JPH0268150A - Surface modification of particles - Google Patents

Abstract

PURPOSE:To efficiently separate a mother substance and a daughter substance by a method wherein particles to be treated are received in the chamber surrounded by the surface of a rotary tray and the inner wall surface of a fixed ring and the daughter substance is released while the particles to be treated are centrifugally fluidized and gas is subsequently introduced into said chamber. CONSTITUTION:A freely rotatable circular rotary tray 2 wherein the longitudinal cross-section of the tray surface 2A thereof has a shape curved in a recessed state and a stationary fixed ring 1 formed so that the longitudinal cross-section of the inner wall surface 1A thereof has a shape curved in a recessed state and provided in coaxial relation to the rotary tray are provided. The tray surface 2A of the rotary tray 2 and the inner wall surface 1A of the fixed ring 1 are formed into a continuous smooth surface excepting the fine gap 29 between the rotary tray and the fixed ring. Particles to be treated or particles to be treated and a modifying medium are received in the modifying chamber 23 surrounded by the tray surface 2A and the inner wall surface 1A of this apparatus and the rotary tray 2 is rotated in this state to release a daughter substance from the particles to be treated and air is introduced into the modifying chamber 23 from the gap 29 and the released daughter substance is fed by an air stream to be discharged out of the chamber 23.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for surface modification of particles in which a child substance is peeled off from a target particle having a child substance attached to the particle surface of a parent substance.

Specifically, the present invention relates to a method of centrifugally flowing the particles to be treated or the particles to be treated and a modifying medium to exfoliate child substances from the surface of the particles to be treated.

[Prior art] Conventionally, as this type of surface modification method, in addition to the sieving method,
Methods using inertial force classifiers, rotating cage classifiers, etc. are known. 3 to 5 are explanatory diagrams of conventionally known reforming methods, and FIG. 3 is a schematic perspective view using the sieving method. Reference numeral 4° denotes a sieve, and the grains to be treated are fed onto the sieve, and the grains to be treated are rocked and vibrated up and down or back and forth on the sieve, and the grains to be treated are rubbed together. The parent substance and the child substances are separated, and after separation, the parent substance is recovered as a residue on the sieve, and the child substance is recovered as the bottom of the sieve. Fourth
The figure is a schematic diagram of a reforming method using an inertial force classifier, in which particles to be treated are ejected at high speed toward a wall surface, and the particles collide with the wall surface due to the kinetic energy obtained. The impact of this collision causes the child substances to separate. At this time, if air is simultaneously flowed parallel to the wall surface from below to above, the parent substance will fall against the air flow, and the child substances will be carried upwards along with the air. Figure 5 shows a reforming method using a rotating cage classifier, in which a rotating cylinder 4
1 is rotated at an appropriate angle, air is flowed upward from the bottom of the rotating cylinder 41, and conversely, air is flowed upward from the rotating cylinder 41 from the chute 42 arranged above the rotating cylinder 41.
When the granules to be treated are supplied to the upper part of the rotating cylinder 41, the granules to be treated rub against each other in the rotating cylinder 41 and are conveyed toward the lower part of the rotating cylinder 41.
The child substances flow down to the lower part, and the child substances are carried out from the upper part of the rotating cylinder 41 along with the air, and are separated from each other.

[Problems to be Solved by the Invention] The above-mentioned reforming methods each have the following drawbacks. That is, in the classification method in the sieving method, when the child substances are hard, the separation of the child substances is insufficient, and when the parent substance is used as a product, the quality is likely to deteriorate.

In the reforming method using a classifier that uses inertial force, kinetic energy is given to the grains to be treated so that they collide with the wall surface at high speed, so if the separation efficiency between the parent material and child material is poor, repeated collisions are required. , This tends to cause deformation of the parent material, and when the particles to be treated collide with the wall surface, part of the child material bites into the parent material, making it impossible to sufficiently peel off the child material. For these reasons, when the base material is used as a product, the quality tends to deteriorate.

In the reforming method using a rotating cage classifier, the separation efficiency of child substances is poor, and even if the rotation speed is increased to improve the separation efficiency, the rotation speed is limited due to the synchronous speed, forcing low speed rotation. It will be done.

Further, the child material once separated from the parent material remains in the rotating cylinder together with the parent material for a long time. For this reason, the child substances that have been peeled off tend to adhere to or bite into the parent substance, resulting in insufficient peeling of the child substances.As a result, when the parent substance is used as a product, The quality tends to deteriorate, and the child substances that have been peeled off often stick together.

Furthermore, in any of the conventional examples shown in FIGS. 3 to 5, surface modification could hardly be performed on 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 method for modifying the surface of granules in which a child substance is peeled off from a target particle having a child substance attached to the particle surface of a parent substance. .

In the method for surface modification of granules according to claim (1), the axis of rotation is oriented in the vertical direction, and at least the central portion has a dish surface whose diameter expands downward, and the longitudinal cross section of the dish surface is It has a rotatable circular rotary plate having a concavely curved shape, and an inner wall surface whose diameter decreases upward at least at the upper part, and the longitudinal section of the inner wall surface has a shape that is concavely curved. and a stationary fixed ring disposed coaxially around the rotating plate and stationary, and a plate surface of the rotating plate and an inner wall surface of the fixed ring form a minute gap between the rotating plate and the fixed ring. Use a device that is formed with a continuous smooth surface, except for

Then, with the to-be-treated granules or the to-be-treated granules and the modifying medium accommodated in the reforming chamber surrounded by the dish surface and the inner wall surface of the apparatus, the rotary plate is rotated so that the surface of the to-be-treated granules is At the same time as separating the child substances from the grains, gas is introduced into the reforming chamber through a small gap between the rotating plate and the fixed ring, and the child substances separated from the grains to be treated are transported by air flow and discharged outside the reforming chamber. let

In the rotary plate according to claim (2), the center portion of the plate surface expands in diameter downward, the intermediate portion following the center portion is approximately horizontal, and the outer circumferential portion following the intermediate portion expands in diameter. It has a shape that expands in diameter. Further, the fixed ring has a shape in which the diameter increases upward at the lower part, is substantially vertical at the middle part continuing from the lower part, and decreases in diameter upward at the upper part continuing from the middle part. There is.

[Operation] The particles to be treated or the particles to be treated and the modification medium are stored in a chamber surrounded by the plate surface of the rotating plate and the inner wall surface of the fixed ring, and by rotating the rotating plate, the particles to be treated are The granules and the reforming medium revolve in the circumferential direction at a speed slower than the rotational speed of the rotating plate, and also perform circular motion in the vertical direction circulating between the plate surface and the inner wall surface, and a rope is a combination of these two movements. (This movement is commonly known as centrifugal flow.)

As a result, the grains to be treated or the grains to be treated and the modifying medium rub against each other, and the child substances are peeled off from the surface of the grains to be treated. Further, in parallel with this, gas is introduced from the gap between the rotary plate and the fixed ring, so that the separated baby material is carried by the air current and quickly discharged outside the room, where it is separated from the parent material.

The surface modification device employed in the present invention centrifugally flows the grains to be treated and the modifying medium, and the grinding effect on the surface of the grains to be treated is significant. Therefore, the child substance is peeled off within a short time. Since the child substances separated by the introduced air are quickly discharged, the mother substance and the child substances can be efficiently separated.

In addition, even if the parent material is soft and the child materials are hard, or even if the parent material is hard and the child materials are soft, it is possible to change the residence time of the grains to be treated in the device and to This problem can be easily solved by simply changing the degree of rubbing between the grains to be treated and the modifying medium.

Furthermore, child substances can be reliably separated even from small-diameter particles.

In claim (2), the centrifugal flow of the grains to be treated and the modification medium is carried out more smoothly, so that the surface modification effect is extremely high.

[Example] Examples 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 the main part.

Reference numeral 1 is a fixed ring, and 2 is a rotating plate. The fixed ring 1 is fixed on the upper side of a drum-shaped casing 4 whose bottom surface is sealed with a plate 3, and the plate 3 is supported by a pedestal 5. A support block 6 is fixed to the rotating plate 2, and the support block 6 is supported by the plate 3 via a bearing device 7. That is, the central part of the plate 3 has an opening 8.
is bored, and the flange portion 10 of the bearing housing 9
is engaged with the edge of the opening 8 and fixed with 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 the reducer 1 via a joint 13.
It is connected to the output shaft 15 of No. 4. Reference numeral 17 is a variable speed motor for driving, and is connected to the reduction gear 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 periphery of the lower end, and the flange 19 is placed on a flange 20 protruding from the outer periphery of the upper end of the fixed ring 1, and is fixed with bolts 21. A discharge pipe 22 is installed in the center of the M member 18, and inside the discharge pipe 22 are a fixed YJ1, a rotary plate 2, and a lid member 1.
It communicates with the reforming chamber 23 surrounded by 8. Lid member 18
is provided with an input pipe 24, and the inside of the input pipe 24 communicates with the inside of the reforming chamber 23.

Next, the construction of the fixed ring 1 and rotating plate 2 will be explained in detail with reference to FIG.

The fixed ring 1 is of an annular shape installed with the axial direction in the vertical direction, and the diameter is the largest at a midway portion in the height direction (hereinafter referred to as the middle portion) lb. Fixed theorem 1 is that the central part 1b
A lower portion (hereinafter referred to as the lower portion) lc slightly decreases in diameter downward, and a portion (hereinafter referred to as the upper portion) la from the middle portion upwardly decreases in diameter. Therefore, the inner wall surface IA of the fixed ring 1 slightly expands in diameter from the lower part 1c toward the middle part 1b, and the middle part 1b is approximately vertical.
It has a shape that decreases in diameter from b toward the upper part 1a, and the inner wall surface IA has a concavely curved longitudinal section. A flange 25 is provided protruding from the outer peripheral surface of the middle portion 1 b of the fixed ring 1 , and the flange 25 is placed on a flange 26 protruding from the outer periphery of the upper end of the casing 3 and fixed with bolts 27 .

The plate surface of the rotary plate 2 has a shape whose diameter increases downward in the central portion 2a, is approximately horizontal in the intermediate portion 2b continuing from the central portion, and is approximately horizontal in the outer circumferential portion 2c continuing from the intermediate portion 2b. It has a shape that increases in diameter toward the top. This plate surface 2
A is curved concavely as a whole, and the inner wall surface IA of the fixed ring 1 and the plate surface 2A are continuous smooth surfaces except for a minute gap 29 between the fixed ring 1 and the rotating plate 2. is forming.

A pointed cap 30 is attached to the center of the rotating plate 2, and a shaft hole 32 is bored in the center of the zero-turning plate 2, which is fixed with a bolt 31. It is fitted into the shaft hole 32. The lower end of the bolt 31 is connected to a piece 33 provided at the upper end of the support block 6.
are screwed together.

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

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

Furthermore, a powder collecting means (not shown) such as a bag filter is connected to the discharge pipe 22.

An example of a method for page-breaking the surface of granules using the apparatus configured as described above will be described next.

A large number of reforming media made of, for example, spherical balls are charged into the reforming chamber 23 in advance. First, for example, grains to be treated, each of which has a parent substance attached to its surface with a child substance different from the parent substance, are introduced into the apparatus through the input pipe 24. As the rotary plate 2 rotates, the particles to be treated and the reforming medium circulate between the inner wall surface IA of the fixed ring 1 and the plate surface 2A. l1l
(arrow S) and the revolving motion around the axis of the rotary plate 2 to perform a spiral motion (centrifugal flow) like a rope,
During this time, the particle surface of the granules to be treated is ground or stripped.

That is, when the rotary plate 2 is rotated, the reforming medium is moved in the outer circumferential direction by centrifugal force, and this velocity energy causes it to crawl up the inner wall surface IA of the fixed ring 1, and when the climbing force becomes smaller than gravity, the reforming medium It leaves the inner wall surface IA and falls onto the plate surface 2A of the rotating plate 2. The reforming medium that has moved onto the dish surface 2A is moved toward the fixed ring 1 again along this dish surface 2A.

Further, when the rotary plate 2 is rotated, the reforming medium revolves in the circumferential direction at a speed slower than the rotational speed of the rotary plate 2. Therefore, the modifying medium is distributed between the dish surface 2A and the inner wall surface IA as described above.
In addition to the circular movement S in the vertical direction that circulates, the rotating plate 2 also performs an orbital movement that rotates around the axis, and these two movements are combined to create a spiral movement (centrifugal flow) that resembles a rope.
Do this.

In this way, the reforming medium moves up the inner wall surface IA while maintaining its movement in the circumferential direction of the rotary plate 2, but when the inner wall surface IA is fixed, the reforming medium moves up the inner wall surface IA. The composite 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 IA and the reforming medium. Therefore, the speed difference between the reforming medium and the inner wall surface IA becomes extremely large, and the pulverization and grinding action of the reforming medium when moving on the inner wall surface IA becomes extremely strong.

Furthermore, since the reforming medium that has separated from the inner wall surface IA and landed on the dish surface 2A smoothly rolls down along the dish surface 2A, the reforming medium that has moved down the dish surface 2A is moved down the inner wall surface IA. Since the drive can convert the potential energy obtained during upward movement into kinetic energy in the radial direction, the energy once applied to the reforming medium can be used effectively for the peeling action without being wasted unnecessarily. Can be done. Furthermore, when descending along the dish surface 2A, the reforming medium
Since the material slides with the material, the child material is peeled off even during this downward movement.

When an appropriate amount of air is introduced into the reforming chamber 23 through the piping 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 sub-substances in the skin of the grains to be treated are ground. Alternatively, the epidermis is peeled off by stripping, and the peeled epidermis is commandeered from the discharge pipe 22 along with air. In this way, the grains to be treated are separated into a child material and a parent material.

Note that, since gas is blown into the centrifugally flowing grains to be treated and the reforming medium through the gap 29, the child substances separated from the grains to be treated are immediately transported by airflow and discharged. Therefore, the child material that has been peeled off does not adhere to the parent material again.

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

In this way, the child substances can be reliably peeled off from the surface of the grains to be treated, and highly purified parent substances or child substances can be efficiently obtained. In addition, this matrix material is obtained by peeling off only the child substances of the epidermis, is hardly subjected to crushing action, etc., and has a warp shape, so that a suitable matrix material in particle form can be recovered.

According to the method of the present invention, it is possible to peel off child substances of different types, and in some cases, child substances of the same quality, from the surface of particles made of various substances as parent substances.
This method is suitable for peeling off child substances such as oxides, nitrides, and carbides from the particle surfaces of metals (pure metals or alloys) such as nickel, cobalt, and aluminum.

For example, the present invention can be suitably employed in peeling off slag adhering to the surface of pure iron particles. When peeling slag from the surface of metal particles, the particle size of the particles to be treated is 10 mm or less, particularly 0.1 to 5 mm, and especially 0.1 mm to 5 mm, especially when a more outstanding peeling effect than conventional techniques is to be obtained. 1~inm
It is preferable to set it as approximately. In addition, in this case, the slag is less than 50% by weight (hereinafter abbreviated as %) relative to the iron, especially 10% to
The one with 20% adhesion is suitable.

In the method of the present invention, exfoliation of child substances can be promoted by using a modifying medium or a particle to be treated that serves as a modifying medium. Particles made of the same material as the host material of the granules to be treated are suitable as the modifying medium, but if they are hard particles (e.g. steel balls, ceramic balls, corundum balls), the granules to be treated and the modifying medium are different. It may be made of a material.

In addition, a modifying medium with a diameter of about 10 mm is suitable for grinding, but for more efficient grinding, the diameter of the particles to be treated should be 5 to 20% of the diameter of the modifying medium. It is better to make it happen. Note that the M-embedded particles may be crushed in advance to a certain particle size or less, or unpulverized particles with a particle size that meets the above conditions may be prepared from the beginning.

In the present invention, only the grains to be treated may be charged into the reforming chamber 23 and the rotary plate 2 may be rotated without using a reforming medium. In this way, when the particles to be treated are subjected to centrifugal flow, the particles to be treated rub against each other, and the child substances are separated.

When only the grains to be treated are charged into the reforming chamber 23 in this manner, some of the grains to be treated may have a large diameter. In this way, the large-diameter particles undergo centrifugal flow in the same way as the reforming medium, exerting a strong grinding action and making it possible to separate the child substances from the small-diameter particles to be treated. (Of course, child substances are also peeled off from large-diameter particles to be treated.) When using large-diameter particles to be treated in this way, the diameter of the large-diameter particles is the same as that of the small-diameter particles to be treated. It is preferable that the particle diameter be about 5 to 20 times the diameter, and the amount of large diameter particles should be about 100 to 200% of the small diameter particles.

Note that the rotating plate 2 is rotated at, for example, 50 to 11,000 rpm.

In the method of the present invention, it is preferable to use a batch type operation in which a predetermined amount of granules to be treated is put into the reforming chamber 23, the apparatus is operated for a predetermined time, and then all the base material is taken out from the reforming chamber 23. A continuous treatment method may be used in which the granules to be treated are continuously inputted from the input pipe 24 and the treated base material is continuously extracted from the reforming chamber 23. When performing this continuous treatment, the matrix material can be extracted, for example, by using the gap 29 or from a separately provided matrix material extraction port (not shown). When extracting the base material from the gap, a scraper (not shown) is provided on the bottom surface of the rotary plate 2.
The base material that has fallen through the gap may be collected and discharged from an outlet (not shown) provided in the plate 3 or the casing 4.

Note that even if the base substance is not removed from the gap 29, a scraper may be provided on the rotary plate to scrape up and discharge the substance that has fallen from the gap.

In the present invention, air is normally used as the gas blown into the gap, but if the base material is a metal that is easily oxidized, 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 grains to be treated with an average grain size Q of 9 mm (base material diiron, child material Nislag, average adhesion amount of slag is 17% of iron) and a modifying medium (
150 kg of iron (with an average particle size of 10 mm) was charged. The specifications of the device are as follows.

Maximum inner diameter of the fixed ring: 1200mm Inner diameter of the upper end of the fixed ring: 800mm Maximum inner diameter of the rotating plate: 1000mm Height from the bottom of the plate surface to the top of the fixed ring: 600mm Interval: 1mm While rotating the rotating plate 2 at 25 Orpm Air was supplied through the pipe 35 at a rate of 1200 m''/hr, and after 15 minutes, the apparatus was stopped, and the entire amount of particles was taken out from the reforming chamber 23 and weighed, and the weight was 80 kg.In addition, as a result of analysis, The slag content was 5%.With zero loss of the reforming medium, the slag removal rate reached 76% and the iron recovery rate reached 92%.

When the same granules were modified for the same amount of time using the conventional method shown in Figure 3.4.5, the slag removal rates were 0.5%, 48%, and 60%. .

In carrying out the method of the present invention, the rotational speed of the rotary plate may be constant, but it may also be varied regularly or irregularly. By varying the rotational speed, irregularity is imparted to the movement of the reforming medium and the grains to be treated, thereby improving the grinding action.

[Effects of the Invention] As is clear from the above examples, the present invention peels off the child substances while subjecting the particles to be treated to centrifugal flow, and introduces gas into the place where the child substances have been peeled off, thereby removing the peeled particles. Since the substance is quickly separated from the parent substance and discharged, the separated child substances do not recombine with the parent substance, and the separated child substances do not combine with each other, so it can be done in a short time and efficiently. Moreover, the child substance can be peeled off reliably and easily, and the child substance can be taken out reliably and easily. Therefore, regardless of whether the child substance or the parent substance is used as a product, it is possible to recover them at a high yield.

That is, since the granules to be treated repeatedly stall the centrifugal force applied by the rotating plate with the fixed ring, the grinding action between the granules to be treated or between the granules and the reforming medium is significant. Then, gas is continuously introduced through the gap between the rotating plate and the fixed ring, and the child material separated from the reformed material by grinding is immediately conveyed by air current and discharged, so that the parent material and child material can be separated. is carried out continuously, efficiently and smoothly. As a result, the residence time of the grains to be treated within the reforming device is short, and the reforming process can be carried out in a short time.

Furthermore, since the optimum separation operation can be performed simply by changing the amount of gas blown into the reforming chamber while keeping other operating conditions constant, deformation of the host material and destruction of the host material are less likely to occur. According to the method of the present invention, it is possible to significantly enhance the grinding effect and to significantly reduce the unit power required for grinding.

According to the method of the present invention, it is possible to efficiently surface-modify even small particles, for example, with a particle size of 1 mm or less, which could not be surface-modified using conventional methods.

In particular, according to claim (2) of the present invention, surface modification can be carried out more efficiently.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a main part of the apparatus according to the embodiment, and FIG. 2 is a side view of the whole. FIG. 3, FIG. 4, and FIG. 5 are explanatory diagrams of conventional examples. 1... Fixed ring, 2... Rotating plate, IA... Inner wall surface, 2A... Disc surface, 3... Plate,
4...Casing, 14...Reducer, 17
...Motor, 18...Lid member, 22...Discharge pipe, 23...Reforming chamber, 24...Input pipe, 29...
··gap.

Claims (2)

[Claims] (1) In a method for surface modification of granules in which a child substance is peeled from a particle to be treated which has a child substance attached to the particle surface of a parent substance, the axis of rotation is oriented in the vertical direction and at least the central part a rotatable circular rotary plate having a plate surface whose diameter expands downward, and a vertical cross section of the plate surface is curved in a concave shape; has an inner wall surface,
The longitudinal section of the inner wall surface is curved in a concave shape, and includes a fixed ring coaxially disposed around the rotating plate and stationary, the plate surface of the rotating plate and the inner part of the fixed ring. Using a device in which the wall surface is formed into a continuous smooth surface except for a small gap between the rotating plate and the fixed ring, the above-mentioned material is placed in a reforming chamber surrounded by the dish surface and the inner wall surface of the device. A rotary plate is rotated in a state in which the particles to be treated or the particles to be treated and the modifying medium are accommodated, and the child substances are peeled off from the surface of the particles to be treated, and the minute particles between the rotating plate and the fixed ring are separated. A method for surface modification of granules, characterized in that gas is introduced into the reforming chamber through a gap, and child substances exfoliated from the granules to be treated are transported by air flow and discharged outside the reforming chamber. (2) The rotary plate has a diameter that expands downward at the center portion of the disk surface, is approximately horizontal at the intermediate portion following the center portion, and expands upward at the outer peripheral portion following the intermediate portion. The fixed ring has a diameter that expands upward at a lower part, is approximately vertical at a middle part continuing from the lower part, and narrows upward at an upper part following the middle part. Claims having the shape (
1) Surface modification method of granules.