A method for measuring the dispersion degree of powder materials

Abstract

The present invention discloses a method for measuring the dispersion degree of powder materials, which is characterized in that: a dispersion liquid is prepared from the powder materials as the medium for buoyancy measurement, the buoyancy change of the float in the medium is measured, the dispersion force of the dispersion liquid medium is calculated, and the dispersion degree of the powder materials is obtained. The technical solution of the present invention can be applied to the measurement of the dispersion degree of powder materials, including titanium dioxide, clay, kaolin, calcium carbonate, diatomite, silicon dioxide, carbon black, white carbon black, etc. The measurement device has a low cost, the measurement method is simple, the measurement accuracy is high, and continuous and uninterrupted measurement can be achieved to obtain the continuous change value of the dispersion degree of the powder materials over time. The dispersion degree values of the powder materials at different positions in the dispersion system can also be measured simultaneously.

Description

Technical Field

[0001] The present invention relates to a technology for measuring the dispersion degree of powder materials, in particular to a method for measuring the dispersion degree of powder materials. Background Art

[0002] Dispersibility generally refers to the property that solid particles or droplets can be dispersed into fine particles and suspended in a dispersion medium such as water or other homogeneous liquid media without flocculation or precipitation. The degree to which a substance is dispersed in the dispersion medium without flocculation or precipitation is represented by a numerical value called the dispersion degree. The degree of dispersion of a substance affects the manifestation of some physical and chemical properties of the substance, and the degree of dispersion of a substance is directly related to the properties of the substance, the surface area, the surface structure of the particles, and the use of additives. Therefore, the dispersion performance and dispersion degree are important parameters reflecting the properties of a substance. For example, titanium dioxide, as a widely used powder material, its dispersion performance in aqueous and non-aqueous media is also one of the important indicators for evaluating its quality. When the dispersion performance of titanium dioxide in coatings is poor, it will affect the performance of high whiteness and high hiding power of titanium dioxide, and even seriously lead to the presence of particles and precipitation in the coatings. Therefore, by various control means, improving the dispersibility of powder materials is beneficial to both powder material manufacturers and downstream industries for quality control.

[0003] Of course, to control and improve the dispersion performance of powder materials, the problem of how to measure the dispersion degree must be solved first. However, at present, there is less research on the dispersion performance of powder materials at home and abroad, and there is also little research on the measurement methods of dispersion degree, so there is great room for improvement. With the fierce competition in the domestic powder material market, customers have higher and higher requirements for the application performance indicators of powder materials. Therefore, it is of great significance for powder material enterprises to quickly and accurately detect the water dispersibility of titanium dioxide. At present, the measurement methods for the dispersion degree including the dispersibility of powder materials mainly include the following categories: One is the pipetting method, that is, quantitatively extracting liquid from a specific area in a dispersion system at a specific time, and then calculating the mass of the dispersed substance (such as titanium dioxide) contained in the liquid. For example, the content of the dispersed substance can be obtained by the drying method; the second is the photometric method: sampling (or directly measuring) the dispersion system at a certain time and a certain position for photometric measurement (such as turbidity, transmittance, etc.); in addition, there are also microscopic observation methods, scraping fineness meter methods, etc. For the above measurement methods, such as the pipetting method, the taken-out liquid needs to be dried, so it takes a long time, has large human errors, and poor result reproducibility. For example, in the turbidity method, because the hiding power of titanium dioxide is too strong, the prepared dispersion liquid still has a strong hiding power, and the turbidity cannot be directly measured with the original solution. The original solution needs to be diluted by more than 20 times, which will cause large measurement errors. In addition, due to the different measurement methods for dispersibility, the measurement reference systems of various methods are also different, and the measured results are not comparable. Coupled with the relatively cumbersome measurement methods, there is no simple, accurate and unified standard for the measurement of dispersion degree.

[0004] As disclosed in Chinese Patent CN113125297A, a method for detecting the dispersibility of titanium dioxide in water is provided. The method for detecting the dispersibility of titanium dioxide in water according to the present invention quantitatively characterizes the dispersibility of titanium dioxide in water through steps such as the preparation of a slurry with a specific ratio of titanium dioxide, weighing the mass of the slurry and the residue on the sieve, and calculating the measurement result using a formula, and realizes the grading evaluation of the dispersibility of titanium dioxide in water. The problems are as follows: The invention uses externally added dispersants and defoamers, which will cause interference to the dispersibility of titanium dioxide itself and bring errors. In addition, this method uses a filter screen with a certain pore size to allow the titanium dioxide dispersed in water to pass through in a filtering manner, and those that cannot pass through the filter screen are judged as large undispersed particles. This method has limitations and is affected by factors such as the viscosity of the solution, the pressure change of the flushing water flow, and the duration of the measurement, resulting in a large influence of the measurement result on the change of operating conditions. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for measuring the dispersity of powder materials. It can realize simple and rapid measurement of the dispersity, and can continuously measure without interruption, obtain the continuous change value of the dispersity of the powder material over time, and can also measure the dispersity values at different positions in the dispersion system of the powder material at the same time.

[0006] The technical solution of the present invention: A method for measuring the dispersity of powder materials, by preparing a dispersion liquid from the powder material as the medium for buoyancy measurement, measuring the change in the buoyancy of the float in the medium, calculating the dispersing force of the dispersion liquid medium, and obtaining the dispersity of the powder material.

[0007] The above-mentioned method for measuring the dispersity of powder materials specifically includes the following steps:

[0008] S1. Initial value measurement: Pull the float with a lead wire, record the pulling force of the float in the air as F 空气 , add water as the medium in the measuring cylinder, put the float into the measuring cylinder, and record the pulling force of the float as F 水 , adjust the height position of the float in the measuring cylinder, and the pulling force of the float at different heights is F 水1、 F 水2、 F 水3 ,...;

[0009] S2. Preparation of the dispersion liquid: Prepare a dispersion liquid from the powder material, use m 样 grams of the powder material, add m 水 grams of water, and stir evenly to obtain the dispersion liquid;

[0010] S3. Initial dispersion force measurement: Inject the dispersion liquid into the measuring cylinder, place the float into the measuring cylinder, record the pulling force of the float as F0, adjust the height position of the float in the measuring cylinder, and the pulling forces of the float at different heights are F 01、 F 02、 F 03 ,...;

[0011] S4. Dispersion force measurement after standing: After step S3, keep standing for t hours, and then conduct the dispersion force measurement again. Record the pulling force of the float as F t , adjust the height position of the float in the measuring cylinder, and the pulling forces of the float at different heights are F t1、 F t2、 F t3 ,...;

[0012] S5. Calculation of dispersion degree:

[0013] Dispersion degree = (m 样 + m 水 ) × F0 × (F t - F 水 ) ÷ [m 样 × F0 × (F t + F 水 ) - F t × F 水 × (m 样 + m 水 )] × 100%.

[0014] In the above method for measuring the dispersion degree of powder materials, the density of the float should be greater than the density of the dispersion liquid.

[0015] In the above method for measuring the dispersion degree of powder materials, the time t is 0.5 - 6 hours.

[0016] Advantages of the present invention: The present invention proposes a method for calculating the dispersion degree by measuring a physical quantity of pulling force and through the change of the buoyancy of the float in the powder material as the medium. This method can solve the problems of time-consuming and inconsistent methods in measuring the dispersion degree of powder materials such as titanium dioxide in the dispersion medium, can achieve simple and rapid determination of the dispersion degree, and can continuously measure without interruption to obtain the continuous change value of the dispersion degree of the powder material over time. It can also measure the dispersion degree values at different positions in the dispersion system of the powder material simultaneously. Compared with the existing technology, the detection method is simple and fast. Compared with the pipetting method, it saves the problem of drying time-consuming for removing the liquid and the defects of being unable to restore and continuously measure after pipetting; compared with the photometric method, it can measure high-concentration dispersion liquids and avoid the difficulty of poor light transmittance of high-concentration solutions.

[0017] To prove the effectiveness of the present invention, the applicant conducted relevant experiments using different powder materials, and the specific experimental data are as follows:

[0018] Table 1 Measurement of the dispersibility of titanium dioxide in water

[0019]

[0020] Table 2 Measurement of the dispersibility of clay in water

[0021]

[0022] The technical solution of the present invention can be applied to the measurement of the dispersion degree of powder materials, including titanium dioxide, clay, kaolin, calcium carbonate, diatomite, silicon dioxide, carbon black, white carbon black, etc. The measurement device has a low cost, a simple measurement method, high measurement accuracy, and can achieve continuous and uninterrupted measurement, obtaining the continuous change value of the dispersion degree of the powder material over time. It can also simultaneously measure the dispersion degree values at different positions in the dispersion system of the powder material. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Attached Figure 1 is a schematic structural diagram of the present invention;

[0024] Attached Figure 2 is a schematic structural diagram of the float of the present invention;

[0025] Attached Figure 3 is another schematic structural diagram of the present invention;

[0026] Attached Figure 4 is a graph showing the relationship between the dispersion degree of titanium dioxide measured by the titanium dioxide dispersion degree detection device of the present invention and the dispersion degree measured at different static times of the titanium dioxide dispersion liquid and the static time. DETAILED DESCRIPTION OF THE INVENTION

[0027] The following further describes the present invention in conjunction with the drawings and embodiments, but it shall not be used as a basis for limiting the present invention.

[0028] Embodiment 1 of the present invention: The titanium dioxide dispersion degree measurement device adopted in this method includes a measurement cylinder 1 and a float 2. A pull rope and a tensile force detection module 3 are connected to the float 2, and the measurement cylinder 1 is placed on a lifting system 4. The tensile force detection module 3 can adopt devices such as a tensile force sensor, a balance, etc. The lifting system 4 is used to adjust the height of the float 2. By the change of the buoyancy of the float 2 in the medium of the measurement cylinder 1, the dispersion force of the dispersion liquid medium in the measurement cylinder 1 is calculated through the tensile force detection module 3, and the dispersion degree of the powder material is obtained.

[0029] A hook 201 is provided on the float 2 to connect the tensile force detection module 3.

[0030] The float 2 is provided with a cavity 202, and weights can be added to the cavity 202 to adjust the density of the float 2.

[0031] A lamp 203 is provided inside the float 2 to facilitate observing whether the position of the float 2 is normal.

[0032] The lifting system 4 includes a tray 401. The tray 401 is connected to a lifting mechanism 402, and a measuring scale 403 is provided on the lifting mechanism 402. The lifting mechanism 402 can be an automatic lifting mechanism powered by a motor, pneumatic, hydraulic, etc., or a manual lifting method. The lifting mechanism is used to adjust the vertical position of the float 2 in the measuring cylinder 1.

[0033] A method for measuring the dispersity of powder materials. A dispersion liquid is prepared from the powder materials as the medium for buoyancy measurement. The buoyancy change of the float in the medium is measured, and the dispersing force of the dispersion liquid medium is calculated to obtain the dispersity of the powder materials.

[0034] Specifically, it includes the following steps:

[0035] S1. Initial value measurement: The float is pulled by a lead wire, and the tensile force of the float in the air is recorded as F 空气 , 100 ml of water is added to the measuring cylinder as the medium, the float is placed in the measuring cylinder, and the tensile force of the float is recorded as F 水 , and the height position of the float in the measuring cylinder is adjusted to be exactly at the 80 ml mark;

[0036] S2. Preparation of dispersion liquid: A dispersion liquid is prepared from titanium dioxide. 5 grams of titanium dioxide is added to 100 grams of water, and after stirring evenly, the dispersion liquid is obtained;

[0037] S3. Initial dispersing force measurement: The dispersion liquid is injected into the measuring cylinder, the float is placed in the measuring cylinder, the tensile force of the float is recorded as F0, and the height position of the float in the measuring cylinder is adjusted to be exactly at the 80 ml mark;

[0038] S4. Dispersing force measurement after standing: After the dispersion liquid stands for 15.5 hours in step S3, the dispersing force measurement is performed again, and the tensile force of the float is recorded as F t , and the height position of the float in the measuring cylinder is adjusted to still be at the 80 ml mark;

[0039] S5. Calculation of dispersity:

[0040] Dispersity = 105×F0×(F t - F 水 )÷[5×F0×(F t + F 水 ) - F t ×F 水 ×105]×100%.

[0041] The above-mentioned dispersion measurement result is the dispersion of titanium dioxide for 15.5 hours.

[0042] Example 2 of the present invention: A kaolin dispersion measurement device includes a measuring cylinder 1 and a float 2. A pulling rope and a pulling force detection module 3 are connected to the float 2, and the measuring cylinder 1 is placed on a lifting system 4. The pulling force detection module 3 can adopt devices such as a pulling force sensor, a balance, etc.

[0043] A hook 201 is provided on the float 2 to connect the pulling force detection module 3.

[0044] A cavity 202 is provided inside the float 2, and weights can be added to the cavity 202 to adjust the density of the float 2.

[0045] A lamp 203 is provided inside the float 2 to facilitate observing whether the position of the float 2 is normal.

[0046] The lifting system 4 includes a tray 401. The tray 401 is connected to a lifting mechanism 402. The lifting mechanism 402 includes a bracket 404. A pulley 405 is provided on the bracket 404, and the pulley 405 is connected to the pulling rope of the float 2 through a rope take-up device 406. The lifting mechanism is used to adjust the up and down position of the float 2 inside the measuring cylinder 1.

[0047] A method for measuring the dispersion of powder materials uses a dispersion liquid prepared from the powder materials as a medium for buoyancy measurement, measures the change in the buoyancy of the float in the medium, calculates the dispersive force of the dispersion liquid medium, and obtains the dispersion of the powder materials.

[0048] Specifically, it includes the following steps:

[0049] S1. Initial value measurement: The float is pulled by a lead wire, and the pulling force received by the float in the air is recorded as F 空气 , water is added to the measuring cylinder as the medium, the float is placed in the measuring cylinder, and the pulling force of the float is recorded as F 水 , the height position of the float in the measuring cylinder is adjusted, and the pulling force of the float at different heights is F 水1、 F 水2、 F 水3 , ······;

[0050] S2. Preparation of the dispersion liquid: Kaolin is used to prepare a dispersion liquid. 10 grams of kaolin is added to 100 grams of water, and after stirring evenly, a dispersion liquid is obtained;

[0051] S3. Initial dispersive force measurement: The dispersion liquid is injected into the measuring cylinder, the float is placed in the measuring cylinder, the pulling force of the float is recorded as F0, and the height position of the float in the measuring cylinder is adjusted to be at 50 ml;

[0052] S4. Measurement of dispersion force after standing: After step S3, keep it for 4 hours, measure the dispersion force again, and record the pulling force of the float as F. t , adjust the height position of the float in the measuring cylinder to be at 50 ml.

[0053] S5. Calculation of dispersion degree:

[0054] Dispersion degree = 110 × F0 × (F t - F 水 ) ÷ [10 × F0 × (F t + F 水 ) - F t × F 水 × 110] × 100%.

[0055] The above measurement result of the dispersion degree is the dispersion degree of kaolin after 4 hours.

[0056] Example 3 of the present invention: A calcium carbonate dispersion degree measuring device includes a measuring cylinder 1 and a float 2. A pulling rope and a pulling force detection module 3 are connected to the float 2, and the measuring cylinder 1 is placed on a lifting system 4. The pulling force detection module 3 can adopt devices such as a pulling force sensor and a balance.

[0057] A hook 201 is provided on the float 2 to connect the pulling force detection module 3.

[0058] A cavity 202 is provided inside the float 2, and a counterweight can be added to the cavity 202 to adjust the density of the float 2.

[0059] The lifting system 4 adopts an existing automatic lifting mechanism powered by a motor, pneumatic, hydraulic, etc., or manual lifting to adjust the up and down position of the float 2 in the measuring cylinder 1.

[0060] A method for measuring the dispersion degree of a powder material, by preparing a dispersion liquid of the powder material as a medium for buoyancy measurement, measuring the change in the buoyancy of a float in the medium, calculating the dispersion force of the dispersion liquid medium, and obtaining the dispersion degree of the powder material.

[0061] The above method for measuring the dispersion degree of a powder material specifically includes the following steps:

[0062] S1. Initial value measurement: Hold the float with a lead wire, record the pulling force of the float in the air as F 空气 , add water as a medium in the measuring cylinder, put the float into the measuring cylinder, record the pulling force of the float as F 水 , adjust the height position of the float in the measuring cylinder, and the pulling force of the float at different heights is F 水1、 F 水2、 F 水3 ,...;

[0063] S2. Preparation of Dispersed Liquid: Prepare a dispersed liquid with calcium carbonate. Add 20 grams of calcium carbonate to 100 grams of water and stir evenly to obtain the dispersed liquid;

[0064] S3. Measurement of Initial Dispersing Power: Inject the dispersed liquid into a measuring cylinder, place the float into the measuring cylinder, record the pulling force of the float as F0, and adjust the height position of the float in the measuring cylinder to 50 ml;

[0065] S4. Measurement of Dispersing Power after Standing: After step S3, keep it for 2 hours, and then measure the dispersing power again. Record the pulling force of the float as F t , and adjust the height position of the float in the measuring cylinder to 50 ml;

[0066] S5. Calculation of Dispersion Degree:

[0067] Dispersion Degree = 120 × F0 × (F t - F 水 ) ÷ [20 × F0 × (F t + F 水 ) - F t × F 水 × 120] × 100%.

[0068] The density of the float should be greater than the density of the dispersed liquid.

[0069] The above measurement result of the dispersion degree is the dispersion degree of calcium carbonate for 2 hours.

Claims

1. A method for measuring the dispersion degree of a powder material, characterized in that: Prepare a dispersed liquid from powder materials as the medium for buoyancy measurement, measure the change in the buoyancy of the float in the medium, calculate the dispersive force of the dispersed liquid medium, and obtain the dispersibility of the powder materials; Specifically, it includes the following steps: S1. Initial value measurement: Hold the float with a lead wire and record the pulling force on the float in the air as F 空气 , add water as a medium into the measuring cylinder, put the float into the measuring cylinder, and record the pulling force of the float as F 水 , adjust the height position of the float in the measuring cylinder, and the pulling force of the float at different heights is F 水1、 F 水2、 F 水3 , ······; S2. Preparation of the dispersion liquid: Prepare a dispersion liquid from the powder material. Use m 样 grams of the powder material and add m 水 grams of water. After stirring evenly, a dispersion liquid is obtained; S3. Initial dispersion force measurement: Inject the dispersion liquid into the measuring cylinder, place the float into the measuring cylinder, record the pulling force of the float as F0, adjust the height position of the float in the measuring cylinder, and the pulling force of the float at different heights is F 01、 F 02、 F 03 , ······; S4. Measurement of dispersing force after standing: After step S3, let it stand for t hours, then measure the dispersing force again, and record the pulling force of the float as F t , adjust the height position of the float in the measuring cylinder, and the pulling force of the float at different heights is F t1、 F t2、 F t3 ,...; S5. Dispersibility calculation: Dispersion = (m 样 + m 水 ) × F0 × (F t - F 水 ) ÷ [m 样 × F0 × (F t + F 水 ) - F t × F 水 × (m 样 + m 水 )] × 100%.

2. The method for measuring the dispersion degree of the powder material according to claim 1, wherein: The density of the float should be greater than the density of the dispersed liquid.

3. The method for measuring the dispersion degree of the powder material according to claim 1, wherein: The time t is 2 - 6 hours.

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