JP2007217729A - Method for regulating grain size of sintered ore, and oscillation-type classifier therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for regulating a grain size of a sintered ore, which inhibits the sintered ore from powdering when crushing the fired and sintered ore and classifying the grains into the sintered ore having an appropriate grain size as a raw material for a blast furnace, consequently can efficiently reduce a powdering rate, and besides, prevents the sintered ore having grain sizes exceeding the appropriate grain size from being transported as the raw material for the blast furnace, and to provide an oscillation-type classifier preferably used therefor. <P>SOLUTION: The oscillation-type classifier 9 has: a dispersively charging mechanism 19 for scattering the crushed sintered ore in a width direction of a screen; the first screen 15 having the mesh dimension of 5 mm; and the second screen 16 having the mesh dimension of 50 mm. The regulating method includes classifying the crushed sintered ore into a powdered ore under the first screen 15, the grains with an appropriate size under the second screen 16, and coarse grains on the second screen 16, while using the oscillation-type classifier 9. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sinter ore sizing method for adjusting the particle size (sizing) to a sinter having an appropriate particle size as a blast furnace raw material by crushing and classifying the fired sinter ore, and the shaking used at that time. It relates to a dynamic classifier.

  A conventional sinter ore sizing method is shown in FIG. The sintered ore fired on the sinter 1 with a pallet of about 5 m × 1 m is roughly crushed to a size of about 200 mm by the primary crusher 2. The coarsely crushed sintered ore is cooled by the cooler 3 and then sieved by a first stage sieve 55 having a screen of about 100 mm. The massive sintered ore exceeding 100 mm that has been screened on the sieve by the first-stage sieve 55 is supplied to the secondary crusher 4 and crushed with a target of 50 mm or less. The sintered ore crushed by the secondary crusher 4 merges with the lower sieve of the first stage sieve 55 and is supplied to the second stage sieve 56. Then, the screens of the second screen 56, the third screen 57, the fourth screen 58 and the screens of the screen are sequentially reduced, and 5 mm to 50 mm, which is an appropriate particle size as a blast furnace raw material, on the screens of the respective screens 56 to 58. The sinter having a particle size of 5 mm to 50 mm is supplied to the blast furnace 10. Note that the sintered ore having a particle size of 5 mm or less (hereinafter referred to as pulverized ore) generated during the crushing and classification is recovered as a sieve under the fourth-stage sieve 58 and is again used as a sintering material as a sintering machine. Returned to 1

  And, as the primary crusher 2, a single spike roll crusher in which a claw-like crusher called a demon tooth is provided on one roll is used, and the secondary crusher 4 is opposed to the primary crusher 2. A double roll crusher is used in which teeth that mesh with each other are provided on two rolls. In addition, a vibrating sieve having an amplitude of several millimeters is used for each of the first-stage sieve 55 to the fourth-stage sieve 58 serving as a classifier.

  A problem in the conventional sinter ore sizing method as described above is that the generation ratio (pulverization rate) of the pulverized ore to the baked sintered ore is considerably large. It has reached ~ 30%. The fact that there are many pulverized ores that are inappropriate as blast furnace raw materials and returned to the sintering machine means that productivity of the sinter ore sizing process is reduced and excess energy is consumed. Therefore, it is important to reduce the powdering rate in the sizing process.

  One of the reasons for the high pulverization rate in the sinter ore sizing process is that multiple-stage vibrating sieves are used to classify a large amount of sintered ore. There is a problem that pulverized ore is generated by pulverizing due to a transport drop while transferring the sieve.

  In view of this, several techniques have been proposed that attempt to reduce the powdering rate in the sizing process by improving the classification process using a vibrating sieve.

  For example, in Patent Document 1, by using a primary vibrating sieve arranged upstream of a crusher, an intermediate-sized sintered ore that is easily pulverized is collected in advance to reduce the load on the secondary vibrating sieve. A technique for improving classification efficiency and reducing the pulverization rate is disclosed.

  Further, in Patent Document 2, by reducing the sieve area of the second stage vibrating sieve arranged downstream of the crusher and reducing the supply amount to the third stage vibrating sieve, A technique that attempts to suppress the generation of pulverized ore is disclosed.

  However, in any of the techniques described in Patent Document 1 or Patent Document 2, in any case, a multi-stage vibrating sieve is used as a classifier, and thus the sintered ore transfers the multi-stage vibrating sieve. The problem that pulverized ore is generated by pulverizing due to a transport drop in the meantime is inevitable.

  Furthermore, the problem in the conventional sinter ore sizing method as shown in FIG. 7 is that the tops of the vibrating sieves 56 to 58 are collected as sintered ore for blast furnace raw material, As a result, an improper sintered ore having a particle size exceeding 50 mm may be conveyed to the blast furnace.

  That is, as shown in FIG. 8, even if the roll interval Gp of the secondary crusher 4 is set to the upper limit value (50 mm) of the appropriate particle size range, the elliptical crush whose long side exceeds the upper limit value (50 mm) In the conventional sintered ore sizing method as shown in FIG. 7, an elliptical crushed object whose long side exceeds the upper limit value is generated in each vibrating sieve 56 because the objects are generated with a certain probability. It is sieved on a ~ 58 sieve, conveyed as a blast furnace raw material, and stored in a raw material hopper. As a result, clogging may occur due to conveyor conveyance or raw material hopper cutting out, which may cause trouble.

  Therefore, in order to solve the above problem, the present applicant has proposed a new sinter ore sizing method in Japanese Patent Application No. 2005-342274 (unpublished application 1).

  That is, as shown in FIG. 5 and FIG. 6, the first screen 15 having a screen size of 5 mm and the second screen 16 having a screen size of 50 mm are shown. Are arranged so as to be inclined, and a peristaltic motion that reciprocates in the vertical direction and the inclined direction so as to feed the sintered ore on the first screen 15 and the second screen 16 downward in the inclined direction. Using the oscillating classifier 8 provided with the eccentric drive mechanism 17 for causing the first screen 15 and the second screen 16 to perform, the sintered ore (pulverized ore) having a particle size of less than 5 mm is applied to the first screen 15. Classification is performed under a sieve, and sintered ore (suitable grains) with a particle size of 5 mm to 50 mm is classified under the sieve of the second screen 16, and sintered ore (coarse particles) with a particle size greater than 50 mm is classified with a sieve of the second screen 16. It has proposed a sizing method of sintered ore, which was to form a two-minute class.

  In the sinter ore sizing method described in the unpublished application 1, three types of pulverized ore, appropriate grains, and coarse grains are obtained using an oscillating classifier 8 having two different screen sizes. Since it is classified into seeds, the generation of pulverized ore due to a transport drop while transferring multiple classifiers (vibrating sieves) as in the past is suppressed, and the pulverization rate can be reduced. it can. In addition, appropriate grains are classified under the sieve of the second screen 16 and conveyed as a blast furnace raw material, and improper coarse grains are classified and collected on the sieve of the second screen 16, so that an inappropriate coarse particle is collected. Grains are no longer transported as blast furnace raw material, and troubles in the conveyor and raw material hopper can be avoided.

  Usually, as the classification screen, a mesh screen knitted fine lines so as to have a mesh of a predetermined size, a punching screen punched flat plate to have holes of a predetermined size, Bar screens having a predetermined size gap by arranging bar members (bars) in parallel at predetermined intervals are selectively used based on their advantages and disadvantages.

  A mesh screen having a small mesh size can be easily manufactured, but since a fine wire having a wire diameter of 2 to 3 mm is used, the durability is somewhat inferior. Although the punched screen is durable, the ratio (opening ratio) of the total area of the air holes to the entire area of the screen is small, and the classification efficiency is slightly inferior. The bar screen is durable, but it is difficult to manufacture a bar screen with a small gap between the bars.

  Therefore, in the above sizing method, a mesh screen is used for the first screen 15 having a small mesh size, and any screen is used for the second screen 16 having a large mesh size.

Incidentally, here, the mesh of the mesh screen, the holes of the punched screen, and the gap between the bars of the bar screen are collectively referred to as “sieving mesh”, and the size thereof is called “sieving size”.
Japanese Patent Laid-Open No. 6-279872 JP 2001-181714 A

  However, in the sinter ore sizing method described in the aforementioned unpublished application 1, it is standard that the width Ws of the first screen 15 and the second screen 16 of the swing classifier 8 is about 2 m. On the other hand, the width Wc of the conveyor 20 that conveys the sintered ore crushed by the secondary crusher 4 is as narrow as about 0.5 m, and the conveyor belt of the conveyor 20 is V-shaped. Many.

  Therefore, since the sintered ore is locally charged from the conveyor 20 onto the first screen 15, the charged sintered ore is only a part of the entire width of the first screen 15 and the second screen 16. The classification efficiency (classification efficiency) does not increase. Further, when the amount of sintered ore that is locally introduced onto the first screen 15 increases, the wear of the first screen 15 increases.

  The present invention has been made in view of the circumstances as described above. When the sintered ore is crushed and classified to adjust the particle size to a sintered ore having an appropriate particle size as a blast furnace raw material, Suppressing the generation and efficiently reducing the pulverization rate, and the sinter ore sizing method in which the sintered ore with a particle size exceeding the appropriate range is not conveyed as a blast furnace raw material, An object of the present invention is to provide a swing classifier suitable for use in the above.

  In order to solve the above problems, the present invention has the following features.

  [1] In a sinter ore sizing method for adjusting the particle size to a sintered ore in a predetermined particle size range by crushing and classifying the sintered ore, When classifying into a sintered ore having a particle size smaller than a predetermined particle size range, a sintered ore having a particle size within a predetermined particle size range, and a sintered ore having a particle size larger than a predetermined particle size range, a first sieve having a predetermined sieve size is provided. Using a classifier provided with a screen and a second screen having a screen size larger than that of the first screen, the sintered ore having a particle size smaller than the predetermined particle size range is classified under the screen of the first screen, A sinter ore sizing method for classifying a sinter having a particle size in the predetermined particle size range under a sieve of the second screen, the crushed sinter being dispersed in a screen width direction on the screen. A sinter ore sizing method, characterized in that it is charged.

  [2] The sinter ore sizing method according to [1], wherein a sintered ore having a particle size larger than a predetermined particle size range is crushed again and supplied to the classifier again.

  [3] As a classifier, a first screen having a predetermined screen size and a second screen having a screen size larger than the first screen are arranged to be inclined, respectively, on the first screen and the second screen. Peristaltic classification provided with an eccentric drive mechanism for causing the first screen and the second screen to perform a peristaltic motion that reciprocates in the vertical direction and the inclining direction so as to feed the classifying object downwardly inclined. The sinter ore sizing method according to [1] or [2], wherein a machine is used.

  [4] A first screen having a predetermined screen size and a second screen having a screen size larger than that of the first screen are inclined and arranged on the classification objects on the first screen and the second screen. An eccentric drive mechanism for causing the first screen and the second screen to perform a peristaltic motion that reciprocates in the vertical direction and the tilt direction so as to feed the tilt downward is provided, and the screen size of the first screen A peristaltic type that classifies into a classifier having a smaller particle size, a classifier having a particle size larger than the screen size of the first screen and smaller than the screen size of the second screen, and a classifier having a particle size larger than the screen size of the second screen. This classifier is equipped with a width-direction dispersion feeding mechanism for dispersing the crushed sintered ore in the screen width direction and feeding it onto the screen. Swing type classifier, characterized in that.

  In the present invention, a classifier having a plurality of screens having different screen sizes is used to classify sintered ore having a predetermined particle size range under the screen screen. The generation of pulverized ore due to slag can be suppressed and the pulverization rate can be reduced, and the sintered ore with a particle size exceeding the specified particle size range is classified on the sieve. The ore is no longer transported as blast furnace raw material, and troubles in the conveyor transport and raw material hopper can be avoided. Moreover, since the crushed sintered ore is dispersed in the screen width direction and thrown onto the screen, it can be classified using the entire screen width, and good classification efficiency can be obtained. In addition, wear of the screen can be suppressed.

  A first embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a process flow diagram in the sinter ore sizing method according to the first embodiment of the present invention, and FIG. Incidentally, the processing flow diagram (FIG. 5) and the explanatory diagram (FIG. 6) of the swing classifier in the unpublished application 1 are substantially the same.

  That is, in this embodiment, as shown in FIG. 1, the sintered ore fired on the sinter 1 with a pallet of about 5 m × 1 m is roughly coarsened to a size of about 200 mm by the primary crusher 2. It is crushed. The coarsely crushed sintered ore is cooled by the cooler 3 and then supplied to the secondary crusher 4 where it is crushed with a target size of 50 mm or less. The sintered ore crushed by the secondary crusher 4 is supplied to the swing classifier 8. And in the rocking classifier 9, the sintered ore having a particle size appropriate for the blast furnace raw material (5 mm to 50 mm) and the sintered ore having a particle size smaller than the lower limit (5 mm) of the appropriate particle size range, Each is classified as a sieve. In addition, sintered ore having a particle size larger than the upper limit (50 mm) of the appropriate particle size range, such as the oval crushed material shown in FIG. 8, is classified on a sieve. Thereafter, the classified sintered ore having a particle size of 5 mm to 50 mm is supplied to the blast furnace 10. Further, the sintered ore (pulverized ore) having a particle size smaller than 5 mm is recovered and returned again to the sintering machine 1 as a sintering raw material.

  As shown in FIG. 2, the swing classifier 9 used in this embodiment includes a first screen 15 and a second screen 16 that are inclined inside the chamber 14 and arranged in series from above. The screen of the first screen 15 has a lower limit value of 5 mm of the predetermined particle size range, and the screen of the second screen 16 has an upper limit value of 50 mm of the predetermined particle size range. The first screen 15 and the second screen 16 are inclined downwardly to the sintered ore on the first screen 15 and the second screen 16 by an eccentric drive mechanism 17 such as a crank mechanism or a planetary gear. The rocking motion reciprocally moves in the vertical direction and the tilt direction. As a result, the amplitude can be increased as compared with existing vibrating sieves, and the repulsive force can be applied to the sintered ore to increase the classification efficiency.

  And this embodiment is different from the unpublished application 1 in that the sintered ore transported from the secondary crusher 4 by the transport conveyor 20 is dispersed in the screen width direction and thrown onto the first screen 15. In order to do so, the width direction dispersion input mechanism 19 is provided above the first screen 15.

  For example, as shown in FIGS. 3 (a) and 3 (b), the width-direction dispersion charging mechanism 19 includes an inclined plate 19a and a dispersing wedge 19b attached to the upper surface of the inclined lower end of the inclined plate 19a. is there. The sintered ore conveyed from the secondary crusher 4 by the conveying conveyor 20 is supplied to the upper surface of the inclined upper end of the inclined plate 19a, and then dispersed in the screen width direction by the dispersing wedge 19b. 1 screen 15 is inserted.

  When the sinter is supplied from the secondary crusher 4 to such a swing classifier 9, the sinter (pulverized ore) having a particle size smaller than 5 mm under the sieve is classified by the first screen 15. By the classification by the second screen 15, sintered ore (appropriate grains) having a particle size of 5 mm to 50 mm is recovered under the sieve, and the sintered ore having a particle size larger than 50 mm is collected on the sieve of the second screen 15. Coarse grains) are recovered.

  Thereafter, as described above, the sintered ore having a particle size of 5 mm to 50 mm is supplied to the blast furnace 10, and the sintered ore (pulverized ore) having a particle size smaller than 5 mm is recovered, and again as a sintering raw material, a sintering machine Returned to 1

  In this embodiment, the entrance side of the secondary crusher 4 is provided with an inclined surface that can smoothly put the sintered ore sent from the cooler 3 between the crushing rolls, and the inclined surface is a sintered ore. Is provided with a dispersion charging mechanism 18 having an inclination for dispersing the powder in the crushing roll width direction.

  Thus, in this embodiment, the rocking classifier 8 having two types of screens having different sieve sizes is used to classify into three types of powdered ore, appropriate grains, and coarse grains. Therefore, generation | occurrence | production of the pulverized ore by the conveyance drop while transferring a several classifier (vibration sieve) like the past is suppressed, and reduction of a pulverization rate can be aimed at. In addition, appropriate grains are classified under the sieve of the second screen 16 and conveyed as a blast furnace raw material, and improper coarse grains are classified and collected on the sieve of the second screen 16, so that an inappropriate coarse particle is collected. Grains are no longer transported as blast furnace raw material, and troubles in the conveyor and raw material hopper can be avoided. In addition, since the crushed sintered ore is dispersed in the screen width direction by the width direction dispersion input mechanism 19 and input onto the first screen 15, it can be classified using the entire screen width, Good classification efficiency can be obtained, and screen wear can be suppressed.

  Next, a second embodiment of the present invention will be described.

  FIG. 4 is a process flow diagram in the sinter ore sizing method according to the second embodiment of the present invention. In the second embodiment, the coarse ore particles (sintered ore having a particle size larger than 50 mm) classified on the sieve of the second screen 16 in the sinter ore sizing method according to the first embodiment described above. Then, after being supplied again to the secondary crusher 4 and crushed, it is supplied again to the swing classifier 8. That is, it is a three-class classification type closed circuit sizing process.

  In such a second embodiment, the roll interval Gp of the secondary crusher 4 is widened to suppress the generation amount of powdered material during crushing without applying excessive force to the sintered ore, and the roll interval Since the coarse particles generated by expanding Gp are collected on the screen of the second screen 16 and crushed again, the particle size distribution is adjusted. In addition, when the roll rotation speed of the secondary crusher 4 is made the same as that of the first embodiment by increasing the roll interval Gp, the processing amount (passage amount) per unit time is increased. Therefore, when the processing amount per unit time is the same as in the first embodiment, the roll rotation speed can be reduced, the impact force on the sintered ore during crushing can be reduced, and the amount of powdered material generated Can be suppressed.

  And also in this embodiment, using the swing type classifier 9 having two types of screens with different sieve sizes, it is classified into three types of powdered ore, appropriate grains and coarse grains, As in the past, generation of pulverized ore due to a transport drop while transferring a plurality of classifiers (vibrating sieves) is suppressed, and the pulverization rate can be reduced. In addition, appropriate grains are classified under the sieve of the second screen 16 and conveyed as a blast furnace raw material, and improper coarse grains are classified on the sieve of the second screen 16, so improper coarse grains are classified into the blast furnace. It is no longer conveyed as a raw material, and troubles in the conveyor and raw material hopper can be avoided. In addition, since the crushed sintered ore is dispersed in the screen width direction by the width direction dispersion input mechanism 19 and input onto the first screen 15, it can be classified using the entire screen width, Good classification efficiency can be obtained, and screen wear can be suppressed.

  In the above, using a classifier provided with a first screen 15 having a screen size of 5 mm and a second screen 16 having a screen size of 50 mm, a lower limit (5 mm) of an appropriate particle size range. Sintered ore with a smaller particle size is classified under the sieve of the first screen 15, and sintered ore with an appropriate particle size range (5 to 50 mm) is classified under the sieve of the second screen 16. However, a third screen having a screen size (for example, 15 mm) larger than the screen size of the first screen 15 and smaller than the screen size of the second screen 15 is provided between the first screen 15 and the second screen 16. Using a classifier disposed in the middle, the sintered ore having a particle size smaller than the lower limit (5 mm) of the appropriate particle size range is classified under the sieve of the first screen 15, and the appropriate particle size range (5 mm to 50 mm). )so The sintered ore having a small particle size (5 mm to 15 mm) is classified under the sieve of the third screen, and the sintered ore having a large particle size (15 mm to 50 mm) is obtained in the second screen 16 even in an appropriate particle size range (5 mm to 50 mm). It can also be classified under a sieve.

It is a processing flow figure in a 1st embodiment of the present invention. It is explanatory drawing of the rocking classifier used in the 1st Embodiment of this invention. It is a figure explaining the width direction dispersion | distribution injection | throwing-in mechanism in the 1st Embodiment of this invention. It is a processing flowchart in the 2nd Embodiment of this invention. It is a processing flow figure of Japanese Patent Application No. 2005-342274. It is explanatory drawing of the rocking | swiveling classifier of Japanese Patent Application No. 2005-342274. It is a processing flow figure in a prior art. It is explanatory drawing of the crushing state in a secondary crusher.

Explanation of symbols

1 Sintering Machine 2 Primary Crusher 3 Cooling Machine 4 Secondary Crusher 8 Oscillating Classifier 9 Oscillating Classifier 10 Blast Furnace 14 Chamber 15 First Screen 16 Second Screen 17 Eccentric Drive Mechanism 18 Dispersion Input Mechanism 19 Width Directional dispersion feeding mechanism 19a Inclined plate 19b Dispersing wedge 20 Conveyor 54 Secondary crusher 55 First stage sieve 56 Second stage sieve 57 Third stage sieve 58 Fourth stage sieve

Claims (4)

  In the sinter ore sizing method for adjusting the particle size to a sintered ore having a predetermined particle size range by crushing and classifying the fired sintered ore, the crushed sintered ore is divided into a predetermined particle size range. A first screen having a predetermined mesh size for classification into a sinter having a smaller particle size, a sinter having a particle size in a predetermined particle size range, and a sinter having a particle size larger than a predetermined particle size range; Using a classifier provided with a second screen having a sieve size larger than the first screen, the sintered ore having a particle size smaller than the predetermined particle size range is classified under the first screen, and the predetermined screen A sinter ore sizing method in which sintered ore having a particle size in a particle size range is classified under the sieve of the second screen, and the crushed sintered ore is dispersed in the screen width direction and charged onto the screen. A method for regulating the size of sintered ore.   The sinter ore sizing method according to claim 1, wherein the sinter having a particle size larger than a predetermined particle size range is crushed again and supplied to the classifier again.   As a classifier, a first screen having a predetermined screen size and a second screen having a screen size larger than the first screen are arranged to be inclined, and classification objects on the first screen and the second screen A peristaltic classifier having an eccentric drive mechanism for causing the first screen and the second screen to perform a peristaltic motion that reciprocates in the vertical direction and the slant direction so as to feed the slant downwardly to the screen is used. The sinter ore sizing method according to claim 1 or 2. A first screen having a predetermined screen size and a second screen having a screen size larger than the first screen are arranged to be inclined, and are inclined with respect to the classification object on the first screen and the second screen. Equipped with an eccentric drive mechanism for causing the first screen and the second screen to perform a peristaltic movement that reciprocates in the vertical direction and the tilt direction so as to feed downward, and a particle size smaller than the screen size of the first screen And a peristaltic classifier that classifies into a classifier having a particle size larger than the screen size of the first screen and smaller than the screen size of the second screen, and a classifier having a particle size larger than the screen size of the second screen. It is equipped with a width direction dispersion input mechanism for dispersing the crushed sintered ore in the screen width direction and putting it on the screen. Swing type classifier which is characterized.

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