Method for preparing high-grade calcium carbonate whisker by using low-content calcium carbonate

Abstract

The invention belongs to the field of preparation of calcium carbonate whiskers, and particularly relates to a method for preparing high-grade calcium carbonate whiskers from low-content calcium carbonate, which comprises the following steps: S1, preparing calcium carbonate ore: crushing the ore into 40-80mm raw materials; s2, high-temperature calcination: putting the crushed ore into a vertical kiln at the temperature of 1000-1200 DEG C for 16 hours, and waiting for material cooling; s3, screening: screening out impurities by using a vibrating screen at the speed of 500-800 revolutions; s4, filtering and precipitating: pouring the sieved material into a digestion tank, pouring water without impurities into the digestion tank, and covering the material with water which is 20cm higher than the material for 48 hours; s5, fine polyester: using a vibrating screen at a rotating speed of 500-800. The calcium carbonate whisker prepared by the steps of crushing, high-temperature calcining, screening, filtering, precipitating, fine polyester, size mixing, NaMg internalizing agent preparation, calcium carbonate whisker preparation, dehydration, drying and modification is high in grade, and can meet actual use requirements.

Description

Technical Field

[0001] The invention relates to the technical field of preparation of calcium carbonate whiskers, and in particular to a preparation method of high-grade calcium carbonate whiskers by utilizing low-content calcium carbonate. Background Art

[0002] Calcium carbonate whiskers are a new type of inorganic filler material with excellent performance and broad application prospects. Basic characteristics: Calcium carbonate whiskers are non-toxic, odorless, white fluffy solids, and needle-shaped single crystals under a microscope. Its chemical formula is CaCO 3 , with high purity (up to 98% or more) and high mechanical strength. Performance advantages: It has comprehensive properties such as vibration reduction, anti-skid, noise reduction, and wave absorption, stable friction performance, and good thermal decay and thermal recovery performance. In plastics and resins, it can significantly improve the toughness and strength of the material. Application areas: Widely used in reinforced plastics, friction materials, papermaking, coatings and other fields. As a filling material, it can reduce product costs and improve product performance;

[0003] In the prior art, the grade of calcium carbonate whiskers prepared using low-content calcium carbonate is low and cannot meet the use requirements. Therefore, we propose a preparation method for high-grade calcium carbonate whiskers using low-content calcium carbonate to solve the above problem. Summary of the invention

[0004] The purpose of the present invention is to solve the disadvantage that the grade of calcium carbonate whiskers prepared by using low-content calcium carbonate in the prior art is low and cannot meet the use requirements, and a preparation method of high-grade calcium carbonate whiskers prepared by using low-content calcium carbonate is proposed.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for preparing high-grade calcium carbonate whiskers using low-content calcium carbonate comprises the following steps:

[0007] S1, calcium carbonate ore: crush the ore into 40-80mm raw materials;

[0008] S2. High temperature calcination: Place the ore crushers in a vertical kiln at a temperature of 1000-1200°C for 16 hours, and wait for the materials to cool down;

[0009] S3, screening: use a vibrating screen at 500-800 rpm to screen out impurities;

[0010] S4, filtration and sedimentation: pour the sieved material into the digestion tank, pour the impurity-free water into the digestion tank, the water covers the material and is 20cm higher than the material;

[0011] S5, fine washing: use a vibrating screen, 500-800 rotation speed, repeatedly vibrate 5-6 times, each time vibrating, pass the aged water in the digester on the vibrating screen, repeatedly vibrate and wash;

[0012] S6. Slurry adjustment: Add the cleaned material into the aged water in the digester to make the density of the material reach 15-18g / cm 3 ;

[0013] S7, prepare NaMg internalizing agent: components NaCl:MgCl:sodium citrate:water=4.5:

[0014] 4.5:1:100, add in order, stir with a mixer to make the pH value reach 6-7;

[0015] S8, preparation of calcium carbonate whiskers: in a reaction kettle for producing calcium carbonate whiskers, the slurry-adjusted material is added with a NaMg internalizing agent;

[0016] S9, dehydration: carried out in a dehydrator, speed 1200 rpm, time: 2h;

[0017] S10, drying: carried out in a cyclone dryer for 40-80 minutes at a constant temperature of 90 degrees;

[0018] S11, modification: carried out simultaneously with drying, when drying is carried out for 20 minutes, silicon dioxide powder is introduced at a ratio of 100:1-1.5 for 20-40 minutes.

[0019] Preferably, the preparation of calcium carbonate whiskers is carried out in a reaction kettle for the production of calcium carbonate whiskers, the material after slurry adjustment is added with NaMg internalizing agent, and the ratio is 1:0.5-2, depending on the pH value of the NaMg internalizing agent, if it is 6, then it is 1:1, stirring is 30-40 revolutions, and CO is introduced. 2 , the flow rate is 10L / min, the pressure is 0.5-2Pa, the pH value is adjusted to 7.3-8.5, the temperature is 73-80 degrees, when the pH value is lower than 7, the whiskers stop growing, and when it is higher than 9, the whisker diameter-to-length ratio is poor.

[0020] Preferably, in S1, the crushing steps are as follows: coarse crushing: using a jaw crusher to perform preliminary crushing on large pieces of ore to obtain smaller stones; medium crushing: using a cone crusher or an impact crusher to perform medium crushing on the stones after coarse crushing to further reduce the size of the stones; fine crushing: using a sand making machine to perform fine crushing on the stones after medium crushing to obtain a particle size that meets the requirements, and screening the finely crushed stones through a vibrating screen to separate stones of different particle sizes to meet different needs.

[0021] Preferably, in S2, the high-temperature calcination is specifically as follows: preheating: the raw material enters the preheating section and exchanges heat with the high-temperature flue gas to remove moisture and improve activity; calcination: the preheated raw material enters the calcination section and undergoes physical and chemical changes at high temperature; the temperature and time need to be controlled to ensure product quality; cooling: the calcined material enters the cooling section to reduce the temperature for subsequent processing and storage; discharging: the cooled material is discharged through the discharging device and enters the next process; waste gas treatment: the waste gas generated during the calcination process needs to be purified and discharged after meeting environmental protection standards, and the waste heat is recycled.

[0022] Preferably, waste heat recovery and utilization are as follows: converting waste heat into steam or hot water through a heat exchanger or a waste heat boiler; using steam or hot water for power generation, heating, and bathing; system monitoring and optimization: real-time monitoring of the waste heat recovery system to ensure normal operation of the system; optimizing and adjusting the system according to the monitoring results to improve waste heat recovery efficiency.

[0023] Preferably, in S4, the screened material is poured into a digester and the material is spread evenly.

[0024] Preferably, in S5, each time the vibration occurs, the aged water in the digester is extracted by a delivery pump, and the aged water is passed through the vibrating screen, and the vibrating and cleaning are repeated.

[0025] Preferably, in S6, the cleaned material is added to the aged water in the digester, and the density of the slurry is monitored, and the density monitoring is achieved by a NA-22 densitometer.

[0026] Preferably, in S9, the working process of the dehydrator is as follows: the motor drives the inner tank to rotate at high speed, and the water in the material in the inner tank is affected by the centrifugal force under the high-speed rotation, and splashes out of the inner tank from the small holes around the inner tank shell.

[0027] Preferably, in S10, during drying, the wet material enters the drying equipment through a conveyor, and heated natural air is also introduced. In the equipment, the fan breaks up the wet or even agglomerated materials, and stirs and mixes them simultaneously during the dispersion process. The materials and the hot air flow flow in parallel to form a spiral motion, so that the materials are evenly distributed and rotated in the air flow; the high-temperature air flow entrains the materials for drying, and the wet raw materials are fully mixed with the high-temperature air flow, thereby effectively removing moisture from the materials; finally, the dried material is separated from the air flow by a separator, and the dried material flows out of the equipment, while the exhaust gas and water vapor are discharged from the top of the equipment.

[0028] In the present invention, the method for preparing high-grade calcium carbonate whiskers using low-content calcium carbonate has the following beneficial effects:

[0029] The calcium carbonate whisker prepared by the present invention through the steps of crushing, high-temperature calcination, screening, aging, fine washing, slurry adjustment, preparation of NaMg internalizing agent, preparation of calcium carbonate whisker, dehydration, drying and modification has high grade and can meet actual use requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The present invention provides a flow chart of a method for preparing high-grade calcium carbonate whiskers using low-content calcium carbonate. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0032] Embodiment 1

[0033] Reference Figure 1 A method for preparing high-grade calcium carbonate whiskers using low-content calcium carbonate comprises the following steps:

[0034] S1, calcium carbonate ore: crush the ore into 40mm raw materials;

[0035] S2, high temperature calcination: put the ore crushed materials in a vertical kiln at a temperature of 1000℃ for 16 hours, and wait for the materials to cool down;

[0036] S3, screening: use a vibrating screen at 500 rpm to screen out impurities;

[0037] S4, filtration and sedimentation: pour the sieved material into the digestion tank, pour the impurity-free water into the digestion tank, the water covers the material and is 20cm higher than the material;

[0038] S5, fine washing: use a vibrating screen, 500 rotation speed, and vibrate repeatedly for 5 times. During each vibration, pass the aged water in the digester through the vibrating screen, and vibrate and wash repeatedly;

[0039] S6. Slurry adjustment: Add the cleaned material into the aged water in the digester to make the density of the material reach 15g / cm 3 ;

[0040] S7, prepare NaMg internalizing agent: components NaCl:MgCl:sodium citrate:water=4.5:

[0041] 4.5:1:100, add in order, stir with a mixer to make the pH value reach 6;

[0042] S8, preparation of calcium carbonate whiskers: in a reaction kettle for producing calcium carbonate whiskers, the slurry-adjusted material is added with a NaMg internalizing agent;

[0043] S9, dehydration: carried out in a dehydrator, speed 1200 rpm, time: 2h;

[0044] S10, drying: carried out in a cyclone dryer for 40 minutes at a constant temperature of 90 degrees;

[0045] S11, modification: carried out simultaneously with drying, when drying is carried out for 20 minutes, silicon dioxide powder is introduced at a ratio of 100:1-1.5 for 20 minutes.

[0046] In this embodiment, the preparation of calcium carbonate whiskers is carried out in a reaction kettle for the production of calcium carbonate whiskers. The slurry-adjusted material is added with NaMg internalizing agent in a ratio of 1:0.5-2, depending on the pH value of the NaMg internalizing agent. If it is 6, it is 1:1, stirred for 30 revolutions, and CO is introduced. 2 , the flow rate is 10L / min, the pressure is 0.5-2Pa, the pH value is adjusted to 7.3, the temperature is 73 degrees, when the pH value is lower than 7, the whiskers stop growing, and when it is higher than 9, the whisker diameter-to-length ratio is poor.

[0047] In this embodiment, in S1, the crushing steps are specifically as follows: coarse crushing: using a jaw crusher to perform preliminary crushing of large pieces of ore to obtain smaller stones; medium crushing: using a cone crusher or an impact crusher to perform medium crushing on the stones after coarse crushing to further reduce the size of the stones; fine crushing: using a sand making machine to perform fine crushing on the stones after medium crushing to obtain a particle size that meets the requirements, and screening the finely crushed stones through a vibrating screen to separate stones of different particle sizes to meet different needs.

[0048] In this embodiment, in S2, high-temperature calcination is specifically as follows: preheating: the raw material enters the preheating section and exchanges heat with the high-temperature flue gas to remove moisture and improve activity; calcination: the preheated raw material enters the calcination section and undergoes physical and chemical changes at high temperature; the temperature and time need to be controlled to ensure product quality; cooling: the calcined material enters the cooling section to reduce the temperature for subsequent processing and storage; discharging: the cooled material is discharged through the discharging device and enters the next process; waste gas treatment: the waste gas generated during the calcination process needs to be purified and discharged after meeting environmental protection standards, and the waste heat is recycled.

[0049] In this embodiment, waste heat recovery and utilization are specifically as follows: converting waste heat into steam or hot water through a heat exchanger or a waste heat boiler; using steam or hot water for power generation, heating, and bathing; system monitoring and optimization: real-time monitoring of the waste heat recovery system to ensure normal operation of the system; optimizing and adjusting the system according to the monitoring results to improve the waste heat recovery efficiency.

[0050] In this embodiment, in S4, the screened material is poured into the digestion tank and the material is spread evenly.

[0051] In this embodiment, in S5, each time the vibration occurs, the aged water in the digester is extracted by a delivery pump, and the aged water is passed through the vibrating screen, and the vibration and cleaning are repeated.

[0052] In this embodiment, in S6, the cleaned material is added to the aged water in the digester, and the density of the slurry is monitored. The density monitoring is achieved by a NA-22 densitometer.

[0053] In this embodiment, in S9, the working process of the dehydrator is as follows: the motor drives the inner tank to rotate at high speed, and the water in the material in the inner tank is affected by the centrifugal force under the high-speed rotation, and splashes out of the inner tank from the small holes around the inner tank shell.

[0054] In this embodiment, in S10, during drying, the wet material enters the drying equipment through the conveyor, and the heated natural air is also introduced. In the equipment, the fan breaks up the wet and even agglomerated materials, and stirs and mixes them at the same time during the dispersion process. The materials and the hot air flow flow in parallel to form a spiral motion, so that the materials are evenly distributed and rotated in the air flow; the high-temperature air flow entrains the materials for drying, and the wet raw materials are fully mixed with the high-temperature air flow, thereby effectively removing moisture from the materials; finally, the dried material is separated from the air flow by a separator, and the dried material flows out of the equipment, while the exhaust gas and water vapor are discharged from the top of the equipment.

[0055] Embodiment 2

[0056] A method for preparing high-grade calcium carbonate whiskers using low-content calcium carbonate comprises the following steps:

[0057] S1, calcium carbonate ore: crush the ore into 60mm raw materials;

[0058] S2, high temperature calcination: put the ore crushed materials in a vertical kiln at a temperature of 1100℃ for 16 hours, and wait for the materials to cool down;

[0059] S3, screening: use a vibrating screen at 700 rpm to screen out impurities;

[0060] S4, filtration and sedimentation: pour the sieved material into the digestion tank, pour the impurity-free water into the digestion tank, the water covers the material and is 20cm higher than the material;

[0061] S5, fine washing: use a vibrating screen, 700 rotation speed, repeatedly vibrate 5 times, each time the vibrating screen is passed through the aged water in the digester, and repeatedly vibrate and wash;

[0062] S6. Slurry adjustment: Add the cleaned material into the aged water in the digester to make the density of the material reach 16g / cm 3 ;

[0063] S7, prepare NaMg internalizing agent: components NaCl:MgCl:sodium citrate:water=4.5:

[0064] 4.5:1:100, add in order, stir with a mixer to make the pH value reach 6.5;

[0065] S8, preparation of calcium carbonate whiskers: in a reaction kettle for producing calcium carbonate whiskers, the slurry-adjusted material is added with a NaMg internalizing agent;

[0066] S9, dehydration: carried out in a dehydrator, speed 1200 rpm, time: 2h;

[0067] S10, drying: carried out in a cyclone dryer for 60 minutes at a constant temperature of 90 degrees;

[0068] S11, modification: carried out simultaneously with drying, when the drying is carried out for 20 minutes, silicon dioxide powder is introduced at a ratio of 100:1-1.5 for 30 minutes.

[0069] In this embodiment, the preparation of calcium carbonate whiskers is carried out in a reaction kettle for the production of calcium carbonate whiskers. The material after slurry adjustment is added with NaMg internalizing agent, and the ratio is 1:0.5-2. It depends on the pH value of the NaMg internalizing agent. If it is 6, it is 1:1. Stirring is 30-40 revolutions, and CO is introduced. 2 , the flow rate is 10L / min, the pressure is 1Pa, the pH value is adjusted to 8, the temperature is 75 degrees, when the pH value is lower than 7, the whiskers stop growing, and when it is higher than 9, the whisker diameter ratio is poor.

[0070] In this embodiment, in S1, the crushing steps are specifically as follows: coarse crushing: using a jaw crusher to perform preliminary crushing of large pieces of ore to obtain smaller stones; medium crushing: using a cone crusher or an impact crusher to perform medium crushing on the stones after coarse crushing to further reduce the size of the stones; fine crushing: using a sand making machine to perform fine crushing on the stones after medium crushing to obtain a particle size that meets the requirements, and screening the finely crushed stones through a vibrating screen to separate stones of different particle sizes to meet different needs.

[0071] In this embodiment, in S2, high-temperature calcination is specifically as follows: preheating: the raw material enters the preheating section and exchanges heat with the high-temperature flue gas to remove moisture and improve activity; calcination: the preheated raw material enters the calcination section and undergoes physical and chemical changes at high temperature; the temperature and time need to be controlled to ensure product quality; cooling: the calcined material enters the cooling section to reduce the temperature for subsequent processing and storage; discharging: the cooled material is discharged through the discharging device and enters the next process; waste gas treatment: the waste gas generated during the calcination process needs to be purified and discharged after meeting environmental protection standards, and the waste heat is recycled.

[0072] In this embodiment, waste heat recovery and utilization are specifically as follows: converting waste heat into steam or hot water through a heat exchanger or a waste heat boiler; using steam or hot water for power generation, heating, and bathing; system monitoring and optimization: real-time monitoring of the waste heat recovery system to ensure normal operation of the system; optimizing and adjusting the system according to the monitoring results to improve the waste heat recovery efficiency.

[0073] In this embodiment, in S4, the screened material is poured into the digestion tank and the material is spread evenly.

[0074] In this embodiment, in S5, each time the vibration occurs, the aged water in the digester is extracted by a delivery pump, and the aged water is passed through the vibrating screen, and the vibration and cleaning are repeated.

[0075] In this embodiment, in S6, the cleaned material is added to the aged water in the digester, and the density of the slurry is monitored. The density monitoring is achieved by a NA-22 densitometer.

[0076] In this embodiment, in S9, the working process of the dehydrator is as follows: the motor drives the inner tank to rotate at high speed, and the water in the material in the inner tank is affected by the centrifugal force under the high-speed rotation, and splashes out of the inner tank from the small holes around the inner tank shell.

[0077] In this embodiment, in S10, during drying, the wet material enters the drying equipment through the conveyor, and the heated natural air is also introduced. In the equipment, the fan breaks up the wet and even agglomerated materials, and stirs and mixes them at the same time during the dispersion process. The materials and the hot air flow flow in parallel to form a spiral motion, so that the materials are evenly distributed and rotated in the air flow; the high-temperature air flow entrains the materials for drying, and the wet raw materials are fully mixed with the high-temperature air flow, thereby effectively removing moisture from the materials; finally, the dried material is separated from the air flow by a separator, and the dried material flows out of the equipment, while the exhaust gas and water vapor are discharged from the top of the equipment.

[0078] Embodiment 3

[0079] A method for preparing high-grade calcium carbonate whiskers using low-content calcium carbonate comprises the following steps:

[0080] S1, calcium carbonate ore: crush the ore into 80mm raw materials;

[0081] S2, high temperature calcination: put the ore crushed materials in a vertical kiln at a temperature of 1200℃ for 16 hours, and wait for the materials to cool down;

[0082] S3, screening: use a vibrating screen at 800 rpm to screen out impurities;

[0083] S4, filtration and sedimentation: pour the sieved material into the digestion tank, pour the impurity-free water into the digestion tank, the water covers the material and is 20cm higher than the material;

[0084] S5, fine washing: use a vibrating screen, 800 rotation speed, repeatedly vibrate 6 times, each time vibrating, pass the aged water in the digester on the vibrating screen, repeatedly vibrate and wash;

[0085] S6. Slurry adjustment: Add the cleaned material into the aged water in the digester to make the density of the material reach 18g / cm 3 ;

[0086] S7, prepare NaMg internalizing agent: components NaCl:MgCl:sodium citrate:water=4.5:

[0087] 4.5:1:100, add in order, stir with a mixer to make the pH value 7;

[0088] S8, preparation of calcium carbonate whiskers: in a reaction kettle for producing calcium carbonate whiskers, the slurry-adjusted material is added with a NaMg internalizing agent;

[0089] S9, dehydration: carried out in a dehydrator, speed 1200 rpm, time: 2h;

[0090] S10, drying: carried out in a cyclone dryer for 80 minutes at a constant temperature of 90 degrees;

[0091] S11, modification: carried out simultaneously with drying, when the drying is carried out for 20 minutes, silicon dioxide powder is introduced at a ratio of 100:1-1.5 for 40 minutes.

[0092] In this embodiment, the preparation of calcium carbonate whiskers is carried out in a reaction kettle for the production of calcium carbonate whiskers. The slurry is used to add NaMg internalizing agent, and the ratio is 1:0.5-2. It depends on the pH value of the NaMg internalizing agent. If it is 6, it is 1:1. The stirring is 40 revolutions, and CO is introduced. 2 , the flow rate is 10L / min, the pressure is 0.5-2Pa, the pH value is adjusted to 8.5, the temperature is 80 degrees, when the pH value is lower than 7, the whiskers stop growing, and when it is higher than 9, the whisker diameter ratio is poor.

[0093] In this embodiment, in S1, the crushing steps are specifically as follows: coarse crushing: using a jaw crusher to perform preliminary crushing of large pieces of ore to obtain smaller stones; medium crushing: using a cone crusher or an impact crusher to perform medium crushing on the stones after coarse crushing to further reduce the size of the stones; fine crushing: using a sand making machine to perform fine crushing on the stones after medium crushing to obtain a particle size that meets the requirements, and screening the finely crushed stones through a vibrating screen to separate stones of different particle sizes to meet different needs.

[0094] In this embodiment, in S2, high-temperature calcination is specifically as follows: preheating: the raw material enters the preheating section and exchanges heat with the high-temperature flue gas to remove moisture and improve activity; calcination: the preheated raw material enters the calcination section and undergoes physical and chemical changes at high temperature; the temperature and time need to be controlled to ensure product quality; cooling: the calcined material enters the cooling section to reduce the temperature for subsequent processing and storage; discharging: the cooled material is discharged through the discharging device and enters the next process; waste gas treatment: the waste gas generated during the calcination process needs to be purified and discharged after meeting environmental protection standards, and the waste heat is recycled.

[0095] In this embodiment, waste heat recovery and utilization are specifically as follows: converting waste heat into steam or hot water through a heat exchanger or a waste heat boiler; using steam or hot water for power generation, heating, and bathing; system monitoring and optimization: real-time monitoring of the waste heat recovery system to ensure normal operation of the system; optimizing and adjusting the system according to the monitoring results to improve the waste heat recovery efficiency.

[0096] In this embodiment, in S4, the screened material is poured into the digestion tank and the material is spread evenly.

[0097] In this embodiment, in S5, each time the vibration occurs, the aged water in the digester is extracted by a delivery pump, and the aged water is passed through the vibrating screen, and the vibration and cleaning are repeated.

[0098] In this embodiment, in S6, the cleaned material is added to the aged water in the digester, and the density of the slurry is monitored. The density monitoring is achieved by a NA-22 densitometer.

[0099] In this embodiment, in S9, the working process of the dehydrator is as follows: the motor drives the inner tank to rotate at high speed, and the water in the material in the inner tank is affected by the centrifugal force under the high-speed rotation, and splashes out of the inner tank from the small holes around the inner tank shell.

[0100] In this embodiment, in S10, during drying, the wet material enters the drying equipment through the conveyor, and the heated natural air is also introduced. In the equipment, the fan breaks up the wet and even agglomerated materials, and stirs and mixes them at the same time during the dispersion process. The materials and the hot air flow flow in parallel to form a spiral motion, so that the materials are evenly distributed and rotated in the air flow; the high-temperature air flow entrains the materials for drying, and the wet raw materials are fully mixed with the high-temperature air flow, thereby effectively removing moisture from the materials; finally, the dried material is separated from the air flow by a separator, and the dried material flows out of the equipment, while the exhaust gas and water vapor are discharged from the top of the equipment.

[0101] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for preparing high-grade calcium carbonate whiskers using low-content calcium carbonate, characterized in that: The following steps are involved: S1, calcium carbonate ore: crush the ore into 40-80mm raw materials; S2, high temperature calcination: put the ore crushed materials into the vertical kiln at a temperature of 1000-1200℃ for 16 hours, and wait for the materials to cool down; S3, screening: use a vibrating screen at 500-800 rpm to screen out impurities; S4, filtration and sedimentation: pour the sieved material into the digestion tank, pour the impurity-free water into the digestion tank, the water covers the material and is 20cm higher than the material; S5, fine washing: use a vibrating screen, 500-800 rotation speed, repeatedly vibrate 5-6 times, each time vibrating, pass the aged water in the digester on the vibrating screen, repeatedly vibrate and wash; S6. Slurry adjustment: Add the cleaned material into the aged water in the digester to make the density of the material reach 15-18g / cm 3 ; S7, prepare NaMg internalizing agent: ingredients NaCl: MgCl: sodium citrate: water = 4.5: 4.5: 1: 100, add in order, stir with a stirrer to make the pH value reach 6-7; S8, preparation of calcium carbonate whiskers: in a reaction kettle for producing calcium carbonate whiskers, the slurry-adjusted material is added with a NaMg internalizing agent; S9, dehydration: carried out in a dehydrator, speed 1200 rpm, time: 2h; S10, drying: carried out in a cyclone dryer for 40-80 minutes at a constant temperature of 90 degrees; S11, modification: carried out simultaneously with drying, when drying is carried out for 20 minutes, silicon dioxide powder is introduced at a ratio of 100:1-1.5 for 20-40 minutes.

2. A method for preparing high-grade calcium carbonate whiskers using low-content calcium carbonate according to claim 1, characterized in that: Preparation of calcium carbonate whiskers: It is carried out in a reactor for the production of calcium carbonate whiskers. The slurry is used to add NaMg internalizing agent, and the ratio is 1:0.5-2, depending on the pH value of the NaMg internalizing agent. If it is 6, it is 1:

1. Stirring is 30-40 revolutions, CO2 is introduced, the flow rate is 10L / min, the pressure is 0.5-2Pa, the pH value is adjusted to 7.3-8.5, the temperature is 73-80 degrees, when the pH value is lower than 7, the whiskers stop growing, when it is higher than 9, the whisker diameter-to-length ratio is poor.

3. A method for preparing high-grade calcium carbonate whiskers using low-content calcium carbonate according to claim 2, characterized in that: In S1, the crushing steps are specifically as follows: coarse crushing: using a jaw crusher to perform preliminary crushing on large pieces of ore to obtain smaller stones; medium crushing: using a cone crusher or an impact crusher to perform medium crushing on the stones after coarse crushing to further reduce the size of the stones; fine crushing: using a sand making machine to perform fine crushing on the stones after medium crushing to obtain a particle size that meets the requirements, and screening the finely crushed stones through a vibrating screen to separate stones of different particle sizes to meet different needs.

4. A method for preparing high-grade calcium carbonate whiskers using low-content calcium carbonate according to claim 3, characterized in that: In S2, the high-temperature calcination is specifically as follows: preheating: the raw material enters the preheating section and exchanges heat with the high-temperature flue gas to remove moisture and improve activity; calcination: the preheated raw material enters the calcination section and undergoes physical and chemical changes at high temperature; the temperature and time need to be controlled to ensure product quality; Cooling: The calcined material enters the cooling section to reduce the temperature for subsequent processing and storage; Discharging: The cooled material is discharged through the discharging device and enters the next process; Waste gas treatment: The waste gas generated during the calcining process needs to be purified and discharged after meeting environmental protection standards, and the waste heat is recovered and utilized.

5. A method for preparing high-grade calcium carbonate whiskers using low-content calcium carbonate according to claim 4, characterized in that: The specific waste heat recovery and utilization are as follows: converting waste heat into steam or hot water through a heat exchanger or a waste heat boiler; using steam or hot water for power generation, heating, and bathing; system monitoring and optimization: real-time monitoring of the waste heat recovery system to ensure the normal operation of the system; optimizing and adjusting the system according to the monitoring results to improve the waste heat recovery efficiency.

6. A method for preparing high-grade calcium carbonate whiskers using low-content calcium carbonate according to claim 5, characterized in that: In S4, the screened material is poured into a digestion tank and the material is spread evenly.

7. A method for preparing high-grade calcium carbonate whiskers using low-content calcium carbonate according to claim 6, characterized in that: In S5, each time the process vibrates, aged water in the digester is extracted by a delivery pump, and the aged water is passed through the vibrating screen, and the process is repeatedly vibrated and cleaned.

8. A method for preparing high-grade calcium carbonate whiskers using low-content calcium carbonate according to claim 7, characterized in that: In S6, the cleaned material is added to the aged water in the digester, and the density of the slurry is monitored. The density monitoring is achieved by a NA-22 density meter.

9. A method for preparing high-grade calcium carbonate whiskers using low-content calcium carbonate according to claim 8, characterized in that: In S9, the working process of the dehydrator is as follows: the motor drives the inner tank to rotate at high speed, and the water in the material in the inner tank is affected by the centrifugal force under the high-speed rotation, and splashes out of the inner tank from the small holes around the inner tank shell.

10. A method for preparing high-grade calcium carbonate whiskers using low-content calcium carbonate according to claim 9, characterized in that: In S10, during drying, the wet material enters the drying equipment through the conveyor, and the heated natural air is also introduced. In the equipment, the fan breaks up the wet and even agglomerated materials, and stirs and mixes them during the dispersion process. The materials and the hot air flow flow in parallel to form a spiral motion, so that the materials are evenly distributed and rotated in the air flow; the high-temperature air flow entrains the materials for drying, and the wet raw materials are fully mixed with the high-temperature air flow, thereby effectively removing moisture from the materials; finally, the dried material is separated from the air flow by a separator, and the dried material flows out of the equipment, while the exhaust gas and water vapor are discharged from the top of the equipment.

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