Natural rubber rapid flocculation method and natural rubber

Abstract

The invention relates to a method for quickly flocculating natural rubber, which comprises the following steps of: forming a directed vortex from nonmetallic mineral material slurry, adding the directed vortex into bubble-shaped natural rubber mixed liquor through an overflow pipeline, and flocculating to obtain the natural rubber. According to the invention, a natural non-metallic mineral material is used and forms a weak electromagnetic field with an external pipeline after forming a directed vortex; under the weak electromagnetic action, beneficial binding force is generated between the natural rubber and the natural rubber, the balance of a natural rubber mixed solution is rapidly destroyed, the natural rubber is efficiently co-precipitated from the natural rubber mixed solution under the condition of three-phase coexistence, and the flocculation speed and efficiency of the natural rubber are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of primary processing of natural rubber. Further, it relates to a method for rapid flocculation of natural rubber. At the same time, the present invention also relates to natural rubber obtained by the method for rapid flocculation of natural rubber. Background Art

[0002] Natural rubber is mainly extracted from natural fresh latex in natural plants such as Hevea brasiliensis, Parthenium argentatum, and Taraxacum mongolicum. It is necessary to prepare solid natural rubber by flocculating high-molecular rubber from natural fresh latex through a process. However, the industrial flocculation technology is slow flocculation in a flocculation tank, usually taking 24 hours, with a relatively long flocculation time and low flocculation efficiency. In addition, preservatives such as ammonia volatilize for a long time during storage and flocculation, causing adverse effects on the environment. Moreover, due to the relatively long flocculation time, it is easy to cause the reproduction of fungi and a strong smell, which is very likely to affect the performance of natural rubber.

[0003] Based on the above situation, developing a method that can improve the flocculation speed of natural rubber has become an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0004] To solve the problems existing in the prior art, the present invention provides a method for rapid flocculation of natural rubber. By utilizing the mechanism of suspension balance destruction and through a process method with the coexistence of gas, solid, and liquid phases, rapid flocculation of natural rubber is carried out, enabling natural rubber to rapidly flocculate from the natural rubber mixture and realizing the solid-liquid separation of the natural rubber mixture. The process method with the coexistence of gas, solid, and liquid phases uses a non-metallic mineral material that can form a binding force with natural latex. After it is rotated into a directional eddy current in the equipment, it can rapidly form a physical binding force with the natural rubber molecular chain and destroy the suspension balance of natural rubber.

[0005] One of the objects of the present invention is to provide a method for rapid flocculation of natural rubber. The method includes forming a directional eddy current with the non-metallic mineral material slurry and adding it to the foamed natural rubber mixture through a pipeline to flocculate natural rubber.

[0006] Among them, the mass ratio of the non-metallic mineral material slurry to the foamed natural rubber mixture is 1:2.5 - 20, preferably 1:2.5 - 8.

[0007] The present invention adopts a three-phase co-precipitation rapid flocculation method, where gas, liquid, and solid coexist in a suspension system. The gas in the three phases refers to the gas filled when forming the foamed natural rubber mixture; the liquid in the three phases refers to the liquid natural rubber mixture; the solid in the three phases refers to the non-metallic mineral material in the non-metallic mineral material slurry.

[0008] The non-metallic mineral materials in the non-metallic mineral material slurry have directional conductivity and can form a directional eddy current under the action of a rotational force. When the non-metallic mineral material slurry forming the directional eddy current passes through a pipeline, the directional movement of its eddy current can construct an orientation electrophoresis flow with the pipeline, thereby constituting a weak electromagnetic field. Under the action of this weak electromagnetic field, rubber and graphite can be combined more quickly, effectively, and fully. The present invention utilizes the binding force between the non-metallic mineral materials and natural rubber to disrupt the emulsion equilibrium state of the natural rubber mixture, prompting the natural rubber solid to rapidly flocculate and deposit from the equilibrium suspension, achieving solid-liquid separation, and ultimately achieving the purpose of rapid flocculation of natural rubber.

[0009] In a preferred embodiment of the present invention, the non-metallic mineral material slurry includes non-metallic mineral materials, additives, and water;

[0010] In the non-metallic mineral material slurry, based on 100 parts by weight of water:

[0011] Non-metallic mineral materials 0.5 - 10 parts by weight

[0012] Additives 0.01 - 3 parts by weight

[0013] Water 100 parts by weight;

[0014] More preferably, in the non-metallic mineral material slurry, based on 100 parts by weight of water:

[0015] Non-metallic mineral materials 3 - 10 parts by weight

[0016] Additives 0.2 - 1.0 parts by weight

[0017] Water 100 parts by weight.

[0018] In a preferred embodiment of the present invention, the pipeline is made of one or more of copper, steel, aluminum, titanium, carbon fiber, and ultra-high molecular weight polyethylene materials, or can also be a mesh composite pipeline woven with the aforementioned materials. Preferably, the pipeline is a copper mesh sandwich ultra-high molecular weight polyethylene pipeline, that is, the pipeline is composed of ultra-high molecular weight polyethylene coated with a copper mesh.

[0019] In a preferred embodiment of the present invention, the non-metallic mineral material is at least one of graphite, kaolin, montmorillonite, diatomite, illite, attapulgite, talcum powder, and graphene. Those skilled in the art can select a suitable non-metallic mineral material according to actual needs. It should be noted that the graphene may include one or more of single-layer graphene, bilayer graphene, and multi-layer graphene. The non-metallic mineral material is preferably graphite. Particularly preferably, the non-metallic mineral material is at least one of natural fine flake graphite, natural cryptocrystalline graphite, synthetic graphite, and coal-based graphite. The charge characteristics of graphite enable it to stably form a directional eddy current under the continuous action of a rotational force. The directional movement of this eddy current and the external pipeline form a weak electromagnetic field. The magnetic field action promotes the rapid formation of a greater physical binding force between graphite and the long-chain natural rubber molecular chains, destroys the emulsion equilibrium state of the natural rubber mixture, and prompts the rapid flocculation and deposition of natural rubber solids from the equilibrium suspension.

[0020] In a preferred embodiment of the present invention, in the non-metallic mineral material, the content of the non-metallic mineral is greater than 50 wt%, preferably greater than 85 wt%. Those skilled in the art can select a suitable content of the non-metallic mineral according to actual needs to further enhance the weak electromagnetic field formed by the non-metallic mineral material slurry and the overflow pipeline, thereby improving the binding force between the non-metallic mineral material and natural rubber and enabling the natural rubber to flocculate more quickly.

[0021] In a preferred embodiment of the present invention, the maximum particle size of the non-metallic mineral material does not exceed 20 microns, and the D97 of the non-metallic mineral material is 3 - 5 microns. It should be noted that D97 refers to the particle size corresponding to when the cumulative particle size distribution number of the non-metallic mineral material reaches 97%, specifically meaning that 97% of the powder particle sizes of the non-metallic mineral material are in the range of 3 - 5 microns. Those skilled in the art can select a suitable particle size of the non-metallic mineral material according to actual needs to further enhance the weak electromagnetic field formed by the non-metallic mineral material slurry and the overflow pipeline, thereby improving the binding force between the non-metallic mineral material and natural rubber and enabling the natural rubber to flocculate more quickly.

[0022] In a preferred embodiment of the present invention, the auxiliary agent is a surfactant. Those skilled in the art can select one or a combination of multiple ones from conventional surfactants according to actual needs. Particularly preferably, the auxiliary agent is at least one of stearic acid, lauric acid, carboxylic acid, ammonia water, pine oil, octylphenol polyoxyethylene ether, sucrose ester, sorbitan fatty acid ester, polysorbate, polyoxyethylene alkanolamide, and N-dodecyl bisquaternary ammonium salt.

[0023] The non-metallic mineral material has a lamellar structure, and the additive can make the non-metallic mineral material have better hydrophilicity, helping water molecules enter the lamellar structure of the non-metallic mineral material, so that the non-metallic mineral material with a lamellar structure is fully dispersed in water, increasing the contact probability between the non-metallic mineral material and solid rubber, being conducive to the combination of the two, and further quickly destroying the suspension balance of the natural rubber mixture.

[0024] In a preferred embodiment of the present invention, the foamed natural rubber mixture includes natural fresh latex and a preservative;

[0025] In the natural rubber mixture, based on 100 parts by weight of natural fresh latex:

[0026] Natural fresh latex 100 parts by weight

[0027] Preservative 0.01 - 10 parts by weight;

[0028] More preferably, in the natural rubber mixture, based on 100 parts by weight of natural fresh latex:

[0029] Natural fresh latex 100 parts by weight

[0030] Preservative 0.5 - 3 parts by weight.

[0031] It should be noted that in the present invention, natural fresh latex refers to fresh milk in the field.

[0032] In a preferred embodiment of the present invention, the preservative is at least one of sorbic acid, potassium sorbate, calcium sorbate, sodium sorbate, sodium diacetate, sodium alginate, ethyl paraben, and ammonia water. Those skilled in the art can select a suitable preservative according to actual needs.

[0033] In a preferred embodiment of the present invention, the foamed natural rubber mixture is prepared by the following method:

[0034] Mix natural fresh latex and a preservative, introduce gas and stir to obtain the foamed natural rubber mixture.

[0035] The present invention can specifically adopt the following technical solutions:

[0036] The foamed natural rubber mixture is prepared by the following method:

[0037] Mix natural fresh latex and a preservative, and through a rotating device, quickly rotate and stir to obtain a mixture of the two. During the stirring process, fill gas into the mixture of the two, and continuously stir for a period of time to form a foamed mixture, which is the foamed natural rubber mixture.

[0038] In a preferred embodiment of the present invention, the gas is at least one of air, nitrogen, helium, neon, argon, krypton, and xenon. Those skilled in the art can select a suitable gas according to actual needs to form a foamed natural rubber mixture.

[0039] In a preferred embodiment of the present invention, the method for rapid flocculation of natural rubber comprises the following steps:

[0040] S1: Mix the components of the non-metallic mineral material slurry according to the weight parts to obtain the non-metallic mineral material slurry; stir the non-metallic mineral material slurry to obtain a non-metallic mineral material slurry with a directed vortex formed therein.

[0041] S2: Mix the components of the foamed natural rubber mixture according to the weight parts, introduce a gas and stir to obtain a foamed natural rubber mixture.

[0042] S3: The non-metallic mineral material slurry with a directed vortex is added into the foamed natural rubber mixture through a pipeline, stirred and flocculated; stop stirring, and perform solid-liquid separation to obtain natural rubber.

[0043] In a preferred embodiment of the present invention, in step S1, the stirring speed is 100 - 1000 revolutions per minute, and the stirring time is 5 - 30 minutes; in step S2, the stirring speed is 50 - 800 revolutions per minute, and the stirring time is 5 - 15 minutes; in step S3, the stirring speed is 100 - 400 revolutions per minute, and the stirring time is 3 - 10 minutes. More preferably, pressure filtration or standing is used for solid-liquid separation, and the standing time is 5 - 60 minutes. Those skilled in the art can select appropriate stirring time, stirring speed and standing time according to actual needs.

[0044] The present invention can specifically adopt the following technical solutions:

[0045] The method for rapid flocculation of natural rubber comprises the following steps:

[0046] S1: Mix the components of the non-metallic mineral material slurry according to the weight parts to obtain the non-metallic mineral material slurry; stir the non-metallic mineral material slurry, with a stirring speed of 100 - 1000 revolutions per minute and a stirring time of 5 - 30 minutes, to obtain a non-metallic mineral material slurry with a directed vortex formed therein.

[0047] S2: Mix the components of the foamed natural rubber mixture according to the weight parts, introduce at least one of air, nitrogen, helium, neon, argon, krypton, and xenon, and at the same time start the stirring device to stir, with a stirring speed of 50 - 800 revolutions per minute and a stirring time of 5 - 15 minutes, to obtain a foamed natural rubber mixture.

[0048] S3: Feed the slurry of non-metallic mineral materials forming a directed eddy current into the foamed natural rubber mixture through a pipeline at a speed of 10 - 100 g / 10 s, stir at a speed of 100 - 400 revolutions per minute for 3 - 10 minutes, then stop stirring and let it stand for 5 - 60 minutes to obtain natural rubber. It should be noted that during the stirring process, the natural rubber has started to rapidly flocculate.

[0049] The second object of the present invention is to provide a natural rubber obtained by the method for rapid flocculation of natural rubber according to the first object of the present invention.

[0050] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0051] 1. The present invention uses natural non-metallic mineral materials, which form a directed eddy current and constitute a weak electromagnetic field with the external pipeline; under the action of the weak electromagnetic field, it has a beneficial binding force with natural rubber, rapidly destroys the balance of the natural rubber mixture, and efficiently co-precipitates natural rubber from the natural rubber mixture under the condition of three-phase coexistence, improving the flocculation speed and efficiency of natural rubber.

[0052] 2. The introduction of non-metallic mineral materials in the present invention can not only improve the speed and efficiency of natural rubber flocculation, but also the blend of it with natural rubber can reduce the energy consumption in the subsequent processing of rubber, improve the dispersibility of various additives, and improve the dispersion uniformity.

[0053] 3. The method for rapid flocculation of natural rubber of the present invention has a novel process and a simple process. Specific Embodiments

[0054] The present invention will be specifically described below in combination with specific embodiments. It is necessary to point out here that the following embodiments are only for further illustration of the present invention and cannot be construed as limiting the protection scope of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention still fall within the protection scope of the present invention.

[0055] The raw materials used in the examples and comparative examples are all conventional commercially available raw materials.

[0056] In the present invention, natural fresh latex is derived from natural plants such as Hevea brasiliensis, Parthenium argentatum, and Taraxacum mongolicum, and is a milky white liquid freshly collected.

[0057] In the present invention, the non-metallic mineral materials are commercially available products, and the technical parameter part of their specifications includes the maximum particle size and D97.

[0058] Example 1

[0059] S1: Prepare a graphite aqueous slurry forming a directed eddy current

[0060] Weigh 100 g of pure water, 6 g of natural cryptocrystalline graphite (with a carbon content of 85%, a particle size Dmax of 6 microns, and D97 of 3 microns), 0.25 g of octylphenol polyoxyethylene ether, and 0.03 g of pine oil respectively. Mix the aforementioned substances to prepare a graphite aqueous slurry. Place the graphite aqueous slurry in a blender and perform rotary stirring at a stirring speed of 400 revolutions per minute for 15 minutes to obtain a graphite aqueous slurry with a directed vortex formed.

[0061] S2: Prepare a foamed natural rubber mixture

[0062] Weigh 700 g of natural fresh latex with a solid content of 30%, add 5 g of ammonia water to the natural fresh latex to prepare a mixture. Place the mixture in a blender and perform rotary stirring while introducing air at a stirring speed of 200 revolutions per minute for 10 minutes. Rotate and stir to generate bubbles until a foamed mixture is obtained, resulting in a foamed natural rubber mixture, and continue stirring for use.

[0063] S3: Flocculate to obtain natural rubber

[0064] Add the graphite aqueous slurry with a directed vortex formed into the foamed natural rubber mixture uniformly and stably at a speed of 30 g every 10 seconds through an overflow stainless steel pipe. When continuously stirring at a stirring speed of 300 revolutions per minute for about 2 minutes, flocculent lumps begin to appear. When continuously stirring for about 5 minutes, the natural rubber forms into clusters and flocculates. At this time, the blender can no longer stir, and take out the flocculent lumps; for the remaining liquid part, let it stand for 30 minutes, and solid-liquid separation occurs. Collect the solid and the liquid respectively, and the collected solid is natural rubber. The solid rubber is further processed and dried through subsequent processes.

[0065] The total time taken for the rapid flocculation method of natural rubber in this example is 60 min, which is much lower than the flocculation time of industrial flocculation technology, improving the flocculation speed and efficiency of natural rubber. At the same time, a total of 215 g of solid rubber is collected in this example. Although the flocculation time is shortened and the efficiency is improved, the total amount of flocculated natural rubber is not affected.

[0066] Example 2

[0067] S1: Prepare a graphite aqueous slurry with a directed vortex formed

[0068] Weigh 100 g of pure water, 5 g of natural fine flake graphite (with a carbon content of 95%, a particle size Dmax of 10 microns, and D97 of 5 microns), 0.05 g of polyoxyethylene alkanolamide, and 0.75 g of N-dodecyl bisquaternary ammonium salt respectively. Mix the aforementioned substances to prepare a graphite aqueous slurry. Place the graphite aqueous slurry in a blender and perform rotary stirring at a stirring speed of 250 revolutions per minute for 27 minutes to obtain a graphite aqueous slurry with a directed vortex formed.

[0069] S2: Prepare a foamed natural rubber mixture

[0070] Weigh 300 g of natural fresh latex with a solid content of 42%, and add 0.3 g of calcium sorbate to the natural fresh latex to prepare a mixture. Place the mixture in a blender and stir it while rotating, and at the same time, fill it with nitrogen. The stirring speed is 300 revolutions per minute, and the stirring time is 5 minutes. Rotate and stir to produce bubbles until a foamed mixture is obtained, and a foamed natural rubber mixture is obtained. Keep stirring for later use.

[0071] S3: Flocculate to obtain natural rubber

[0072] Pass the graphite aqueous slurry with a directed eddy current through an overflow ultra-high molecular weight polyethylene copper mesh core pipeline, and uniformly and stably add it to the foamed natural rubber mixture at a speed of 20 g per 10 seconds. When continuously stirring at a stirring speed of 200 revolutions per minute for about 6 minutes, flocculent lumps begin to appear. When continuously stirring for about 8 minutes, the natural rubber forms into a mass of flocs until the blender can no longer stir, and collect the flocs. The remaining liquid is filtered by pressure, and the solid and liquid are collected separately. The collected solid is natural rubber. The solid rubber is further processed and dried.

[0073] The rapid flocculation method of natural rubber in this example took a total of 70 minutes and collected 130.5 g of solid flocs, which is much lower than the flocculation time of industrial flocculation technology, and improves the flocculation speed and efficiency of natural rubber.

[0074] Example 3

[0075] S1: Prepare a diatomite mineral aqueous slurry

[0076] Weigh 100 g of pure water, 5 g of natural diatomite (diatomite content is 83%, particle size Dmax is 7 microns, D97 is 3 microns), 3 g of coal-based graphite with a carbon content of 85%, 0.05 g of glycerol, and 0.5 g of N-dodecyl bisquaternary ammonium salt. Mix the above substances to prepare a diatomite aqueous slurry. Place the diatomite aqueous slurry in a blender and stir it while rotating. The stirring speed is 600 revolutions per minute, and the stirring time is 7 minutes to obtain a diatomite mineral aqueous slurry with a directed eddy current.

[0077] S2: Prepare a foamed natural rubber mixture

[0078] Weigh 700 g of natural fresh latex with a solid content of 25%, and add 0.3 g of lauric acid to the natural fresh latex to prepare a mixture. Place the mixture in a blender and stir it while rotating, and at the same time, fill it with dry air with a humidity less than 40%. The stirring speed is 400 revolutions per minute, and the stirring time is 10 minutes. Rotate and stir to produce bubbles until a foamed mixture is obtained, and a foamed natural rubber mixture is obtained. Keep stirring for later use.

[0079] S3: Flocculate to obtain natural rubber

[0080] The diatomite mineral water-based slurry forming a directed eddy current is added to the foamed natural rubber mixture through an overflow copper pipe at a uniform and stable speed of 22 g every 10 seconds. When continuously stirring at a stirring speed of 150 revolutions per minute for about 5 minutes, flocculent lumps begin to appear. When continuously stirring for about 5 minutes, the natural rubber forms into clusters and flocculates until the mixer cannot work and can no longer stir. Let it stand for 45 minutes, the solid and liquid are separated, and the solid and liquid are collected separately. The collected solid is natural rubber.

[0081] The rapid flocculation method of natural rubber in this embodiment takes a total of 90 minutes and collects 207 g of solid flocculants, which is much lower than the flocculation time of industrial flocculation technology, improving the flocculation speed and efficiency of natural rubber.

[0082] Comparative Example 1

[0083] S1: Prepare a graphite water-based slurry

[0084] Weigh 100 g of pure water, 6 g of natural cryptocrystalline graphite (with a carbon content of 85%, a particle size Dmax of 6 microns, and a D97 of 3 microns), 0.25 g of octylphenol polyoxyethylene ether, and 0.03 g of pine oil respectively. Mix the aforementioned substances to prepare a graphite water-based slurry. Place the graphite water-based slurry in a mixer and rotate and stir it. The stirring speed is 400 revolutions per minute, and the stirring time is 5 minutes.

[0085] S2: Prepare a foamed natural rubber mixture

[0086] Weigh 700 g of natural fresh latex with a solid content of 30%, add 5 g of ammonia water to the natural fresh latex to prepare a mixture. Place the mixture in a mixer and rotate and stir it. At the same time, introduce air. The stirring speed is 200 revolutions per minute, and the stirring time is 10 minutes. Rotate and stir to generate bubbles to form a foamed mixture, obtaining a foamed natural rubber mixture, and continue to stir for use.

[0087] S3: Flocculate to obtain natural rubber

[0088] Add the graphite water-based slurry to the foamed natural rubber mixture through an overflow stainless steel pipe at a uniform and stable flow rate of 30 g every 10 seconds. When continuously stirring at a stirring speed of 300 revolutions per minute for about 5 minutes, flocculent lumps begin to appear. When continuously stirring for about 5 minutes, the natural rubber forms into clusters and flocculates. At this time, the mixer cannot continue to stir, and take out the flocculent lumps; for the remaining liquid part, let it stand for 30 minutes, the solid and liquid are separated, and the solid and liquid are collected separately. The collected solid is natural rubber. The solid rubber is further processed and dried through subsequent processes.

[0089] The rapid flocculation method of natural rubber in this comparative example took a total of 52 minutes, and 210 g of solid rubber was collected. Although the flocculation time was shortened and the efficiency was improved, the total amount of flocculated natural rubber decreased. No vortex was formed in the graphite aqueous slurry, resulting in poor uniformity of the graphite aqueous slurry and a tendency to stratify. Therefore, the dispersion degree of the graphite aqueous slurry in the rubber emulsion was weak, and finally, the solid rubber could not be fully flocculated and precipitated during the flocculation process, and obvious agglomeration of the solid rubber occurred, leading to a rapid decline in the product consistency and uniformity.

[0090] Comparative Example 2

[0091] S1: Prepare a graphite aqueous slurry with a directed vortex

[0092] Weigh 100 g of pure water, 6 g of natural cryptocrystalline graphite (with a carbon content of 85%, a particle size Dmax of 6 μm, and a D97 of 3 μm), 0.25 g of octylphenol polyoxyethylene ether, and 0.03 g of pine oil respectively. Mix the above substances to prepare a graphite aqueous slurry. Place the graphite aqueous slurry in a blender and rotate and stir it at a stirring speed of 400 revolutions per minute for 15 minutes to obtain a graphite aqueous slurry with a directed vortex.

[0093] S2: Prepare a natural rubber mixture

[0094] Weigh 700 g of natural fresh latex with a solid content of 30%, and add 5 g of ammonia water to the natural fresh latex to obtain a natural rubber mixture.

[0095] S3: Flocculate to obtain natural rubber

[0096] Add the graphite aqueous slurry with a directed vortex to the natural rubber mixture uniformly and stably through an overflow stainless steel pipe at a flow rate of 30 g every 10 seconds. When continuously stirring at a stirring speed of 300 revolutions per minute for about 10 minutes, flocculent lumps start to appear. When continuously stirring for about 8 minutes, the natural rubber forms into clusters and flocculates. At this time, the blender can no longer stir, and take out the flocculent lumps; for the remaining liquid part, let it stand for 30 minutes, and solid-liquid stratification occurs. Collect the solid and liquid respectively, and the collected solid is natural rubber. The solid rubber is further processed and dried through subsequent processes.

[0097] The rapid flocculation method of natural rubber in this comparative example took a total of 70 minutes, and 211 g of solid rubber was collected. Although the flocculation time was shortened and the efficiency was improved, the total amount of flocculated natural rubber decreased, and the product yield decreased. After solid-liquid separation, the low-molecular rubber components in the liquid phase increased significantly, the flocculation was insufficient, and the difficulty of subsequent sewage treatment increased.

[0098] The natural rubber mixture was not aerated, resulting in an insufficient amount of space being established between the large and small molecules in the natural rubber mixture to allow the non-metallic mineral slurry to quickly and evenly enter the suspension and rapidly break the balance. Ammonia water was added to the natural fresh latex to maintain the relative balance of the suspension state of the natural fresh latex. After the graphite aqueous slurry was added to the natural rubber mixture, the graphite particles quickly sank, so the graphite particles could not fully bind to the natural rubber, and some graphite particles precipitated with the water molecules, resulting in a double decrease in the amount of flocculation and the flocculation speed. At this time, agglomeration occurred in the natural rubber coprecipitated rubber, which was prone to being undercooked after drying, and the ash content in the finished natural rubber was uneven, the product quality was non-uniform, the product quality declined, and the difficulty of material balance increased; in the liquid phase, there were unbound free non-metallic mineral materials, increasing the difficulty of post-treatment of sewage.

[0099] Comparative Example 3

[0100] S1: Prepare a graphite aqueous slurry with a directed vortex

[0101] Weigh 100 g of pure water, 6 g of natural cryptocrystalline graphite (with a carbon content of 85%, a maximum particle size Dmax of 6 μm, and a D97 of 3 μm), 0.25 g of octylphenol polyoxyethylene ether, and 0.03 g of pine oil. Mix the above substances to prepare a graphite aqueous slurry. Place the graphite aqueous slurry in a blender and rotate and stir it at a stirring speed of 400 revolutions per minute for 15 minutes to obtain a graphite aqueous slurry with a directed vortex.

[0102] S2: Prepare a foamed natural rubber mixture

[0103] Weigh 700 g of natural fresh latex with a solid content of 30%, add 5 g of ammonia water to the natural fresh latex to prepare a mixture. Place the mixture in a blender and rotate and stir it while introducing air at a stirring speed of 200 revolutions per minute for 10 minutes. Rotate and stir to generate bubbles until a foamed mixture is obtained to get a foamed natural rubber mixture, and continue to stir for later use.

[0104] S3: Flocculate to obtain natural rubber

[0105] Add the graphite aqueous slurry with a directed vortex to the foamed natural rubber mixture evenly and stably at a flow rate of 30 g every 10 seconds. When continuously stirring at a stirring speed of 300 revolutions per minute for about 5 minutes, flocculent lumps start to appear. When continuously stirring for about 5 minutes, the natural rubber agglomerates and flocculates. At this time, the blender can no longer stir, and take out the flocculent lumps; for the remaining liquid part, let it stand for 30 minutes, and solid-liquid separation occurs. Collect the solid and the liquid separately. The collected solid is natural rubber. The solid rubber is further processed and dried through subsequent processes.

[0106] The rapid flocculation method of natural rubber in this comparative example took a total of 65 minutes, and a total of 212 g of solid rubber was collected. Although the flocculation time was shortened and the efficiency was improved, the total amount of flocculated natural rubber decreased. The overflow pipe maintains the directional vortex orientation of the non-metallic mineral material slurry. When the overflow pipe is not used, the orientation of the non-metallic mineral material slurry rapidly weakens. On the one hand, since the specific gravity of the non-metallic mineral material is greater than that of rubber molecules and water molecules, the non-metallic mineral material rapidly sinks, reducing the chance of combination between the non-metallic mineral material and rubber molecules and weakening the binding force between the non-metallic mineral material and rubber molecules, resulting in a decrease in the flocculation amount and flocculation speed of solid rubber. On the other hand, the rapid weakening of the orientation of the non-metallic mineral material slurry will also cause the graphite water-based slurry to be unable to maintain a good degree of dissociation. Therefore, during the co-sedimentation process of the graphite water-based slurry and the natural rubber mixture, large rubber agglomerate particles will appear, the binding force between rubber molecules will decrease, the loss of small molecule materials will increase, and the consistency and uniformity of the rubber product will decrease.

Claims

1. A method for rapid flocculation of natural rubber, characterized in that: The method includes forming a directional eddy current in the non-metallic mineral material slurry and adding it to the foamed natural rubber mixture through a pipeline to obtain natural rubber by flocculation; Among them, the mass ratio of the non-metallic mineral material slurry to the foamed natural rubber mixture is 1:2.5 to 20, preferably 1:2.5 to 8.

2. The method according to claim 1, characterized in that: The non-metallic mineral material slurry includes non-metallic mineral materials, additives and water; In the non-metallic mineral material slurry, based on 100 parts of water: Non-metallic mineral materials 0.5 to 10 parts by weight Additives 0.01 to 3 parts by weight Water 100 parts by weight; Preferably, in the non-metallic mineral material slurry, based on 100 parts of water: Non-metallic mineral materials 3 to 10 parts by weight Additives 0.2 to 1.0 parts by weight Water 100 parts by weight.

3. The method according to claim 1, characterized in that: In the non-metallic mineral material, the content of non-metallic minerals is greater than 50 wt%, preferably greater than 85 wt%; and / or The maximum particle size of the non-metallic mineral material does not exceed 20 microns, and the D97 of the non-metallic mineral material is 3 to 5 microns.

4. The method according to claim 2, characterized in that: The non-metallic mineral material is at least one of graphite, kaolin, montmorillonite, diatomite, illite, attapulgite, talcum powder, graphene, preferably graphite, more preferably at least one of natural fine flake graphite, natural cryptocrystalline graphite, synthetic graphite, coal series graphite; and / or The additive is a surfactant, preferably at least one of stearic acid, lauric acid, carboxylic acid, ammonia water, pine oil, octylphenol polyoxyethylene ether, sucrose ester, sorbitan fatty acid ester, polysorbate, polyoxyethylene alkanolamide, N-dodecyl bisquaternary ammonium salt; and / or The pipeline is made of one or more of copper, steel, aluminum, titanium, carbon fiber, ultra-high molecular weight polyethylene materials.

5. The method according to claim 1, characterized in that: The foamed natural rubber mixture includes natural fresh latex and a preservative; Based on 100 parts of natural fresh latex in the natural rubber mixture: Natural fresh latex 100 parts by weight Preservative 0.01 to 10 parts by weight; Preferably, in the natural rubber mixture, based on 100 parts of natural fresh latex: Natural fresh latex 100 parts by weight Preservative 0.5 to 3 parts by weight.

6. The method according to claim 5, characterized in that: The preservative is at least one of sorbic acid, potassium sorbate, calcium sorbate, sodium sorbate, sodium diacetate, sodium alginate, ethyl paraben, ammonia water.

7. The method according to any one of claims 5 to 6, characterized in that: The foamed natural rubber mixture is prepared by the following method: Mix natural fresh latex and a preservative, introduce gas and stir to obtain a foamed natural rubber mixture.

8. The method according to claim 7, characterized in that: The gas is at least one of air, nitrogen, helium, neon, argon, krypton, xenon.

9. The method according to any one of claims 1 to 8, characterized in that The method includes: S1: Mix the components of the non-metallic mineral material slurry according to the parts by weight to obtain the non-metallic mineral material slurry; stir the non-metallic mineral material slurry to obtain a non-metallic mineral material slurry with a directed vortex formed therein. S2: Mix the components of the foamed natural rubber mixture according to the parts by weight, introduce gas and stir to obtain a foamed natural rubber mixture. S3: The non-metallic mineral material slurry with a directed vortex formed therein is added into the foamed natural rubber mixture through a pipeline, stirred and flocculated; stop stirring, perform solid-liquid separation to obtain natural rubber. Preferably, In step S1, the stirring speed is 100 - 1000 revolutions per minute, and the stirring time is 5 - 30 minutes; and / or In step S2, the stirring speed is 50 - 800 revolutions per minute, and the stirring time is 5 - 15 minutes; and / or In step S3, the stirring speed is 100 - 400 revolutions per minute, and the stirring time is 3 - 10 minutes. More preferably, pressure filtration or standing is used for solid-liquid separation, and the standing time is 5 - 60 minutes.

10. A natural rubber prepared by the method according to any one of claims 1 - 9.