Preparation method and application of tough composite filter aid

Abstract

The invention discloses a preparation method and application of a tough composite filter aid, and relates to the technical field of filter aid preparation, the preparation method comprises the following steps: S01, rice hull crushing, S02, rice hull powder sorting, S03, wood powder crushing, S04, wood powder sorting, S05, basic magnesium carbonate selection, S06, anti-mildew agent selection, and S07, composite powder preparation, poplar wood with low cost is adopted as a raw material, the production cost is effectively reduced, and the production efficiency is improved. Through a fine crushing and sorting process, the rice hull powder and the wood flour show higher toughness, the anti-cracking performance of a filter cake is remarkably improved, the continuity and the stability of the filtering process are ensured, porous petal-spherical tetrahydrate basic magnesium carbonate is selected as an active component, the filtering efficiency is remarkably improved through the porous characteristic of the porous petal-spherical tetrahydrate basic magnesium carbonate, and the service life of the filter cake is prolonged. And the method plays an important role in enhancing the toughness of the filter cake.

Description

Technical Field

[0001] The invention relates to the technical field of filter aid preparation, in particular to a preparation method and application of a tough composite filter aid. Background Art

[0002] Filter aid is a kind of filter agent, which is a consumable product for filtering and separating solid-liquid mixtures. It is mainly used as a filter aid for cooling oil used in lathes, milling machines, rough grinding machines, rolling mills, etc.

[0003] The filter aids currently available on the market include diatomaceous earth filter aids with porous structures, granular fiber organic filter aids prepared from needle-like paper fibers, and selected wood powder filter aids. Diatomaceous earth filter aids are inorganic materials with high rigidity and poor flexibility. They are easy to compact when used for filtering, and the filter cake is easy to crack. The solid-liquid mixture will leak through the cracks, and the requirements of filtering technical indicators cannot be met. Granular paper fiber filter aid is a mixture of a large amount of granular fibers and a small amount of needle-like fibers. It has good toughness and the filter cake does not crack. It is the most ideal filter aid, but it is expensive. Selected wood powder filter aid is an organic material. Although it is less rigid than diatomaceous earth, it is not tough enough and the filter cake is easy to crack. In addition, it is not a porous structure, and the filtering effect is not very ideal.

[0004] In summary, it is necessary to develop a new tough composite organic filter aid that overcomes the shortcomings of diatomaceous earth filter cakes that are easy to crack, granular paper fiber filter aids that are expensive, and wood powder filter aids that are non-porous and have filter cakes that also crack. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a preparation method and application of a tough composite filter aid, which solves the problems raised in the background technology.

[0006] To achieve the above objectives, the present invention is implemented through the following technical scheme: a preparation method and application of a tough composite filter aid, the steps of which are as follows:

[0007] S01. Rice husk crushing: Select pure rice husk as raw material. In view of the high toughness and difficult-to-crush characteristics of rice husk fiber, use a crushing machine specially suitable for fiber materials for fine crushing; S02. Rice husk powder sorting: The crushed rice husk powder is screened and separated by a screen sorting machine or a grader sorting machine to ensure the consistency of the powder particle size; S03. Wood powder crushing: Select low-cost and light-weight wood, such as poplar, tung, pine, cypress or oak. Poplar wood with light color and low lignin content is preferred, and a special wood powder crusher is used for crushing; S04. Wood powder sorting: The crushed The wood powder is also carefully sorted by a screen sorter or a grader sorter. Considering the cost factor, the screen sorter is preferred; S05. Selection of basic magnesium carbonate: The porous petal-shaped spherical basic magnesium carbonate tetrahydrate sold on the market is used as the active ingredient of the composite filter aid; S06. Selection of mildew inhibitor: o-phenylphenol and biphenyl mildew inhibitors sold on the market are used as the mildew inhibitor of the composite filter aid; S07. Preparation of composite powder: According to a specific mass ratio, the above-screened rice husk powder, poplar powder, basic magnesium carbonate tetrahydrate and mildew inhibitor are evenly mixed to form a composite filter aid with good toughness.

[0008] Preferably, in step S01, during the rice husk crushing stage, a high-efficiency tough fiber special crusher designed for tough fiber materials is used to achieve deep processing of rice husk fibers. The crusher converts rice husk fibers into powders with a specific particle size distribution through optimized mechanical force. The particle size of the rice husk powder obtained after crushing is controlled according to the normal distribution principle to ensure that 95% of the particle diameters are concentrated in a narrow range of 5 to 300 μm. This strict control of the particle size distribution is achieved by adjusting the rotation speed of the crusher. The rotation speed of the crusher directly affects the crushing effect of the material and the final particle size distribution.

[0009] Preferably, the rice husk powder is sorted in S02, and the crushed rice husk powder is sorted by a sorting machine. The sorting machine is a screen sorting machine or a classifying machine, and the classifying machine is preferred. The air volume of the classifying machine is adjusted, and 93% of the rice husk powder with an average diameter of 40 to 200 um is selected as a component of the composite material. The average diameter of the rice husk powder is slightly larger than the diameter of the wood powder, and the average diameter is greater than 5% to 20%. In this way, the rice husk powders can overlap with each other to achieve the effect of toughening the filter cake. If the average diameter is too small, they cannot be overlapped, and if it is too large, they are stacked to reduce the permeability.

[0010] Preferably, in step S03, the pulverization process of the wood powder needs to follow specific process requirements to ensure the quality of the final product. First, the selected poplar wood needs to be peeled and cut into small wood strips by sawing. A rotary knife grinder is used in the coarse pulverization stage to process the wood strips into large wood particles of 5 to 20 mm. Subsequently, in the fine pulverization stage, a fixed / moving knife disc shearing grinder is selected for pulverization according to the particle size and characteristics of the required wood powder. The grinder produces a large amount of irregular granular wood powder through the shearing principle, of which the granular amount needs to reach more than 75% to ensure the performance of the wood powder in the filtration process;

[0011] Among them, during the crushing process, the particle size distribution of wood powder can be controlled by adjusting the parameters of the crusher, such as the gap between the hammers and the aperture of the screen; ultimately, the volume particle size of the wood powder should be normally distributed, and 95% of the particles are distributed in the range of 3 to 500um to meet the strict requirements on the particle size of wood powder in industrial applications; in addition, the fineness adjustment function of the wood powder machine allows arbitrary adjustment between 20-325 mesh to meet different application requirements.

[0012] Preferably, in step S04, the wood powder sorting process requires the application of precise screen sorting machine technology. The preferred economical screen sorting machine adopts a double-layer mesh design. The upper mesh is configured with an aperture of 185μm (80 mesh), and the lower mesh is 30μm (500 mesh). In order to ensure that wood powder with a particle size of less than 30μm passes through the screen smoothly, the lower screen is equipped with an ultrasonic vibration device, which uses ultrasonic acceleration to promote the screening efficiency of the material, effectively prevent mesh clogging, and significantly improve screening accuracy and processing capacity.

[0013] Among them, 93% of the volume particle size of the sorted wood powder is strictly controlled within the range of 30 to 185μm, ensuring that the wood powder particle size is 5% to 20% smaller than the average diameter of rice husk powder; precise control of particle size is crucial to the performance of the composite filter aid, in which rice husk powder plays the role of toughening the filter cake, while wood powder particles support the structure and create the required pores, thereby maintaining the high permeability of the filter cake.

[0014] Preferably, in the process of selecting the tetrahydrate basic magnesium carbonate in S05, it is necessary to carefully screen the tetrahydrate basic magnesium carbonate of different volume particle sizes and forms. The substance exists in various forms, such as Figure 5 As shown, it includes non-porous powder, porous petal sphere and porous petal rod, and porous petal spherical magnesium carbonate tetrahydrate with a volume particle size between 75 and 150 μm is selected as the key component of the composite filter aid. The selected porous petal spherical magnesium carbonate tetrahydrate exhibits excellent adsorption performance due to its porous structure, which helps to improve the filtration efficiency and plays an important role in enhancing the toughness of the filter cake; in addition, the porous structure can also effectively supplement the deficiency of wood powder particles, optimize the pore structure of the filter cake, and thus improve the overall filtration performance.

[0015] Preferably, the selection of the mildewproof agent in S06 is to address the problem of composite powder mildew caused by insufficient sealing of the packaging in high humidity areas. A mildewproof agent needs to be added to prevent the occurrence of mildew. Commercially available o-phenylphenol and biphenyl are selected as mildewproof agents, and o-phenylphenol with a crystal particle size in the range of 10 to 100 um is preferably used as the composite component.

[0016] Preferably, the ratio of the rice husk powder, wood powder, porous petal spherical basic magnesium carbonate tetrahydrate, and o-phenylphenol in the composite powder selected in S07 is:

[0017]

[0018] Preferably, the rice husk powder, wood powder, porous petal-shaped spherical magnesium carbonate tetrahydrate and o-phenylphenol in the composite powder in S07 are mixed evenly in proportion to obtain a toughened composite filter aid with an average (diameter) volume particle size of 93% of the composite powder in the range of 30 to 200 um, a bulk density of 220 to 350 g / L and a permeability of 4.5 to 18D; the average diameter of the rice husk powder, the volume particle size of the wood powder, the volume particle size of the magnesium carbonate tetrahydrate in the composite powder, and the ratio of the three components will particularly affect the permeability, bulk density and toughness of the filter cake of the composite powder; if the composite powder is fluffy and has a small bulk density, the fluidity is poor, and when used, the composite powder will be uneven when spread out, thereby affecting the filtering effect.

[0019] Preferably, it is used to filter cooling oil of machining lathes, milling machines, rough grinding machines, rolling mills, etc.; its method of use is: place a tough composite filter aid on the filter cloth of the filtering equipment and spread it evenly, then slowly inject a mixture of lathe, milling machine, rough grinding machine cooling oil and impurities, when the mixture of lathe, milling machine, rough grinding machine cooling oil and impurities is placed in a tough composite filter aid, wait for the cooling oil to penetrate completely, take out the filtered solid waste from the filter cloth and scrape it clean, and reuse the filtered cooling oil to achieve a complete filtration process.

[0020] The present invention provides a preparation method and application of a tough composite filter aid, which has the following beneficial effects:

[0021] The preparation method and application of the tough composite filter aid adopts low-cost poplar wood as raw material, effectively reducing the production cost. Through fine crushing and sorting processes, rice husk powder and wood powder show higher toughness, significantly improving the crack resistance of the filter cake, ensuring the continuity and stability of the filtration process. By selecting porous petal-shaped spherical basic magnesium carbonate tetrahydrate as an active ingredient, its porous characteristics significantly improve the filtration efficiency and play an important role in enhancing the toughness of the filter cake.

[0022] In addition, through strict control of particle size distribution, it is ensured that 95% of the particle diameters are concentrated in a specific range, thereby improving the filtration efficiency and the uniformity of the filter cake. Through precise proportions, rice husk powder, wood powder, magnesium carbonate tetrahydrate and mildew inhibitors are mixed to form a composite filter aid with good toughness and filtration performance, optimizing the overall performance of the product. Through optimized particle size and proportion, the obtained composite filter aid has a high permeability and suitable stacking density, further improving the filtration efficiency. This technology is suitable for a variety of industrial filtration processes, including the filtration of cooling oils for turning, milling, rough grinding, rolling mills, etc. It has broad application prospects, uses natural materials, reduces the impact on the environment, and is in line with the current trend of sustainable development. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the process of the present invention;

[0024] Figure 2 This is a particle size analysis report diagram of Example 1 of the present invention;

[0025] Figure 3 This is a particle size analysis report diagram of Example 2 of the present invention;

[0026] Figure 4 This is a particle size analysis report diagram of Example 3 of the present invention;

[0027] Figure 5 This is a microscopic image of the porous petal-shaped spherical tetrahydrate basic magnesium carbonate of the present invention. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] In the following examples, the raw materials used are clean rice husk material, peeled poplar wood material, porous petal spherical tetrahydrate basic magnesium carbonate material, and o-phenylphenol material.

[0030] Embodiment 1:

[0031] Step 1: Crushing rice husks: Select clean rice husks and crush them with a special high-efficiency tough fiber crusher. Adjust the speed of the crusher. When 95% of the average diameter of the crushed powder is distributed between 5 and 300 um, fix the crusher speed setting and then carry out production crushing.

[0032] In step 2, the rice husk powder is sorted. The crushed rice husk powder is sorted by a classifier, and the air volume of the classifier is adjusted to select 93% of the rice husk powder with an average diameter of 40 to 200 um as the use component of the composite material.

[0033] Step 3: Pulverize wood powder. The wood used for pulverizing is poplar wood. First, the poplar wood is sawn and cut into small wood strips, and then roughly pulverized. The coarse pulverization uses a rotary knife crusher to crush into large wood particles with a volume particle size of about 2000 to 30000um. Then fine pulverization is performed. The fine pulverization is performed using a fixed and movable knife disc shearing crusher to obtain wood powder with a normal volume particle size distribution, and the average volume particle size is 95% distributed in 3 to 500um. The number of granules in the wood powder is required to be ≥75%.

[0034] Step 4: sorting wood powder. Use a screen sorter to sort the wood powder. Use a vibrating screen sorter with a two-layer screen. Turn on the ultrasonic generator. The aperture of the upper screen is 185um (80 mesh), and the aperture of the lower screen is 30um (500 mesh). Take the wood powder between the upper and lower screens as the composite powder component. 93% of this wood powder has an average volume particle size of 30 to 185um.

[0035] Step 5: Select porous petal-shaped spherical magnesium carbonate tetrahydrate with a volume particle size of 75 to 150 μm as the composite component.

[0036] Step 6: Select o-phenylphenol crystalline powder with a volume particle size of 25 to 70 μm as a composite component.

[0037] Step 7: The selected rice husk powder, wood powder, porous petal spherical basic magnesium carbonate tetrahydrate, and o-phenylphenol are mixed into composite powder according to the following proportions:

[0038]

[0039] The bulk density of the composite powder of Example 1 is shown in Table 1, the permeability of the composite powder is shown in Table 2, and the particle size is shown in Appendix Figure 2 Table 1 Composite powder bulk density of Example 1

[0040]

[0041] Table 2 Composite powder permeability of Example 1

[0042]

[0043] Embodiment 2:

[0044] Steps 1 to 6 are the same as those in Example 1. In step 7, the selected rice husk powder, wood powder, porous petal spherical basic magnesium carbonate tetrahydrate, and o-phenylphenol are mixed in the following proportions:

[0045]

[0046] The bulk density of the composite powder of Example 2 is shown in Table 3, the permeability of the composite powder is shown in Table 4, and the particle size is shown in Appendix Figure 3 Table 3 Bulk density of composite powder in Example 2

[0047]

[0048] Table 4 Composite powder permeability of Example 2

[0049]

[0050] Embodiment 3:

[0051] Steps 1 to 6 are the same as in Example 1. In step 7, the selected rice husk powder, wood powder, porous petal spherical tetrahydrate basic magnesium carbonate, and o-phenylphenol are mixed in the following proportions.

[0052]

[0053] The bulk density of the composite powder of Example 3 is shown in Table 5, the permeability of the composite powder is shown in Table 6, and the particle size is shown in Appendix Figure 4 Table 5 Bulk density of composite powder in Example 3

[0054]

[0055] Table 6 Composite powder permeability of Example 3

[0056]

[0057] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0058] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for preparing a tough composite filter aid, It is characterized in that The steps are as follows: S01. Rice husk crushing: Pure rice husk is selected as the raw material. In view of the high toughness and difficult-to-crush characteristics of rice husk fiber, a crushing machine specially suitable for fiber materials is used for fine crushing; S02. Rice husk powder sorting: The crushed rice husk powder is screened and separated by a screen sorter or a classifier sorter to ensure the consistency of the powder particle size; S03. Wood powder crushing: Choose wood with low cost and light specific gravity, such as poplar, tung, pine, cypress or oak, preferably poplar wood with light color and low lignin content, and use a special wood powder crusher for crushing; S04. Wood powder sorting: The crushed wood powder is also carefully sorted by a screen sorter or a grader sorter. Considering the cost factor, the screen sorter is preferred; S05. Selection of basic magnesium carbonate: porous petal-shaped spherical basic magnesium carbonate tetrahydrate sold on the market is used as the active ingredient of the composite filter aid; S06. Selection of mildew-proof agent: Select o-phenylphenol and biphenyl mildew-proof agents sold on the market as mildew-proof components of the composite filter aid; S07. Prepare composite powder: Mix the above-screened rice husk powder, poplar wood powder, magnesium carbonate tetrahydrate and mildew inhibitor in a specific mass ratio to form a composite filter aid with good toughness.

2. A method for preparing a tough composite filter aid according to claim 1, Features: In step S01, during the rice husk crushing stage, a high-efficiency tough fiber special crusher designed for tough fiber materials is used to achieve deep processing of rice husk fiber. The crusher converts rice husk fiber into powder with a specific particle size distribution through optimized mechanical force. The particle size of the rice husk powder obtained after crushing is controlled according to the normal distribution principle to ensure that 95% of the particle diameters are concentrated in a narrow range of 5 to 300 μm.

3. A method for preparing a tough composite filter aid according to claim 1, Features: In the S02, the rice husk powder is sorted, and the crushed rice husk powder is sorted by a sorting machine. The sorting machine is a screen sorting machine or a classifying machine, and the classifying machine is preferred. The air volume of the classifying machine is adjusted, and 93% of the rice husk powder with an average diameter of 40 to 200 um is selected as a component of the composite material. The average diameter of the rice husk powder is slightly larger than the diameter of the wood powder, and the average diameter is greater than 5% to 20%.

4. A method for preparing a tough composite filter aid according to claim 1, Features: In step S03, the pulverization process of wood powder needs to follow specific process requirements to ensure the quality of the final product. First, the selected poplar wood needs to be peeled and cut into small wood strips by sawing. A rotary knife crusher is used in the coarse pulverization stage to process the wood strips into large wood particles of 5 to 20 mm. Then, in the fine pulverization stage, a fixed / moving knife disc shearing crusher is selected for pulverization according to the particle size and characteristics of the required wood powder. The crusher produces a large amount of irregular granular wood powder through the shearing principle, of which the granular amount needs to reach more than 75% to ensure the performance of the wood powder in the filtration process. During the pulverizing process, the particle size distribution of wood powder can be controlled by adjusting the parameters of the pulverizer, such as the gap between the hammers and the aperture of the screen. Ultimately, the volume particle size of the wood powder should be normally distributed, with 95% of the particles distributed in the range of 3 to 500 um to meet the strict requirements for wood powder particle size in industrial applications. In addition, the fineness adjustment function of the wood powder machine allows arbitrary adjustment between 20-325 mesh to meet different application requirements.

5. A method for preparing a tough composite filter aid according to claim 1, Features: In step S04, the wood powder sorting process requires the application of precise screen sorting machine technology. The preferred economical screen sorting machine adopts a double-layer mesh design. The upper mesh is configured with an aperture of 185μm (80 mesh), while the lower mesh is 30μm (500 mesh). In order to ensure that wood powder with a particle size less than 30μm passes through the screen smoothly, the lower screen is equipped with an ultrasonic vibration device, which uses ultrasonic acceleration to promote the screening efficiency of the material, effectively prevent mesh blockage, and significantly improve screening accuracy and processing capacity. After sorting, 93% of the volume particle size of the wood powder is strictly controlled within the range of 30 to 185μm, ensuring that the wood powder particle size is 5% to 20% smaller than the average diameter of rice husk powder.

6. A method for preparing a tough composite filter aid according to claim 1, Features: In the process of selecting the basic magnesium carbonate tetrahydrate in S05, it is necessary to carefully screen the basic magnesium carbonate tetrahydrate of different volume particle sizes and forms. The substance exists in various forms, including non-porous powder, porous petal spheres and porous petal rods. The porous petal sphere-shaped basic magnesium carbonate tetrahydrate with a volume particle size between 75 and 150 μm is selected as the key component of the composite filter aid.

7. A method for preparing a tough composite filter aid according to claim 1, Features: The selection of the mildewproof agent in S06 is aimed at the problem of composite powder mildew caused by insufficient sealing of the packaging in high humidity areas. A mildewproof agent needs to be added to prevent the occurrence of mildew. Commercially available o-phenylphenol and biphenyl are selected as mildewproof agents, and o-phenylphenol with a crystal particle size in the range of 10 to 100 um is preferably used as the composite component.

8. A method for preparing a tough composite filter aid according to claim 1, Features: The ratio of the four ingredients of rice husk powder, wood powder, porous petal spherical basic magnesium carbonate tetrahydrate, and o-phenylphenol in the composite powder selected in S07 is:

9. A method for preparing a tough composite filter aid according to claim 1, Features: The rice husk powder, wood powder, porous petal-shaped spherical magnesium carbonate tetrahydrate and o-phenylphenol in the composite powder in S07 are mixed evenly in proportion to obtain a toughened composite filter aid with a composite powder having an average (diameter) volume particle size of 93% in the range of 30 to 200 um, a bulk density of 220 to 350 g / L and a permeability of 4.5 to 18D.

10. Use of a tough composite filter aid according to any one of claims 1 to 9, Features: Used to filter cooling oil of machining lathe, milling, rough grinding, rolling mill, etc.; its usage method is: place a tough composite filter aid on the filter cloth of the filtering equipment and spread it evenly, then slowly inject a mixture of lathe, milling, rough grinding, rolling mill cooling oil and impurities, when the mixture of lathe, milling, rough grinding, rolling mill cooling oil and impurities is placed in a tough composite filter aid, wait for the cooling oil to penetrate completely, take out the filtered solid waste from the filter cloth and scrape it clean, and then reuse the filtered cooling oil to achieve a complete filtration process.

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