JPS63121605A - Treatment of over size powder in iron powder disintegrating equipment - Google Patents

Abstract

PURPOSE:To improve the yield of under size powder by redisintegrating the over size powder, which is obtd. after classification of the disintegrated matter of the plate-shaped iron powder cake produced by an iron powder reduction furnace, at the rotating speed of a redisintegrating machine according to the demanded apparent density of the product iron powder. CONSTITUTION:The plate-shaped iron powder cake solidified by the iron powder reduction furnace is disintegrated by primary and secondary disintegrating machine. The disintegrated matter is sieved to the under size powder of the diameter smaller than the prescribed grain size and the over size powder of the diameter larger than said size. The over size powder is redisintegrated by the redisintegrating machine. The disintegrating hammer of said redisintegrating machine rotates at variable speeds. The hammer rotates at the speed higher as the density is higher and at the speed lower as the density is lower, according to the demanded apparent density.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is produced by coarsely pulverizing an iron powder cake using a primary pulverizer, finely pulverizing it using a secondary pulverizer, and then classifying it. The present invention relates to a method for processing over powder, and particularly to a method that can improve the recovery efficiency of over powder as product iron powder and improve the overall yield.

[Conventional technology]

Generally, iron powder that has been reduced in a reduction furnace is extracted as a solidified plate-shaped iron powder cake, so it is first coarsely pulverized by a primary granulator, and then coarsely granulated by a secondary granulator. After being finely pulverized, it is passed through a vibrating sieve and sifted into under powder and over powder.

Then, the under powder is recovered as product iron powder, and the over powder is re-disintegrated by a re-pulverizing machine, and the under powder is recovered after being sieved by a vibrating sieve.

[Problem that the invention seeks to solve]

By the way, the above-mentioned re-pulverizing machine uses the same model as the feather mill that is conventionally adopted as a secondary crushing machine, but the feather mill
Since the mill can only change the Rossdol mesh, it is difficult to control the product quality according to the required apparent density of the product iron powder. If a re-crushing machine compatible with this is installed, the re-crushing function will not be sufficient for over-powder in the case of medium and low-density product iron powder, and it will be difficult to obtain under-powder even if re-crushing is performed. There is a problem that the yield is low.

The present invention has been made in order to solve the problems of the conventional apparatus described above, and it is possible to re-disintegrate the product iron powder according to the required apparent density, and to process over-powder that can improve the yield of under-powder. The purpose is to provide a method.

[Means for solving problems]

The present invention provides a method for processing over-powder in which the over-powder is re-pulverized in an iron powder disintegrating equipment that sieves the iron powder cake into under-powder and over-powder after primary and secondary disintegration. In , the rotation speed of the crushing hammer of the over powder re-pulverizing machine was changed to a higher speed for higher densities and a lower speed for lower densities, depending on the required apparent density of the product iron powder, to re-crack the over powder. It is a feature.

[Effect]

According to the method for treating oversized powder in iron powder crushing equipment according to the present invention, the rotation speed of the re-granulator is changed according to the required apparent density of the product iron powder, so the particle size of the generated oversized powder is The over powder can be re-disintegrated with the rotational energy corresponding to the rotational energy, and the degree of disintegration can be easily adjusted for over powder of high, medium, and low density, and as a result, the yield of under powder can be improved.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIGS. 1 to 4 are diagrams for explaining an over-powder processing method in an iron powder crushing facility according to an embodiment of the present invention.

In the figure, reference numeral 1 denotes a primary crushing equipment for coarsely pulverizing a solid iron powder cake that has been subjected to reduction treatment in a reduction furnace (not shown) and is conveyed by a steel belt 2. A variable speed granulator 4 as a primary granulator is provided at the lower part of the installed chute 3, and a discharge chute 4a of the granulator 4 is provided with a horizontal transfer lift 5 extending horizontally and a vertical transfer lift 6 extending vertically upward. It is configured by connecting them sequentially.

7 is a secondary disintegration equipment for finely disintegrating and classifying the coarsely disintegrated iron powder. A bread fur hopper 10 is connected to the lower part of the bread fur hopper 10 via a bellows-type expansion joint 9, and a vibration feeder 11 is arranged at the lower part of the bread fur hopper 10 through the expansion joint 9. Feather mill 1 as a granulator
2 is installed, and a vibrating sieve 13 is connected to the lower part of the feather mill 12 via an expansion joint 9.

Further, a 90-mesh screen is stretched between the upper sieve tub 13a and the lower sieve tub 13b of the vibrating sieve machine 13. An over powder collection pipe 14a is connected to the upper sieve tub 13a, the lower end of the collection pipe 14a is connected to an over powder vibrating conveyor 15, and an under powder collection pipe 14b is connected to the lower sieve tub 13b. The lower end of the collection pipe 14b is connected to the under powder vibrating conveyor 16. Note that 20 is a recovery hopper for recovering the sifted under powder.

Reference numeral 21 denotes a first re-crushing device for re-crushing the over-flour, which is connected to the over-flour vibrating conveyor 15.
．． A buffer hopper lOa that accommodates the overflow collected by the vertical transfer lift 6a, and the buffer hopper 10
a vibrating feeder lla connected to a, and the feeder IL
It is comprised of a variable speed re-pulverizer 23 for re-pulverizing the oversized powder conveyed by a, and a vibrating sieve 13 connected to the re-pulverizer 23.

The variable speed re-granulator 23 has a rotational speed of 3
0"100m/5ecO, and is a high circumferential speed pulverizer in which a knife type or stirrup type pulverizer is attached to the rotor as a pulverizing hammer. Also, the drive device 27 of this variable speed pulverizer 23 has a , a hammer speed control device 28 is connected, and this control device 28 is configured to control the rotation of the rotor at a higher speed as the required apparent density S of the product iron powder in the secondary disintegrator 12 increases. In other words, on the 2nd day of this control device, depending on the steel type, the
.

The apparent density S-rotational speed V map shown in (b) is stored, and the required rotational speed V is stored according to the required apparent density S.
is mapped and the speed of the drive device 27 is controlled based on this map.

Here, the map shown in Fig. 4 above was determined in advance through an experiment, and this experiment was carried out using a knife type atomizer as the atomizing hammer for the variable speed a23 a23 for two types of over powder (X, Y) with different steel types. The pulverizer was pulverized by using a stirrup-type pulverizer and a pulverizer screen having a hole diameter of 1 or 2 φ while changing its rotational speed.

Figure 4 (al indicates the case where Over@X is re-milled,
Figure 4-) shows the case where the over powder Y is re-disintegrated, in which the Ol symbol indicates the case where a knife-type hammer is used, and the △ and M symbols indicate the case where a stirrup-type hammer is used. Also, both of the above symbols! A = ri indicates the case when the screen is passed through a screen with 1 x play φ, and the white box indicates the case where the screen is passed through a screen with 2 play φ.

Further, a flow rate detector 29 is installed downstream of the variable speed granulator 23.
is arranged, and its detected flow rate is >fi f1 (not shown)
input to the control device. This flow rate control device is configured to control the conveyance frequency of the vibrating feeder 11a so that the detected flow rate becomes a flow rate corresponding to the sieving capacity of the vibrating sieve machine 13.

Furthermore, the upper sieve tub +38 of the vibrating sieve W113
An over powder collection pipe 14a is connected to the collection pipe 14.
a is branched into a vertical transfer lift 6a and an over powder recovery conveyor 25 by a switching damper 24. The recovery conveyor 25 is connected to a second re-pulverizing device 22 that further re-pulverizes the oversized powder from the first re-pulverizing device 21.

This second re-pulverizing device 22 is for crushing the over powder into product iron powder for another purpose, and its configuration is the same as that of the first re-pulverizing device described above.
It is almost the same as the re-crushing device 21, and includes a panferhofper 10b, a variable speed high-speed crusher 23a, and a vibrating sieve l113.
It is composed of d, etc.

Next, a case will be described in which the method of this embodiment is implemented using the above-mentioned apparatus.

The iron powder cake conveyed by the steel belt 2 is
Coarsely granulated by the primary granulator 4, transfer lifts 5, 6,
Feather powder is stored in a buffer hopper 10 by a vibrating conveyor 8, and is fed into a feather as a secondary crusher by a vibrating feeder 11.
After being transported to a mill 12 and finely granulated there, it is sieved into under powder and over powder by a vibrating sieve 13, and this under powder is sent to a recovery hopper 20 as product iron powder.
will be collected.

Further, the overflour collected by the overflour vibrating conveyor 15 is transferred to the buffer hopper 10a by the vertical transfer lift 6a, and the overflour stored in the hopper 10a is supplied to the variable speed crusher 23. This re-granulator 23 has its rotational speed V controlled by a control device 28 at variable speed according to the apparent density S of the product iron powder. The steel type is Y and the required apparent density S of the product iron powder is 2°8g7
In the case of cc, the rotational speed V=6011/S is read from the map shown in FIG. 4(b), and control is performed using this speed. Further, as the apparent density S further decreases, the rotational speed (2) is lowered, and as the apparent density S becomes larger, the rotational speed (2) is increased. As a result, the desired underpowder can be obtained.

Furthermore, the iron powder from the re-granulator 23 is passed through a vibrating sieve 13.
The sifted under powder is transferred to the recovery hopper 20, and the over powder is transferred to the second re-granulation device 22, where they are further re-granulated at the same rotational speed as the secondary purpose product iron powder. It is processed.

As described above, according to the method of this embodiment, the oversized powder from the secondary disintegrating equipment 7 is redissolved by the first redisintegrator 21 at a rotational speed according to the required apparent density and particle size distribution of the product iron powder. Since it is made into granules, the degree of disintegration of the over powder can be adjusted to suit the product, and as a result, the re-collection of the under powder can be greatly improved, and the yield of product iron powder can be improved.

In addition, in this embodiment, since the overflow from the first re-crushing device 21 is further re-cracked, the overflow, which was conventionally disposed of as waste, can be used for secondary purposes such as product iron powder, such as welding rods. It can be used as a core wire, and the overall yield can be improved.

In addition, in the above example, the over powder from the secondary crushing equipment is transferred to the first pulverizer. Although the second re-crushing device 21 and 22 re-cracked the granules twice, in the present invention, it is not necessarily necessary to re-crack the grains twice.
− times may be used.

〔Effect of the invention〕

As described above, according to the over-powder processing method in the iron powder disintegrating equipment according to the present invention, the over-powder after being classified is processed by the variable speed re-granulator at a rotation speed according to the required apparent density of the product iron powder. Since the powder is re-disintegrated, the degree of disintegration of the over-powder can be easily adjusted according to the required apparent density, and the yield of the under-powder can be improved.

[Brief explanation of the drawing]

Fig. 1 is an overall configuration diagram of iron powder disintegration equipment for explaining an over-powder processing method according to an embodiment of the present invention, and Fig. 2 shows its primary and secondary disintegrators and first re-disintegrator parts. Configuration diagram,
Figure 3 is a block diagram of the first re-granulator, and Figure 4 is a characteristic diagram showing the relationship between the rotational speed and apparent density of the variable-speed pelletizer. It is. In the figure, 4 is a variable speed granulator M (primary granulator), 12 is a feather mill (secondary granulator), and 23 is a variable speed regranulator. Patent Applicant Kobe Steel Co., Ltd. Representative Patent Attorney Tsutomu Tsutomu Figure 3

Claims (1)

[Claims] (1) After the plate-shaped iron powder cake solidified in the iron powder reduction furnace is sequentially primary and secondary granulated using a primary and secondary granulator according to the specified required apparent density, In an iron powder disintegration equipment that sieves into small-diameter under-powder and large-diameter over-powder, the above-mentioned over-powder is re-pulverized by a re-pulverizer, the above-mentioned The granulating hammer of the re-granulator is rotated at a variable speed so that the rotation speed is higher as the density is higher and lower as the density is lower, depending on the required apparent density in the secondary granulator. Over powder processing method in iron powder granulation equipment.