CN112851175B

CN112851175B - Device and method for preparing cement retarder by adopting industrial waste residues

Info

Publication number: CN112851175B
Application number: CN202110192065.0A
Authority: CN
Inventors: 雍毅; 吴怡; 尹朝阳; 薛嘉; 郭卫广; 刘恒博; 黄祥
Original assignee: SICHUAN ACADEMY OF ENVIRONMENTAL SCIENCES
Current assignee: SICHUAN ACADEMY OF ENVIRONMENTAL SCIENCES
Priority date: 2021-02-20
Filing date: 2021-02-20
Publication date: 2022-08-23
Anticipated expiration: 2041-02-20
Also published as: CN112851175A

Abstract

The invention discloses a device and a method for preparing cement retarder by using industrial waste residues, wherein the device comprises a cleaning device, a centrifugal device, a modification device and a forming device which are sequentially arranged, the modification device is a stirring tank, the stirring tank is divided into an upper stirring tank and a lower stirring tank by a partition plate, the upper stirring tank and the lower stirring tank are respectively provided with a stirrer and a controller electrically connected with the stirrer, the upper end of the upper stirring tank is provided with a plurality of feeding ports, a metering scale and a first electromagnetic valve, the lower stirring tank is provided with a discharging port, a pH detection device and a second electromagnetic valve, and an inverted funnel-shaped disc is arranged above the upper stirring tank. The device can dehydrate and modify industrial waste residues, can prepare phosphogypsum into a cement retarder with excellent performance, and reduces the production cost while consuming industrial solid wastes such as carbide slag, industrial alkaline slag, fly ash and the like, thereby bringing certain economic benefit.

Description

Device and method for preparing cement retarder by adopting industrial waste residues

Technical Field

The invention relates to the technical field of cement retarders, in particular to a device and a method for preparing a cement retarder by using industrial waste residues.

Background

Phosphogypsum cannot be directly used as a retarder of cement. Firstly, the phosphogypsum contains a large amount of water-soluble phosphorus pentoxide, water-soluble fluorine, organic matters and other harmful impurities, so that the phosphogypsum is acidic and corrosive to a certain extent, and C can be delayed ₃ A and C ₃ S and other cement minerals have early hydration speed, so that the setting time of the cement is prolonged, and the early strength is reduced. And secondly, the phosphogypsum is wet powder, the attached water content is 15-30%, the phosphogypsum is unstable, the transportation and the metering are not facilitated, and the blockage and the agglomeration of a silo, the paste grinding in a cement mill and the like are easily caused.

The caustic soda industry in China has huge capacity, and about 13.6kg of caustic sludge (containing 35.9 percent of water) is generated when 1t of finished caustic soda is produced. The alkaline residue mainly contains industrial residue containing calcium salts such as calcium carbonate, calcium sulfate, silicon dioxide, calcium chloride, etc., and also contains small amount of magnesium hydroxide, calcium hydroxide, iron aluminum oxide, and sodium chloride. The alkaline residue is alkaline, and the pH value is about 10. Most enterprises aim at the situation that salt mud is almost piled up or buried after being subjected to filter pressing, and the treatment method is high in cost and inevitably affects the environment. The cost for waste residue discharge of a factory producing 80 ten thousand of soda ash every year is about 1000 ten thousand yuan. Therefore, the alkaline residue is effectively utilized, waste is changed into valuable, and the method has obvious social benefit and economic benefit and broad prospect.

The fly ash is the main solid waste discharged by coal-fired power plants and coal gangue and coal slime comprehensive utilization power plants. The pH value of the fly ash is 8-11. The fly ash mainly comprises silicon dioxide and aluminum oxide (the content of silicon oxide is about 48 percent, the content of aluminum oxide is about 27 percent) as chemical components, and comprises ferric oxide, calcium oxide, magnesium oxide, potassium oxide, sodium oxide, sulfur trioxide and unburned organic matters as other components.

The method for preparing the cement retarder by the phosphogypsum in the prior art comprises the following steps: mixing phosphogypsum, slag powder or fly ash and quicklime powder or carbide slag powder, adding an alkali catalyst, mixing and balling to obtain the calcium-lime-fly-ash ball, wherein the requirements of the raw material quicklime powder are that the CaO content is more than or equal to 65% and the 90-mum screen residue is less than or equal to 7%, the requirements of the fly ash are that the grade II fly ash is used, the requirement of the slag powder is that the grade S75 slag powder is used, and the requirements of the carbide slag powder are that the CaO content of free water and bound water are subtracted is more than or equal to 65% and the 90-mum screen residue is less than or equal to 7%. The raw materials are screened to a certain degree, and the centralized finishing and conversion of the industrial waste residue cannot be carried out.

Disclosure of Invention

The invention aims to provide a device and a method for preparing a cement retarder by using industrial waste residues, the device and the method can be used for uniformly mixing the industrial waste residues to prepare the cement retarder, economic benefits are brought under the condition of eliminating industrial solid wastes, and the device is simple in structure and convenient to operate.

In order to achieve the purpose, the invention provides a device for preparing cement retarder by using industrial waste residues, which comprises a cleaning device, a centrifugal device, a modification device and a forming device which are sequentially arranged, wherein the modification device is a stirring tank, the stirring tank is divided into an upper stirring tank and a lower stirring tank by a partition plate, the upper stirring tank and the lower stirring tank are respectively provided with a stirrer and a controller electrically connected with the stirrer, the upper end of the upper stirring tank is provided with a plurality of feeding ports, a metering scale and a first electromagnetic valve, the lower stirring tank is provided with a discharging port, a pH detection device and a second electromagnetic valve, and an inverted funnel-shaped disc is arranged above the upper stirring tank.

The beneficial effect who adopts above-mentioned scheme is: removing soluble phosphorus, fluorine, organic matters and other impurities in most of fresh phosphogypsum by a cleaning device, removing water filled during cleaning by a centrifugal device, placing the phosphogypsum in a disc, stirring the mixture by a stirrer after industrial carbide slag, alkali slag and fly ash enter an upper stirring tank from a feeding port to form a modifier, pouring the phosphogypsum into the upper stirring tank from the disc, mixing by the stirrer to modify acidic phosphogypsum, metering the raw materials entering the upper stirring tank by a metering scale, opening the feeding port by a first electromagnetic valve, and controlling the adding amount; and (3) the uniformly mixed mixture enters a lower stirring tank from a partition plate, stands and ages in the lower stirring tank, and can be adjusted to meet the construction requirements by adding industrial carbide slag according to the pH value detected by a pH detection device. Finally, preparing the mixture into spherulites with uniform particle sizes through a forming device, and using the spherulites for cement condensation; wherein the controller can be model ohm dragon CP1H-X40DT-D PLC controller.

Furthermore, the cleaning device comprises a step pool, a plurality of water inlet pipelines are arranged at the edge of the upper portion of the step pool, a water outlet pipeline is arranged at the lower end of the step pool, a gauze net is arranged at the bottom of the step pool, a traction rope is arranged at the edge of the gauze net, and the traction rope is movably connected with the mechanical arm.

The beneficial effect who adopts above-mentioned scheme is: the method is characterized in that fresh phosphogypsum is put into a cleaning device, a plurality of water inlet pipelines are flushed with water simultaneously, a large impact force can be exerted on impurities of the phosphogypsum, a stepped pool can have a staged cleaning effect on the phosphogypsum, and finally, a gauze net is pulled by a mechanical arm so that the cleaned phosphogypsum can be collected.

Further, the centrifugal device is a punching bag centrifuge, and the forming device is a disk pelletizer.

The beneficial effect who adopts above-mentioned scheme is: the punching bag centrifuge can be a PSD type centrifuge, and the disc balling machine can be PQ (T) -500; the motor of the punching bag centrifuge drives the rotary drum to rotate, the materials are added into the rotary drum through the top feeding pipe and tend to the rotary drum under the action of centrifugal force, and liquid phase penetrates through the filter cloth and the filter holes in the drum wall to be discharged. The solid phase is trapped in the rotary drum, the machine cover is opened after the machine is stopped to release the locking pin of the liquid blocking plate, the liquid blocking plate and the filter bag filled with filter residue are lifted to the discharging position by a lifting device, the special lifting claw is released to open one end of the filter bag, and the filter cake automatically falls down. The raw material powder is made into the ball core with uniform granularity in the disk balling machine, then the ball core is fed into the balling disk, the ball core is acted by centrifugal force, friction force and gravity in the disk after entering the balling disk, the ball core moves along a parabola, and the moisture in the ball is continuously extruded out of the surface in the continuous rolling process, and the ball core and the raw material powder are mutually bonded and grow gradually in the moving process due to the caking property and plasticity of the materials. The material ball has certain strength due to the caking property of the material and the natural volatilization of the surface liquid film. When the parameters of the ball forming disc, such as the inclination angle, the disc edge height, the rotating speed, the moisture and the like are fixed, the material balls with different grain diameters leave the disc edge to roll downwards according to different departure angles due to different gravity, and then are discharged out of the disc from the edge part of the disc along with the rotation of the inclined disc body.

Further, the pH detection device comprises a pH automatic detector, a display and a display lamp which are electrically connected with the controller.

The beneficial effect who adopts above-mentioned scheme is: the model of the pH automatic detector can be an SIN-pH6.3 model, the pH value of the mixture is detected through the pH automatic detector, the pH value is displayed on the display, if the pH value does not reach 7, the display lamp cannot be turned on, new industrial carbide slag needs to be continuously added for alkalinity adjustment, and after the alkalinity is higher than 7, the controller controls the display lamp to be turned on to prompt a worker that the alkalinity does not need to be continuously adjusted.

Further, the disc is provided with rotary contracting teeth, and the shape of the rotary contracting teeth is triangular.

The beneficial effect who adopts above-mentioned scheme is: the phosphogypsum on the disc can be uniformly scattered into the upper stirring pool by rotating the contraction teeth to be continuously mixed with the mixture.

Furthermore, a material conveying pipe and a third electromagnetic valve are arranged in the partition plate, and the third electromagnetic valve is electrically connected with the controller.

The method for preparing the cement retarder by adopting the device for preparing the cement retarder from the industrial waste residues comprises the following steps:

(1) circularly cleaning fresh phosphogypsum in a cleaning device for 3-5 times, wherein the liquid-solid ratio is 3: 1-6: 1;

(2) taking out the cleaned phosphogypsum, and centrifugally dewatering or aging for 2-4 months in a centrifugal device to obtain dewatered phosphogypsum;

(3) storing the dehydrated phosphogypsum into a disc, and mixing industrial carbide slag, alkaline residue and fly ash according to a mass ratio of 50-70: 20-30: 5-15, inputting the mixture into an upper stirring pool from a feeding port, and stirring the mixture and the dehydrated phosphogypsum for the first time;

(4) opening a material conveying pipe, inputting the mixture obtained in the step (3) into a lower stirring pool, after piling for 1-5 days, adjusting the pH value to be more than 7, and carrying out secondary stirring;

(5) and (4) preparing the obtained substance after the secondary stirring into the cement retarder with fixed particles by a disc granulator.

The beneficial effect who adopts above-mentioned scheme is: firstly, cleaning fresh phosphogypsum to remove most of dissolved phosphorus, fluorine and organic matters, so as to prevent the dissolved phosphorus, fluorine and organic matters from prolonging the delayed coagulation time of cement and reducing the strength of the cement; secondly, centrifugal dehydration or aging is carried out, so that the water content of the phosphogypsum with high water content after cleaning can be reduced to be within 15%; the mixture of the industrial carbide slag, the alkaline residue and the fly ash can be used as a modifier, the phosphogypsum contains free acid, and the pH values of the carbide slag, the alkaline residue and the fly ash are alkaline, so that the free acid in the phosphogypsum can be neutralized, the leaching of soluble phosphorus and fluorine in the phosphogypsum can be reduced, the influence of the soluble phosphorus and fluorine on a retarder can be reduced, the product quality can be improved, the pH value is finally adjusted to be higher than 7, and the requirement of construction requirements on cement setting time can be met. And the cement retarder can be prepared into 10-30mm spherulites through a disc granulator, so that the construction is convenient.

Furthermore, the mixture of the industrial carbide slag, the alkaline residue and the fly ash accounts for 1 to 5 percent of the mass percent of the phosphogypsum.

Furthermore, the rotation speed of centrifugal dehydration is 800-2000 r/min, and the dehydration time is 10-20 min.

In summary, the invention has the following advantages:

1. the phosphogypsum is modified by the carbide slag, so that the obtained phosphogypsum has good performance, is used for a cement retarder, not only can achieve the effect of retarding natural gypsum, but also can increase the strength of cement, and can prolong the service life of the cement; the phosphogypsum is modified by the carbide slag, because the carbide slag and the phosphogypsum are large industrial waste residues, the raw material source is rich, the cost is low, and the modification of the carbide slag can obtain good modification effect only by reacting for 2 hours under the normal temperature condition by the preparation method of the invention; the carbide slag modified phosphogypsum has the advantages of low cost, simple process condition, rich raw material sources and the like;

2. the modified phosphogypsum can be completely used as a coagulation regulator of cement, and simultaneously consumes industrial solid wastes such as carbide slag, industrial alkaline residue, fly ash and the like, so that the production process is simple, the production cost is reduced, the ecological environment is protected, and certain economic benefit is brought.

Drawings

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

FIG. 2 is a schematic view of the cleaning apparatus;

FIG. 3 is a schematic view of the stirring tank;

FIG. 4 is a schematic structural view of a disk;

wherein, 1, a mechanical arm; 2. a water inlet pipe; 3. a hauling rope; 4. a gauze mesh; 5. a step pool; 6. feeding the mixture into a stirring pool; 7. a lower stirring tank; 8. a disc; 9. a feed port; 10. a stirrer; 11. a delivery pipe; 12. a second electromagnetic valve; 13. a discharge port; 14. and a first electromagnetic valve.

Detailed Description

The invention provides a device for preparing cement retarder by using industrial waste residues, which comprises a cleaning device, a centrifugal device, a modification device and a forming device which are sequentially arranged, wherein the modification device is a stirring tank which is divided into an upper stirring tank 6 and a lower stirring tank 7 by a partition plate, the upper stirring tank 6 and the lower stirring tank 7 are respectively provided with a stirrer 10 and a controller electrically connected with the stirrer 10, the upper end of the upper stirring tank 6 is provided with a plurality of feeding ports 9, a metering scale and an electromagnetic valve I14, the lower stirring tank 7 is provided with a discharging port 13, a pH detection device and an electromagnetic valve II 12, and an inverted funnel-shaped disc 8 is arranged above the upper stirring tank 6.

Wherein, belt cleaning device includes

ladder pond

5, and 5 upper portion edges in ladder pond are provided with a plurality of inlet channels 2, and the lower extreme is provided with outlet conduit, and the bottom is provided with gauze net 4, and gauze net 4 edges are provided with haulage rope 3, haulage rope 3 and arm 1 swing joint.

Wherein, the centrifugal device is a punching bag centrifuge, and the forming device is a disk balling machine.

Wherein, pH detection device includes pH automated inspection appearance, display and the display lamp all with controller electric connection.

Wherein, the disc 8 is provided with rotary contraction teeth, and the shape of the rotary contraction teeth is triangular.

Wherein, a material conveying pipe 11 and a third electromagnetic valve are arranged in the clapboard, and the third electromagnetic valve is electrically connected with the controller.

Example 1

(1) cleaning of

Firstly, cleaning fresh phosphogypsum in a cleaning device, and cleaning and filtering for 5 times by adopting circulating water in a factory according to a liquid-solid ratio of 4:1 to remove most of dissolved phosphorus, fluorine and organic matters;

(2) centrifugation

Taking out the cleaned phosphogypsum by using the mechanical arm 1, and then carrying out medium-high speed centrifugal dehydration, wherein the rotating speed of a centrifugal machine is 1000r/min, the centrifugal time is 20min, the water content of the phosphogypsum is reduced to be within 12%, and the removed percolate enters a percolate collecting pool and is simply treated as part of production reuse water in a field;

(3) one-time stirring

Industrial carbide slag, alkaline residue and fly ash are mixed according to the mass ratio of 70: 20: 10, conveying the mixture from a feeding port 9 to an upper stirring tank 6 for mixing and stirring to prepare an alkaline modifier, adding the modifier accounting for 3% of the mass of the phosphogypsum into the cleaned and dehydrated phosphogypsum, stirring and uniformly mixing for the first time, inputting the mixture into a lower stirring tank 7, and stacking and reacting for 5 days;

(4) second stirring

Testing the pH value of the modified phosphogypsum after the stockpiling reaction by using a pH automatic detector, secondarily adding industrial carbide slag according to the pH value, adjusting the pH value to be more than 7, and secondarily stirring to obtain a cement retarder;

(5) is made into

And (4) preparing the obtained substance after the secondary stirring into the cement retarder with fixed particles by a disc granulator.

Example 2

(1) cleaning of

Firstly, cleaning fresh phosphogypsum in a cleaning device, and cleaning and filtering for 3 times by using circulating water in a factory according to a liquid-solid ratio of 6:1 to remove most of dissolved phosphorus, fluorine and organic matters;

(2) aging of the mixture

Taking out the cleaned phosphogypsum by using the mechanical arm 1, aging for 4 months to reduce the water content of the phosphogypsum to be within 15 percent, and allowing the removed percolate to enter a percolate collecting tank to be simply treated as part of production reuse water in a field;

(3) one-time stirring

Mixing industrial carbide slag, alkaline residue and fly ash according to a mass ratio of 60: 25: 15, conveying the mixture from the feeding port 9 to the upper stirring tank 6 for mixing and stirring to prepare an alkaline modifier, adding the modifier accounting for 4% of the mass of the phosphogypsum into the cleaned and dehydrated phosphogypsum for primary stirring and uniform mixing, and inputting the mixture into the lower stirring tank 7 for stockpiling and reacting for 5 days;

(4) second stirring

Testing the pH value of the modified phosphogypsum after the stockpiling reaction by using a pH automatic detector, adding industrial carbide slag for the second time according to the pH value, adjusting the pH value to be more than 7, and stirring for the second time to obtain the cement retarder.

(5) Is made into

Example 3

(1) cleaning of

Firstly, cleaning fresh phosphogypsum in a cleaning device, and cleaning and filtering for 4 times by adopting in-plant circulating water according to a liquid-solid ratio of 6:1 to remove most dissolved phosphorus, fluorine and organic matters;

(2) centrifugation

Taking out the cleaned phosphogypsum by using the mechanical arm 1, and then carrying out medium-high speed centrifugal dehydration, wherein the rotating speed of a centrifugal machine is 2000r/min, the centrifugal time is 10min, the water content of the phosphogypsum is reduced to be within 10%, and the removed percolate enters a percolate collecting pool and is simply treated as part of production reuse water in a field;

(3) one-time stirring

Industrial carbide slag, alkaline residue and fly ash are mixed according to the mass ratio of 70: 25: 5, conveying the mixture from a feeding port 9 to an upper stirring tank 6 for mixing and stirring to prepare an alkaline modifier, adding the modifier accounting for 1% of the mass of the phosphogypsum into the cleaned and dehydrated phosphogypsum, stirring and uniformly mixing for the first time, inputting the mixture into a lower stirring tank 7, and storing the mixture for reaction for 5 days;

(4) the second stirring

Testing the pH value of the modified phosphogypsum subjected to stockpiling reaction by using a pH automatic detector, adding industrial carbide slag for the second time according to the pH value, adjusting the pH value to be more than 7, and stirring for the second time to obtain a cement retarder;

(5) is made into

And (4) preparing the resultant after the secondary stirring into the cement retarder with fixed particles by a disc granulator.

The cement retarders prepared in examples 1-3 were tested, and the contents of the materials are shown in table 1:

TABLE 1 Cement retarder test index

As can be seen from Table 1, in the cement retarder prepared by the device and the method, the contents of the attached water, the calcium sulfate dihydrate, the water-soluble phosphorus pentoxide, the water-soluble fluoride ions and the water-soluble magnesium oxide all meet the use indexes of the cement retarder, the contents of the water-soluble sodium oxide and the water-soluble chloride ions are 0, the setting time is a composite test index, the modified phosphogypsum can be completely used as a setting regulator of cement, and industrial solid wastes such as carbide slag, industrial caustic sludge, fly ash and the like are simultaneously eliminated, so that the production process is simple, the production cost is reduced, the ecological environment is protected, and certain economic benefits are brought.

While the embodiments of the invention have been described in detail in connection with the drawings, the invention should not be construed as limited to the scope of the patent. Various modifications and changes may be made by those skilled in the art without inventive step within the scope of the appended claims.

Claims

1. The device for preparing the cement retarder by adopting the industrial waste residues is characterized by comprising a cleaning device, a centrifugal device, a modification device and a forming device which are sequentially arranged, wherein the modification device is a stirring tank which is divided into an upper stirring tank (6) and a lower stirring tank (7) by a partition plate, the upper stirring tank (6) and the lower stirring tank (7) are respectively provided with a stirrer (10) and a controller electrically connected with the stirrer (10), the upper end of the upper stirring tank (6) is provided with a plurality of feeding ports (9), a metering scale and a first electromagnetic valve (14), the lower stirring tank (7) is provided with a discharging port (13), a pH detection device and a second electromagnetic valve (12), and an inverted funnel-shaped disc (8) is arranged above the upper stirring tank (6); a material conveying pipe (11) and a third electromagnetic valve are arranged in the partition plate, and the third electromagnetic valve is electrically connected with the controller;

the cleaning device comprises a stepped pool (5), wherein a plurality of water inlet pipelines (2) are arranged at the edge of the upper part of the stepped pool (5), a water outlet pipeline is arranged at the lower end of the stepped pool, a gauze net (4) is arranged at the bottom of the stepped pool, a traction rope (3) is arranged at the edge of the gauze net (4), and the traction rope (3) is movably connected with a mechanical arm (1);

the centrifugal device is a punching bag centrifuge, and the forming device is a disc granulator;

the disc (8) is provided with rotary contraction teeth, and the rotary contraction teeth are triangular;

the use method of the device for preparing the cement retarder by adopting the industrial waste residues comprises the following steps:

(3) storing the dehydrated phosphogypsum into a disc (8), and mixing industrial carbide slag, alkaline slag and fly ash according to a mass ratio of 50-70: 20-30: 5-15 are input into an upper stirring pool (6) from a feed port (9) and are stirred with the dehydrated phosphogypsum for the first time;

(4) opening a material conveying pipe (11), inputting the mixture obtained in the step (3) into a lower stirring pool (7), after piling for 1-5 days, adjusting the pH value to be more than 7, and carrying out secondary stirring;

2. The apparatus for preparing cement retarder from industrial slag according to claim 1, wherein the pH detection device comprises a pH automatic detector, a display and a display lamp, all of which are electrically connected with the controller.

3. The apparatus for preparing cement retarder from industrial slag according to claim 1, wherein the mixture of industrial carbide slag, alkali slag and fly ash accounts for 1-5% of the mass fraction of phosphogypsum.

4. The apparatus for preparing cement retarder from industrial residue according to claim 1, wherein the rotational speed of the centrifugal dehydration is 800-2000 r/min, and the dehydration time is 10-20 min.