JPS602369B2 - Sintering operation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a combustion operation method when the particles of carbonaceous material (for example, coke, hereinafter referred to as coke) are enlarged. The purpose of this invention is to provide a method for improving quality by controlling the amount of oxidation (deposited), and thereby making it effective as a measure to suppress N○x.

In conventional sintering, coke powder is added to powdered ore as a fuel, mixed and humidified, then placed in a bag in a sintering machine, and the coke on the surface layer is ignited in an ignition furnace. It is dawning due to the heat of combustion.

Therefore, the combustion status of coke, which is the heat source, is a major factor in Akatsuki Aya. In order to maintain the combustion of this coke under optimal conditions, it is important to maintain appropriate permeability of the raw material layer. In order to ensure air permeability, the particle size of the mixed powder ore and the added moisture that affects pseudo-granulation during the mixing and humidity conditioning process are important.

Air permeability can be improved by increasing the particle size of the mixed powder ore, but
In the case of Akatsukijima, a ``glue'' part is required to maintain the strength of the so-called bonded calcined ore, which is the melt, and a certain amount of Tsumugi grain ore is also required, and there is a limit in terms of ore particle size.

Regarding addition of water, the optimum amount of water for pseudo-granulation of raw materials is optimal for breathability, and the amount of water is also limited.

Therefore, in normal continuous operation, regulations are imposed on both the particle size of fine ore and the amount of water added. For the above reasons, there is a limit to the improvement of ventilation in the scale striped layer.

Therefore, in normal breaking, the particle size of fine ore is increased to the extent permitted from the quality standpoint, and mixing is strengthened or binder is added in order to promote the formation of pseudo-granules in the fine grain part of fine ore. There is. When coarse coke is used in such a normal fried layer, ventilation is greatly improved.
Therefore, under a constant suction force, the amount of air sucked in increases and the coke burns faster.

As a result, the high temperature maintenance time, which affects the quality of the sintered ore, becomes shorter and the quality deteriorates. Table 1 shows the sintering results when normal coke powder was used and when coarse coke of a predetermined size or more was used. Table 1: Dawning results using the conventional method *Notes 1 to 4 are average diameters as shown in Table 1, and are 1.6 as the average diameter of symbol C and 0.
By using hammer-grained coke of Yanagi or higher and E, F or higher, the braking time becomes shorter in normal brining operations, which has the drawback of lowering product yield, falling strength, etc. be.

The present inventors have conducted various investigations into competitive coagulation using coarse-grained coke. It was discovered that by controlling the optimum high temperature maintenance time, which is the condition for coke formation, it is possible to overcome the deterioration in the quality of the feed ore that is caused by the use of coarse coke in the conventional dovetailing operation. .

In addition, the inventors have already found and proposed that the N○× generated from the Akatsuki factory, which is an environmental pollution problem, can be suppressed by using lees coke, but this countermeasure is also more effective. The effect of making it effective is also great.

Effective methods of controlling to reduce the amount of air suction include, for example, a method of controlling by suction force, and a method of increasing overall air permeability by increasing the layer thickness.

Examples will be described below.

To obtain phase grain coke with a predetermined particle size or more, there is a method of reducing the crushing ability of coke powder to increase the average particle size, or separating the pongee grains on less than one side and using coarse particles on one side or more. There are ways to do this.

There is also a method described in claim 3.

For example, C in coke breeze used in conventional competitive operation.
This is a method of granulating with inorganic or organic binders such as a0, bentonite, cement, and sulfite pulp waste liquid. When quicklime is added to the conventional coke powder symbols A and B in Tables 1 to 4 and mixed with a drum mixer while controlling the humidity, the coke powder of less than 1 side will adhere to more than 1 layer of coke and become granulated, and the average diameter will be growing. The results for this granulated coke are shown in Tables 2 to 4, G and Day.
In addition, the binder may be added to coke powder of less than 1 type obtained by conventional separation from coke powder and coke powder crushed to a total amount of less than 1 side, and used to make coarse coke of more than 1 size using a desk granulator. is also possible. Cement was added to less than one cell pulverulent coke and granulated using a disk granulator, and the results are shown in symbols 1 and J in Tables 2 to 4.

Table 2 Result of dawn when suction power is controlled *Note 1: 10 shots of quicklime were added to coke powder with symbol A.

Granulation *Note 2: Symbol B 〃 *Note 3: Less than 1 skin of coke powder is added to 5 parts of cement and mixed and granulated *Note 4:
〃Table 3: Dawning results when controlling the thickness of adjacent layers (negative pressure during firing was constant for 1000 days and 20 days)
Table Particle size distribution of coke used The results in Table 2 are for 50k9 dawn.

This result was obtained by reducing the suction force and controlling the suction air. The way to control the suction power is to open and close the damper of Katsuodo. There are methods to reduce the capacity of the air, but here we use a damper to control it. As is clear from Table 2, the deterioration in quality of coarse coke with a particle size larger than the predetermined particle size shown in Table 1 can be overcome.

Compared to the conventionally used fine coke with symbols A and B, the coalescence time becomes the same even with coarse coke with symbols C to J by implementing the above-mentioned operation method, and this is the opposite. In other words, the suction force is controlled to match the dawning time, and both quality and productivity have shown excellent results.

Next, Table 3 shows the results when the sintered layer thickness was increased to reduce the suction air.

Even when the layer thickness is increased, the coarse coke with symbols C to J shows superior results compared to the conventional coke powder with symbols A and B. Judging from the above results in Tables 1, 2, and 3, it is clear from Table 1 that quality deteriorates when the average diameter increases to 1.61 mm. The lees coke mentioned above has also deteriorated.

Next, from the results in Tables 2 and 3, it is clear that even coarse-grained coke with a predetermined grain size or higher can improve the flashing property.
The predetermined particle size of coarse coke is 1.6 as an average diameter.
It is limited to more than a kite or more than one side. In the case of pseudo-grained coarse coke, it may be disintegrated during processes such as transportation, mixing of fine ore, and charging.

Therefore, even if the amount of coke breeze increases by less than one cell due to collapse, as long as the permeability is improved,
The effect can be expected to be sufficient, and the effect can also be expected by combining the method of controlling the suction force with the control of the sintered layer and layer thickness. Furthermore, the use of coarse coke tends to increase the temperature within the sintered bed, and it is natural that it can be expected to reduce the amount of coke. As is clear from the examples above, in the present invention, excellent bran streaking properties can be expected by using coke with a predetermined particle size or more, and the effect is significant when considering the already discovered effect of suppressing NO spread in combination. It is something.

Table 4 shows the distribution of coke used.

Items with the same symbols in Tables 1 to 4 are the same type of coke. Table 5 shows the blending ratio of raw materials. Table 5 Mixing ratio

Claims (1)

[Claims] 1. When sintering fine ore using a downward suction sintering machine,
Sufficient sintered ore quality can be obtained by using coarse particles with an average particle size of 1.6 mm or more, or coarse particles with a total particle size of 1 mm or more as the carbonaceous material used as fuel, and by controlling the amount of oxygen-containing gas sucked. A sintering operation method characterized by maintaining a certain sintering time. 2. The sintering operation method according to claim 1, characterized in that fine particles of less than 1 mm in the carbon material are separated and coarse particles of 1 mm or more are used. 3 Carbon material having fine particles less than 1 mm is pseudo-granulated or agglomerated with an inorganic or organic binder such as CaO, bentonite, cement, or sulfite pulp waste liquid, and the average particle size is 1.6 mm or more. The sintering operation method according to claim 1, characterized in that coarse particles having a total particle diameter of 1 mm or more are used.