JPH02301525A - Method for charging raw material into sintering machine - Google Patents

Abstract

PURPOSE:To increase the C concn. at the upper layer of the mixed material without deteriorating the permeability of the mixed material layer at the time of operating a Dwight-Lloyd sintering machine by charging a powdery carbonizing material into the charging part formed in the upper layer of the mixed material on a pallet. CONSTITUTION:The mixed material 9 in a feed hopper 2 is discharged onto the pallet 1, its upper surface is smoothed by a cutoff plate 4 as the pallet 1 is traveled in the A direction. Since the tips of the slitting rods 13 fixed to the plural branch pipes 12 branched from the lower end of a breeze hopper 5 are positioned at a specified depth from the upper surface of the material layer 9, plural slit grooves 16 are formed to a constant depth in the upper material layer 9. Coke powder 10 in the hopper 5 is charged into the grooves 16 from a long hole-shaped opening 15 with its longitudinal direction almost parallel to the direction A and provided at the lowermost part of the branch pipe 12.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention provides a method for producing sintered ore, in which mixed raw materials are charged onto the pallet of the sintering machine and the carbon concentration is controlled. Concerning raw material charging method.

(Prior art) Conventionally, a method of manufacturing sintered ore using a Dwight Lloyd sintering machine is generally known, and a blend of sintered ore is cut out at a fixed rate from an ore feed hopper. There is a method in which the raw materials are charged onto the balent of a sintering machine, and air is blown downward from above the loaded blended raw material layer to burn the coke powder mixed in the blended raw materials for sintering. It is taken.

In this method, the sintering raw material and coke 75) are uniformly mixed and charged onto a pallet as a blended raw material from an ore feed hopper, so sintering progresses in the upper layer of the blended raw material due to cold air suction. Heat tends to be insufficient, while in the lower layer, the suction air is preheated and heated within the blended raw material layer, resulting in excess heat.

As a result, the upper layer of the blended raw materials becomes brittle, resulting in a decrease in the strength of the sintered ore and poor yield.
Japanese Patent Application No. 62-209577 by the same applicant has been proposed as a raw material charging method that improves these problems. That is, a cylindrical body is provided parallel to the pallet advancing direction at a position from the middle layer to the upper layer of the blended raw material layer charged on the balent, and 5 of the total amount of carbonized material required to sinter the blended raw materials is provided. There is a known method for controlling the carbon concentration by blowing ~20wt% of coke powder or coal powder from the middle layer to the upper layer of the mixed raw material layer charged above the balent from the above-mentioned cylinder (the invention solved the problem). As mentioned above, 5 to 20 wt% of powdered carbonized material such as coke powder or coal powder is blown into the middle to upper layer of the mixed raw material layer charged on the pallet of the sintering machine, and carbon When the concentration is increased and the sintering reaction is performed, the temperature of the upper layer of the blended raw materials increases, and the lack of heat in the upper layer is resolved.

However, up to 20wt of powdered carbonized material is added to the upper layer of the blended raw materials.
% charging, there is a problem in that the rotational strength of the sintered mineral product is considerably lower in the upper layer than in the middle and lower layers.

In addition, in order to prevent the strength of the upper layer of the blended raw material from decreasing, it is necessary to further increase the amount of powdered carbonized material charged into the upper layer, but if more than 20vvL% is charged, the upper layer of the blended raw material will become overheated. The air permeability of the blended raw material layer deteriorates, resulting in a decrease in productivity. In other words, if the upper layer of the blended raw materials is compensated for the heat, excess heat will occur and the high temperature zone (melting zone) will expand, which will reduce the permeability of the blended raw material layer on the ballast of the sintering machine and reduce the firing speed and productivity. A problem occurs.

The present invention provides a method for charging raw materials into a sintering machine that can improve the strength and yield of sintered ore by controlling the carbon concentration in the upper layer of the blended raw materials without impeding the air permeability of the blended raw material layer. The purpose is to provide a method.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the method of charging raw materials into a sintering machine of the present invention involves loading the blended raw materials cut out at a constant rate from an ore feed pump into a sintering machine. When the powdered carbonized material mixed in the blended raw materials is combusted and sintered, the powdered carbonized material mixed in the blended raw materials is sintered. After charging the blended raw materials and smoothing the upper surface, filling parts are formed at regular intervals in the width direction of the pallet in the upper layer of the blended raw materials and have a constant depth, and powdered carbonized material is charged into the filled parts. It is characterized by

(Function) According to the method of the present invention, filling portions having a constant temperature are formed at regular intervals in the pallet width direction of the upper layer of blended raw materials charged onto a sintering machine pallet, and the filling portions have a temperature of ↑5. )-shaped carbonized material is charged and sintered. The amount of powdered carbonized material charged is
20 to 2 of the total amount of carbonized material required to sinter the blended raw materials
5 wt% is desirable.

The amount of the powdered carbonized material to be charged must be adjusted at the appropriate time depending on the strength of the sintered ore and the permeability of the blended raw material layer. If it decreases, increase the depth of the filling part. However, if the amount exceeds a certain amount, the upper layer of the blended raw material will become overheated, and the high temperature zone will also expand to the middle and lower layers, reducing air permeability. Ensure breathability of the blended raw material layer.

As mentioned above, by adjusting the depth of the filling section into which the powdered carbonized material is charged and the number of filling sections formed as appropriate depending on the sintering situation, the carbon concentration can be adjusted without impeding the air permeability of the blended raw material layer. can be controlled to improve the strength and yield of sintered ore.

(Example) An example of the present invention will be described in detail below based on a conceptual diagram of a Dwight Lloyd type sintering machine shown in FIG. sign (
+3 is a pallet, and the pallets (1) are arranged in an endless manner so as to move in the direction of arrow A in the figure. An ore feed hopper (2) is arranged above the pallet (1), and a roll feeder (3) is provided below the ore feed hopper (2).
) is provided. Subsequently, a cut-off plate (4) is arranged in the advancing direction of the balent (1), and then a breeze bar (5) is arranged in parallel with the ore feeding hopper (2) above the pallet (1). Further, the reference numeral (6) is the ignition/heat retention furnace, the reference numeral (7) is the main exhaust flue, and the reference numeral (8) is the wind box.

In the sintering machine configured as described above, the blended raw material (9) for sintering stored in the ore feed hub (2) is cut out by the roll feeder (3) and placed on a pallet (
1) Charged on top. As the balent (1) advances, the upper surface of the raw material (9) charged on the pallet (1) is smoothed by the cant-off plate (4), and the raw material (9) is kept at a constant layer height. is maintained.

Next, the lower end (11) of the breeze hopper (5) in which coke powder (10) is stored as carbonized material
Then, while forming a filling portion (hereinafter referred to as a slit-like groove) (16) with a certain depth as described later in the upper layer of the blended raw material (9), the coke powder (10) is loaded into the slit-like groove (16). Also, the lower end (11) of this breeze hopper (5)
) Details will be explained based on the schematic front view in Fig. 2 and the schematic plan view in Fig. 3.A pallet (1) has a plurality of branch pipes (12
)- is arranged to branch from the lower end of the breeze hopper (5). A slit forming rod (13) is fixed on the side of each branch pipe (12L) with a fastener (14) so as to be movable in the vertical direction.
An elongated opening (5) is provided at the bottom of the bar so that the longitudinal direction thereof is substantially parallel to the traveling direction (A) of the valentine (1).

The lower end (11) of the breather pipe (5) has the above-described structure, and as the pallet (1) charged with the blended raw materials (9) advances in the six directions of arrows in the figure, the branch pipe (12) )- through a fastener (14) is positioned so that the tip of the slit-forming rod (13) is at a constant depth from the top surface of the blended raw material (9) layer. As shown in the enlarged cross-sectional view of the raw material charging state, a plurality of slit-like grooves (16L-) are formed at a constant depth in the upper layer of the mixed raw material (9).

Multiple slit-shaped ia (16) formed at the tip of the slit-forming rod (+3) in the upper layer of the blended raw material (9)
- Coke powder (10) is charged into each of the plurality of branch pipes (12L-) which are branched below the breeze chamber (5) through elongated openings (15). ) (10) is appropriately charged at 20 to 25 wL% of the total amount of carbonized material required to sinter the blended raw materials, and powdered carbonized material such as coke powder (lO) is charged in a slit-like groove (16
)-The method of charging may be carried out continuously or intermittently depending on the sintering conditions.

As described above, a plurality of slit-like grooves (16) are formed in the upper layer of the blended raw material (9), and the slit-like grooves (16)
)--Total carbonized substance Wt)) 20-25 W L %
An example of charging coke powder (10) corresponding to Mj is shown, but the depth of the slit groove (16) can be adjusted depending on the sintered state of the finished product, or the number of slits 1f4 (16) formed can be increased or decreased. By doing so, it is possible to control the carbon 4 degree of the upper layer of the blended raw material (9) and promote a good sintering reaction without impairing air permeability.

Further, a cross section of a sintered layer on a pallet obtained by the method of the present invention will be explained with reference to the schematic diagram of FIG. Reference numeral (17) is a great bar constituting the bottom of the balent (1), and in the sintered layer sintered on the great bar (17), most of the lower layer is a portion with excellent strength ( a), and furthermore, the slit-like groove (16
) is also a part (a) with excellent strength, but in order to maintain breathability, the slit-like grooves (16
) The parts other than the vicinity are fragile parts (b).

FIG. 6 is a distribution diagram showing the free carbon concentration in the height direction of the blended raw material layer. According to the conventional raw material charging method, the free carbon concentration is high in the upper layer of the blended raw material and low in the lower layer. Although the amount of free carbon in the upper layer of the blended raw material is large, the lack of heat in the upper layer cannot be denied. Since powder is charged, the free carbon concentration in the upper layer of the blended raw material increases significantly near the slit-shaped tube compared to the conventional raw material charging method, and the amount of free carbon in the upper layer of the blended raw material increases in the lower layer. This shows that coke powder is being charged at a constant rate.

Figure 7 shows the heat pattern in the sintered bed layer;
In order to maintain air permeability in the blended raw material layer created by the conventional raw material charging method, the free carbon m in the upper layer cannot be raised above a certain value, so the temperature inside the layer is 1200'C.
Although it rises to a near high temperature, the time for holding the high temperature in the lower layer becomes shorter,
As a result, the high temperature retention time of the middle and lower layers is also shortened.

On the other hand, in the case of the raw material charging method according to the present invention, since the raw material layer is formed by charging a specified amount of coke powder into the slit-shaped groove formed on the upper surface of the blended raw material layer to be charged, the slit-shaped groove Nearby, the temperature inside the layer rose to nearly 1200°C,
In addition, the high temperature retention time becomes long, and there is no possibility of insufficient heat, especially in the upper layer.

FIG. 8 is a graph showing the rotational strength. According to the conventional charging method, the rotational strength from the middle layer to the upper layer of the blended raw material layer decreases significantly. On the other hand, according to the raw material charging method according to the present invention, there is almost no difference in rotational strength from the middle layer to the lower layer of the blended raw material layer compared to the conventional charging method, but from the upper layer near the slit-shaped groove The rotational strength increases significantly towards the middle part.

(Effects of the Invention) According to the raw material charging method of the present invention, filling portions are formed at regular intervals in the pallet width direction in the upper layer of the blended raw materials and have a constant depth, and a required amount of powdered carbonization is formed in the filling portions. ¥! Since IJ quality is charged, an increased amount of powdery carbonized material can be charged without impairing the air permeability of the blended raw material layer. Therefore, the carbon concentration in the upper layer of the blended raw material layer can be increased, and the strength and yield of the sintered ore can be improved, as well as productivity.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing a method of charging raw materials into a sintering machine according to the present invention, Fig. 2 is a schematic front view showing a charging section for powdered carbonized material, and Fig. 3 is a schematic diagram showing a plane between the two in Fig. 2. , Fig. 4 is a partially enlarged sectional view showing the raw material charging state, Fig. 5 is a schematic diagram showing the cross section of the sintered layer on the pallet, and Fig. 6 is a distribution diagram showing the free carbon concentration in the height direction of the raw material layer. , FIG. 7 is a graph showing temperature changes within the sintered bed layer, and FIG. 8 is a graph showing rotational strength. CI) - Pallet, (2) - Feed hosoba, (5) - Breeze hosoba, (9) - Blended raw materials, (10) - Coke powder, (12) - Branch pipe, (13L - Slit forming rod, (16)
) - filling part. Figure 1 Figure 2 Figure 4 Figure 6 Figure 8 Figure 7 Elapsed time after ignition (minutes)

Claims (1)

[Claims] The blended raw materials cut out at a constant rate from the ore feed hopper are charged onto the pallet of the sintering machine, and air is blown from above to below the charged blended raw material layer to mix it into the blended raw materials. When burning and sintering the powdered carbonized material, after charging the mixed raw materials onto the pallet and smoothing the upper surface, 1. A method for charging raw materials into a sintering machine, the method comprising: forming a filling section having a sintering structure, and charging powdered carbonized material into the filling section.