smelting process by using the coke cooling dust instead of pulverized coal input as fuel during the continuous copper smelting process, so as not to go through the crushing and crushing process like conventional coal pulverization, because of the production of cheap and high-quality fuel This can improve the quality of copper, reduce costs, and save energy.

In addition, it is possible to protect the environment by using coke-cooled dust with less air pollution, it is a very useful invention that can recycle the coke-cooled dust, which was previously used only as a low-adding charcoal, as a high-value resources.

Claims (2)

Coke-cooled by-products in the coke-making process of steelworks, chemical composition consists of 0.35 to 0.8% moisture, 10.5 to 12.3% ash, 0.85 to 1.1% volatiles, and 86.3 to 87.8% fixed carbon. Pulverized coal substitutes for copper smelting using coke-cooled dust, characterized in that it is used as fuel for copper smelting. The method of claim 1, wherein the particle size of the coke cooling dust is 0.5m or less, pulverized coal substitute material in the copper smelting using coke cooling dust.