A paraffin suspension forming agent, its preparation method and use

Abstract

The application provides a paraffin suspension forming agent, which comprises 0.5-6 parts of paraffin, 100 parts of C3-C5 alcohol and 0.01-1 parts of a dispersion stabilizer by weight; the dispersion stabilizer is dissolved in the C3-C5 alcohol to form a liquid phase of the paraffin suspension forming agent; and the paraffin exists in the liquid phase in the form of nano and / or micro paraffin particles and paraffin molecules. The application also provides a preparation method and application of the paraffin suspension forming agent.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hard alloy material, in particular to a paraffin suspension forming agent used in the production process of hard alloy, and a preparation method and application thereof. BACKGROUND

[0002] In the production process of hard alloy (cermet), a certain amount of forming agent must be added before forming. A good forming agent can effectively eliminate defects in the compact, such as pores, inclusions, delamination, cracks, etc. These small defects are not easy to eliminate in the sintering process, which seriously affects the product quality. The forming agent is an intermediate auxiliary material in the production process of hard alloy (cermet) products, and must be completely removed in the degreasing process before the compact is sintered. Any residue will bring hidden dangers to the production process control and product quality. Therefore, the forming agent is a key factor directly affecting the performance of hard alloy compact and alloy.

[0003] At present, the forming agents widely used by hard alloy production enterprises mainly include three types: rubber, paraffin and polyethylene glycol (PEG). These three types of forming agents have their own advantages and disadvantages in performance. At present, different product models are selected in the production process. The advantages of rubber forming agent are low forming pressure, good shape retention, and can be used for the forming of complex products. The disadvantages are high impurity content, easy to age, not suitable for spray drying process, not easy to remove in vacuum, and mainly used in the production of medium and low grade products and complex shaped products. The advantages of polyethylene glycol (PEG) forming agent are soluble in alcohol and water, especially suitable for spray drying process. It has high purity, is easy to remove, has equivalent residual carbon to paraffin, good forming performance and high compact strength. The disadvantages are high water absorption, high pressing pressure during compacting, high requirements for temperature and humidity of the environment, and in order to completely remove it, hydrogen gas is needed, which significantly increases the danger of the production process. The advantages of paraffin forming agent are suitable for both spray drying process and general mixer granulation with paraffin. In addition, since paraffin is a mixture containing various hydrocarbons and is a saturated straight-chain hydrocarbon with relatively low molecular weight, it can be completely volatilized at high temperature without residual material, and it can be easily removed in vacuum, which can significantly reduce the complexity of carbon content control in the production process of hard alloy and improve the accuracy of carbon content control in the production process of hard alloy. The particle is not easy to age, and thus the quality of the hard alloy product is improved. Therefore, the application of paraffin forming agent in hard alloy is becoming more and more widespread. The disadvantages are that the bulk density of the prepared mixture is small, the compression ratio is large, which leads to high pressing pressure in the pressing process, low compact strength, and difficulty in forming complex shaped products. The pressing performance of the mixture is greatly affected by temperature.

[0004] Application No. CN201110076735.9 discloses a water-based hard alloy mixture with a paraffin-based forming agent. The paraffin is emulsified by using an emulsifier to disperse the paraffin into an emulsion state. Although the problem of uniform dispersion of paraffin in the mixture can be solved, the scheme uses deionized water as a solvent. At present, most mixture production enterprises use alcohol as a wet grinding medium. When it is added to the mixture for ball milling, the demulsification of the paraffin-based forming agent occurs immediately due to the surface energy of alcohol being much higher than that of the forming agent, resulting in a significant decrease in the uniform dispersion of the paraffin in the mixture, failing to achieve the original purpose. Secondly, the scheme does not consider the current problem of using spray drying equipment for the mixture. Since the current spray drying equipment is designed mainly for the alcohol ball milling medium system, the boiling point of alcohol is 78°C, while the boiling point of the forming agent system is 100°C. Under the same mass of mixture, more energy is needed to achieve the purpose of drying, which not only requires more energy consumption, but also needs to modify the spray drying equipment, increasing the investment cost. Patent Nos. CN201711083055.3 and CN202010298108.9 disclose a forming agent for hard alloy rods, which uses high-melting-point paraffin and low-melting-point paraffin to match each other, plus a small amount of modifier. This method does not solve the fundamental problem of poor compatibility of paraffin in alcohol ball milling medium, so the improvement effect is limited.

[0005] Specifically, in the production process of hard alloy compacts, the raw material used is the mixture, which is prepared by calculating the ingredients, ball milling, drying, and other processes to prepare a granular mixture with accurate composition, uniform distribution of ingredients, and certain particle size. In order to obtain high-quality hard alloy products, the components must be uniformly distributed, which is usually achieved by wet milling method. Wet milling can play a role in material crushing and particle size uniformization. At present, the most commonly used medium in wet milling process is alcohol. In the modern hard alloy mixture production process, the forming agent paraffin is added to the hard alloy mixture in a certain proportion for grinding. Since the ball milling medium alcohol is a polar solvent, and paraffin is non-polar, paraffin cannot be well dispersed in this system, which cannot form an effective coating on the surface of the mixture particles, resulting in small bulk density and large compression ratio of the particles after subsequent spray drying, leading to large pressing pressure in the subsequent pressing process, low compact strength, difficult forming of complex-shaped products, and easy dropping of fine products, which seriously affects the qualified rate of the final product and directly affects the production efficiency.

[0006] When the wet grinding medium is alcohol (ordinary industrial alcohol with a volume fraction of 92% or more), the obtained mixture is relatively loose, and the oxygen content can meet the requirements. When the forming agent paraffin is added to the cemented carbide mixture at a certain proportion for grinding, the alcohol is polar, and the paraffin is non-polar. The paraffin cannot be dissolved in the alcohol, and the paraffin cannot be uniformly dispersed in the mixture system, so that the paraffin cannot form effective coating on the surface of the mixture particles, and finally leads to the phenomenon that some mixture particles have paraffin coating, some have partial coating, and some even have no paraffin coating. Even if there is a coating, the thickness of the coating is uneven. These particles cannot avoid the same problem on the surface after subsequent spray drying, so that the mixture has large pressing pressure, low compact strength, and is difficult to form complex-shaped products in the subsequent pressing process. SUMMARY

[0007] The first object of the present application is to provide a paraffin suspension forming agent, wherein the paraffin is uniformly dispersed in the liquid medium in the form of micro / nano particles. The above-mentioned liquid medium not only can disperse the micro / nano paraffin particles well, but also can play the role of the ball milling medium of the mixture, and does not need to add other wet grinding media.

[0008] The second object of the present application is to provide a preparation method of the paraffin suspension forming agent.

[0009] The third object of the present application is to apply the above-mentioned micro / nano paraffin particles to the forming agent (binder) of the cemented carbide mixture to meet the requirements of the spray drying process in the modern cemented carbide mixture production.

[0010] The present application is realized by the following technical solutions:

[0011] A paraffin suspension forming agent, the paraffin suspension forming agent comprises 0.5-6 parts of paraffin and 0.01-1 parts of a dispersion stabilizer by weight, and comprises 100 parts of C3-C5 alcohol by volume;

[0012] The dispersion stabilizer is dissolved in the C3-C5 alcohol to form a liquid phase of the paraffin suspension forming agent;

[0013] The paraffin exists in the liquid phase in the form of nano and / or micro paraffin particles and paraffin molecules;

[0014] The paraffin suspension forming agent is used for the forming of green compacts of cemented carbide.

[0015] The C3-C5 alcohol comprises at least one of propanol, isopropanol, sec-butyl alcohol, 3-pentanol or tert-butyl alcohol.

[0016] The dispersion stabilizer comprises at least one of polyethyleneimine, PEG, oleic acid or PVP.

[0017] The PEG comprises PEG-800, PEG1000, PEG1500, PEG2000, PEG4000 or PEG6000.

[0018] The PVP comprises K15, K17, K25, K30 or K90.

[0019] The polyethyleneimine comprises PEI-20000 or PEI-30000.

[0020] The C3-C5 alcohol comprises isopropyl alcohol and sec-butyl alcohol; or

[0021] The C3-C5 alcohol comprises propyl alcohol and tert-butyl alcohol; or

[0022] The C3-C5 alcohol comprises isopropyl alcohol and 3-pentanol; or

[0023] The C3-C5 alcohol comprises propyl alcohol and isopropyl alcohol.

[0024] The isopropyl alcohol and sec-butyl alcohol are in a volume ratio of 9:1.

[0025] The propyl alcohol and tert-butyl alcohol are in a volume ratio of 7:3.

[0026] The isopropyl alcohol and 3-pentanol are in a volume ratio of 8:2 or 9:1.

[0027] The propyl alcohol and isopropyl alcohol are in a volume ratio of 3:7.

[0028] The paraffin wax particles are one selected from 52# paraffin wax, 54# paraffin wax, 56# paraffin wax, 58# paraffin wax or 60# paraffin wax; or

[0029] The paraffin wax particles are two or more paraffin waxes selected from 52# paraffin wax, 54# paraffin wax, 56# paraffin wax, 58# paraffin wax or 60# paraffin wax mixed in any ratio.

[0030] A preparation method of the paraffin wax suspension forming agent, comprising the following steps:

[0031] Dissolving the paraffin wax and the dispersion stabilizer in the C3-C5 alcohol after heating to obtain a liquid phase system;

[0032] Reducing the temperature of the liquid phase system, and stirring or shearing the liquid phase system at high speed when the paraffin wax begins to precipitate until the liquid phase is cooled to room temperature.

[0033] The preparation method of the paraffin suspension forming agent comprises the step of dissolving paraffin and dispersion stabilizer in C3-C5 alcohol at 60-70 DEG C to obtain a liquid phase system.

[0034] The preparation method of the paraffin suspension forming agent comprises the step of reducing the temperature of the liquid phase system to 50-56 DEG C, and stirring or shearing the liquid phase system at high speed when paraffin starts to precipitate until the liquid phase cools to room temperature.

[0035] The application of the paraffin suspension forming agent is applied to the forming of green compacts of cemented carbide.

[0036] Compared with the prior art, the application has the following advantages:

[0037] 1. The paraffin forming agent provided by the application significantly improves the uniformity and effect of coating of paraffin on the powder particles of cemented carbide mixture. At present, in the production process of cemented carbide mixture, ball milling process is usually used to make the mixture have a certain particle size, and most of the processes are wet milling processes, and the wet milling medium is usually industrial alcohol. In the actual production process, in order to shorten the time and improve the production efficiency, the forming agent paraffin (in the form of blocks or macroscopic particles) is usually added to the ball mill together with the cemented carbide mixture for ball milling. The paraffin molecules mainly reach the surface of the cemented carbide mixture particles by diffusion, adsorption and collision in the ball milling process. Since alcohol is a polar solvent and paraffin is a non-polar substance, the solubility of paraffin in alcohol is extremely low (almost insoluble), that is, the concentration of paraffin in alcohol is extremely low, which leads to the difficulty of paraffin molecules in forming a good coating on the surface of the mixture in the ball milling process. In the application, C3 alcohol, C4 alcohol or C5 alcohol and their mixture are used as the wet milling medium without changing the properties of the wet milling medium (i.e. grinding aid). On the one hand, by changing the wet milling medium (the solvent in the application), the solubility of paraffin in the wet milling medium is increased, and by using mixed alcohol, the solubility of paraffin in alcohol is greatly increased. On this basis, by adding a cosolvent and a dispersion stabilizer and an interfacial treatment agent, the solubility of paraffin is further increased, and the adhesion between the paraffin molecules and the surface of the cemented carbide particles is also improved. On the other hand, since the solid paraffin in the form of blocks or macroscopic particles has been dispersed into micro / nano particles, these microparticles reduce the surface tension of paraffin by diffusion, adsorption and other physical effects and by the surface activity of the added cosolvent to reduce the surface energy of paraffin, thereby significantly improving the uniformity and effect of coating of paraffin on the surface of the powder particles of the cemented carbide mixture. The main purpose of using mixed dispersants is to achieve synergistic effect. On the one hand, the uniformity of the micro / nano paraffin particles in the liquid medium, and on the other hand, the storage stability of the prepared suspension is improved, which is convenient for industrialized production and application.

[0038] 2. The paraffin forming agent provided by the present application can significantly reduce the amount of paraffin used in the production of cemented carbide, thereby facilitating the control of total carbon content in the production of cemented carbide products. The control of total carbon content in the production of cemented carbide is of great importance, and the focus of carbon control is the production of the mixture. The research results of W-C-Co phase diagram of cemented carbide show that the carbon content has upper and lower limits, the theoretical carbon content in WC is 6.123%, the lower limit of carbon content is related to the content of metal Co, and the upper limit of carbon is mainly related to the total carbon in the raw material WC, the amount of forming agent and the degreasing process. At present, most of the domestic manufacturers that produce cemented carbide mixture by paraffin forming process use wet milling process, and industrial alcohol is used as the wet milling medium. Because the solubility of the forming agent paraffin in alcohol is extremely small (almost insoluble), the amount of paraffin in molecular state around the surface of the cemented carbide mixture particles is very small (almost zero). At the same time, because the paraffin added in the actual production process is in the form of block or macroscopic particle, the contact between paraffin and cemented carbide mixture particles is mainly realized through mutual collision in the ball milling process. However, because the density of paraffin is much smaller than that of cemented carbide mixture, most of the paraffin floats on the surface of the ball milling container, which further reduces the opportunity of mutual contact between the block or macroscopic paraffin particles and the cemented carbide mixture particles, that is, the probability of mutual collision is reduced, and thus the possibility of forming effective coating of paraffin on the surface of cemented carbide particles is also very low. In the actual production process, in order to achieve the purpose of good forming of subsequent cemented carbide particles and meet the actual coating requirements, it is obvious that only a large amount of excess block or macroscopic solid paraffin can achieve the purpose. In the present application, on the one hand, by changing the wet milling medium (the solvent in the present application), the solubility of paraffin (in molecular state) is increased, and on this basis, by adding the effects of cosolvent and dispersion stabilizer and interfacial treatment agent, not only the solubility of paraffin (in molecular state) is further increased, but also the adhesion between paraffin molecules and the surface of cemented carbide particles is improved, thereby significantly improving the contact ability between paraffin molecules and cemented carbide and the internal driving force of the alloy surface being coated; on the other hand, because the block or macroscopic solid paraffin has been dispersed into micro / nano particles, the probability of mutual collision between the particles and the cemented carbide mixture in the ball milling process is also significantly increased, thereby coating the surface of the cemented carbide mixture. Compared with the original process of directly adding block or similar powder solid paraffin forming agent, in the case of coating the same amount of cemented carbide particles, the amount of paraffin required will be significantly reduced. The existing experimental results show that the amount of forming agent provided by the present application can be reduced by 50-70%, which significantly reduces the residual amount of carbon in the subsequent degreasing process, thereby facilitating the control of total carbon content in the production of cemented carbide products.

[0039] 3. The molding agent provided by the present application is beneficial to improve the uniformity of the particle size of the mixture and the stability of the appearance. In order to meet the molding requirements of the subsequent cemented carbide product, the process performance index requirements of the mixture are proposed in the actual application process. In addition to strictly producing according to the spray drying process parameters and operation standards, one of the important influencing factors is the slurry state, which includes slurry viscosity, surface tension, slurry composition, gas content in the slurry, slurry temperature, etc. In the case of the same ball milling amount of the mixture and the fixed liquid-solid ratio, the use of the paraffin molding agent prepared by the present application reduces the amount of paraffin, reduces the viscosity of the slurry, improves the flowability, and makes the uniformity and effect of the particle surface coating better. The number of large particles is significantly reduced, and the amount of residue on the screen is significantly reduced during sieving, so that the prepared slurry after spray drying has better particle formation, improved uniformity, and improved hardness. The prepared particles are round and smooth, and the stability is improved (see the TGA test comparison results of the mixture prepared by the paraffin suspension liquid molding agent prepared by the present application and the mixture prepared by a certain listed company using block paraffin as a molding agent in the following table). Figure 3 )。

[0040] 4. The molding agent provided by the present application can shorten the degreasing time of the green body, improve the production efficiency of the cemented carbide product, and expand the production capacity. Degreasing is an important process or procedure for producing cemented carbide products, which aims to remove the molding agent completely without defects and deformation, and ensure that the chemical composition of the degreased green body is controlled within the permitted range, so as not to affect the quality or quality of the subsequent sintered product. Since the amount of paraffin molding agent in the present application is reduced by 50-70%, the amount of paraffin coated on the surface of the mixture is correspondingly reduced by 50-70%. At the current degreasing temperature of 450-500℃, the degreasing time can be shortened by 1-2 hours, thereby achieving the purpose of improving the production efficiency of the cemented carbide product and expanding the production capacity.

[0041] 5. The molding agent provided by the present application can reduce energy consumption and carbon emissions. Since the use of the paraffin molding agent provided by the present application can reduce the amount of paraffin by 50-80% and the amount of degreasing, the degreasing time is correspondingly shortened, thereby reducing energy consumption; at the same time, the amount of CO2 emitted by the decomposition of high-temperature paraffin is correspondingly reduced. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 The results of the particle size and distribution of the paraffin suspension liquid molding agent prepared in Example 1 are shown (laser particle size analyzer detection). As shown in the following table, Figure 1 It can be seen that the D50 of the paraffin particles in the paraffin suspension liquid molding agent prepared in Example 1 is 580μm.

[0043] Figure 2 The TGA test comparison results of the mixture prepared by the paraffin suspension liquid molding agent prepared in Example 1 after spray drying and the sample obtained by a certain listed company using block paraffin as a molding agent are shown. As shown in the following table, Figure 2It can be seen that the paraffin is substantially removed at a temperature of about 278°C, at which time the sample prepared using the paraffin suspension forming agent of the present application has a thermal weight loss rate of about 1.1%, while the sample prepared using the paraffin suspension forming agent provided by the certain company has a thermal weight loss rate of about 2.7%. Since the lost part is paraffin, the effective reduction of the weight ratio of paraffin is about 60%.

[0044] Figure 3 A metallographic photograph of the mixture prepared using the paraffin suspension forming agent prepared in Example 1 after spray drying is shown.

[0045] Figure 4 The results of the size and distribution of paraffin particles in the paraffin suspension forming agent prepared in Example 2 are shown. It can be seen that the D50 of the paraffin particles in the paraffin suspension forming agent prepared in Example 2 is 114 μm. Figure 4

[0046] Figure 5 The results of the size and distribution of paraffin particles in the paraffin suspension forming agent prepared in Example 3 are shown. It can be seen that the D50 of the paraffin particles in the paraffin suspension forming agent prepared in Example 3 is 398 μm. Figure 5

[0047] Figure 6 The results of the size and distribution of paraffin particles in the paraffin suspension forming agent prepared in Example 4 are shown. It can be seen that the D50 of the paraffin particles in the paraffin suspension forming agent prepared in Example 4 is 117 μm. Figure 6

[0048] Figure 7 The results of the size and distribution of paraffin particles in the paraffin suspension forming agent prepared in Example 5 are shown. It can be seen that the D50 of the paraffin particles in the paraffin suspension forming agent prepared in Example 5 is 109 μm. Figure 7

[0049] Figure 8 The results of the size and distribution of paraffin particles in the paraffin suspension forming agent prepared in Example 6 are shown. It can be seen that the D50 of the paraffin particles in the paraffin suspension forming agent prepared in Example 6 is 113 μm. Figure 8

[0050] Figure 9 The results of the size and distribution of paraffin particles in the paraffin suspension forming agent prepared in Example 7 are shown. It can be seen that the D50 of the paraffin particles in the paraffin suspension forming agent prepared in Example 7 is 107 μm. Figure 9 ​​​​​​

[0051] Figure 10 The results of the particle size and distribution of the paraffin in the paraffin suspension molding agent prepared in Example 8 are shown (laser particle size analyzer). From the results, it is known that the D50 of the paraffin particles in the paraffin suspension molding agent prepared in Example 8 is 85 μm. Figure 10

[0052] Figure 11 The results of the particle size and distribution of the paraffin in the paraffin suspension molding agent prepared in Example 9 are shown (laser particle size analyzer). From the results, it is known that the D50 of the paraffin particles in the paraffin suspension molding agent prepared in Example 9 is 0.47 μm. Figure 11

[0053] Figure 12 The results of the particle size and distribution of the paraffin in the paraffin suspension molding agent prepared in Example 10 are shown (laser particle size analyzer). From the results, it is known that the D50 of the paraffin particles in the paraffin suspension molding agent prepared in Example 10 is 9 μm. Figure 12

[0054] Figure 13 The results of the particle size and distribution of the paraffin in the paraffin suspension molding agent prepared in Example 11 are shown (laser particle size analyzer). From the results, it is known that the D50 of the paraffin particles in the paraffin suspension molding agent prepared in Example 11 is 45 μm. Figure 13

[0055] Figure 14 The results of the particle size and distribution of the paraffin in the paraffin suspension molding agent prepared in Example 12 are shown (laser particle size analyzer). From the results, it is known that the D50 of the paraffin particles in the paraffin suspension molding agent prepared in Example 12 is 27 μm. Figure 14

[0056] Figure 15 The results of the particle size and distribution of the paraffin in the paraffin suspension molding agent prepared in Example 13 are shown (laser particle size analyzer). From the results, it is known that the D50 of the paraffin particles in the paraffin suspension molding agent prepared in Example 13 is 4.6 μm. Figure 15

[0057] Figure 16 The results of the particle size and distribution of the paraffin in the paraffin suspension molding agent prepared in Example 14 are shown (laser particle size analyzer). From the results, it is known that the D50 of the paraffin particles in the paraffin suspension molding agent prepared in Example 14 is 4.7 μm. Figure 16

[0058] Figure 17 ​​​​​​​The results of the particle size and distribution of the paraffin in the paraffin suspension forming agent prepared in Example 15 are shown (laser particle size analyzer detection). It can be seen that the D50 of the paraffin particles in the paraffin suspension forming agent prepared in Example 15 is 2.2 μm. Figure 17 The results of the particle size and distribution of the paraffin in the paraffin suspension forming agent prepared in Example 15 are shown (laser particle size analyzer detection). It can be seen that the D50 of the paraffin particles in the paraffin suspension forming agent prepared in Example 15 is 2.2 μm. DETAILED DESCRIPTION

[0059] The present application is further described below in conjunction with specific examples. In the present application, 1 mass part corresponds to 1 kg; 1 volume part corresponds to 1 L.

[0060] Example 1

[0061] The paraffin suspension forming agent was prepared from the following components in the indicated mass or volume parts:

[0062] 52# paraffin 0.5 parts (mass parts) ;

[0063] wet grinding medium: propanol 100 parts (volume parts) ;

[0064] dispersion stabilizer PEG-1500 0.01 parts (mass parts).

[0065] The paraffin suspension forming agent was prepared from the following components in the indicated mass or volume parts:

[0066] S1 100 parts (volume parts) of the wet grinding medium were added to the reaction kettle, stirred and heated, and the solution temperature was heated to about 65°C;

[0067] S2 0.5 parts (mass parts) of 52# paraffin and 0.01 parts (mass parts) of PEG-1500 were added to the reaction kettle under heat preservation, and stirred and mixed uniformly to form a colorless uniform transparent liquid phase system;

[0068] S3 heating was stopped, and the liquid phase system was cooled, and a small amount of white flocculent substance appeared at about 55°C, at which time a high-speed shearing emulsifier was used to stir the system liquid phase until room temperature,

[0069] S4 the liquid phase product was poured out from the reaction kettle, and the product was a white suspension, which was the target product.

[0070] Example 2

[0071] The paraffin suspension forming agent was prepared from the following components in the indicated mass or volume parts:

[0072] 60# paraffin 1 part (mass parts) ;

[0073] wet grinding medium: isopropanol 100 parts (volume parts) ;

[0074] dispersion stabilizer K-30 0.05 parts (mass parts).

[0075] The preparation method of the paraffin suspension forming agent is as follows:

[0076] S1, 100 parts (volume parts) of wet grinding medium are added into a reaction kettle, stirred and heated, and the solution temperature is heated to about 65℃;

[0077] S2, 1 part (mass parts) of 60# paraffin and 0.05 parts (mass parts) of K-30 are added into the reaction kettle under insulation, and stirred and uniformly mixed to form a colorless, uniform and transparent liquid phase system;

[0078] S3, the heating is stopped, and the liquid phase system is cooled, and a small amount of white flocculent substance begins to appear at about 55℃, at this time, the high-speed shearing emulsifier is used to stir the liquid phase system until room temperature,

[0079] S4, the liquid phase product is poured out from the reaction kettle, and the product is a white suspension, which is the target product.

[0080] Example 3

[0081] The paraffin suspension forming agent is prepared from the following components in the following mass or volume parts:

[0082] 56# paraffin 1.5 parts (mass parts);

[0083] Wet grinding medium: mixed propyl alcohol 100 parts (volume parts);

[0084] Dispersing stabilizer PEG-800 0.1 parts (mass parts).

[0085] The above-mentioned mixed propyl alcohol is composed of propyl alcohol and isopropyl alcohol in a volume ratio of 1:1.

[0086] The preparation method of the paraffin suspension forming agent is as follows:

[0087] S1, 100 parts (volume parts) of wet grinding medium are added into a reaction kettle, stirred and heated, and the solution temperature is heated to about 65℃;

[0088] S2, 1.5 parts (mass parts) of paraffin and 0.1 parts (mass parts) of PEG-800 are added into the reaction kettle under insulation, and stirred and uniformly mixed to form a colorless, uniform and transparent liquid phase system;

[0089] S3, the heating is stopped, and the liquid phase system is cooled, and a small amount of white flocculent substance begins to appear at about 55℃, at this time, the high-speed shearing emulsifier is used to stir the liquid phase system until room temperature,

[0090] S4, the liquid phase product is poured out from the reaction kettle, and the product is a white suspension, which is the target product.

[0091] Example 4

[0092] The paraffin suspension forming agent is prepared from the following components in the following mass or volume fractions:

[0093] Paraffin: mixed paraffin 2 parts (mass parts);

[0094] Wet grinding medium: mixed alcohol 100 parts (volume parts);

[0095] Dispersing stabilizer: mixed dispersing stabilizer 0.5 parts (mass parts).

[0096] The mixed paraffin is composed of 50# paraffin and 60# paraffin in a mass ratio of 3:7; the mixed alcohol is composed of isopropyl alcohol and sec-butyl alcohol in a volume ratio of 9:1; and the mixed dispersing stabilizer is composed of K30 and PEG1500 in a mass ratio of 1:1.

[0097] The preparation method of the paraffin suspension forming agent is as follows:

[0098] S1: 100 parts (volume parts) of wet grinding medium are added to a reaction kettle, heated and stirred, and the solution temperature is heated to about 65°C;

[0099] S2: 2 parts (mass parts) of mixed paraffin and 0.5 parts (mass parts) of mixed dispersing stabilizer are added to the reaction kettle under heat preservation, and stirred and mixed uniformly to form a colorless and uniform transparent liquid phase system;

[0100] S3: heating is stopped, and the liquid phase system is cooled, and a small amount of white flocculent substance appears at about 55°C, at which time a high-speed shearing emulsifier is used to stir the system liquid phase until room temperature,

[0101] S4: the liquid phase product is poured out from the reaction kettle, which is a white suspension, i.e. the target product.

[0102] Example 5

[0103] The paraffin suspension forming agent is prepared from the following components in the following mass or volume fractions:

[0104] Paraffin: mixed paraffin 3 parts (mass parts);

[0105] Wet grinding medium: mixed alcohol 100 parts (volume parts);

[0106] Dispersing stabilizer PEG-2000 1 part (mass parts).

[0107] The mixed paraffin is composed of 54# paraffin and 56# paraffin in a mass ratio of 1:1; and the wet grinding medium mixed alcohol is composed of propanol and tert-butyl alcohol in a volume ratio of 7:3.

[0108] The preparation method of the paraffin suspension forming agent is as follows:

[0109] S1 add 100 parts (volume parts) of wet grinding medium to the reaction kettle, heat, stir, heat the solution temperature to about 65℃;

[0110] S2 add 3 parts (mass parts) of mixed paraffin wax, 1 part (mass parts) of PEG-2000 to the reaction kettle under insulation, mix uniformly under stirring to form a colorless uniform transparent liquid phase system;

[0111] S3 stop heating, cool the liquid phase system, a small amount of white flocculent appears at about 55℃, at this time, use a high-speed shearing emulsifier to stir the system liquid phase until room temperature;

[0112] S4 pour the liquid phase product from the reaction kettle, which is a white suspension, that is, the target product.

[0113] Example 6

[0114] The paraffin wax suspension forming agent is prepared from the following components in the following mass or volume parts:

[0115] Paraffin wax: mixed paraffin wax 4 parts (mass parts);

[0116] Wet grinding medium: mixed alcohol 100 parts (volume parts);

[0117] Dispersing stabilizer: mixture 1 part (mass parts).

[0118] The above-mentioned mixed paraffin wax is composed of 56# paraffin wax and 60# paraffin wax in a mass ratio of 1:1; the wet grinding medium mixed alcohol is composed of isopropyl alcohol and 3-pentanol in a volume ratio of 8:2; the dispersing stabilizer mixture is composed of K-15 and PEG-600 in a mass ratio of 1:1.

[0119] The preparation method of the paraffin wax suspension forming agent is as follows:

[0120] S1 add 100 parts (volume parts) of wet grinding medium to the reaction kettle, heat, stir, heat the solution temperature to about 65℃;

[0121] S2 add 4 parts (mass parts) of mixed paraffin wax, 0.5 parts (mass parts) of dispersing stabilizer mixture to the reaction kettle under insulation, mix uniformly under stirring to form a colorless uniform transparent liquid phase system;

[0122] S3 stop heating, cool the liquid phase system, a small amount of white flocculent appears at about 55℃, at this time, use a high-speed shearing emulsifier to stir the system liquid phase until room temperature;

[0123] S4 pour the liquid phase product from the reaction kettle, which is a white suspension, that is, the target product.

[0124] Example 7

[0125] The paraffin suspension forming agent is prepared from the following components in the following mass or volume fractions:

[0126] Paraffin: mixed paraffin 6 parts (mass parts);

[0127] Wet grinding medium: mixed alcohol 100 (volume parts);

[0128] Dispersing stabilizer PEG-1500 0.5 (mass parts).

[0129] The mixed paraffin is composed of 56# paraffin and 58# paraffin in a mass ratio of 6:4; and the ball grinding medium mixed alcohol is composed of propanol and isopropanol in a volume ratio of 3:7.

[0130] The preparation method of the paraffin suspension forming agent is as follows:

[0131] S1: 100 parts (volume parts) of wet grinding medium mixed alcohol are added to a reaction kettle, heated, stirred, and the solution temperature is heated to about 65°C;

[0132] S2: 6 parts (mass parts) of mixed paraffin and 0.5 parts (mass parts) of PEG-1500 are added to the reaction kettle under heat preservation, stirred and uniformly mixed to form a colorless and uniform transparent liquid phase system;

[0133] S3: stop heating, cool the liquid phase system, and a small amount of white flocculent substance appears at about 55°C, at this time, a high-speed shearing emulsifier is used to stir the system liquid phase until room temperature;

[0134] S4: the white suspension liquid is poured out from the reaction kettle, which is the target product.

[0135] Example 8

[0136] The paraffin suspension forming agent is prepared from the following components in the following mass or volume fractions:

[0137] Paraffin: mixed paraffin 10 parts (mass parts);

[0138] Wet grinding medium: mixed alcohol 100 (volume parts);

[0139] Dispersing stabilizer PEI-20000 0.3 (mass parts).

[0140] The mixed paraffin is composed of 56# paraffin and 58# paraffin in a mass ratio of 6:4; and the ball grinding medium mixed alcohol is composed of propanol and isopropanol in a volume ratio of 3:7.

[0141] The preparation method of the paraffin suspension forming agent is as follows:

[0142] S1 add 100 parts (volume parts) of wet grinding medium mixed alcohol to the reaction kettle, heat, stir, heat the solution temperature to about 65℃;

[0143] S2 add 10 parts (mass parts) of mixed paraffin wax, 0.3 parts (mass parts) of PEI-20000 to the reaction kettle under insulation, mix uniformly under stirring, form a colorless uniform transparent liquid phase system;

[0144] S3 stop heating, cool the liquid phase system, a small amount of white flocculent appears at about 55℃, at this time, use a high-speed shearing emulsifier to stir the system liquid phase until room temperature;

[0145] S4 pour out the white suspension liquid from the reaction kettle, which is the target product.

[0146] Example 9

[0147] The paraffin wax suspension forming agent is prepared from the following components in the following mass or volume parts:

[0148] Paraffin wax: mixed paraffin wax 16 parts (mass parts);

[0149] Wet grinding medium: mixed alcohol 100 (volume parts);

[0150] Dispersing stabilizer PEI-30000 0.4 (mass parts).

[0151] The above-mentioned mixed paraffin wax is composed of 56# paraffin wax and 58# paraffin wax in a mass ratio of 6:4; the ball mill medium mixed alcohol is composed of propanol and isopropyl alcohol in a volume ratio of 3:7.

[0152] The preparation method of the paraffin wax suspension forming agent is as follows:

[0153] S1 add 100 parts (volume parts) of wet grinding medium mixed alcohol to the reaction kettle, heat, stir, heat the solution temperature to about 65℃;

[0154] S2 add 10 parts (mass parts) of mixed paraffin wax, 0.3 parts (mass parts) of PEI-20000 to the reaction kettle under insulation, mix uniformly under stirring, form a colorless uniform transparent liquid phase system;

[0155] S3 stop heating, cool the liquid phase system, a small amount of white flocculent appears at about 55℃, at this time, use a high-speed shearing emulsifier to stir the system liquid phase until room temperature;

[0156] S4 pour out the white suspension liquid from the reaction kettle, which is the target product.

[0157] Example 10

[0158] The paraffin wax suspension forming agent is prepared from the following components in the following mass or volume parts:

[0159] Paraffin wax: mixed paraffin wax 8 parts (mass parts) ;

[0160] Wet grinding medium: mixed alcohol 100 (volume parts) ;

[0161] Dispersing stabilizer PEI-30000 0.4 (mass parts).

[0162] The above-mentioned mixed paraffin wax is composed of 56# paraffin wax and 58# paraffin wax in a mass ratio of 6:4; the ball milling medium mixed alcohol is composed of propanol and tert-butanol in a volume ratio of 3:7.

[0163] The preparation method of the paraffin wax suspension forming agent is as follows:

[0164] S1 add 100 parts (volume parts) of wet grinding medium mixed alcohol to the reaction kettle, heat, stir, and heat the solution temperature to about 65℃;

[0165] S2 add 8 parts (mass parts) of mixed paraffin wax and 0.4 parts (mass parts) of PEI-30000 to the reaction kettle under heat preservation, mix uniformly under stirring, and form a colorless and uniform transparent liquid phase system;

[0166] S3 stop heating, cool the liquid phase system, and a small amount of white flocculent substance begins to appear at about 55℃, at this time, use a high-speed shearing emulsifier to stir the system liquid phase until room temperature;

[0167] S4 pour out the white suspension liquid from the reaction kettle, which is the target product.

[0168] Example 11

[0169] The paraffin wax suspension forming agent is prepared from the following components in the following mass or volume parts:

[0170] Paraffin wax: mixed paraffin wax 7 parts (mass parts) ;

[0171] Wet grinding medium: mixed alcohol 100 (volume parts) ;

[0172] Dispersing stabilizer PEI-30000 0.4 (mass parts).

[0173] The above-mentioned mixed paraffin wax is composed of 56# paraffin wax and 58# paraffin wax in a mass ratio of 6:4; the ball milling medium mixed alcohol is composed of propanol and tert-butanol in a volume ratio of 3:7.

[0174] The preparation method of the paraffin wax suspension forming agent is as follows:

[0175] S1 add 100 parts (volume parts) of wet grinding medium mixed alcohol to the reaction kettle, heat, stir, and heat the solution temperature to about 65℃;

[0176] S2, under the condition of keeping warm, 7 parts (mass parts) of mixed paraffin and 0.4 parts (mass parts) of PEI-30000 are added into the reaction kettle, and are mixed uniformly under stirring to form a colorless, uniform and transparent liquid phase system;

[0177] S3, the heating is stopped, and the liquid phase system is cooled; a small amount of white flocculent substance begins to appear at about 55℃; at this time, the liquid phase system is stirred by using a high-speed shearing emulsifier until the room temperature is reached;

[0178] S4, the white suspension liquid is poured out from the reaction kettle, and is the target product.

[0179] Example 12

[0180] The paraffin suspension liquid forming agent is prepared by using the following components in the following mass or volume parts:

[0181] Paraffin: mixed paraffin 9 parts (mass parts);

[0182] Wet grinding medium: mixed alcohol 100 (volume parts);

[0183] Dispersing stabilizer PEI-30000 0.4 (mass parts).

[0184] The mixed paraffin is composed of 56# paraffin and 58# paraffin in a mass ratio of 6:4; and the ball milling medium mixed alcohol is composed of propanol and 3-pentanol in a volume ratio of 3:7.

[0185] The preparation method of the paraffin suspension liquid forming agent is as follows:

[0186] S1, 100 parts (volume parts) of wet grinding medium mixed alcohol are added into the reaction kettle, heating and stirring are performed, and the solution temperature is heated to about 65℃;

[0187] S2, under the condition of keeping warm, 9 parts (mass parts) of mixed paraffin and 0.4 parts (mass parts) of PEI-30000 are added into the reaction kettle, and are mixed uniformly under stirring to form a colorless, uniform and transparent liquid phase system;

[0188] S3, the heating is stopped, and the liquid phase system is cooled; a small amount of white flocculent substance begins to appear at about 55℃; at this time, the liquid phase system is stirred by using a high-speed shearing emulsifier until the room temperature is reached;

[0189] S4, the white suspension liquid is poured out from the reaction kettle, and is the target product.

[0190] Example 13

[0191] The paraffin suspension liquid forming agent is prepared by using the following components in the following mass or volume parts:

[0192] Paraffin: mixed paraffin 8 parts (mass parts);

[0193] Wet grinding medium: mixed alcohol 100 (volume parts) ;

[0194] Dispersing stabilizer PEI-30000 0.4 (mass parts).

[0195] The mixed paraffin wax is composed of 56# paraffin wax and 58# paraffin wax in a mass ratio of 6:4; and the ball milling medium mixed alcohol is composed of propanol and isopropyl alcohol in a volume ratio of 2:8.

[0196] The preparation method of the paraffin wax suspension forming agent is as follows:

[0197] S1, 100 parts (volume parts) of wet grinding medium mixed alcohol are added to a reaction kettle, heated, stirred, and the solution temperature is heated to about 65°C;

[0198] S2, 8 parts (mass parts) of mixed paraffin wax and 0.4 parts (mass parts) of PEI-30000 are added to the reaction kettle under heat preservation, stirred and uniformly mixed to form a colorless, uniform and transparent liquid phase system;

[0199] S3, the heating is stopped, and the liquid phase system is cooled, and a small amount of white flocculent substance begins to appear at about 55°C, at this time, a high-speed shearing emulsifier is used to stir the liquid phase system until room temperature;

[0200] S4, the white suspension liquid is poured out of the reaction kettle, which is the target product.

[0201] Example 13

[0202] The paraffin wax suspension forming agent is prepared from the following components in the following mass or volume parts:

[0203] Paraffin wax: mixed paraffin wax 7 parts (mass parts) ;

[0204] Wet grinding medium: mixed alcohol 100 (volume parts) ;

[0205] Dispersing stabilizer PEI-30000 0.4 (mass parts).

[0206] The mixed paraffin wax is composed of 56# paraffin wax and 58# paraffin wax in a mass ratio of 6:4; and the ball milling medium mixed alcohol is composed of propanol and isopropyl alcohol in a volume ratio of 4:6.

[0207] The preparation method of the paraffin wax suspension forming agent is as follows:

[0208] S1, 100 parts (volume parts) of wet grinding medium mixed alcohol are added to a reaction kettle, heated, stirred, and the solution temperature is heated to about 65°C;

[0209] S2, 8 parts (mass parts) of mixed paraffin wax and 0.4 parts (mass parts) of PEI-30000 are added to the reaction kettle under heat preservation, stirred and uniformly mixed to form a colorless, uniform and transparent liquid phase system;

[0210] S3 stop heating, cool the liquid phase system, a small amount of white flocculent appears at about 55℃, at this time, the high-speed shearing emulsifier is used to stir the liquid phase system until room temperature;

[0211] S4 pour the white suspension liquid from the reaction kettle, which is the target product.

[0212] Example 14

[0213] The paraffin suspension liquid forming agent is prepared from the following components in the following mass or volume fractions:

[0214] Paraffin: mixed paraffin 8 parts (mass parts);

[0215] Wet grinding medium: mixed alcohol 100 (volume parts);

[0216] Dispersing stabilizer PEI-30000 0.5 (mass parts).

[0217] The mixed paraffin is composed of 56# paraffin and 58# paraffin in a mass ratio of 6:4; the ball milling medium mixed alcohol is composed of propanol and isopropanol in a volume ratio of 3:7.

[0218] The preparation method of the paraffin suspension liquid forming agent is as follows:

[0219] S1 add 100 parts (volume parts) of wet grinding medium mixed alcohol to the reaction kettle, heat and stir, and heat the solution temperature to about 65℃;

[0220] S2 add 8 parts (mass parts) of mixed paraffin and 0.5 parts (mass parts) of PEI-30000 to the reaction kettle under heat preservation, mix uniformly under stirring, and form a colorless and uniform transparent liquid phase system;

[0221] S3 stop heating, cool the liquid phase system, a small amount of white flocculent appears at about 55℃, at this time, the high-speed shearing emulsifier is used to stir the liquid phase system until room temperature;

[0222] S4 pour the white suspension liquid from the reaction kettle, which is the target product.

[0223] Example 15

[0224] The paraffin suspension liquid forming agent is prepared from the following components in the following mass or volume fractions:

[0225] Paraffin: mixed paraffin 6 parts (mass parts);

[0226] Wet grinding medium: mixed alcohol 100 (volume parts);

[0227] Dispersing stabilizer PEI-30000 0.3 (mass parts).

[0228] The mixed paraffin wax is composed of 56# paraffin wax and 58# paraffin wax in a mass ratio of 6:4; the ball-milling medium mixed alcohol is composed of propanol and isopropanol in a volume ratio of 3:7.

[0229] The preparation method of the paraffin wax suspension forming agent is as follows:

[0230] S1, 100 parts (volume parts) of wet-milling medium mixed alcohol are added into a reaction kettle, heated, stirred, and the solution temperature is heated to about 65°C;

[0231] S2, 6 parts (mass parts) of mixed paraffin wax and 0.3 parts (mass parts) of PEI-30000 are added into the reaction kettle under heat preservation, stirred and uniformly mixed to form a colorless and uniform transparent liquid phase system;

[0232] S3, the heating is stopped, and the liquid phase system is cooled, and a small amount of white flocculent substance appears at about 55°C, at this time, a high-speed shearing emulsifier is used to stir the liquid phase system until room temperature;

[0233] S4, the white suspension is poured out from the reaction kettle, which is the target product.

[0234] As can be seen from Examples 9-15, the forming agent prepared by the formula of Example 9 is a white suspension with very small particle size close to emulsion, and thus it can be seen that PEI-30000 can greatly improve the solubility of paraffin wax in the mixed alcohol composed of propanol and isopropanol, and ultimately reduce the particle size of paraffin wax.

[0235] The forming agent prepared by the above examples is added into an industrial liquid-phase ball mill cylinder at a proportion of 1.5% of the mass of the mixed material, and ball-milled for 48 hours, and after the slurry is sieved through a 325 mesh screen, the slurry is spray dried to obtain paraffin forming agent coated mixed material particles, which are molded to form standard bending performance test bars, 33 bars for each example, and the test results are the average values. The bending strength test results of the cemented carbide mixed material samples prepared according to the above examples are shown in Table 1.

[0236] Table 1 Bending strength test results of cemented carbide mixed material samples prepared by the above examples

[0237]

[0238]

[0239] As can be seen from the above table, the forming agent prepared in Example 9 can greatly increase the bending strength of the cemented carbide mixture sample. This is because the D50 of the forming agent prepared in Example 9 is 0.47 microns, which is a sub-micron suspension, so it can make the coating uniformity and coating effect of paraffin on the surface of the cemented carbide mixture powder particles optimal. Examples 9-15 show that PEI can increase the solubility of paraffin in alcohol. Unexpectedly, Example 9 also prepared a sub-micron suspension.

[0240] As a comparison, paraffin was added to an industrial liquid-phase ball mill cylinder in a proportion of 4% by mass, and ethanol was used as the ball mill medium to mill for 48 hours. After the slurry was sieved through a 325-mesh sieve, the obtained slurry was spray dried to obtain mixture particles coated with paraffin forming agent, and standard bending performance test samples were prepared after molding. Each example had 33 samples, and the test results were the average values. The bending strength detection result of the cemented carbide mixture sample prepared by the above method was 48.2 MPa.

Claims

1. A paraffin suspension forming agent, characterized in that: the paraffin suspension forming agent comprises 0.5-6 parts by weight of paraffin and 0.01-1 parts by weight of a dispersion stabilizer; and 100 parts by volume of a C3-C5 alcohol; the dispersion stabilizer is dissolved in the C3-C5 alcohol to form a liquid phase of the paraffin suspension forming agent; the paraffin exists in the liquid phase in the form of nano- and / or micro-sized paraffin particles and paraffin molecules; the paraffin suspension forming agent is used for the forming of green compacts of cemented carbide; and the paraffin suspension forming agent is prepared by the following steps: dissolving the paraffin and the dispersion stabilizer in the C3-C5 alcohol heated to a temperature, to obtain a liquid phase system; and reducing the temperature of the liquid phase system, and stirring or shearing the liquid phase system at a high speed when the paraffin begins to precipitate, until the liquid phase cools to room temperature.

2. The paraffin suspension forming agent according to claim 1, characterized in that: the C3-C5 alcohol comprises at least one of propanol, isopropanol, sec-butanol, 3-pentanol or tert-butanol; the dispersion stabilizer comprises at least one of polyethyleneimine, PEG, oleic acid or PVP; the PEG comprises PEG-800, PEG1000, PEG1500, PEG2000, PEG4000 or PEG6000; the PVP comprises K15, K17, K25, K30 or K90; and the polyethyleneimine comprises PEI-20000 or PEI-30000.

5. The paraffin suspension forming agent according to claim 2, characterized in that: the C3-C5 alcohol comprises isopropanol and sec-butanol; or the C3-C5 alcohol comprises propanol and tert-butanol; or the C3-C5 alcohol comprises isopropanol and 3-pentanol; or the C3-C5 alcohol comprises propanol and isopropanol; the volume ratio of the isopropanol and the sec-butanol is 9:1; the volume ratio of the propanol and the tert-butanol is 7:3; the volume ratio of the isopropanol and the 3-pentanol is 8:2 or 9:1; and the volume ratio of the propanol and the isopropanol is 3:

7.

6. The paraffin suspension forming agent according to claim 4, characterized in that: the paraffin particles are one selected from 52# paraffin, 54# paraffin, 56# paraffin, 58# paraffin or 60# paraffin; or the paraffin particles are paraffin particles formed by mixing two or more of 52# paraffin, 54# paraffin, 56# paraffin, 58# paraffin or 60# paraffin in any ratio.

7. A method for preparing the paraffin suspension forming agent according to claim 1, comprising the following steps: dissolving the paraffin and the dispersion stabilizer in the C3-C5 alcohol heated to a temperature, to obtain a liquid phase system; and reducing the temperature of the liquid phase system, and stirring or shearing the liquid phase system at a high speed when the paraffin begins to precipitate, until the liquid phase cools to room temperature.

8. The method for preparing the paraffin suspension forming agent according to claim 7, characterized in that: the step of dissolving the paraffin and the dispersion stabilizer in the C3-C5 alcohol heated to a temperature, to obtain a liquid phase system, comprises the step of dissolving the paraffin and the dispersion stabilizer in the C3-C5 alcohol heated to 60-70°C, to obtain a liquid phase system.

9. The method for preparing the paraffin suspension forming agent according to claim 7, characterized in that: ​ ​ ​ ​ 3. The paraffin suspension forming agent of claim 1, wherein: ​ 4. The paraffin suspension forming agent of claim 3, wherein: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 7. The method for preparing the paraffin suspension forming agent as described in claim 1, characterized in that, ​ ​ ​ ​ ​ ​ comprising the step of reducing the temperature of the liquid phase system to 50-56°C, and subjecting the liquid phase system to high speed agitation or shear until the liquid phase cools to room temperature as the paraffin wax begins to precipitate.

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