JPS61291926A - Manufacture of cokes fines for sintering - Google Patents

Abstract

PURPOSE:To pelletize cokes fines without requiring days and place for curing, by mixing cokes fines generated in manufacturing process for cokes lump and raw material fines generated in ironworks at a specified ratio, and pelletizing the mixture on a pelletizer while adding a specified quantity of water. CONSTITUTION:Cokes fines generated in manufacturing process for cokes lump and raw material fines generated in ironworks are stored in hoppers 1 and 2 respectively. These are gotton out therefrom to a pug mill 4 by a measuring and getting out apparatus 3 at a ratio of 40-70% raw material fines to 60-80% cokes fines. This is mixed by the mill 4, then sent on the pelletizer 5 and pelletized while adding 10-20% water. The pelletized cokes fines are stored in a hopper 6.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is directed to the production of coke powder for sintering, which can reduce fuel consumption by improving the combustion efficiency of coke powder used in the production of sintered ore. It is about the method.

(Prior art, problems) Fuel coke powder used in the production of sintered ore is generally produced by classifying the bottom of blast furnace lump coke, and crushing +51 with a crusher such as a rod mill to adjust the particle size. are used.

It has been known for a long time that the particle size of coke powder for sintering greatly affects its combustion. 1-5 In order to improve the combustion efficiency, reduce fuel consumption, and improve the productivity of sintered ore in coke powder for sintering, as well as reduce NOx generated during coke combustion, It is said that particles with a particle size of 1 to 3+sm are most suitable.

However, recently, coke dry fire extinguishing equipment (CDQ)
The generation of fine coke with an average particle size of less than 11Iffi is increasing due to the operation of the It is advantageous in terms of cost to process these fine coke particles within the steelworks as much as possible, and there is a demand for their use as a substitute for coke powder for sintering compound raw materials.

Conventionally, when using these fine coke powders as sintering fuel, there are two methods: directly mixing them into sintering compound raw materials such as iron ore and limestone in the same way as normal coke powder, and using various types of bangu and fine powders. The conventional method is to mix coke, turn it into atomized particles by granulation or other methods, and adjust the particle size to a predetermined particle size, for example, from 1 to 311 II, and then mix it with the raw materials for use.

However, the former method has the drawback that the combustion efficiency of the coke breeze is greatly reduced due to the particle size of the coke powder, resulting in a decrease in fuel consumption and a deterioration in the quality of the sintered ore. On the other hand, according to the latter method, coke powder with a satisfactory particle size can be obtained, but not only does it involve a considerable increase in cost due to the use of pine goo such as cement, but it is also difficult to make use of the effectiveness of pine goo. It requires curing for several days and also requires a yard for curing.

Therefore, since the conventional techniques inevitably lead to a decrease in the quality of the sintered ore and an increase in the cost of producing the sintered ore, there has been a demand for the development of a technique for efficiently using a large amount of fine coke.

(Means for Solving the Problems) The present invention is intended to solve the above-mentioned problems, and uses fine coke powder generated in the manufacturing process of lump coke as raw material fine powder generated in a steelworks, and fine coke powder 60. After mixing at a ratio of 40 to 20% of the fine powder raw material to ~80%, 1. This is a method for producing coke powder for sintering, which is characterized by granulating the coke on a pelletizer while adding 10 to 20% water. Fine coke refers to coke with an average particle size of less than 1+*m, and fine coke generated in the process of producing lump coke includes, for example, dust collected from CDQ, fire extinguishing dust, and the like. *Fine raw materials generated in steel plants include converter dust, sintering dust, pellet feed, etc.

(Function) The present invention converts pulverized coke having the particle size distribution shown in Table 1 generated in the process of producing lump coke such as CDQ into converter dust, sintered dust, pellet feed, etc. having the particle size shown in Table 2. This is a granulation technology for pulverized coke that uses pulverized raw materials as cores.

Regarding the blending ratio of fine coke and fine raw materials, as shown in Figure 4, the ratio of fine raw materials to fine coke is 20/80.
The above shows combustion efficiency, sintering productivity, and strength of finished sintered ore that are almost comparable to ordinary coke breeze.
At 0/60 or more, it becomes almost constant and there is no significant improvement. Therefore, the blending ratio of fine coke and fine raw material is preferably 60 to 80% of fine coke and 40 to 20% of fine raw material.
After mixing in this ratio using a mixing device such as a pug mill,
Pelletize on a pelletizer while adding 10 to 20% water over the top.

Regarding the amount of added water, as shown in Figure 5, if it exceeds 20%, the crushing strength of the granules decreases significantly, and if it is less than 10%, it tends to decrease, so the range of 10 to 20% is considered appropriate.

As mentioned above, since the present invention is a granulation technology for fine coke, it does not use any cutting materials, so there is no need for days or yards for strength development measures such as curing. Immediately after graining, it can be mixed into the raw material for sintering and used as a fuel for producing sintered ore.

In the present invention, no bangu is used in granulating the fine coke, and the strength of the granulated coke is maintained by the fine raw material added as the core.
By pre-mixing these, the apparent weight of the fine coke increases, which increases the frictional force when the mixture is rolled by the pelletizer, and as a result increases the strength of the granulated fine coke. It also suppresses extreme increase in particle size.

(Example) FIG. 1 is a schematic diagram showing an embodiment of the present invention.

The fine coke and the fine raw material are each stored in the hopper shown in 1.2, and from there they pass through the weighing and cutting device 3, and as mentioned above, the fine coke 60 to 80% and the fine raw material 2
It is cut out to have a blending ratio of 0 to 40%, and then 4
Mix by pug mill. At this time, adding water into the pug mill to compensate for the addition of water during granulation is an effective means for assisting granulation.

The raw materials mixed in the pug mill are then granulated on the pan pelletizer shown in 5 while adding water at a rate of 10 to 20%. This granulated material is stored in a hopper 6 and cut out at a predetermined ratio in the sintered mixed raw material. I changed it.

The granulated coke powder cut out from the hopper No. 6 is introduced into the sintering blending system from before the mixer 7 for mixing raw materials for the sintering machine, and is mixed into the blended raw materials for use. Each of the above-mentioned facilities 1 to 7 is connected by a belt conveyor, and the granulation work is carried out continuously like the sintered ore production.

In addition, the results of a test using the granulated coke powder produced by the present invention in the production of sintered ore are shown in Figures 2 and V.
As shown in Figure 3, when granules with an average particle diameter of 4.8 s+s were used as a 30% substitute for normal coke powder, the results were as follows.
There was almost no change in productivity or product yield, and no change was observed in combustion efficiency.

In addition, the replacement rate for fine coke is
In the case of using the present invention, the improvement was 70 to 75%, whereas in the case of the present invention, it was 95%, which is an improvement of more than 20%.

(Effects of the Invention) As explained above, according to the present invention, fine coke can be granulated without using banhgu and therefore without requiring days or space for curing. Granulation costs can be reduced compared to conventional methods, and using granulated fine coke for sinter production improves the replacement rate by more than 20% compared to using fine coke instead. becomes possible.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of the equipment used in the examples of the present invention, Figure 2 is a diagram illustrating the particle size distribution of granulated fine coke, and Figure 3 is the use of granulated fine coke to produce sintered ore. FIG. 4 is a diagram illustrating the influence of the blending of fine coke and fine raw materials, and FIG. 5 is a diagram illustrating the influence of added moisture. In the figure, 1 is a fine coke hopper, 2 is a fine raw material hopper, 3 is a measuring and cutting device, 4 is a pug mill, 5 is a pan pelletizer, 6 is a receiving hopper for granulated fine coke, and 7 is a sintering machine raw material mixing mixer. be.

Claims (1)

[Claims] (1) Fine coke powder generated in the manufacturing process of lump coke is combined with fine powder raw material generated in the steelworks and fine coke powder 60-8
1. A method for producing coke powder for sintering, which comprises mixing fine powder raw materials at a ratio of 40 to 20% to 0%, and then granulating the mixture on a pelletizer while adding 10 to 20% water.