JPH04259335A - Production of sintered ore - Google Patents

Abstract

PURPOSE:To improve the strength and yield in the upper layer part of a sintering bed. CONSTITUTION:A roller 7 formed intermittently with annular projections in the transverse direction of a pallet on the outer periphery is freely rotatably and freely vertically movably provided on the surface of a sintering raw material layer 5 between a charging chute 3 and an ignition furnace 6. The roller 7 is press fitted at a specified depth into the surface of the sintering raw material layer 5 to compact the upper layer part of the sintering raw material layer 5. Many recessed grooves are formed by these projections on the surface, by which the raw materials are sintered. The roller 7 used in this invention is formed by mounting the annular projections 8 having 10 to 50mm height(h) and 3 to 10mm thickness at 100 to 500mm mounting intervals (b) on the outer periphery of the roller having the length slightly shorter than the width of the pallet. The strength and yield in the upper layer part of the sintering bed are improved with inexpensive equipment.

Description

[Detailed description of the invention]

0001

FIELD OF INDUSTRIAL APPLICATION This invention relates to a method for producing sintered ore that improves the strength and yield of the upper layer of a sintered bed.

0002

[Prior art] Sintering raw materials are loaded onto a moving pallet,
In a sintered ore production method in which sintered ore is produced by igniting the surface of a sintered raw material layer and sucking it downward, the strength of the upper layer of the sintered bed (sintered layer) is low, resulting in poor yield. This is thought to be because the upper layer of the sintering bed is cooled by the drawn-in cold air, and there is no longer enough temperature and time for sintering (lack of heat).

In order to prevent the strength of the upper layer of the sintering bed from decreasing, a method has been used in the past in which a heat retention furnace is provided following the ignition furnace and hot air is sucked into the sintered bed after ignition. This method using a heat retention furnace has the disadvantage of high equipment costs. For this reason, several proposals have been made for methods to replace the heat retention furnace. JP-A-58-217642 discloses a system in which coke is unevenly distributed in an ore feeding tank on a pallet in the direction in which the pallet advances, and mixed raw materials with a large amount of coke at the top are charged to the pallet using a drum feeder. Japanese Patent Publication No. 63-206
Publication No. 436 discloses that carbon material or a mixture of carbon material and sintering raw material is added to a position immediately before a sieve surface or to fine grains that have passed through a sieve surface, in which a plurality of rod-shaped materials are arranged at different inclination angles with the lower side thereof being chevron-shaped. In this method, a large amount of coke is added to the upper layer of the sintering raw material layer.

0004

[Problem to be solved by the invention] JP-A-58-2176
No. 42 requires a separate coke supply device for unevenly distributing coke in the ore feed tank. Further, Japanese Patent Application Laid-open No. 63-206436 also requires a coke feeding device, and both have the problem of high equipment costs.

[0005] Furthermore, due to the sintering compaction of the sintered bed, irregular and long cracks appear in the upper layer, which causes a decrease in yield (irregular cracks cause uneven firing of the sintered bed, (yield decreases).

It is an object of the present invention to provide an inexpensive method of improving the strength and yield of the upper layer of a sinter bed.

[0007]

[Means for Solving the Problems] The present invention aims to achieve the above-mentioned objects, and includes ring-shaped protrusions formed at intervals in the width direction of the pallet between the sintering raw material charging chute and the ignition furnace. This method of producing sintered ore is characterized by providing a roller and compacting the surface of the sintered raw material layer with the roller.

[0008]

[Operation] By compacting the surface of the sintering raw material layer, the sintering rate of the upper layer is moderately suppressed, and the strength and yield of the upper layer are improved. The protrusions of the rollers form a large number of grooves in the surface layer of the sintering bed in parallel to the direction in which the pallet travels, thereby suppressing a decrease in air permeability due to compaction. In addition, cracks that occur in the upper layer are dispersed and uneven burning is reduced.

[0009]

EXAMPLES Examples of the present invention will be described in detail below. FIG. 1 is an explanatory diagram of the method of the present invention. A certain amount of the sintering raw material fed to the surge hopper 1 is cut out by a roll feeder 2 and charged onto a moving pallet 4 via a charging chute 3. The sintered raw material layer 5 charged and formed to a constant thickness on the pallet 4 is ignited on its surface in an ignition furnace 6 and sintered downward by downward suction. In the present invention, on the surface of the sintered raw material layer 5 between the charging chute 3 and the ignition furnace 6, a roller 7 having ring-shaped protrusions formed on the outer periphery at intervals in the width direction of the pallet is provided. It is set up so that it can be moved. Note that since the pallet is rotated by movement, a drive device is not required. Then, a roller is press-fitted into the surface of the sintering raw material layer 5 to a certain depth to compact the upper layer of the sintering raw material layer 5, and sintering is performed by forming a large number of concave grooves made of protrusions on the surface. . The press-fitting depth d of the roller is hereinafter referred to as the consolidation depth.

As shown in FIG. 2, the roller 7 used in the present invention has a ring-shaped protrusion 8 with a height h of 10 to 50 mm and a thickness of 3 to 10 mm on the outer periphery of the roller whose length is slightly shorter than the width of the pallet. They are attached and formed at an attachment interval b of 100 to 500 mm.

Table 1 shows the operating specifications when the method of the present invention was carried out by changing the compaction depth of the rollers, the height of the protrusions, etc., and the operating specifications of a comparative example.

0012

[Table 1]

Comparative Example (1) is the result of a conventional method that does not use a compaction roller, and Comparative Example (2) is a result of a test using a roller without protrusions to confirm the effect of roller compaction. be. It was found that consolidation increases strength and reduces return ore consumption, but it also lowers production rate. This is because although consolidation improved the strength and yield of the upper layer, the air permeability decreased and the production rate decreased.

That is, the two are in an inversely proportional relationship, and it has been impossible with conventional techniques to improve them independently. Inventions (1) to (3) are the results of carrying out the method of the present invention with a consolidation depth of 20 mm, a constant interval of 300 mm between protrusions, and varying the height of the protrusions. As the height of the protrusion increases, the strength decreases (the return unit increases)
But the production rate increased.

[0015] Further, in the present invention (4) and (5), the consolidation depth was kept constant at 20 mm, the height of the protrusions was fixed at 30 mm, and the intervals at which the protrusions were attached were varied. The present invention (2),
From the results of (4) and (5), increasing the spacing between protrusions increases the strength (returning ore consumption rate decreases), but the production rate decreases. Next, the present invention (6) and (7) are obtained by setting the height of the protrusions to 10 mm and the mounting interval of the protrusions to a constant value of 300 mm, and varying the consolidation depth. The present invention (1),
From the results of (6) and (7), when the consolidation depth was increased, the strength increased (return ore consumption rate decreased), but the production rate decreased. This shows the same tendency as Comparative Examples (1) and (2). From these Examples, the present invention has a higher yield than Comparative Example (1) in all cases, and a higher production rate than Comparative Example (2).

[0016]

[Effects of the Invention] Since the present invention is constructed as described above, it is possible to improve the strength and yield of the upper layer of the sintering bed with inexpensive equipment, and also disperse cracks caused by compaction of the sintering bed. This can reduce uneven cooking.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the method of the present invention.

FIG. 2 is a perspective view of a roller used in the present invention.

[Explanation of symbols]

3 Charging chute 4 Palette 5　Sintering raw material layer 6 Ignition furnace 7 Roller 8.Protrusion

Claims (1)

[Claims] 1. A roller having ring-shaped protrusions formed at intervals in the width direction of the pallet is provided between the sintering raw material charging chute and the ignition furnace, and the surface of the sintering raw material layer is compacted by the roller. Sintered ore manufacturing method.