JP3273652B2 - Sintering method for sinter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for screening metallurgical ore such as iron ore after sintering.

[0002]

2. Description of the Related Art The size of such a sintered ore is widely distributed depending on its properties, and in order to supply the product to the next process such as a blast furnace, it is necessary to sieve it to a particle size suitable for the process. There is.

[0003] As means for carrying out this sieving efficiently, Japanese Patent Application Laid-Open No. 63-28481 discloses an ore sieving process using a coarse ore sieving line comprising two two-bed sieving apparatuses. A re-sieving line consisting of a two-bed sieve and a one-bed sieve is provided with a crusher between each line, and the crusher and each sieving line are bypassed to perform a sieving treatment and a crush sieving. It is disclosed that a flow of processing and pulverization processing is formed.

[0004] Thus, there is an advantage that the product ore processing of the raw ore including the sintered ore can be efficiently performed and the product size can be made uniform.

[0005]

However, in this sieving method, sieved ores of all sizes which are sieved by primary sieving are not directly recovered as products, but are sieved again by secondary sieving. As a result, the yield is poor due to the processing efficiency and the pulverization characteristics, and the processing capacity for the sinter which is sieved by the secondary sieve has to be increased.

An object of the present invention is to provide a sieving method capable of efficiently sieving sinter ore conforming to product standards and improving the processing efficiency of the entire sintering process.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a method for sintering a sintered ore by a sieving apparatus arranged in a plurality of stages. Sieving, separating on and below the sieve, separating the upper and lower sieves with a sieve of 40 to 60 mm, and crushing on the sieve of 40 to 60 mm sieve And a sieve of at least 4 mm and a top of the crushed 40 to 60 mm sieve under a sieve of 10 to 20 mm and a crushed sieve of 40 to 60 mm are sieved by a second sieve. This is a method for sintering a sintered ore comprising a step of returning to a raw material, and a step of carrying out a product above and below a sieve of 40 to 60 mm as a product.

[0008] The sieve arranged in the first stage has a structure in which a grizzly is provided in a predetermined area on the rear surface.

[0009]

The present invention has been completed based on new findings concerning the crushing characteristics of sintered ore.

That is, a. Since sinter is a fusion bond of iron ore, the coke powder as fuel may have an uneven distribution, and the bond strength is also uneven. The larger the size, the more thermal stress it receives, and it has cracks and pores inside during the cooling process. It has been found that the larger the size, the greater the gravitational acceleration energy when subjected to an impact, and the easier it is to break due to the internal structure.

[0011] Based on this knowledge, a powdering test (SI test) for giving a drop impact is performed.
It was found that the size was extremely high in powdering rate. Therefore, by extracting the sintered ore of about 10 to 60 mm in the vicinity of 15 to 50 mm by primary sieving to obtain a product, useless increase of the processing amount due to continuous pulverization and sieving is prevented.

Further, the coarse particles on the sieve are crushed by utilizing the property that the coarser the particles are, the more coarse the particles are, the more the coarse particles on the secondary sieve are crushed, and this is again passed through the secondary sieve. The upper portion of the sieve is taken out as a product. Thereby, the product conversion rate of the sintered ore can be increased, and the powderization rate can be minimized.

Here, the area under the second sieve is at least 4 mm, but is preferably in the range of 4 to 6 mm in order to stably operate the blast furnace as a product. Furthermore, sieving on a 10-20 mm sieve of the first stage sieve to 40-60 mm with a grizzly on the rear surface of the first stage can reduce vibration, suppress powdering and improve sieving efficiency. It is preferable because it is possible.

[0014]

FIG. 1 shows a flow chart for carrying out the present invention.

In FIG. 1, a sintering raw material A is cut out by a cutting device 1.
Is supplied to the sintering machine 2 and the ore B obtained by the sintering machine 2 is temporarily stored in the hopper 3 for sieving. 4
Is a primary sieving device arranged in the first stage among the sieving devices arranged in two stages, and has a 15 mm sieve. Reference numeral 5 denotes a secondary sieving device disposed immediately below the sifter, which has a 4 mm sieve. Reference numeral 6 denotes a crusher for crushing the upper portion of the sieve in the secondary sieving device 5. 7 is a sieving apparatus for separating a large size of the primary sieve, and has a sieve of 50 mm.

The sintered ore B cut out from the hopper 3 is
The mixture is sieved by a primary sieving device 4 with a sieve of 15 mm, further passed through a secondary sieving device 5, and the fraction C having a size of less than 4 mm is returned to the sintering machine 2 as returned ore. Further, sieve top fraction D of the primary sieving device 4 is supplied to a sieving device 7 subsequent, where it is sieved, is a sieve above component E ₁ of the lower component E ₂ sieves the foregoing 4~15mm The sintered ore of about 4 to 50 mm is formed into a product as a raw material to be supplied to a blast furnace or the like and is extracted. Sieve upper component E ₁ of 50mm greater in the secondary sieving device 7 is crushed by the crusher 6.

The sinter G crushed by the crusher 6 is returned to the secondary sieving apparatus 5, and the portion below the sifter of less than 4 mm is sieved from the sinter B directly supplied from the sintering machine 2. It is charged into the sintering machine 2 as returned ore with the lower part C.

As the above-mentioned sieving apparatus, a sieving apparatus having a structure in which a primary sieving apparatus 4 and a sieving apparatus 7 having a size above the primary sieving unit can be used.
Shows a specific structure of the secondary sieving apparatus 5.

In FIG. 1, the primary sieving device 4
Is a cast steel mesh 5 arranged at the upper part as a sieve on the inclined upper surface.
1 and a grizzly net 52 disposed below.
And is conveyed as a product by the belt conveyor 54.

The upper portion of the sieve is crushed by a crusher 6 disposed immediately below the end of the inclined upper surface sieve, and the upper surface of the secondary sieving device 5 is crushed by a chute 55 disposed below the sieving device. Drop on sieve 41.

The screen 4 on the upper surface of the secondary screening device 5
1 is made of an expanded metal net, and the portion below the sieve is returned to the sintering machine as return ore, and the portion above the sieve is used as a product.

Further, in the present invention, in order to prevent the sinter from being powdered, a chute for supplying the hopper 3 from the sintering machine 2 shown in FIG. Can be used.

In FIG. 3, reference numeral 8 denotes a chute disposed between the sintering machine 2 and the hopper 3 shown in FIG.
The chute 8 comprises a receiving surface 81 for temporarily receiving the sinter dropped from the end of the sintering machine 2 and a basket 82 following the receiving surface 81. For this reason, the sinter B dropped from the end of the sintering machine 2 is temporarily deposited on the receiving surface 81, and is transferred into the basket 82 by the amount of the deposited sinter B exceeding the angle of repose. You. In this case, the sinter ore B on which the falling energy is deposited gives frictional resistance and suppresses the speed, so that acceleration can be reduced and powdering can be prevented.

[0024]

According to the present invention, the following effects can be obtained.

(1) Among the sintered ores, an intermediate size that is easily pulverized is selectively recovered and formed into a product, so that the efficiency of the product can be improved.

(2) By recovering intermediate-size products on the primary sieve, the load on the secondary sieve can be reduced, and thus the secondary sieve equipment capacity can be reduced.

(3) The primary sieving device and the secondary sieving device
Because they can be arranged in series in stages, the powdering itself can be minimized.

[Brief description of the drawings]

FIG. 1 shows an example of a sieving apparatus for carrying out the present invention.

FIG. 2 shows an example of another sieving apparatus for carrying out the present invention.

FIG. 3 shows an example of a chute for preventing pulverization that can be applied when carrying out the present invention.

[Explanation of symbols]

A Sintering raw material B Sinter ore C Under-sieving of secondary sieving device D Over-sieving of primary sieving device E ₁ Over-sieving of secondary sieving device E ₂ Under-sieving of sieving following primary sieving Sinter ore after crushing of GE ₂ 1 Cutting device 2 Sintering machine 3 Hopper 4 Primary sieving device 41 Screen of primary sieving device 5 Secondary sieving device 51 Cast steel net 52 Grizzly net 53 Sieving device Chute 54 Belt conveyor 55 Chute 6 Crusher 7 Sieving device following primary sieve 8 Chute 81 Chute receiving surface 82 Chute basket

──────────────────────────────────────────────────続 き Continuing from the front page (72) Osamu Miyazaki Inventor 1-1, Hibata-cho, Tobata-ku, Kitakyushu-shi, Fukuoka Prefecture Nippon Steel Corporation Yawata Works (58) Field surveyed (Int.Cl. ⁷ , DB Name) C22B 1/00-61/00

Claims (1)

(57) [Claims] 1. A sieving method for sintered ore by a sieving apparatus arranged in a plurality of stages, wherein the sinter is sieved with a sieve mesh arranged in the first stage being 10 to 20 mm, and the sieved ore is sieved and sieved. A step of separating the top of the sieve with a sieve of 40 to 60 mm and a step of crushing the top of the sieve of 40 to 60 mm with a sieve of 40 to 60 mm; 40-60 crushed and crushed
a sieve of at least 4 mm and a sieve of at least 4 mm by a second sieve and returning the raw material to the sintering machine as returned ore under the sieve. And carrying out the product under the sieve as a product.