CN112321303A

CN112321303A - Ceramic powder making process and system thereof

Info

Publication number: CN112321303A
Application number: CN202110000858.8A
Authority: CN
Inventors: 李金华; 林庆生
Original assignee: Foshan Lanzhijing Technology Co ltd
Current assignee: Foshan Lanzhijing Technology Co ltd
Priority date: 2021-01-04
Filing date: 2021-01-04
Publication date: 2021-02-05

Abstract

The invention relates to the technical field of ceramic wet powder making, in particular to a ceramic powder making process and a system thereof; the ceramic powder process comprises the following steps: step S1, drying the pug to obtain pug with water content of 12-14%; step S2, sequentially rubbing the mud blocks by more than 2 screens, wherein the apertures of the screen holes of the screens become smaller layer by layer, and the particle diameters of the mud blocks become smaller layer by layer when the mud blocks pass through the screen holes of the screens layer by layer; meanwhile, hot air is introduced below the screen mesh, so that the mud blocks are repeatedly heated and dried by the flowing hot air in the friction movement and falling processes, and finally powder particles with the particle size of less than 1.5mm and the water content of 9-10% are obtained; the invention decomposes the drying of the pug into the steps of primary drying, granulation and rounding, and the specific surface area of the powder particles is rapidly increased in the last two working procedures, thereby being beneficial to the rapid volatilization of moisture, improving the drying speed and reducing the energy consumption.

Description

Ceramic powder making process and system thereof

Technical Field

The invention relates to the technical field of ceramic wet powder making, in particular to a ceramic powder making process and a ceramic powder making system.

Background

The ceramic industry is a high-energy-consumption and high-pollution industry. The wet powder process is an important process in the production process of ceramic products.

The traditional wet-process powder-making process flow comprises the steps of material preparation, ball milling and pulping, sieving, iron removal, spray drying and granulation. Wherein, the process of spray drying granulation is mainly carried out in a spray drying tower, the spray drying tower is the main equipment for heat energy consumption and conversion, and the energy consumption accounts for more than 35 percent of the total cost of ceramic production.

The process of spray drying granulation is generally that ceramic slurry containing 30-40% of water is pressurized by a plunger pump and sprayed into a spray drying tower by a spray gun meeting the aperture requirement, meanwhile, high-temperature hot air (800-1050 ℃ in the furnace) generated by combustion of a hot blast stove enters the spray drying tower, the hot air flowing rapidly in the spray drying tower is fully contacted with atomized slurry droplets, the water in the slurry droplets is taken away rapidly, the water and other waste gas are pumped away by a negative pressure draught fan, and the slurry droplets evaporated with the water are changed into ceramic powder particles.

This way of dry granulation presents the following problems:

1. the hot blast stove provides a heat source for the spray drying tower, most of the fuel of the hot blast stove is coal fuel such as coal water slurry or coal dust, and the coal fuel can discharge a large amount of pollutants such as SOx, NOx and dust when being combusted, the pollutants are main pollution sources in the ceramic production process, although the current enterprises are provided with post-treatment devices to solve the pollution problem, the purchase and operation costs of the post-treatment devices are high, the production cost of the enterprises is increased, and the hot blast stove does not meet the national requirements of energy conservation and emission reduction;

2. the energy consumption is large, and every 100 tons of powder are prepared, the drying mode needs to consume 70KG of coal fuel and about 15 degrees of electricity, and the drying cost is very high.

In order to solve the problems of high energy consumption, high pollution and high cost of the traditional wet process, the Chinese patent application with the application number of 2019102196264 provides a ceramic wet process low-temperature powder preparation process. In the scheme, the slurry is subjected to dehydration treatment, low-temperature drying treatment and crushing treatment in sequence to finally obtain powder particles. In the process, low-temperature drying treatment is carried out by ceramic pug drying equipment, wherein hot air is mainly used for heating and drying crushed pug, and pug with the water content of 18-25% is dried into pug blocks with the water content of 7-10% at one time so as to facilitate subsequent crushing and granulation. The process mainly utilizes the waste heat of the kiln, so that excessive combustion energy is not required to be consumed, the energy consumption in the ceramic production process is greatly reduced, the production benefit is improved, pollutants are effectively reduced, and the production cost of enterprises is greatly reduced. However, this process also has the following disadvantages.

1. The mud blocks are large, the block diameter is about 5cm, the temperature of drying equipment is lower by about 80 ℃, so that the water content of the mud blocks is reduced by about 12% at one time, and the required drying time is long. Therefore, in order to ensure the production efficiency, the length of the single-layer drying equipment needs to be about 300m, the occupied area is large, even if multilayer drying equipment is adopted, for example, the length of 6 layers of drying equipment still reaches more than 60 meters, and the drying cavity of the multilayer drying equipment is large in size and difficult to fully ventilate, so that the humidity of hot air in the cavity is high, and the drying speed is reduced;

2. the drying process of the mud block is a process of firstly speeding up and then slowing down, and after the surface of the mud block is dried, the water in the center is difficult to volatilize, so that the drying efficiency is low and the drying time is long;

3. the dried mud block has uneven dryness, and has a sandwich condition of dry outside and wet inside, so that when the mud block is crushed and granulated subsequently, the water content of the mud block at the center is high, the screen mesh is easily stuck during granulation, and the obtained powder particles are also easily agglomerated.

Disclosure of Invention

The invention provides a ceramic powder making process, aiming at solving the problems of long drying time, large volume of drying equipment and large difference of water contents of the surface and the core of a dried mud block in the existing ceramic low-temperature wet powder making process.

In order to achieve the functions, the technical scheme provided by the invention is as follows:

a ceramic powder process comprises the following steps:

step S1, drying the pug to obtain pug with water content of 12-14%;

step S2, sequentially rubbing the mud blocks by more than 2 screens, wherein the apertures of the screen holes of the screens become smaller layer by layer, and the particle diameters of the mud blocks become smaller layer by layer when the mud blocks pass through the screen holes of the screens layer by layer; meanwhile, hot air is introduced below the screen mesh, so that the mud blocks are repeatedly heated and dried by the flowing hot air in the friction movement and falling processes, and finally powder particles with the particle size of less than 1.5mm and the water content of 9-10% are obtained.

Preferably, the process further comprises:

and step S3, putting the powder particles into a rounding device, introducing hot air into the rounding device, polishing the surfaces of the powder particles, and further drying to obtain the rounded particles with the water content of 7-8%.

Preferably, the number of the screen cloth is 5, 5 the screen cloth from top to bottom set up layer by layer in proper order, the aperture of the sieve mesh of screen cloth is 3.5 ~ 3mm, 2.8 ~ 2.5mm, 2.3 ~ 2mm, 1.8 ~ 1.5mm and 1.3 ~ 0.8mm respectively.

Preferably, the hot air is hot flue gas obtained by performing electrostatic dust removal on the kiln tail gas or dry hot air obtained by performing heat exchange on the kiln tail gas.

Preferably, the temperature of the hot air is between 40 ℃ and 100 ℃.

Preferably, in step S3, a negative pressure dust suction process is performed during the powder particle rounding process.

The invention also provides a ceramic powder making system adopting the process, which comprises a filter press, a mud cutting device, a ceramic mud drying device and a ceramic mud multi-stage granulation device which are sequentially connected through a conveying belt, wherein air inlets and air outlets of the ceramic mud drying device and the ceramic mud multi-stage granulation device are respectively connected with an air inlet pipe and an exhaust pipe.

Preferably, the multistage granulating equipment for the ceramic pug comprises a granulating bin, wherein at least 2 friction granulating layers are arranged in the granulating bin, and each friction granulating layer is provided with at least 1 friction granulating assembly;

the friction granulation assembly comprises a rotating shaft, a plurality of scrapers and an arc-shaped screen, and the scrapers are uniformly fixed on the rotating shaft; the circular arc-shaped screen mesh is coaxial with the rotating shaft and is arranged right below the rotating shaft, and a plurality of screen holes are formed in the circular arc-shaped screen mesh; a friction gap is formed between the scraper and the circular arc-shaped screen;

the aperture of the sieve pore of the friction granulation component positioned on the lower layer is smaller than that of the corresponding sieve pore of the friction granulation component positioned on the upper layer;

the granulation cabin is provided with more than 1 air inlet and air outlet.

Preferably, the two side edges of the circular arc-shaped screen are provided with guide posts, the front side plate and the rear side plate of the granulation cabin are provided with guide grooves matched with the guide posts, and the left side plate is provided with a replacement opening allowing the circular arc-shaped screen to enter and exit.

Preferably, the ceramic powder making system further comprises rounding equipment, and the rounding equipment is connected with the ceramic pug multistage granulation equipment through a conveying belt; rounding equipment includes the cylinder, the inner wall spiral of cylinder coils there is the sand grip to the ceramic granule rounding, the cylinder both ends are provided with feed inlet and discharge gate respectively, the cylinder is close to the one end of feed inlet is provided with and is used for letting in hot-blast air intake, and the other end is provided with the air exit.

The invention has the beneficial effects that:

1. the process of drying the pug with the water content of 18-25% to the pug with the water content of 8-10% by adopting the ceramic pug drying equipment in the prior art at one time is decomposed into the steps of reducing the water content of the pug or powder particles step by step in the three processes of primary drying, granulation and rounding, thereby reducing the time for drying the pug by the ceramic pug drying equipment, being beneficial to saving energy, improving the drying speed and realizing the miniaturization of the drying equipment;

2. by arranging a plurality of layers of screens with gradually-reduced apertures, the particle size of the mud block is gradually reduced layer by layer in the granulation process of the mud block friction screen, the specific surface area is rapidly increased, and the rapid volatilization of moisture is facilitated, so that the drying speed is improved, the energy consumption is reduced, and hot air is introduced to dry the powder particles, so that the surfaces of the powder particles can rapidly lose moisture and lose viscosity, and the powder particles are prevented from being bonded into blocks;

3. the outer layer and the core of the mud block can be kneaded for multiple times by the multi-layer screen in the process of friction granulation, so that the moisture of the outer layer and the core is uniform to facilitate drying, and the problem that the moisture of the core is volatilized due to the drying of the outer layer is solved.

Drawings

FIG. 1 is a process flow diagram of the present invention;

FIG. 2 is a schematic structural diagram of a multistage ceramic pug granulating apparatus;

FIG. 3 is a schematic structural view of FIG. 2 with the left side plate omitted;

FIG. 4 is a schematic structural view of FIG. 2 with the motor and front bezel omitted;

FIG. 5 is a schematic diagram of a friction pelletizing assembly;

FIG. 6 is a schematic structural view of a rounding apparatus;

fig. 7 is a block diagram of the second embodiment.

Detailed Description

The invention will be further elucidated with reference to the accompanying figures 1 to 7:

the first embodiment is as follows:

the ceramic powder manufacturing process shown in fig. 1 comprises the steps of material preparation, ball milling, sieving, iron removal and slurry tank homogenization in sequence, so as to obtain slurry with the water content of 30-40%, then dehydrating the slurry through equipment such as a filter press and the like to obtain blocky pug (filter cake) with the water content of 18-25%, and then cutting the blocky pug into pug with the length of about 5cm and the water content of 18-25% through high-speed pug cutting equipment.

The above-described steps may be performed by referring to existing equipment and techniques. No further description is given in this embodiment.

The process also comprises the following steps of drying the pug:

step S1, drying the pug to obtain pug with water content of 12-14%;

In this embodiment, we are equipped with 5 layers of screens from top to bottom in sequence, and the effect of granulation is better when the aperture of the screen hole of the screen is 3.5-3 mm, 2.8-2.5 mm, 2.3-2 mm, 1.8-1.5 mm and 1.3-0.8 mm respectively from top to bottom. Preferably, the apertures of the 5 layers of the screen mesh are 3mm, 2.5mm, 2mm, 1.5mm and 0.8mm in sequence; of course, the number of layers of the screen and the aperture of each layer can be adjusted accordingly according to the actual production situation. The screen cloth is half circular arc, and the top of every layer of screen cloth all is equipped with more than 1 with the coaxial rotatory scraper blade of screen cloth, and the scraper blade is stirred when rotatory and is located the clod of screen cloth top, extrudees the clod simultaneously, makes clod friction screen cloth, is extruded the less granule of formation particle diameter finally from the sieve mesh, falls into on the sieve mesh of one deck down, so the successive layer down, finally obtains the powder granule that the particle diameter is about 0.8 mm. During the extrusion, friction and granulation process of the mud block, the water content of the mud block is gradually reduced layer by layer in the process that the grain diameter of the mud block is gradually reduced layer by layer due to the continuous drying effect of hot air.

In the existing low-temperature powder making process, due to the limitation of subsequent granulation process and equipment technology, the mud needs to be dried to 8% -10% before the dried mud blocks can be crushed and granulated by the existing ceramic mud crushing and granulating equipment. Therefore, the mud block to be treated has higher requirement on the dryness and is only suitable for the mud block with the water content not more than 10 percent. When the water content of the clods is high, such as 12% -14% of the present embodiment, two problems are caused: firstly, because the aperture of the sieve mesh on the circular arc screen mesh of the prior art is only 0.5-1 mm, the through holes are easily stuck by the mud blocks with higher water content, and secondly, the powder particles can be bonded together again to form large particles after granulation. The invention adopts the friction granulation in the flowing hot air environment, when the mud blocks with higher water content are subjected to friction granulation, the mud blocks adhered on the sieve pores are contacted with the hot air or hot sieve, the surface water is quickly lost, the volume is reduced, the surface viscosity is reduced, and the mud blocks are easy to fall off from the sieve pores and are not easy to adhere with each other.

In the granulation process, the mud blocks are changed into powder particles with smaller particle size, and the specific surface area is increased, so that the evaporation of the moisture of the powder particles is facilitated, the drying speed of the mud blocks is improved, and the drying cost is saved.

In addition, in the process of multilayer granulation, the outer layer of the mud block obtained by the previous layer of friction granulation is drier than the core part due to the drying effect of flowing hot air, and in the process of granulation of the next layer of friction screen, the outer layer and the core part of the mud block are kneaded again, so that the dryness of the mud block is more uniform; on the other hand, the pug with higher water content in the core part of the original pug is exposed to be more beneficial to the evaporation of the moisture of the particles.

Because the powder process of the invention adopts a friction granulation mode, the finally obtained powder particles may not be round enough, and in order to obtain more round powder particles and improve the fluidity of the powder particles, the process of the invention also comprises the following steps:

In the step, the powder particles are ground and polished by a rounding device, so that the ceramic particles are more round; hot air enters the roller of the rounding equipment through the air inlet, so that the temperature in the roller is increased, and the phenomenon that fine ceramic powder is attached to the inner wall of the roller due to too low temperature is avoided; meanwhile, the hot air can further dry powder particles during polishing. The powder particles after rounding treatment mainly comprise ceramic powder with smaller particle size and ceramic particles with the particle size meeting the requirement. Generally, ceramic powder with a mesh size of less than 120 meshes is not suitable for making green bricks and needs to be screened out in subsequent processes. In step S3, the hot air can dry the powder particles, and the ceramic powder can diffuse into the roller during the rotation of the roller, so the hot air can take away the fine ceramic powder from the roller as much as possible to remove the ceramic powder.

In order to fully achieve the effect of removing the ceramic powder, if the dryness of the powder particles meets the requirement in the rounding treatment process, the negative pressure dust suction treatment can be continuously carried out in the roller under the condition of closing the hot air.

The hot air used in the process of the invention can be separately heated hot air; or hot flue gas generated after tail gas of a kiln for firing ceramics is subjected to electrostatic dust removal or dry hot air generated after the tail gas of the kiln is subjected to heat exchange with the tail gas of the kiln, so that the production cost can be reduced. The temperature of the hot air is between 40 ℃ and 100 ℃.

In the step S1, the ceramic pug drying device disclosed in the chinese utility model patent with application number 2019203757149 may be used to dry the pug.

Fig. 2 to 5 show a multistage ceramic pug granulating apparatus for drying and granulating pug in multiple layers in step S2, which comprises a granulating bin 1, wherein the granulating bin 1 is rectangular and hollow, and comprises a left side plate 11, a right side plate 12, a front baffle 13 and a rear baffle 14. At least 2 friction granulation layers are arranged in the granulation bin 1, and each friction granulation layer is provided with at least 1 friction granulation assembly 2. In the present embodiment, the inside of the granulation chamber 1 is divided into a first friction granulation layer 100, a second friction granulation layer 101, a third friction granulation layer 102, a fourth friction granulation layer 103 and a fifth friction granulation layer 104 from top to bottom, wherein the number of friction granulation components 2 in the odd-numbered friction granulation layers, i.e. the first, third and fifth friction granulation layers, is 1, and the number of friction granulation components 2 in the even-numbered friction granulation layers, i.e. the second and fourth friction granulation layers, is 2. It should be noted that the number of the friction granulation layers in the granulation chamber 1 and the number of the friction granulation assemblies 2 contained in each friction granulation layer can be adjusted accordingly depending on the size of the apparatus.

The granulation cabin 1 is provided with more than 1 air inlet 121 and air outlet 112, and the air outlet 112 and the air inlet 121 are respectively connected with an exhaust fan and a blower through pipelines. In this embodiment, as shown in fig. 4, the number of the air outlets 112 and the air inlets 121 is 2, and the air outlets and the air inlets are respectively formed on the left side plate 11 and the right side plate 12. Wherein the air inlet 121 is respectively arranged below the circular arc-shaped screens 23 of the second and fifth friction granulation layers; the air outlet 112 is provided below the circular arc-shaped screens 23 of the first and fourth frictional granulation layers, respectively. The number of the air inlets 121 and the air outlets 112 can be increased or decreased as required, the arrangement positions of the air inlets 121 and the air outlets are based on the fact that the sufficient flow of hot air in the granulation chamber 1 is facilitated, and the hot air is introduced into the air inlets 121.

In order to ensure that the particles processed by the previous friction granulation layer all fall into the next friction granulation layer, the front baffle 13 and the rear baffle 14 respectively comprise a plurality of material blocking plates in the embodiment, the material blocking plates are arranged on the front side and the rear side of each friction granulation layer, and the material blocking plates mainly play two roles of material blocking and material guiding.

As shown in fig. 5, the friction granulation assembly 2 includes a rotating shaft 21, a plurality of scrapers 22, and a circular arc-shaped screen 23. In the present embodiment, the rotating shaft 21 of the friction granulation assembly 2 is mounted on the left and

right side plates

11 and 12 of the granulation chamber 1 through bearings, so that the friction granulation assembly 2 is disposed in the granulation chamber 1. A round mounting plate 24 is fixedly arranged on the left side surface and the right side surface of the rotating shaft 21 close to the granulation cabin 1; a plurality of scrapers 22 are uniformly fixed on the rotating shaft 21 through a circular mounting plate 24; the circular arc-shaped screen 23 is coaxial with the rotating shaft 21 and is fixed right below the rotating shaft 21, and a plurality of screen holes (not shown in the figure) are uniformly formed in the circular arc-shaped screen 23; there is a gap, which we refer to as a friction gap 200 in this specification, between the extreme end of the scraper 22 and the upper surface of the circular arc-shaped screen 23. In order to enhance the effect of friction crushing of the mud cake, as shown in fig. 5, a certain inclination angle is formed between the scraper 22 and the circular arc-shaped screen 23. The rotating shaft 21 shown in fig. 5 is rotated counterclockwise, so that the scrapers 22 squeeze the clods on the circular arc-shaped screen 23 instead of shoveling the clods on the circular arc-shaped screen 23 during the friction granulation process, thereby achieving better effect of friction extrusion granulation. The turning shaft 21 is driven to rotate by a driving mechanism, and in the present embodiment, the turning shaft 21 is connected to a motor 25 fixedly mounted on the right side plate 12 and driven to rotate by the motor 25.

The circular arc-shaped screen 23 is a wearing part, in order to facilitate replacement of the circular arc-shaped screen 23, guide posts 231 are arranged on two side edges of the circular arc-shaped screen 23, guide grooves 1314 matched with the guide posts 231 are arranged on the front baffle 13 and the rear baffle 14, a replacement opening 111 allowing the circular arc-shaped screen 23 to enter and exit is formed in the left side plate 11, and the shape of the replacement opening 111 is the same as the longitudinal section of the circular arc-shaped screen 23. When replacing the circular arc-shaped screen 23, it is only necessary to pull out the old circular arc-shaped screen from the replacement opening 111, put in the new circular arc-shaped screen from the replacement opening 111, and push the guide post 231 on the circular arc-shaped screen 23 to the rightmost part in cooperation with the guide groove 1314.

In order to reduce the particle size of the powder particles layer by layer during the granulation process, the aperture of the sieve pores on the lower friction granulation assembly 2 is smaller than the corresponding sieve pores on the upper friction granulation assembly 2. Generally, the aperture of the sieve holes on the friction granulation assembly 2 with 5 friction granulation layers is 3.5-3 mm, 2.8-2.5 mm, 2.3-2 mm, 1.8-1.5 mm and 1.3-0.8 mm in sequence, the device has better effect in granulation. The apertures of the 5-layer mesh in this example were 3mm, 2.5mm, 2mm, 1.5mm and 0.8mm in this order. The friction gaps 200 on the friction granulation assemblies 2 in different layers are different, the size of the friction gap 200 is determined by actual production conditions, so that the friction gap 200 is in a proper size, generally, in order to ensure the friction granulation efficiency, the friction gap 200 is not too large, and only needs to be slightly larger than or equal to the aperture of the sieve hole.

When in use, mud blocks enter the granulation cabin 1 from the feeding port 3 above the equipment, are impacted by the scraper 22 of the friction granulation component 2 positioned in the first friction granulation layer 100 and then fall onto the circular arc-shaped screen 23, when the scraper 22 rotates to the position above the circular arc-shaped screen 23, particles on the circular arc-shaped screen 23 are extruded into the friction gap 200 between the scraper 22 and the circular arc-shaped screen 23 by the rotating extrusion of the scraper 22, so that the particles extruded into the friction gap 200 rub against sieve holes on the circular arc-shaped screen 23, and then the particles are rubbed to form small-particle-size particles and/or strip-shaped mud materials with smaller diameter and fall into the second friction granulation layer 101 from the sieve holes, and meanwhile, large particles which are not rubbed and granulated are scraped and circularly thrown by the scraper 22 again to continuously carry out friction granulation; the small particles entering the next friction granulation layer are processed into particles or strip-shaped pugs with smaller diameters by the friction granulation component 2 positioned on the layer, and the particles are downward layer by layer, and finally powder particles with the particle diameters meeting the requirements are obtained through multistage friction granulation and are discharged from a discharge port 4 of the friction granulation equipment and then are sent to the next procedure.

Compared with the existing granulation equipment, the granulation equipment of the embodiment improves the granulation efficiency mainly in the following two aspects:

1. by arranging a plurality of friction granulation layers, a plurality of friction granulation assemblies 2 positioned in different friction granulation layers work simultaneously, and compared with the existing single-layer granulation equipment, the processing capacity in unit time is improved;

2. the size of the powder particles prepared by the friction granulation component 2 of different friction granulation layers becomes smaller layer by layer, namely the sieve pores of the circular arc-shaped sieve mesh 23 positioned in the first friction granulation layer 100 are far larger than the sieve pores of the traditional granulation equipment, so that the speed of the mud blocks passing through the first-level sieve pores is improved, namely the speed is fast when the mud blocks pass through the large-sized granulation.

As the water content of the mud blocks produced in each batch is basically kept consistent, during the friction granulation, the powder particles with the water content and the particle size meeting the requirements can be obtained by controlling the feeding speed of the friction granulation and the temperature and the speed of the air flow.

Shown in fig. 6 is a rounding device, which comprises a roller 601 and a feeding hopper 602, wherein the inner wall of the roller is spirally wound with a convex strip for rounding ceramic particles, the two ends of the roller 601 are respectively provided with a feeding port and a discharging port, a dust suction port is arranged at one end close to the discharging port of the roller 601, the feeding hopper 602 is arranged at one end close to the feeding port of the roller 601, the axis of the roller 601 is obliquely arranged on a fixed frame 7 along the horizontal direction, and one end of the discharging port is lower than one end of the feeding port. Under the action of the gravity of the powder particles, the powder particles can gradually move from one end of the feeding hole to one end of the discharging hole when rolling in the roller 601. The abrasive particle motor 5 is fixedly connected with the fixed frame 7 and drives the roller 601 to rotate through a belt.

The number of the rollers 601 is at least 1, and the number of the rollers 601 of the rounding device shown in fig. 6 is 3. Of course, in practice, the number of rollers 601 may be increased or decreased to increase or decrease the rounding path, depending on the manufacturing requirements of the powder particles. The quantity of the rollers 601 is increased, so that the rounding effect of the rounding equipment on powder particles can be improved.

An air inlet 603 for introducing hot air is arranged at one end of the roller 601 at the foremost end, which is close to the feed inlet, and an air outlet 604 is arranged at one end of the roller 601 at the rearmost end, which is close to the discharge outlet.

When the air inlet is not communicated with hot air and the air outlet is exhausted by the exhaust fan, negative pressure is formed in the roller 601 at the moment, and the effect of negative pressure dust collection is achieved.

When the roller 601 rolls along the axis of the roller, friction exists between powder particles and the raised lines and between the powder particles and the inner wall of the roller, and the friction can polish the powder particles, so that the powder particles are more round; hot air can enter the interior of the roller through the air inlet, so that the temperature in the roller is increased, and therefore, the phenomenon that fine ceramic powder is attached to the inner wall of the roller due to too low temperature can be avoided; secondly, the powder particles can be dried continuously; in addition, the hot air can take the fine ceramic powder out of the drum as much as possible.

Compared with the existing low-temperature powder making process, the ceramic powder making process has the following remarkable advantages:

1. the process of drying the pug with the water content of 18-25 percent to the pug with the water content of 8-10 percent by adopting ceramic pug drying equipment in the prior art is decomposed into the step-by-step reduction of the water content of the pug or powder particles in 3 processes of primary drying, granulation and rounding. The method has the significance that the relation between the evaporation of the water in the mud block and the required time is not linear but has the characteristics of first-speed and last-slow, the reason is mainly that the volume of the mud block is large, the water in the surface layer of the mud block is primarily evaporated, and the water in the center of the mud block is difficult to volatilize after the surface layer is dried. The process effectively utilizes the characteristic of water evaporation of the mud blocks, and only reduces the water content of the mud blocks to 12-14% under the condition of ensuring the realizable subsequent process in the primary drying process of the ceramic mud material drying equipment, thereby greatly reducing the mud material drying time of the ceramic mud material drying equipment, being beneficial to saving energy, improving the drying speed and realizing the miniaturization of the drying equipment;

2. the multi-level granulation method is adopted in the granulation process, and has the following advantages:

firstly, the aperture of the sieve pore on the first layer is larger, so that the throughput of mud blocks can be improved, and the granulation speed is integrally improved;

secondly, the particle size of the particles becomes smaller layer by layer, and compared with the mud block, the specific surface area of the particles is rapidly increased, so that the moisture is rapidly volatilized, the drying speed is improved, and the energy consumption is reduced;

thirdly, in the process of extruding and granulating the powder particles by each screen layer, the outer layer and the core of the particles are kneaded again, which is beneficial to exposing the core pug with higher water content, thereby improving the evaporation speed of water;

fourthly, the rounding treatment stage is fully utilized to dry the powder particles, and the drying time of the granulation stage is effectively shortened under the condition that the rounding treatment time is not increased.

In conclusion, the process can reduce the time of the primary drying stage of the pug and save energy because the water content of the pug which can be processed in the extrusion friction granulation stage is higher; in addition, the aperture of the screen mesh at the first layer is larger by adopting a multilayer extrusion friction granulation method, so that the throughput of pug is improved by multiple times during extrusion friction granulation, and the granulation speed is improved.

Example two:

the invention also provides a ceramic powder making system adopting the process, which comprises a filter press 10, a mud cutting device 20, a ceramic mud drying device 30 and a ceramic mud multi-stage granulation device 40 which are sequentially connected as shown in figure 7. In addition, a rounding device 50 may be included in the ceramic pulverizing system in order to obtain a more rounded powder particle. The filter press 10, the mud cutting device 20 and the ceramic mud material drying device 30 are conventional devices; the concrete structure of the ceramic pug multistage granulation apparatus 40 and the rounding apparatus 50 refer to the previous description of the present specification and fig. 2 to 6. The filter press 10, the mud cutting device 20, the ceramic mud drying device 30, the ceramic mud multi-stage granulation device 40 and the rounding device 50 are sequentially connected through a conveying belt. In addition, a material distributor can be arranged at the front ends of the feed inlets of the ceramic pug drying equipment 30 and the ceramic pug multistage granulation equipment 40, so that the feeding of the equipment is more uniform.

The air inlets and the air outlets of the ceramic pug drying equipment 30, the ceramic pug multistage granulation equipment 40 and the rounding equipment 50 are respectively connected with an air inlet pipe and an air outlet pipe through an air blower and an exhaust fan, and hot air is introduced into the air inlet pipe. In this embodiment, since the temperatures of the hot air required by the respective apparatuses may be different, the air inlet pipes connected to the ceramic slurry drying apparatus 30, the ceramic slurry multistage granulation apparatus 40, and the rounding apparatus 50 are mutually independent pipes. The exhaust pipes of the ceramic pug drying equipment 30, the ceramic pug multistage granulation equipment 40 and the rounding equipment 50 can also be mutually independent pipelines.

Claims

1. A ceramic powder process is characterized in that: the process comprises the following steps:

step S1, drying the pug to obtain pug with water content of 12-14%;

2. A ceramic milling process as claimed in claim 1, wherein: the process further comprises:

3. A ceramic milling process as claimed in claim 1, wherein: the number of the screen cloth is 5, 5 the screen cloth from the top down set up gradually layer by layer, the aperture of the sieve mesh of screen cloth is 3.5 ~ 3mm, 2.8 ~ 2.5mm, 2.3 ~ 2mm, 1.8 ~ 1.5mm and 1.3 ~ 0.8mm respectively.

4. A ceramic milling process as claimed in claim 1, 2 or 3, wherein: the hot air is hot flue gas generated after electrostatic dust removal of the kiln tail gas or dry hot air generated after heat exchange with the kiln tail gas.

5. A ceramic milling process as claimed in claim 1, 2 or 3, wherein: the temperature of the hot air is between 40 ℃ and 100 ℃.

6. A ceramic milling process as claimed in claim 2, wherein: in step S3, negative pressure dust collection is performed during the process of rounding the powder particles.

7. A ceramic pulverizing system specifically designed using the ceramic pulverizing process of claim 1, characterized in that: the device comprises a filter press, a mud cutting device, a ceramic mud material drying device and a ceramic mud material multistage granulation device which are sequentially connected through a conveying belt, wherein air inlets and air outlets of the ceramic mud material drying device and the ceramic mud material multistage granulation device are respectively connected with an air inlet pipe and an exhaust pipe.

8. The ceramic pulverizing system of claim 7 wherein: the multistage ceramic mud material granulating equipment comprises a granulating bin, wherein at least 2 friction granulating layers are arranged in the granulating bin, and each friction granulating layer is provided with at least 1 friction granulating assembly;

the granulation cabin is provided with more than 1 air inlet and air outlet.

9. The ceramic pulverizing system of claim 8 wherein: guide posts are arranged on two side edges of the circular arc-shaped screen, guide grooves matched with the guide posts are arranged on the front side plate and the rear side plate of the granulation cabin, and a replacement opening allowing the circular arc-shaped screen to enter and exit is formed in the left side plate.

10. The ceramic pulverizing system of claim 7 wherein: the ceramic powder making system also comprises rounding equipment, and the rounding equipment is connected with the ceramic pug multistage granulation equipment through a conveyer belt; rounding equipment includes the cylinder, the inner wall spiral of cylinder coils there is the sand grip to the ceramic granule rounding, the cylinder both ends are provided with feed inlet and discharge gate respectively, the cylinder is close to the one end of feed inlet is provided with and is used for letting in hot-blast air intake, and the other end is provided with the air exit.