JPS5831374B2 - Mixing method of sintering raw materials - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention has the following advantages: By controlling the amount of solid fuel such as coke mixed into the sintering raw material based on the raw material sonicity,
This invention relates to a method of blending sintering raw materials to improve combustion efficiency and quality during the sintering process.

Coke powder is usually used as a solid fuel to be mixed into the sintering raw material, but this coke powder is conventionally cut out at the same time as other raw materials and mixed in a mixer.

However, in the method of mixing coke powder with other raw materials and water at the same time, the coke powder gets mixed into the individual pseudo-granules, and the amount of coke powder that adheres to the surface layer of each pseudo-granule is small, causing problems during the sintering process. This causes deterioration of combustion efficiency.

If the combustion efficiency deteriorates, the quality of the finished sintered ore naturally does not improve, so in the conventional method, it was necessary to increase the amount of coke breeze added.

Furthermore, when coke powder is added to the sintering raw material, the amount of coke powder added is greatly related to the quality of the sintered ore, so the addition must be controlled accurately.

Conventionally, this method involves actually measuring the quality of the finished sintered ore, such as its strength and reduction pulverization rate, and controlling the amount of coke breeze added based on these measured values.

However, with this method, it is difficult to add an appropriate amount of coke due to the difference in raw material particle size and pseudo-particle size, and the time lag in the addition action causes large variations in sinter quality, making it difficult to produce sinter with stable quality. It was difficult.

This invention was made in order to solve the above-mentioned conventional problems, and aims to propose a method of blending coke powder more accurately.

The gist of this invention is to add a predetermined amount of moisture to a sintered blended raw material that does not contain solid fuel such as coke and knead it, and from the relationship between the predetermined air permeability and the amount of solid fuel such as coke added, the kneaded blended raw material This method of blending raw materials for sintering is characterized by adding and mixing a predetermined amount of solid fuel such as coke according to the measured air permeability of the sintering material.

That is, in order to prevent coke from being mixed into pseudo particles during the granulation process when raw materials and fuel (hereinafter represented by coke powder) are simultaneously mixed,
In the process of pseudo-granulating the sintered raw material, only the sintering raw material containing no coke powder and water are kneaded, and the coke powder is added after the pseudo-granulation.

Furthermore, taking into account the difference in raw material particle size and pseudo-granularity, the amount of coke breeze added after pseudo-granulation is determined based on the relationship between the predetermined air permeability and the amount of coke breeze added, and the amount of coke breeze added after pseudo-granulation is adjusted to the actual air permeability after pseudo-negativity. The method was determined accordingly.

In addition, in this invention method, the relationship between the permeability and the amount of coke breeze added in order to find the amount of coke breeze added corresponding to the measured air permeability after pseudo-negation is based on the relationship between the moisture content and the amount of coke breeze added at the bottom. The air permeability of the raw materials after kneading with a mixer is measured, and the amount of coke powder added is determined from the measured value, and the relationship can be expressed, for example, in a diagram as shown in FIG.

In other words, from this chart, when the air permeability after kneading is small, the individual pseudo-granulated particles are of course small, so the amount of coke powder added is small, and the air permeability is small. It can be seen that the amount of coke powder added must be increased.

Therefore, when such a chart is used, by reading the amount of coke powder added corresponding to the measured air permeability and adding it to the blended raw material after cross-talk, the appropriate coke amount can be added to the surface layer of the pseudo-granulated particles. It is possible to apply powdered coke evenly.

According to the method of this invention, since the coke addition is adapted to the raw material particle size and pseudo-hardness, the appropriate amount of coke can always be added and mixed, and therefore the combustion efficiency in the sintering process is extremely high, resulting in good quality sintering. Concretion is obtained.

In addition, since coke powder is added according to the measured air permeability of the mixed raw materials that do not contain coke powder, there is a delay in controllability compared to the conventional method in which the amount of coke powder added is controlled based on the quality of the finished sintered ore. There is no difference in quality, and the variation in quality can be significantly reduced.

Next, an example of an apparatus for carrying out the method of this invention will be explained based on FIG. 2.

1 is a raw material tank, 2 is a conveyor, 3 is a primary mixer,
4 is a mixed raw material hopper, 5 is a conveyor, 6 is a coke powder hopper, 7 is a water supply pipe, 8 is a water injection amount control device, 9 is a moisture meter, 10 is an air permeability meter, 11 is a coke powder addition amount calculation device, Reference numeral 12 indicates a setting device for setting the relationship between the air permeability of the blended raw materials and the amount of coke breeze added, and 13 indicates a coke breeze cutting control device.

That is, each sintered raw material cut out from the raw material tank 1 is sent to the primary mixer 3 via the conveyor 2 and kneaded with moisture supplied from the moisture supply pipe 7.

The kneaded and blended raw materials are put into the next raw material hopper 4, and the air permeability in the hopper is measured using an air permeability meter 10.

Inputting this measured air permeability into the coke breeze addition amount calculating device 11, and determining the amount of coke breeze addition corresponding to the measured air permeability from the relationship between air permeability and coke breeze addition amount that has been input in advance into the setting device 12; According to the value, coke powder is cut out by the coke powder cutting control device 13 and added to the kneaded blended raw material cut out from the raw material hopper 4 and flowing through the conveyor 5.

The raw material after the addition of coke powder is kneaded again in a secondary mixer and charged into a sintering machine.

When adding water to each sintered raw material and kneading it in the primary mixer 3, the water content is measured with a moisture meter 9 in order to keep the water content of the blended raw materials in the primary mixer constant, and the water content is controlled by the water injection amount control device 8. Perform addition control.

Examples of the present invention will be described below.

〔Example〕

Water in the amount shown in Table 1 is added to the raw material not containing coke powder having the blending ratio shown in Table 1, and the mixture is kneaded with a mixer.The permeability of the mixed raw material is measured, and the air permeability - Based on the relationship between the amount of coke powder added and the amount of coke powder added corresponding to the measured air permeability, the amount of coke powder shown in Table 1 was added to the kneaded raw material and mixed, and the sintered blended raw material was sintered using a sintering test steel. did.

The firing conditions at that time are shown in Table 2, and the quality of the obtained sintered ore is shown in Table 3.

For comparison, Table 3 shows the quality of sintered ore obtained by the conventional method obtained by sintering the raw materials shown in Table 1, coke powder, and water simultaneously under the same firing conditions. Also listed.

As is clear from the results in Table 3, according to the method of this invention, sintered ore of better quality can be obtained than the sintered ore produced by the conventional method of kneading raw materials, coke powder, and water at the same time, and the variation in quality is also reduced. few.

Therefore, this invention has significant effects on improving the quality of sintered ore and reducing fuel consumption, and can also be expected to improve productivity.

[Brief explanation of drawings]

FIG. 1 is a chart showing an example of the relationship between raw material permeability and the amount of coke powder added in this invention, and FIG. 2 is an explanatory diagram showing an example of an apparatus for carrying out the method of this invention. 1... Raw material tank, 2, 5... Conveyor 3...
・-Next mixer 4...Blended raw material hopper 6...Coke powder hopper, 7...Moisture supply pipe, 8...Water injection amount control device, 9...Moisture meter, 10...Air permeability Total, 1
1... Coke powder addition amount calculation device, 12... Setting device, 13... Coke powder cutting control device

Claims (1)

[Claims] 1 Add a predetermined amount of moisture to a sintered blended raw material that does not contain solid fuel such as coke, and knead it, and from the relationship of the amount of solid fuel such as coke added that corresponds to the predetermined air permeability, calculate the actual air permeability of the kneaded blended raw material. A method for blending raw materials for sintering, characterized by adding and mixing a predetermined amount of solid fuel such as coke according to the amount of solid fuel.