CN112871399A

CN112871399A - Processing method of nano kaolin

Info

Publication number: CN112871399A
Application number: CN202110007603.4A
Authority: CN
Inventors: 丁彤
Original assignee: Hebei Chuanlong Network Technology Co ltd
Current assignee: Hebei Chuanlong Network Technology Co ltd
Priority date: 2021-01-05
Filing date: 2021-01-05
Publication date: 2021-06-01

Abstract

The invention relates to the technical field of kaolin processing, in particular to a processing method of nano kaolin. Firstly, carrying out primary crushing on kaolin, then carrying out freezing treatment and drying, then carrying out calcination, and finally carrying out powder preparation and final grinding to obtain nano powder. According to the invention, the kaolin is treated by adopting a certain procedure, so that tiny cracks or pores originally existing in the particles of the kaolin are enlarged, and the kaolin is easier to break; and then, special grinding equipment is adopted, the grinding wheel rolls on the grinding surface, the grinding wheel and the grinding surface do not collide and do not relatively slide, and substances of the grinding wheel and the grinding surface cannot fall off and mix into the powder, so that the prepared powder has high purity, and the grinding efficiency is higher than that of a ball mill because the grinding wheel and the grinding surface are in line contact.

Description

Processing method of nano kaolin

Technical Field

The invention relates to the technical field of kaolin processing, in particular to a processing method of nano kaolin.

Background

Kaolin is a non-metallic mineral resource composed mainly of kaolinite minerals, and can be used as refractory material and ceramic material, and also as filler for paper making, rubber, paint, cosmetics, etc. At present, the nano kaolin is generally prepared by an intercalation method, firstly chemical substances and kaolin particles are used for preparing an intercalation complex, then a ball mill is used for grinding the intercalation complex into powder, and the powder is heated and decomposed into sheets. The flaky kaolin powder is suitable for industries such as paint, etc. where the flowability of the matrix is good and the covering property is high, but when used in rubber, etc., the flaky kaolin powder is not as easy to be uniformly mixed with the matrix as the polyhedral powder-like powder, and the performance of the rubber prepared from the flaky kaolin powder is inferior to that of rubber filled with the polyhedral powder-like powder. Further, since the ball mill performs point impact and grinding, the grinding efficiency is low, and the grinding balls in the ball mill collide with each other, and the substances on the grinding balls are easily knocked down and mixed into the powder, thereby lowering the purity of the powder.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a method for processing nano kaolin, aiming at the technical defects, the method comprises the steps of firstly processing the kaolin by adopting a certain procedure, so that tiny cracks or pores originally existing in particles of the kaolin are enlarged, and the kaolin is easier to break; then, special grinding equipment is adopted, the grinding wheel rolls on the grinding surface, the grinding wheel and the grinding surface cannot collide and relatively slide, substances of the grinding wheel and the grinding surface cannot fall off and are mixed into powder, the purity of the prepared powder is high, the grinding wheel and the grinding surface are in line contact, and the grinding efficiency is higher than that of a ball mill; without the intercalation process, a polyhedral-like powder can be produced.

According to the technical scheme adopted by the invention, the processing method of the nano kaolin comprises the following steps:

A. primary crushing: crushing kaolin minerals to obtain kaolin particles with the diameter of 1-5 cm;

B. freezing treatment: b, spraying or soaking the particles obtained in the step A by using water, and then freezing;

C. and (3) drying: drying the particles obtained in the step B to remove most of water;

D. and (3) calcining: c, calcining the particles obtained in the step C at the calcining temperature of 400-450 ℃, and cooling to room temperature after calcining;

E. milling: d, grinding the particles obtained in the step D into powder with the particle size of less than 100 meshes;

F. final grinding: and E, grinding the powder obtained in the step E in special grinding equipment to obtain powder with the diameter less than 1 micron.

Preferably, a filling process is also arranged between the step D calcining and the step E pulverizing, and the specific content is that the particles obtained in the step D are soaked in hot ethanol dissolved with sodium stearate, and then the particles are taken out and dried.

Preferably, a washing step is further provided after the step F, and the specific content is to wash the powder obtained in the step F with hot ethanol to remove sodium stearate therein.

Preferably, the special grinding device in the step E includes a housing, a bin door is disposed on a side surface of the housing, a motor is disposed on an outer side of a bottom of the housing, a rotating shaft of the motor penetrates through the bottom of the housing and enters the housing, and a rotating disc is fixedly connected to a top end of the rotating shaft of the motor; detachable is connected with the grinding pot on the carousel, detachable is connected with the abrasive disc in the grinding pot, abrasive disc top roll connection has the piece of grinding, it is connected with the lift cover to grind a top slidable, the lift cover with grind and be provided with the spring between the piece, the top sliding connection of lift cover and shell, the top of shell is rotated and is connected with the lead screw of taking the hand wheel, the top of lift cover is provided with the screw hole, the lead screw of taking the hand wheel and the top threaded connection of lift cover.

Preferably, the center of the bottom of the grinding pan is provided with a concave table, the cross section of the concave table is a regular polygon, and the center of the upper surface of the rotary table is provided with a boss which is the same as the cross section of the concave table.

Preferably, a plurality of pressure rods are arranged at the lower part of the side surface of the grinding piece, a grinding roller is rotatably connected onto the pressure rods, a plurality of grinding wheels are arranged on the grinding roller, the grinding wheels are in a circular table shape, and the ratio of the diameter of the upper bottom surface of the circular table to the diameter of the lower bottom surface of the circular table is equal to the ratio of the distance between the grinding wheels and the axial line of the grinding piece; the grinding wheels on adjacent grinding rollers are alternately distributed in the axial direction of the grinding rollers, namely, the grinding wheels on one grinding roller are respectively positioned between the grinding wheels on the grinding rollers adjacent to the grinding roller.

Preferably, a plurality of coaxial grinding grooves are formed in the grinding disc, the grinding grooves correspond to the grinding wheels in position one to one, and the bottom surfaces of the grinding grooves are inclined grinding surfaces; the grinding wheel is in rolling connection with the grinding surface, and the angle formed between the grinding surface and the axis of the grinding wheel is the same as the angle formed between the generatrix of the circular truncated cone-shaped grinding wheel and the axis of the grinding wheel; the side of the grinding groove inclines outwards.

Preferably, the side walls of the grinding pan are outwardly inclined.

Preferably, a plurality of pits are arranged on the side surface of the circular truncated cone-shaped grinding wheel, the depth of each pit is 3-50 micrometers, each pit is approximately hemispherical, and the radius of each pit is 0.8-1.2 times of the depth of each pit.

Preferably, a cavity is arranged in the lifting sleeve, second guide strips are arranged on two sides of the cavity, a blocking cap is arranged on the upper portion of the grinding part, and second guide grooves matched with the second guide strips are arranged on two sides of the blocking cap; the lifting sleeve is characterized in that first guide grooves are formed in two sides of the upper portion of the lifting sleeve, and first guide strips matched with the first guide grooves are arranged at the top of the shell.

Compared with the prior art, the invention has the following advantages: 1. firstly, processing kaolin by adopting a certain procedure to enlarge tiny cracks or pores originally existing in the particles of the kaolin, so that the kaolin is easier to break, and the cracks or the pores are filled with sodium stearate, which is beneficial to breaking powder and can prevent the powder from agglomerating to a certain extent; 2. the grinding wheel of the special grinding equipment rolls on the grinding surface, the grinding wheel and the grinding surface do not collide and do not relatively slide, substances of the grinding wheel and the grinding surface cannot fall off and mix into powder, the purity of the prepared powder is high, the grinding wheel and the grinding surface are in line contact, and the grinding efficiency is higher than that of a ball mill; 3. since the intercalation process is not involved, the powder is produced by mechanical crushing, and therefore the produced powder is mostly in the form of a polyhedral-like body.

Drawings

Fig. 1 is a schematic structural diagram of a special grinding device.

Fig. 2 is a schematic structural diagram of a lifting sleeve and a grinding piece of the special grinding equipment.

Fig. 3 is a schematic structural diagram of a grinding member and a grinding pan of the special grinding device.

In the figure: 1. a housing; 11. a bin gate; 12. a first guide bar; 2. a motor; 21. a turntable; 3. grinding the pan; 31. a concave platform; 32. a grinding disk; 321. a grinding groove; 3211. grinding the surface; 4. a grinding member; 41. a blocking cap; 411. a second guide groove; 42. a pressure lever; 43. a grinding roller; 431. a grinding wheel; 5. a spring; 6. a lifting sleeve; 61. a first guide groove; 62. a cavity; 63. a second guide bar; 7. a screw rod with a hand wheel.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings in conjunction with the following detailed description. It should be understood that the description is intended to be exemplary only, and is not intended to limit the scope of the present invention. Moreover, in the following description, descriptions of well-known structures and techniques are omitted so as to not unnecessarily obscure the concepts of the present invention.

Example 1

A processing method of nano kaolin comprises the following steps:

A. primary crushing: the kaolin minerals are crushed to obtain kaolin particles with the diameter of 1-5 cm. The crushing of this step may be carried out by means of a jaw crusher.

B. Freezing treatment: and C, spraying or soaking the particles obtained in the step A by using water, and then freezing. The spraying or soaking time is not suitable to be too long, and the contact force between the particles cannot be too large, so that the particles are prevented from being bonded together. The diameter of 1-5 cm can ensure that the particles can fully absorb moisture and can well prevent the particles from being bonded together. After freezing, the water present in the minute cracks or pores in the particles turns into ice and expands, thereby expanding the cracks.

C. And (3) drying: and D, drying the particles obtained in the step B to remove most of water. The step can adopt a spreading and drying or drying mode.

D. And (3) calcining: and C, calcining the particles obtained in the step C at the calcining temperature of 400-450 ℃, and cooling to room temperature after calcining. The calcination can remove the adsorption water of the kaolin and the intercalation water between layers, so that the crystal structure of the kaolin further has defects and is easier to break.

E. Milling: and D, grinding the particles obtained in the step D into powder with the particle size of less than 100 meshes. This step can be done using a Raymond mill and the smaller the particle size the better.

F. Final grinding: and E, grinding the powder obtained in the step E in special grinding equipment to obtain the nano powder with the diameter less than 1 micron.

The special grinding device in the step E is shown in fig. 1-3, and includes a housing 1, a bin gate 11 is disposed on a side surface of the housing 1, a motor 2 is disposed on an outer side of a bottom of the housing 1, a rotating shaft of the motor 2 penetrates through the bottom of the housing 1 and enters the housing 1, and a rotating disc 21 is fixedly connected to a top end of the rotating shaft of the motor 2; detachable is connected with the grinding pot 3 on the carousel 21, detachable is connected with the abrasive disc 32 in the grinding pot 3, the roll connection in abrasive disc 32 top has grinding 4, 4 top slidable of grinding is connected with lift cover 6, be provided with spring 5 between lift cover 6 and the grinding 4, lift cover 6 and shell 1's top sliding connection, shell 1's top is rotated and is connected with the lead screw 7 of taking the hand wheel, the top of lift cover 6 is provided with the screw hole, the lead screw 7 of taking the hand wheel and the top threaded connection of lift cover 6. A cavity 62 is formed in the lifting sleeve 6, second guide strips 63 are arranged on two sides of the cavity 62, a blocking cap 41 is arranged on the upper portion of the grinding piece 4, and second guide grooves 411 matched with the second guide strips 63 are arranged on two sides of the blocking cap 41; two sides of the upper part of the lifting sleeve 6 are provided with first guide grooves 61, and the top of the shell 1 is provided with first guide strips 12 matched with the first guide grooves 61. The grinding part 4 can be lifted by rotating the screw rod 7 with the hand wheel, and the grinding pot 3 is taken out through the bin gate 11 so as to take away finished product powder or put powder to be ground; the screw 7 with the handwheel can be rotated to lower the grinding piece 4 to be in contact with the grinding disc 32, and the pressure between the grinding piece 4 and the grinding disc 32 can be adjusted.

The center of the bottom of the grinding pan 3 is provided with a concave table 31, the cross section of the concave table 31 is a regular polygon, and the center of the upper surface of the turntable 21 is provided with a boss with the same cross section as that of the concave table 31. This kind of structure is convenient to get and put grinding pot 3.

The side lower part of grinding member 4 is provided with a plurality of depression bars 42, the last rotation of depression bar 42 is connected with grinding roller 43, be provided with a plurality of grinding wheels 431 on grinding roller 43, grinding wheels 431 is the round platform form. The ratio of the diameter of the upper bottom surface of the circular truncated cone to the diameter of the lower bottom surface of the circular truncated cone is equal to the ratio of the distance between the diameter of the upper bottom surface of the circular truncated cone and the axis of the grinding part 4, and the lower bottom surface of the circular truncated cone rotates for a circle when the upper bottom surface of the circular truncated cone rotates for a circle, so that sliding relative to the grinding disc cannot occur, and abrasion caused by sliding friction cannot occur. The grinding wheels 431 of the adjacent grinding rollers 43 are alternately distributed in the axial direction of the grinding rollers 43, that is, the plurality of grinding wheels 431 of a certain grinding roller 43 are respectively located at positions between the plurality of grinding wheels 431 of the grinding roller 43 adjacent thereto. The grinding wheels 431 of the same grinding roller 43 are spaced apart by a certain distance to form a passage for the powder to pass through, and the width of the grinding wheel 431 of the grinding roller 43 adjacent to the grinding roller 43 is close to the width of the passage, so that no grinding position exists during grinding. The grinding disk 32 is provided with a plurality of coaxial grinding grooves 321, and the positions of the grinding grooves 321 and the grinding wheels 431 are in one-to-one correspondence. The bottom surface of the polishing groove 321 is an inclined polishing surface 3211. The grinding wheel 431 is connected with the grinding surface 3211 in a rolling manner. The angle formed between the grinding surface 3211 and the axis of the grinding wheel 431 is the same as the angle formed between the generatrix of the circular truncated cone-shaped grinding wheel 431 and the axis of the grinding wheel 431, so that the grinding wheel 431 and the grinding surface 3211 can be tightly attached to each other, and the contact area is large. The side of the grinding groove 321 is inclined outward to avoid the side contacting the bottom surface of the grinding wheel 431.

The side wall of the grinding pan 3 is inclined outward to avoid the side wall contacting the bottom surface of the grinding wheel 431.

Grinding: during grinding, the motor 2 drives the grinding pan 3 to rotate, so that the grinding wheel 431 rolls on the grinding surface 3211, only a small part of powder is crushed between the grinding wheel 431 and the grinding surface 3211 due to close fit of the grinding wheel 431 and the grinding surface 3211, and most of the rest of powder is blocked by the grinding wheel 431, is discharged into the adjacent grinding groove 321 in the blocking process, and is crushed, blocked and discharged into the adjacent grinding groove 321 again by the grinding wheel 431. The process is repeated continuously, and the diameter of the powder can be completely crushed to be less than 1 micron to form the nano-scale powder. Since the grinding wheel 431 is in line contact with the grinding surface 3211 and the grinding pan 3 rotates one round to roll the whole surface of the grinding surface 3211, the crushing efficiency is high. The grinding wheel 431 is closely attached to the grinding surface 3211, so that the grinding effect is good.

Example 2

The embodiment is basically the same as the embodiment 1, except that a filling process is added between the calcining in the step D and the pulverizing in the step E, and the specific content is that the particles in the step D are soaked in hot ethanol dissolved with sodium stearate, and then the particles are fished out and dried; and F, adding a cleaning process after the step F, wherein the specific content is that the powder obtained in the step F is cleaned by hot ethanol to remove sodium stearate in the powder.

After being soaked in hot ethanol in which sodium stearate is dissolved and dried, the cracks and the defects of the crystal structure in the kaolin particles can contain sodium stearate solids, so that the cracks and the defects can be prevented from healing in the grinding process, and the kaolin particles can be broken more easily. After continuous grinding, a part of sodium stearate is adhered to the surface of the particles, so that the agglomeration phenomenon of the powder is reduced. The grinding efficiency of the example is improved by 19 to 31 percent compared with that of the example 1.

Example 3

The present embodiment is substantially the same as embodiment 1, except that a plurality of concave pits are provided on a side surface of the circular truncated cone-shaped grinding wheel 431, a depth of each concave pit is 3 to 50 micrometers, the concave pits are approximately hemispherical, and a radius of each concave pit is 0.8 to 1.2 times of the depth of each concave pit.

During the grinding process, the kaolin particles become stuck in the pits and a portion of the kaolin particles are exposed outside the pits, and when the kaolin particles are transferred between the grinding wheel 431 and the grinding surface 3211, the kaolin particles are reliably crushed without slipping off and thus not being crushed. The presence of the pits can bring more particles between the grinding wheel 431 and the grinding surface 3211, increasing the number of particles crushed each time, thereby increasing the efficiency of crushing. The pockets on each wheel 431 are not uniform in depth, but are distributed over a range of 3-50 microns, i.e., a portion of the pockets are 3 microns deep and a portion of the pockets are about 4 microns deep. The grinding efficiency of the embodiment is improved by 26-43% compared with that of the embodiment 1.

Example 4

The present embodiment is substantially the same as embodiment 2, except that a plurality of concave pits are provided on a side surface of the circular truncated cone-shaped grinding wheel 431, a depth of each concave pit is 3 to 50 micrometers, the concave pits are approximately hemispherical, and a radius of each concave pit is 0.8 to 1.2 times of the depth of each concave pit.

The grinding efficiency of the embodiment is improved by 21-37% compared with that of the embodiment 2.

Claims

1. The method for processing the nano kaolin is characterized by comprising the following steps:

2. The method for processing nano kaolin according to claim 1, wherein: and D, a filling process is also arranged between the step D calcining and the step E pulverizing, and the specific content is that the particles obtained in the step D are soaked in hot ethanol dissolved with sodium stearate, and then the particles are fished out and dried.

3. The method for processing nano kaolin according to claim 2, wherein: and a washing step is carried out after the step F, and the specific content is that the powder obtained in the step F is washed by hot ethanol to remove sodium stearate in the powder.

4. The method for processing nano kaolin according to claim 1, wherein: the special grinding equipment in the step E comprises a shell (1), a bin door (11) is arranged on the side face of the shell (1), a motor (2) is arranged on the outer side of the bottom of the shell (1), a rotating shaft of the motor (2) penetrates through the bottom of the shell (1) to enter the shell (1), and a rotating disc (21) is fixedly connected to the top end of the rotating shaft of the motor (2); detachable is connected with grinds pot (3) on carousel (21), detachable is connected with abrasive disc (32) in grinding pot (3), abrasive disc (32) top roll connection has grinding piece (4), it is connected with lift cover (6) to grind piece (4) top slidable, be provided with spring (5) between lift cover (6) and the grinding piece (4), the top sliding connection of lift cover (6) and shell (1), the top of shell (1) is rotated and is connected with lead screw (7) of taking the hand wheel, the top of lift cover (6) is provided with the screw hole, lead screw (7) of taking the hand wheel and the top threaded connection of lift cover (6).

5. The method for processing nano kaolin according to claim 4, wherein: the grinding pan (3) is characterized in that a concave table (31) is arranged in the center of the bottom of the grinding pan (3), the cross section of the concave table (31) is a regular polygon, and a boss which is the same as the cross section of the concave table (31) is arranged in the center of the upper surface of the rotary table (21).

6. The method for processing nano kaolin according to claim 4, wherein: a plurality of pressure rods (42) are arranged at the lower part of the side surface of the grinding piece (4), a grinding roller (43) is rotatably connected onto each pressure rod (42), a plurality of grinding wheels (431) are arranged on each grinding roller (43), each grinding wheel (431) is in a circular table shape, and the ratio of the diameter of the upper bottom surface to the diameter of the lower bottom surface of each circular table is equal to the ratio of the distance between each grinding wheel and the axial line of the grinding piece (4); the grinding wheels (431) on the adjacent grinding rollers (43) are alternately distributed in the axial direction of the grinding rollers (43), namely, the grinding wheels (431) on one grinding roller (43) are respectively positioned between the grinding wheels (431) on the grinding roller (43) adjacent to the grinding wheel.

7. The method for processing nano kaolin according to claim 6, wherein: the grinding disc (32) is provided with a plurality of coaxial grinding grooves (321), the positions of the grinding grooves (321) correspond to the positions of the grinding wheels (431) one by one, and the bottom surfaces of the grinding grooves (321) are inclined grinding surfaces (3211); the grinding wheel (431) is in rolling connection with a grinding surface (3211), and the angle formed between the grinding surface (3211) and the axis of the grinding wheel (431) is the same as the angle formed between the generatrix of the circular truncated cone-shaped grinding wheel (431) and the axis of the grinding wheel (431); the side surfaces of the grinding grooves (321) are inclined outwards.

8. The method for processing nano kaolin according to claim 4, wherein: the side wall of the grinding pan (3) inclines outwards.

9. The method for processing nano kaolin according to claim 4, wherein: the side surface of the circular truncated cone-shaped grinding wheel (431) is provided with a plurality of pits, the depth of each pit is 3-50 micrometers, each pit is approximately hemispherical, and the radius of each pit is 0.8-1.2 times of the depth of each pit.

10. The method for processing nano kaolin according to claim 4, wherein: a cavity (62) is arranged in the lifting sleeve (6), second guide strips (63) are arranged on two sides of the cavity (62), a blocking cap (41) is arranged on the upper portion of the grinding piece (4), and second guide grooves (411) matched with the second guide strips (63) are arranged on two sides of the blocking cap (41); the lifting sleeve is characterized in that first guide grooves (61) are formed in two sides of the upper portion of the lifting sleeve (6), and first guide strips (12) matched with the first guide grooves (61) are arranged at the top of the shell (1).