JPH0634939B2 - Surface modification method of granules - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for surface modification of granules, in which the child substance is peeled from the particles to be treated in which the child substance is attached to the particle surface of the mother substance.

More specifically, the present invention relates to a method of centrifugally flowing the particles to be treated or the particles to be treated and the modifying medium to separate the child substance from the surface of the particles to be treated.

[Prior Art] Conventionally, as a surface modification method of this type, in addition to a sieving method,
A method using an inertial force classifier, a rotating basket type classifier, or the like is known. 3 to 5 are explanatory views of a conventionally known reforming method, and FIG. 3 is a schematic perspective view by a sieving method. Reference numeral 40 denotes a sieve, and the particles to be treated are supplied onto the sieve, and the particles to be treated are shaken or vibrated up and down or back and forth respectively on the sieve to rub the particles to be treated with each other. The substance is separated into a child substance, and after the separation, the mother substance is collected as a residue on the sieve and the child substance is collected under the sieve. Fourth
The figure is a schematic diagram of the reforming method using an inertial force classifier.When the particles to be treated are ejected at high speed toward the wall surface, the particles to be treated collide with the wall surface with the kinetic energy obtained. The child matter is peeled off by the impact at the time of this collision. At this time, if air is made to flow from the lower side to the upper side in parallel with the wall surface at the same time, the base substance falls against the flow of air, and the child substance is carried along with the air and carried out upward. FIG. 5 shows a reforming method using a rotating basket type classifier.
While rotating No. 1 at an appropriate angle, air is made to flow from the lower side to the upper side of the rotating cylinder 41, and conversely, the particles to be treated are supplied to the upper side of the rotating cylinder 41 from the chute 42 arranged above the rotating cylinder 41. Then, the particles to be treated are rubbed and conveyed toward the lower part of the rotating cylinder 41 in the rotating cylinder 41, the mother substance flows down to the lower part of the rotating cylinder 41 against the air, and the child substance is discharged from the upper part of the rotating cylinder 41. They are carried along with the air and separated.

[Problems to be Solved by the Invention] Each of the above-mentioned reforming methods has the following drawbacks. That is, in the classification method in the sieving method, the peeling of the child substance is insufficient when the child substance is hard, and the quality tends to deteriorate when the mother substance is used as a product.

In the reforming method using an inertial force classifier, kinetic energy is applied to the particles to be treated and they collide with the wall surface at high speed.Therefore, if the separation efficiency of the matrix substance and the daughter substance is poor, they must be repeatedly collided. Therefore, the base material is likely to be deformed. Further, when the particles to be treated collide with the wall surface, a part of the child substance bites into the mother substance, and the child substance cannot be sufficiently peeled off. For these reasons, the quality tends to deteriorate when the base material is used as a product.

In the reforming method using the rotating basket type classifier, the efficiency of peeling off the child substance is poor. Further, even if the number of rotations is increased to improve the peeling efficiency, the number of rotations is limited because of the synchronous speed, and low speed rotation is forced. Further, the child substance once separated from the base substance stays in the rotating cylinder together with the base substance for a long time. For this reason, since the child substance which has been peeled off with a great deal of reattachment to the mother substance or digging into the mother substance again, peeling of the child substance tends to be insufficient. Therefore, as a result of these, when the matrix material is used as a product, the quality is likely to deteriorate. In addition, the child substances that have been once separated are often solidified together.

Further, in any of the conventional examples shown in FIGS. 3 to 5, almost no surface modification was possible for small particles having a particle size of about 1 mm or less.

[Means for Solving the Problems] The present invention relates to an improvement in a surface modification method of a granular material, in which the child substance is separated from a treated granular material in which the child substance is attached to the particle surface of the mother substance. .

In the method for modifying the surface of granules according to claim (1), the axis of rotation is oriented in the longitudinal direction, and at least the central portion has a dish surface that expands downward, and the longitudinal cross section of the dish surface. Has a shape of a freely rotatable circular rotating dish having a concave shape, and at least an upper portion having an inner wall surface whose diameter decreases upward, and the longitudinal cross section of the inner wall surface has a concave shape. And a stationary ring that is coaxially provided around the rotating dish and is stationary, and the plate surface of the rotating dish and the inner wall surface of the stationary ring have a minute gap between the rotating dish and the stationary ring. Except that the apparatus formed is a continuous smooth surface.

The surface of the granules to be treated is rotated by rotating the rotary dish in a state where the granules to be treated or the granules to be treated and the reforming medium are contained in a reforming chamber surrounded by the dish surface and the inner wall surface of the apparatus. The child substance is peeled off, the gas is introduced into the reforming chamber through the minute gap between the rotary dish and the fixed ring, and the child substance peeled off from the particles to be treated is conveyed by air flow and discharged to the outside of the reforming chamber. Let

In the rotating dish according to claim (2), the central portion of the dish surface is expanded downward, the intermediate portion continuing to the central portion is substantially horizontal, and the outer peripheral portion continuing to the intermediate portion is directed upward. Has a shape to expand the diameter. Further, the fixed ring has a shape in which a lower portion is expanded in diameter upward, is substantially vertical in an intermediate portion continuing to the lower portion, and is reduced in diameter upward in an upper portion continuing to the intermediate portion. There is.

[Operation] The particles to be treated or the particles to be treated and the reforming medium are housed in a chamber surrounded by the dish surface of the rotating dish and the inner wall surface of the fixed ring, and the rotating dish is rotated, whereby the particles to be treated are treated. The reforming medium revolves in the circumferential direction at a slower speed than the rotation speed of the rotating dish, and also makes a vertical circular motion that circulates on the plate surface and the inner wall surface, and twists the rope that combines these two motions. Such a spiral progressive movement (this movement is commonly called centrifugal flow) is performed.
As a result, the particles to be treated or the particles to be treated and the modifying medium rub against each other, and the sub-substances are separated from the surface of the particles to be treated. Further, in parallel with this, when the gas is introduced from the gap between the rotary dish and the fixed ring, the separated child substance is conveyed by air flow and quickly discharged outside the room, and separated from the object substance.

The surface reforming apparatus used in the present invention centrifuges the particles to be treated and the reforming medium, and has a remarkable grinding effect on the surface of the particles to be treated. Therefore, the child substance is peeled off in a short time. Further, since the separated child substance is quickly discharged by the introduced air, the mother substance and the child substance can be efficiently separated.

In addition, when the mother substance is soft and the child substance is hard, or even when the mother substance is hard and the child substance is soft, the residence time of the particles to be treated in the device is changed, This can be easily dealt with only by changing the degree of friction between the particles to be treated and the modifying medium.

Further, the child substance can be reliably peeled off even from the small-diameter particles.

According to claim (2), the centrifugal flow of the particles to be treated and the reforming medium is performed more smoothly, so that the surface reforming effect is extremely high.

Embodiments Embodiments will be described below with reference to the drawings.

FIG. 2 is a side view of an apparatus suitable for carrying out the method of the present invention,
FIG. 1 is a longitudinal sectional view of a main part.

Reference numeral 1 is a fixed ring, and 2 is a rotary dish. The fixed ring 1 is fixed to the upper side of a drum-shaped casing 4 whose bottom surface is sealed by a plate 3, and the plate 3 is supported by a pedestal 5. A support block 6 is fixedly mounted on the rotary plate 2, and the support block 6 is supported by the plate 3 via a bearing device 7. That is, the opening 8 is formed in the central portion of the plate 3, and the flange portion 1 of the bearing housing 9 is formed.
0 is locked to the edge of the opening 8 and fixed by a bolt 11. A drive shaft 12 is connected to the lower side of the support block 6, and the drive shaft 12 is connected to an output shaft 15 of a speed reducer 14 via a joint 13. Reference numeral 17 is a variable speed motor for driving, and is connected to the speed reducer 14.

A lid member 18 is attached to the upper side of the rotary plate 2.
The lid member 18 is provided with a flange 19 on the outer circumference of the lower end thereof, and the flange 19 is placed on a flange 20 formed on the outer peripheral edge of the upper end of the fixed ring 1 and fixed by a bolt 21. A discharge pipe 22 is installed in the center of the lid member 18, and the fixed ring 1, the rotary plate 2 and the lid member 1 are provided in the discharge pipe 22.
It communicates with the reforming chamber 23 surrounded by 8. Lid member 18
Is provided with a charging pipe 24, and the inside of the charging pipe 24 communicates with the inside of the reforming chamber 23.

Next, the configurations of the fixed ring 1 and the rotary plate 2 will be described in detail with reference to FIG.

The fixed ring 1 has a ring shape installed with the axial direction being the vertical direction, and the diameter of the middle portion (hereinafter referred to as the middle portion) 1b in the height direction is the largest. The fixed ring 1 is the middle part 1
A lower portion (hereinafter, referred to as a lower portion) 1c is slightly reduced in diameter from b, and an upper portion (hereinafter, referred to as an upper portion) 1a is reduced in diameter from the middle portion. Therefore,
The inner wall surface 1A of the fixed ring 1 has a diameter that slightly expands from the lower portion 1c toward the middle portion 1b, the middle portion 1b is substantially vertical, and the diameter decreases from the middle portion 1b toward the upper portion 1a. The wall surface 1A has a curved vertical cross section. A flange 25 is provided on the outer peripheral surface of the middle portion 1b of the fixed ring 1,
The flange 25 is placed on a flange 26 formed on the outer periphery of the upper end of the casing 3, and is fixed by a bolt 27.

The plate surface of the rotary plate 2 has a shape in which the diameter increases downward in the central portion 2a, is substantially horizontal in the intermediate portion 2b continuing to the central portion, and is substantially horizontal in the outer peripheral portion 2c continuing to the intermediate portion 2b. The shape is such that the diameter increases upward. This plate surface 2
A is concavely curved as a whole, and the inner wall surface 1A of the stationary ring 1 and the dish surface 2A form a continuous smooth surface except for a minute gap 29 between the stationary ring 1 and the rotary dish 2. Is forming.

A pointed cap 30 is attached to the central portion of the rotary plate 2 and is fixed by a bolt 31. A shaft hole 32 is bored in the central portion of the rotary plate 2, and the support block 6
The upper end of is fitted into the shaft hole 32. Bolt 31
The lower end of the piece 3 is provided on the upper end of the support block 6.
It is screwed to 3.

Although not shown, the inner wall surface 1A of the fixed ring 1 and the rotary plate 2
A liner is attached to each of the dish surfaces 2A.

The plate 3 is provided with an inlet 34 for introducing a gas such as air, and the gas is supplied through a pipe 35 to the gas chamber 3 in the casing 3.
It can be introduced in 6.

A powder collecting means (not shown) such as a back filter is connected to the discharge pipe 22.

Next, an example of the surface modification method of the powder by the apparatus configured as described above will be described.

In advance, a large number of reforming media made of, for example, spherical balls are inserted into the reforming chamber 23. First, for example, the particles to be treated in which the child substance different from the mother substance adheres to the surface of the mother substance particles are charged into the apparatus through the charging pipe 24. The granules to be treated and the reforming medium circulate between the inner wall surface 1A of the fixed ring 1 and the dish surface 2A as the rotating dish 2 rotates (arrow S), and the orbital motion of the rotating dish 2 around the axis. A spiral movement (centrifugal flow) is carried out like a rope due to the synthesis with, and the surface of the particles of the particles to be treated is ground or stripped in the meantime.

That is, when the rotary plate 2 is rotated, the reforming medium is moved in the outer peripheral direction by the centrifugal force, and the velocity energy crawls up the inner wall surface 1A of the fixed ring 1, and when the climbing force becomes smaller than gravity, then It separates from the inner wall surface 1A and falls onto the dish surface 2A of the rotary dish 2. The reforming medium that has moved onto the dish surface 2A is again moved toward the fixed ring 1 along the dish surface 2A.

When the rotating dish 2 is rotated, the reforming medium revolves in the circumferential direction at a speed lower than the rotation speed of the rotating dish 2. Therefore, as described above, the reforming medium is the dish surface 2A and the inner wall surface 1A.
In addition to the circular motion S in the up-and-down direction that circulates around, a revolving motion that rotates around the axis of the rotary plate 2 is also performed, and a spiral progressing motion (centrifugal flow) that twists the rope combining these two motions.
Do.

In this way, the reforming medium moves up the inner wall surface 1A while maintaining the movement of the rotary dish 2 in the circumferential direction. When the inner wall surface 1A is fixed, the reforming medium The combined speed of the circumferential speed (revolution speed) and the creeping speed of the reforming medium directly becomes the speed difference between the inner wall surface 1A and the reforming medium. Therefore, the speed difference between the reforming medium and the inner wall surface 1A becomes extremely large, and the crushing and grinding action by the action of the reforming medium when moving on the inner wall surface 1A becomes extremely strong.

Furthermore, since the reforming medium that has left the inner wall surface 1A and has landed on the dish surface 2A rolls down smoothly along this dish surface 2A, the movement when rolling down the dish surface 2A causes the inner wall surface to move. Since the potential energy obtained when ascending 1 A can be converted into kinetic energy in the radial direction, the energy once applied to the reforming medium can be effectively used for the peeling action without being unnecessarily consumed. You can further,
When descending along the plate surface 2A, the reforming medium is
Since it slides with A, the child substance is peeled off even during this descending motion.

When a proper amount of air is introduced into the reforming chamber 23 through the pipe 35, the gas chamber 36 and the gap 29 and the centrifugal flow as described above is continued for a certain period of time, the child matter of the epidermis of the particles to be treated is ground. Alternatively, it is peeled off, and the peeled skin is carried out from the discharge pipe 22 together with air. In this way, the particles to be treated are separated into a child substance and a mother substance.

Since the gas is blown into the particles and the reforming medium that are centrifugally flowing from the gap 29, the child substances separated from the particles to be processed are immediately conveyed by airflow and discharged. Therefore, the separated child substance does not adhere to the base substance again.

Of course, the introduction of air into the reforming chamber 23 can be performed by suction from the discharge pipe 22 instead of by blowing air from the pipe 35.

In this way, the sub-substance can be reliably peeled off from the surface of the particles to be treated, and the high-purity base substance or sub-substance can be efficiently obtained. In addition, since the matrix substance is obtained by substantially peeling off only the epidermis substance, it has almost no original shape and is almost in the original form, and the matrix substance having a suitable particle shape can be recovered.

According to the method of the present invention, it is possible to peel off a heterogeneous child substance from the particle surface of various substances as a base substance, and in some cases, the same child substance, but the present invention is particularly iron, copper,
It is suitable for exfoliating a child substance made of an oxide, a nitride, a carbide or the like from the particle surface of a metal (pure metal or alloy) such as nickel, cobalt or aluminum.

For example, the present invention can be preferably used when peeling slag adhering to the surface of pure iron particles. When the slag is peeled off from the surface of the metal particles, the particle diameter of the particles to be treated is 10 mm or less, particularly 0.1 to 5 mm, and especially when it is desired to obtain a remarkable peeling effect as compared with the prior art. 1-1m
It is preferable to set it to about m. Further, in this case, the slag is 50% by weight (hereinafter, abbreviated as%) or less with respect to iron, especially 10
Those having -20% adhesion are preferable.

In the method of the present invention, the reforming medium that can promote the exfoliation of the child substance by using the reforming medium or the granules to be treated that functions as the reforming medium is the same material as the parent substance of the granules to be treated. However, if the particles are hard particles (for example, steel balls, ceramic balls, or corundum balls), the particles to be treated and the modifying medium may be made of different materials.

Further, the reforming medium having a diameter of about 10 mm is suitable for milling, but for more efficient milling, the diameter of the particles to be treated is 5 to 20% of the diameter of the reforming medium. It is better to be It should be noted that the particles to be treated may be crushed to a certain size or less in advance, or if the particles are unpulverized, particles having a particle diameter satisfying the above-described conditions may be prepared from the beginning.

In the present invention, the reforming medium may not be used, and only the particles to be treated may be charged into the reforming chamber 23 to rotate the rotary dish 2. In this way, when the particles to be treated are centrifugally flowed, the particles to be treated rub against each other, and the sub-substances are separated.

When only the particles to be treated are charged in the reforming chamber 23 as described above, some of the particles to be treated may have a large diameter. In this way, the large-diameter particles centrifugally flow like the reforming medium, exhibiting a strong grinding action, and the sub-substances can be separated from the small-diameter particles to be treated. (Of course, the child substance is also peeled off from the large-diameter particles to be treated.) When the large-diameter particles to be treated are used, the diameter of the large-diameter particles is smaller than that of the small-particles to be treated. It is preferable that the diameter is about 5 to 20 times the diameter, and the amount of the large diameter particles is about 100 to 200% with respect to the small diameter particles.

The rotary plate 2 is rotated at, for example, 50 to 1000 rpm.

In the method of the present invention, a batch-type operation in which a predetermined amount of particles to be treated is put into the reforming chamber 23, the apparatus is operated for a predetermined time, and then all the matrix substances are taken out from the reforming chamber 23 is preferable. A continuous treatment method may be used in which the particles to be treated are continuously charged from the charging pipe 24 and the treated base material is continuously withdrawn from the reforming chamber 23. When this continuous treatment is performed, for example, the gap 29 can be utilized, or the base substance can be extracted from a separately provided base substance outlet (not shown). When extracting the base substance from the gap, a scraper (not shown) is provided on the lower surface of the rotary dish 2, and the base substance dropped from the gap is scraped off, and the plate 3
Alternatively, the base substance may be discharged from a discharge port (not shown) provided in the casing 4.

Even when the base substance is not extracted from the gap 29, a scraper may be provided on the rotary dish to scrape and discharge the substance dropped from the gap.

In the present invention, air is usually used as the gas blown from the gap, but when a metal that is easily oxidized is used as a base substance, a gas other than air such as nitrogen may be used.

Next, specific examples will be described.

In the apparatus shown in FIGS. 1 and 2, 100 kg of an object to be treated having an average particle diameter of 0.9 mm (matrix substance: iron, child substance: slag. The average amount of slag adhering to iron is 17%) and a reforming medium (average). 150 kg of iron having a particle diameter of 10 mm) was added. The specifications of the device are as follows.

Maximum inner diameter of fixed ring: 1200 mm Upper inner diameter of fixed ring: 800 mm Maximum inner diameter of rotating dish: 1000 mm Height from the bottom of the plate surface to the upper end of the fixed ring: 600 mm Gap: 1 mm Piping while rotating the rotating dish 2 at 250 rpm Air was supplied at a rate of 1200 m ³ / Hr from 35, the apparatus was stopped after 15 minutes, and all the particles were taken out from the reforming chamber 23 and weighed, which was 80 kg. As a result of the analysis, the slag content was 5%. When the loss of the reforming medium was set to zero, the slag removal rate reached 76% and the iron recovery rate reached 92%.

When the same target particles were modified by the conventional method shown in FIGS. 3, 4, and 5 for the same time, the slag removal rates were 0.5%, 48%, and 60%. .

In the case of carrying out the method of the present invention, the rotation speed of the rotary dish may be constant, but it may be changed regularly or irregularly. By varying the rotation speed, irregularity is given to the movement of the reforming medium and the particles to be treated, and the grinding action is improved.

[Effects of the Invention] As is clear from the above examples, the present invention peels off the child substance while centrifugally flowing the particles to be treated, and introduces a gas at the place where the child substance is peeled off to separate the child substance. Since the substance is promptly separated from the parent substance and discharged, the peeled child substances do not bond again to the mother substance, and the peeled child substances do not bond with each other there, and in a short time, efficiently, In addition, the child substance can be reliably and easily peeled off, and the child substance can be reliably and easily taken out. Therefore, regardless of whether the child substance or the mother substance is used as a product, they can be recovered in high yield.

That is, since the particles to be treated repeat the operation of stalling the centrifugal force given by the rotating dish by the fixed ring, the grinding effect between the particles to be treated or the particles to be treated and the modifying medium is remarkable. Then, gas is continuously introduced through the gap between the rotating dish and the stationary ring, and the child substance separated from the reforming substance by grinding is immediately conveyed by air flow and discharged, so that the mother substance and the child substance are separated. Is continuously and efficiently performed smoothly. As a result, the residence time of the particles to be treated in the reforming device is short, and the reforming process can be performed in a short time.

Further, since the optimum separation operation can be performed only by changing the amount of gas blown into the reforming chamber while keeping other operating conditions constant, the deformation phenomenon of the host substance and the destruction of the host substance are unlikely to occur. According to the method of the present invention, it is possible to significantly enhance the milling effect and significantly reduce the power consumption unit required for milling.

According to the method of the present invention, surface modification can be efficiently performed even for small particles having a particle size of 1 mm or less, which cannot be surface modified by the conventional method.

Particularly, according to claim (2) of the present invention, the surface modification can be performed more efficiently.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a main part of the embodiment apparatus, and FIG. 2 is an overall side view. FIG. 3, FIG. 4 and FIG. 5 are explanatory views of a conventional example. 1 ... Stationary ring, 2 ... Rotating pan, 1A ... Inner wall surface, 2A ... Plate surface, 3 ... Plate, 4 ... Casing, 14 ... Reduction gear, 17 ... Motor, 18 ... Lid member , 22 ... discharge pipe, 23 ... reforming chamber, 24 ... input pipe, 29 ... gap.

Claims (2)

[Claims] 1. A method for surface modification of a granular material, wherein a sub-substance is separated from a particle to be treated in which a sub-substance is adhered to the surface of the parent substance particle, wherein the axis of rotation is oriented in the longitudinal direction and at least A rotatable circular rotary plate having a central portion having a dish surface whose diameter expands downward and the longitudinal cross section of the dish surface is concavely curved; and at least an upper portion of which is compressed upward. Has an inner wall surface that
The inner wall surface has a shape in which a vertical cross section is curved in a concave shape, and includes a stationary ring that is coaxially provided around the rotating dish and is stationary. An apparatus is used in which the wall surface is formed as a continuous smooth surface except for a minute gap between the rotary dish and the fixed ring, and the above-mentioned apparatus is provided in the reforming chamber surrounded by the dish surface and the inner wall surface of the apparatus. While rotating the rotary dish in the state of containing the particles to be treated or the particles to be treated and the modifying medium, the sub-substances are separated from the surface of the particles to be treated, and the fine particles between the rotating dish and the stationary ring are A method for modifying the surface of a granular material, characterized in that a gas is introduced into the reforming chamber through a gap, and the child substance separated from the particles to be treated is conveyed by air flow and discharged outside the modifying chamber. 2. The rotating dish has a central portion of the dish surface that expands downward, is substantially horizontal at an intermediate portion that continues to the central portion, and is upward at an outer peripheral portion that extends to the intermediate portion. The fixed ring has a shape in which the lower part expands upward, is substantially vertical in the middle part that continues to the lower part, and contracts upward in the upper part that continues to the middle part. The method for modifying the surface of a granular material according to claim 1, which has a diameter.