JPS6179735A - Manufacture of sintered ore by adding fuel to surface layer - Google Patents

Abstract

PURPOSE:To improve the strength and yield of sintered ore by enriching only a surface layer with fuel and pressing the surface layer. CONSTITUTION:A surface layer stirring unit 6, a fuel adding unit 7 and a press roller 8 are placed between an ore feeding vessel 2 and a firing furnace 4 in a Dwight-Lloyd type sintering apparatus. The surface layer of blended starting materials 1 is stirred before the materials 1 enter the firing furnace 4, and fuel is supplied only to the surface layer from the fuel adding unit 7 to form a fuel enriched layer of 2-100mm thickness. This surface layer is pressed with a press roller 8 to increase the density of the surface layer corresponding to eta30% of the thickness of the whole layer of the blended starting materials 1. The surface of the surface layer is then fired in the firing furnace 4, and the starting materials 1 are sintered.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for producing sintered ore in which the surface layer density is increased and the temperature is increased to t''.

(Conventional technology) In the conventional method for producing sintered ore using a Dwight Lloyd type (hereinafter abbreviated as DL type) sintering device, as shown in Fig. The material is charged into the sintered pallet 10 through the raw material cutting chute 3, and is leveled to a predetermined height.Then, the sintered pallet 10 into which the mixed raw material 1 has been charged is charged.
enters the ignition furnace 4.

Here, the blended raw materials are ignited. Thereafter, the combustion zone is moved downward by suction through the Windex 5, and sintering progresses to the grate surface in the ore discharge section, and sintering is completed.

(Problems to be solved by the invention) In the conventional method, the coke used as fuel is distributed almost uniformly throughout the blended raw materials, and in the current sintering process, where the ignition surface advances downward, heat transfer in the packed bed is difficult. In terms of characteristics, there is a strong tendency for the surface layer to lack heat. Considering ignitability, quality, yield, etc., OOG for ignition has traditionally been used as a countermeasure for this lack of heat. Countermeasures have been taken, such as using large amounts of heat, or installing heat retention furnaces to overcome this lack of heat.

In addition, in the conventional sintering method, the charging density in the upper layer of the sintered raw material tends to be low due to the characteristics of the ore feeding equipment. 90 As a countermeasure to the above-mentioned heat shortage, which also has the problem of lowering the water retention, a raw material blending system and a t-2 series of ore feed tanks were installed as disclosed in Japanese Patent Application Laid-open No. 48-102017, and the total layer thickness was increased. There is a so-called two-stage charging technique in which the fuel is divided into two parts and charged in two stages to increase the amount of fuel in the upper layer. However, this method has the problem of requiring two systems of raw material blending equipment, which increases equipment costs and operating costs.

In addition, although various tests have been conducted to solve the problem of lower charging density in the upper layer, no active approach has been taken to the point of industrialization.

There is an even greater need for cost reduction in the sintering process these days, but in the DL sintering machine, it is possible to reduce the amount of fuel such as OOG used in the ignition furnace and the coke that is the fuel in the raw material, and also to improve the yield. Improvement is an important issue in terms of energy and cost savings.

The present invention improves the ignitability and lack of thermal energy of the blended raw material 1 on the Tsukret (-especially- improves the yield of the upper M part) in a DL type sintering machine without making major equipment modifications. It is an object of the present invention to provide a method for producing sintered ore that can improve the total yield, stabilize quality, and homogenize the bed height direction.

(Elaborate means to solve problems) The ninth aspect of the present invention that achieves the above objects is as follows.

In the method for producing sintered ore using a Dwight Lloyd type sintering machine, a high-fuel blend layer is formed on the surface layer of the blended raw material on the Tsukret to a thickness of 2 to 100 cm, and then the surface layer is pressed to remove the entire layer of the blended raw material. A method for producing sintered ore by adding fuel to the surface layer, which is characterized by densifying the surface layer of the blended raw materials to a thickness of 30 mm within the following range, and then igniting the surface layer to sinter it, and a German-style sintering machine ( : In the method for producing sintered ore, the surface layer of the blended raw materials on the pallet is coated with a thickness of 2 to 100 mm.
Form a high fuel blending layer in the range of gourd, mix the thickness of the high fuel blending layer to less than 30% of the total layer thickness, and then press the surface layer to the range below 30% of the total layer thickness of the blended raw materials. This is a method for producing sintered ore by adding fuel to the surface layer, which is characterized by densifying the surface layer of the blended raw materials in a sintering process, and then igniting the surface layer to sinter it.

Hereinafter, the present invention will be described in detail based on the accompanying drawings.

1 and 2 are side views, partially in section, of an example of an apparatus for carrying out the method of the present invention.

As shown in FIG. 1, the method of the present invention is a DL type sintering machine that continuously produces sintered ore, in which a surface stirring device 6, a fuel addition device 7, Forming press rollers 8 are installed in sequence.

Alternatively, as shown in FIG. 2, a surface mixing device 9 is further installed between the fuel addition device 7 and the forming press roller 8, and the next device is used to mix the surface layer of the blended material l before it enters the ignition furnace 4. Stir and press mold after adding fine coke, solid fuel such as coal, charcoal, or liquid fuel such as tar only to the surface layer, or press mold after mixing the fuel addition device layer, and then press mold in the ignition furnace 4. By igniting, the surface layer becomes denser and hotter, and the synergistic effect of these improves the yield and strength of the upper shoulder of the sintered layer, reducing the variation in quality.In addition, 00G for ignition and coke for fuel This is a sintered ore manufacturing method that aims to save energy by reducing

As the forming press roller 8 used for pressing the surface layer, it is also effective to use a ribbed roller having a plurality of ribs in the width direction in order to improve air permeability.

In the method of the present invention, the high fuel blend layer formed on the surface layer of the blended raw materials on the pallet has a thickness of 2 to 100+ m, and the fuel content in this layer is 5X or more, preferably IOX or more. If the thickness is less than 2cm, it will be difficult to improve the lack of heat in the surface layer, and if the thickness is less than 5X, it will not be much different from the :1 material blending ratio of the blended raw materials, and it will not be possible to form a high fuel blending layer, so it will be reduced to 5. As mentioned above, it is desirably equal to or higher than IOX, and the upper limit is not particularly set because the layer may be made of only fuel.

Blended raw material surface layer (after forming the second high fuel blending layer)
In the case of complete mixing, the depth of mixing should exceed the thickness of the high fuel blend layer and be within 30X of the total layer thickness.

That is, below the high fuel blend layer thickness, only the inside of this layer is mixed. Since this is a region where heat deficiency is significant, it is desirable that the upper limit is 30X.

When forming a high-fuel blend layer over the entire thickness of the blended raw materials and then press-molding the surface layer, the pressing depth is within the range of 10 to 100 m+. If this depth is less than 10+w, the surface layer of the compounded raw material cannot be made highly dense, and if it exceeds 100 m, the air permeability of the surface layer will deteriorate, so the effects of the present invention cannot be expected.

In the method of the present invention, it is necessary to press the surface layer of the blended raw materials so that the influence of the pressing is limited to within 30X of the total layer thickness of the blended raw materials. In other words, this range is shown in Figures 4 and 5.
As shown in the above, the strength and yield of finished products have traditionally been particularly low (upper layer), and it is important to improve the overall product yield by making it possible to improve the overall product yield. It is extremely difficult to densify the raw material to a level exceeding .

Pressing with a roller is effective for increasing the density of the surface layer of the blended raw materials. Therefore, by pressing with a roller having the same diameter as the total layer thickness of the blended raw materials, the total layer thickness of up to 30 mm can be densified.

Therefore, the maximum diameter of the press forming roller used in the method of the present invention is equal to the total layer thickness of the compounded raw materials, and the diameter of the roller is selected depending on the degree of densification of the surface layer.

(Example) The present invention was carried out using a Dwight Lloyd type sintering machine having a strand P length of ios, a nozzle width of 5, and a nominal capacity of 15,000 tons per day.

The operating conditions at this time were a layer thickness of 595 sIIm and a total coke content of 3.0X. Example 1 of the present invention is
3~10% of coke powder is added to the surface layer of the blended raw materials before entering the ignition furnace.
The same amount of coke as this coke powder is subtracted from the total blended raw materials, and the entire surface roller (= therefore 20
The sintered ore was produced by pressing it to a depth of ~50 m to make it denser, and then igniting it in an ignition furnace. For the purpose of comparison, a comparative example was prepared in which raw materials with a coke content of 3.0X were sintered as they were.

Furthermore, in addition to the operations in Example 1, coke powder was charged to the surface layer of the raw materials, and after t, the surface layer was mixed at a depth of 20 to 50 layers, and then the mixed layer was pressed 20 to 50 times with a roller. Example 2 was obtained by igniting the surface layer and producing sintered ore.

The above results are summarized in Table 1, FIG. 7, and FIG. 8.

Table 1. As is clear from FIGS. 7 and 8, the present invention significantly improves the quality of the sintered ore, especially the strength from the upper layer to the middle layer, and also improves the yield to a large degree. This not only improved the overall yield but also improved the stability of quality in the vertical direction of the pallet.

In addition, by increasing the proportion of coke in the surface layer (secondarily, the ignitability was improved, and as shown in Table 1, the amount of OOG as ignition fuel could be reduced).

Table 1 (Effects of the invention) The present invention can improve the quality of sintered ore by enriching fuel only in the surface layer and press-forming the surface layer, thereby improving ignitability and increasing the packing density of the surface layer. . That is, by the method of the present invention, the surface layer of the blended raw material can be evenly heated to a high temperature, resulting in improved strength and yield of the sintered ore.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the main parts of a sintering machine showing an example of an apparatus for implementing the method of the present invention, and FIG. 2 is a main part of a sintering machine showing another example of the apparatus for implementing the method of the present invention. The cross-sectional view and Figure 3 are diagrams showing the relationship between the holding time at 1100°C during sintering and the depth in the layer direction.
Figure M4 is a diagram showing the relationship between the tumbler index (TI) and the position in the bed height direction, Figure 5 is a diagram showing the relationship between the sintered ore product yield and the position in the bed height direction, and Figure M6 is a diagram showing the relationship between the pressurization depth and the position in the bed height direction. Figure 7 shows the relationship between the load of the unit area box, Figure 7 shows the relationship between TI and the position in the layer height direction according to the example of the present invention, and Figure 8 shows the relationship between the product yield and the position in the layer height direction according to the example of the present invention. Figure 9 is a cross-sectional view of the main parts of a sintering machine showing the prior art. 2: Feed tank, 4: Ignition furnace, 6: Surface stirring device, 7: Fuel addition Device, 8; Forming press roller, 9: Surface mixing device. 7t1 diagram πλ diagram

Claims (2)

[Claims] (1) In the sintered ore production method using a Dwight Lloyd sintering machine, the surface layer of the blended raw materials on the pallet has a thickness of 2 to 100 m.
After forming a high fuel blend layer in the range of m, the surface layer is pressed to densify the blended raw material surface layer within a range of 30% or less of the total layer thickness of the blended raw material, and then the surface layer is ignited and sintered. A method for producing sintered ore by adding fuel to the surface layer. (2) In the sintered ore manufacturing method using a Dwight Lloyd sintering machine, the surface layer of the blended raw materials on the pallet has a thickness of 2 to 100 m.
Form a high fuel blend layer in the range of m, exceed the thickness of the high fuel blend layer and mix within 30% of the total layer thickness, then press the surface layer to within a range of 30% or less of the total layer thickness of the blended raw materials. A method for producing sintered ore by adding fuel to the surface layer, characterized in that the surface layer of the blended raw material is densified, and then the surface layer is ignited and sintered.