Method for determining particle size distribution of solid sodium methoxide

Abstract

The invention discloses a method for measuring particle size distribution of solid sodium methoxide, which comprises the following steps of: vibrating, and respectively weighing and recording the first vibration sieve masses A1, B1, C1 and D1 of the sieve bottom and each mesh sieve; then weighing and recording the second vibration sieve mass A2, B2, C2 and D2 of the sieve bottom and the sieve of each mesh respectively; unloading the third-mesh sieve, assembling to obtain a first residual standard inspection sieve, then vibrating, and then respectively weighing and recording the third vibration sieve mass A3, B3 and C3 of the sieve bottom and each-mesh sieve; unloading the second mesh sieve, carrying out vibration after assembling to obtain a second residual standard inspection sieve, and then respectively weighing and recording the fourth vibration sieve mass A4 and B4 of the sieve bottom and the first mesh sieve; respectively calculating the particle size distribution of the solid sodium methoxide based on the obtained mass of each vibration sieve and the corresponding mass of the body; the method is easy to operate, convenient, high in operability, short in analysis time and very suitable for being used as a particle size detection method in solid sodium methoxide batch production.

Description

Technical Field

[0001] The present invention belongs to the field of preparation of solid sodium methoxide, and particularly relates to a method for measuring the particle size distribution of solid sodium methoxide. Background Art

[0002] Solid sodium methoxide is widely used in many fields such as medicine, pesticides, dyes, and chemical engineering. The particle size distribution of solid sodium methoxide has important guiding significance for its production and manufacturing process, and has an important impact on the performance, reaction activity, and stability of solid sodium methoxide products. However, due to the characteristics of solid sodium methoxide such as strong alkalinity, strong corrosiveness, easy moisture absorption, and easy reaction with carbon dioxide in the air, there are many difficulties in accurately measuring its particle size distribution. For traditional particle size measurement methods, whether wet or dry, solid sodium methoxide will react or dissolve with common dispersion media, and it is often difficult to be directly applicable. Moreover, solid sodium methoxide has a great corrosive interference on the optical path system of a laser particle size analyzer; while the traditional screening method cannot achieve a high-precision test effect.

[0003] Therefore, the applicant hopes to seek technical solutions to improve the above technical problems. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a method for measuring the particle size distribution of solid sodium methoxide, which is simple to operate, convenient, highly operable, and has a short analysis time. Compared with the existing wet and dry particle size measurement methods, it has significantly better accuracy and reliability, and is very suitable as a particle size detection method in the batch production of solid sodium methoxide.

[0005] The technical solution adopted by the present invention is as follows: A method for measuring the particle size distribution of solid sodium methoxide, which measures the particle size distribution of solid sodium methoxide in a dry and well-ventilated environment. Among them, the process of measuring the particle size distribution includes: using a standard test sieve assembled in a detachable manner from bottom to top at least including a sieve bottom, a first mesh sieve, a second mesh sieve, a third mesh sieve, and a sieve cover; and the second mesh number of the second mesh sieve is less than the first mesh number of the first mesh sieve and greater than the third mesh number of the third mesh sieve; Weigh and record the body masses A, B, C, and D of the sieve bottom and each mesh sieve respectively; place a solid sodium methoxide sample with a weighed mass E on the third mesh sieve; Vibrate the entire standard test sieve, and then weigh and record the first vibrating sieve masses A1, B1, C1, and D1 of the sieve bottom and each mesh sieve respectively; Vibrate the entire standard test sieve again, and then weigh and record the second vibrating sieve masses A2, B2, C2, and D2 of the sieve bottom and each mesh sieve respectively, ensuring that the difference between the second vibrating sieve mass D2 and the first vibrating sieve mass D1 of the third mesh sieve does not exceed 1 g; After removing the third - mesh sieve from the standard test sieve and assembling the first remaining standard test sieve, vibrate the whole of the first remaining standard test sieve, and then weigh and record the third - vibration - sieve masses A3, B3, and C3 of the sieve bottom, the first - mesh sieve, and the second - mesh sieve respectively; After removing the second - mesh sieve from the first remaining standard test sieve and assembling the second remaining standard test sieve, vibrate the whole of the second remaining standard test sieve, and then weigh and record the fourth - vibration - sieve masses A4 and B4 of the sieve bottom and the first - mesh sieve respectively; Based on the vibration - sieve masses obtained as described above and their corresponding body masses, calculate respectively the differentials W1 of solid sodium methoxide particles from 0μm to passing through the first mesh number, the differential W2 of solid sodium methoxide not passing through the first mesh number to passing through the second mesh number, the differential W3 of solid sodium methoxide particles not passing through the second mesh number to passing through the third mesh number, and the differential W4 of solid sodium methoxide particles not passing through the third mesh number.

[0006] Preferably, calculate respectively the sample mass A5 sieved into the sieve bottom, the sample mass B5 retained in the first - mesh sieve, the sample mass C5 retained in the second - mesh sieve, and the sample mass D5 retained in the third - mesh sieve; where, The sample mass A5 sieved into the sieve bottom = A4 - A; The sample mass B5 retained in the first - mesh sieve = B4 - B; The sample mass C5 retained in the second - mesh sieve = C3 - C; The sample mass D5 retained in the third - mesh sieve = D2 - D; The sum of the sample masses E5 = A5 + B5 + C5 + D5.

[0007] Preferably, the differential W1 of solid sodium methoxide particles from 0μm to passing through the first mesh number = A5 / E5 * 100%, and its corresponding cumulative ratio = W1; The differential W2 of solid sodium methoxide not passing through the first mesh number to passing through the second mesh number = B5 / E5 * 100%, and its corresponding cumulative ratio = W1 + W2; The differential W3 of solid sodium methoxide particles not passing through the second mesh number to passing through the third mesh number = C5 / E5 * 100%, and its corresponding cumulative ratio = W1 + W2 + W3; The differential W4 of solid sodium methoxide particles not passing through the third mesh number = D5 / E5 * 100%, and its corresponding cumulative ratio = W1 + W2 + W3 + W4.

[0008] Preferably, the absolute value of the difference between the sum of the sample masses E5 and the weighed mass E of the solid sodium methoxide sample should be less than 0.2g.

[0009] Preferably, the coarse powder rate of the first mesh sieve = 100% - W1; the fine powder rate of the first mesh sieve = W1; The coarse powder rate of the second mesh sieve = W3 + W4; the fine powder rate of the second mesh sieve = 100% - (W3 + W4); The coarse powder rate of the third mesh sieve = W4; the fine powder rate of the third mesh sieve = 100% - W4; The coarse powder rate refers to the mass ratio of the sample that cannot pass through the corresponding mesh number; the fine powder rate is the mass ratio of the sample that passes through the corresponding mesh number.

[0010] Preferably, the first mesh number is 180 - 220 meshes, the second mesh number is 80 - 100 meshes, and the third mesh number is 40 - 60 meshes.

[0011] Preferably, a fourth mesh sieve is arranged between the sieve bottom and the first mesh sieve, and the fourth mesh number of the fourth mesh sieve is greater than the first mesh number of the first mesh sieve; or a fourth mesh sieve is arranged between the third mesh sieve and the sieve cover, and the fourth mesh number of the fourth mesh sieve is less than the third mesh number of the third mesh sieve.

[0012] Preferably, the process of particle size distribution measurement is carried out in a glove box or a fume hood protected by dry inert gas, and the duration of the process of particle size distribution measurement does not exceed 15 minutes; the standard test sieve is dried in an oven before the particle size distribution measurement.

[0013] Preferably, the vibration is carried out manually or with a vibrating sieve machine; the duration of each vibration does not exceed 30 seconds.

[0014] Preferably, the standard test sieve is made of stainless steel or PVC plastic; wherein, when it is made of PVC plastic, the drying temperature of the corresponding standard test sieve does not exceed 60°C.

[0015] This application proposes a measurement method that can effectively calculate and analyze the particle size distribution of solid sodium methoxide, and can obtain the particle size distribution of sodium methoxide particles at different particle sizes / mesh numbers. It is simple to operate, convenient in method, highly operable, short in analysis time, and has significantly better accuracy and reliability compared with the existing wet and dry particle size measurement methods in the prior art. It is very suitable as a particle size detection method in the batch production of solid sodium methoxide. Detailed implementation mode

[0016] This embodiment provides a method for measuring the particle size distribution of solid sodium methoxide. The particle size distribution of solid sodium methoxide is measured in a dry and ventilated environment. The process of measuring the particle size distribution includes: using a standard test sieve assembled in a detachable manner from bottom to top with at least a sieve bottom, a first mesh sieve, a second mesh sieve, a third mesh sieve, and a sieve cover; and the second mesh number of the second mesh sieve is less than the first mesh number of the first mesh sieve and greater than the third mesh number of the third mesh sieve. Preferably, in this embodiment, in order to avoid sample moisture absorption during the test, in this embodiment, the process of measuring the particle size distribution is carried out in a glove box protected by dry inert gas (in other embodiments, if there is no glove box operating environment, it can also be carried out in a fume hood), and the duration of the process of measuring the particle size distribution does not exceed 15 minutes; the standard test sieve is dried in an oven before measuring the particle size distribution. Weigh and record the body masses A, B, C, and D of the sieve bottom and each mesh sieve respectively; place the solid sodium methoxide sample with a weighed mass E on the third mesh sieve. Vibrate the entire standard test sieve, and then weigh and record the first sieving masses A1, B1, C1, and D1 of the sieve bottom and each mesh sieve respectively. Preferably, in this embodiment, vibration is carried out manually or with a sieve shaker; the duration of each vibration does not exceed 30 seconds to avoid sample moisture absorption.

[0017] Preferably, in this embodiment, the standard test sieve is made of stainless steel and is dried in an oven at 80 °C before measuring the particle size distribution. In other embodiments, the standard test sieve can also be made of PVC plastic; when it is made of PVC plastic, the drying temperature of the corresponding standard test sieve does not exceed 60 °C. Vibrate the entire standard test sieve again, and then weigh and record the second sieving masses A2, B2, C2, and D2 of the sieve bottom and each mesh sieve respectively, ensuring that the difference between the second sieving mass D2 and the first sieving mass D1 of the third mesh sieve does not exceed 1 g. Remove the third mesh sieve from the standard test sieve, assemble the first remaining standard test sieve, vibrate the entire first remaining standard test sieve, and then weigh and record the third sieving masses A3, B3, and C of the sieve bottom, the first mesh sieve, and the second mesh sieve respectively. Remove the second mesh sieve from the first remaining standard test sieve, assemble the second remaining standard test sieve, vibrate the entire second remaining standard test sieve, and then weigh and record the fourth sieving masses A4 and B4 of the sieve bottom and the first mesh sieve respectively. Based on the masses of each vibrating sieve obtained above and their corresponding main body masses, the differentials of solid sodium methoxide particles from 0 μm to passing through the first mesh number, W1, the differential of solid sodium methoxide not passing through the first mesh number to passing through the second mesh number, W2, the differential of solid sodium methoxide particles not passing through the second mesh number to passing through the third mesh number, W3, and the differential of solid sodium methoxide particles not passing through the third mesh number, W4, are calculated respectively.

[0018] Preferably, in this embodiment, the mass of the sample sieved into the sieve bottom, A5, the mass of the sample retained in the first mesh sieve, B5, the mass of the sample retained in the second mesh sieve, C5, and the mass of the sample retained in the third mesh sieve, D5, are calculated respectively; where, The mass of the sample sieved into the sieve bottom, A5 = A4 - A; The mass of the sample retained in the first mesh sieve, B5 = B4 - B; The mass of the sample retained in the second mesh sieve, C5 = C3 - C; The mass of the sample retained in the third mesh sieve, D5 = D2 - D; The sum of the sample masses, E5 = A5 + B5 + C5 + D5; preferably, to ensure the accuracy of the detection, in this embodiment, the absolute value of the difference between the sum of the sample masses, E5, and the weighed mass, E, of the solid sodium methoxide sample should be less than 0.2 g; It is calculated therefrom that the differential of solid sodium methoxide particles from 0 μm to passing through the first mesh number, W1 = A5 / E5 * 100%, and its corresponding cumulative ratio = W1; the differential of solid sodium methoxide not passing through the first mesh number to passing through the second mesh number, W2 = B5 / E5 * 100%, and its corresponding cumulative ratio = W1 + W2; the differential of solid sodium methoxide particles not passing through the second mesh number to passing through the third mesh number, W3 = C5 / E5 * 100%, and its corresponding cumulative ratio = W1 + W2 + W3; the differential of solid sodium methoxide particles not passing through the third mesh number, W4 = D5 / E5 * 100%, and its corresponding cumulative ratio = W1 + W2 + W3 + W4.

[0019] In this embodiment, the coarse powder rate of the first mesh sieve = 100% - W1; the fine powder rate of the first mesh sieve = W1; The coarse powder rate of the second mesh sieve = W3 + W4; the fine powder rate of the second mesh sieve = 100% - (W3 + W4); The coarse powder rate of the third mesh sieve = W4; the fine powder rate of the third mesh sieve = 100% - W4; the coarse powder rate refers to the proportion of the sample mass that cannot pass through the corresponding mesh number; the fine powder rate is the proportion of the sample mass that passes through the corresponding mesh number.

[0020] Preferably, in the present embodiment, the first mesh number is 180 - 220 mesh, the second mesh number is 80 - 100 mesh, and the third mesh number is 40 - 60 mesh; more specifically preferably, in the present embodiment, the first mesh number is 200 mesh (corresponding particle size is 75 μm), the second mesh number is 90 mesh (corresponding particle size is 160 μm), and the third mesh number is 50 mesh (corresponding particle size is 355 μm); for the corresponding specific calculation process, please refer to Table 1a shown below:

[0021] In this embodiment, the particle size distribution results of solid sodium methoxide are shown in Table 1b below:

[0022] Preferably, in other embodiments, according to actual needs, a fourth mesh screen can also be provided between the bottom screen and the first mesh screen, and the fourth mesh number of the fourth mesh screen is greater than the first mesh number of the first mesh screen; or a fourth mesh screen can be provided between the third mesh screen and the screen cover, and the fourth mesh number of the fourth mesh screen is less than the third mesh number of the third mesh screen; referring to the method described above to correspond to its corresponding differential, cumulative ratio, coarse powder rate, and fine powder rate, this embodiment will not be repeated and expanded here.

[0023] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0024] On the basis of the above-described implementation schemes, the present application further proposes the following specific embodiments: Example 1: Weigh 83.03 g of solid sodium methoxide sample according to the above-described embodiment process (the particle size distribution measurement process is carried out in a glove box protected by dry inert gas), and the vibration is carried out in an artificial vibration mode. Each specific vibration action is as follows: first, shake evenly, and then vibrate back and forth and left and right; calculate according to Table 2a shown below:

[0025] The obtained particle size distribution data of solid sodium methoxide can be seen in Table 2b shown below:

[0026] Example 2: The rest of the technical solutions in Example 2 are the same as those in Example 1, except that in Example 2, the particle size distribution measurement process is carried out in a fume hood in a laboratory environment, and calculate according to Table 3a shown below:

[0027] For the particle size distribution data of solid sodium methoxide, please refer to Table 3b below:

[0028] Example 3: The rest of the technical solutions in this Example 3 are the same as those in Example 1, except that in this Example 3, the vibration adopts the vibration mode of a vibrating screen machine and is calculated according to Table 4a below:

[0029] For the particle size distribution data of solid sodium methoxide, please refer to Table 4b below:

[0030] Through the data test results of the above specific Examples 1-3, it can be confirmed that the test method provided in this example is simple to operate, and the parallelism of the test results is good and the applicability is high.

[0031] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, in any sense, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention.

[0032] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for determining the particle size distribution of solid sodium methoxide, characterized in that, The particle size distribution of solid sodium methoxide is measured in a dry and well-ventilated environment. The process of the particle size distribution measurement includes: using a standard test sieve assembled in a detachable manner from bottom to top, including at least a sieve bottom, a first mesh sieve, a second mesh sieve, a third mesh sieve, and a sieve cover; and the second mesh number of the second mesh sieve is less than the first mesh number of the first mesh sieve and greater than the third mesh number of the third mesh sieve. Weigh and record the body masses A, B, C, and D of the sieve bottom and each mesh sieve respectively; place a solid sodium methoxide sample with a weighed mass E on the third mesh sieve. Vibrate the entire standard test sieve, and then weigh and record the first vibration sieve masses A1, B1, C1, and D1 of the sieve bottom and each mesh sieve respectively. Vibrate the entire standard test sieve again, and then weigh and record the second vibration sieve masses A2, B2, C2, and D2 of the sieve bottom and each mesh sieve respectively, ensuring that the difference between the second vibration sieve mass D2 and the first vibration sieve mass D1 of the third mesh sieve does not exceed 1 g. Remove the third mesh sieve from the standard test sieve, assemble the first remaining standard test sieve, vibrate the entire first remaining standard test sieve, and then weigh and record the third vibration sieve masses A3, B3, and C of the sieve bottom, the first mesh sieve, and the second mesh sieve respectively. Remove the second mesh sieve from the first remaining standard test sieve, assemble the second remaining standard test sieve, vibrate the entire second remaining standard test sieve, and then weigh and record the fourth vibration sieve masses A4 and B4 of the sieve bottom and the first mesh sieve respectively. Based on the vibration sieve masses obtained as described above and their corresponding body masses, calculate the differentials W1 of solid sodium methoxide particles from 0 μm to passing through the first mesh number, W2 of solid sodium methoxide not passing through the first mesh number to passing through the second mesh number, W3 of solid sodium methoxide particles not passing through the second mesh number to passing through the third mesh number, and W4 of solid sodium methoxide particles not passing through the third mesh number respectively.

2. The method for measuring the particle size distribution of solid sodium methoxide according to claim 1, characterized in that, Calculate the sample mass A5 screened into the sieve bottom, the sample mass B5 retained in the first mesh sieve, the sample mass C5 retained in the second mesh sieve, and the sample mass D5 retained in the third mesh sieve respectively; where The sample mass A5 screened into the sieve bottom = A4 - A; The sample mass B5 retained in the first mesh sieve = B4 - B; The sample mass C5 retained in the second mesh sieve = C3 - C; The sample mass D5 retained in the third mesh sieve = D2 - D; The sum of sample masses E5 = A5 + B5 + C5 + D5.

3. According to the method for measuring the particle size distribution of solid sodium methoxide as described in claim 2, characterized in that The differential W1 of solid sodium methoxide particles from 0 μm to passing through the first mesh number = A5 / E5 * 100%, and its corresponding cumulative ratio = W1; The differential W2 of solid sodium methoxide not passing through the first mesh number to passing through the second mesh number = B5 / E5 * 100%, and its corresponding cumulative ratio = W1 + W2; The differential W3 of solid sodium methoxide particles not passing through the second mesh number to passing through the third mesh number = C5 / E5 * 100%, and its corresponding cumulative ratio = W1 + W2 + W3; The differential of the solid sodium methoxide particles corresponding to the third mesh number W4 = D5 / E5 * 100%, and its corresponding cumulative ratio = W1 + W2 + W3 + W4.

4. The method for measuring the particle size distribution of solid sodium methoxide according to claim 2 or 3, characterized in that, The absolute value of the difference between the sum of the sample masses E5 and the weighed mass E of the solid sodium methoxide sample should be less than 0.2 g.

5. The method for measuring the particle size distribution of solid sodium methoxide according to claim 3, wherein The coarse powder rate of the first mesh sieve = 100% - W1; the fine powder rate of the first mesh sieve = W1; The coarse powder rate of the second mesh sieve = W3 + W4; the fine powder rate of the second mesh sieve = 100% - (W3 + W4); The coarse powder rate of the third mesh sieve = W4; the fine powder rate of the third mesh sieve = 100% - W4; The coarse powder rate refers to the mass ratio of the sample that cannot pass through the corresponding mesh number; the fine powder rate is the mass ratio of the sample that passes through the corresponding mesh number.

6. The method for measuring the particle size distribution of solid sodium methoxide according to claim 1, wherein The first mesh number is 180 - 220 meshes, the second mesh number is 80 - 100 meshes, and the third mesh number is 40 - 60 meshes.

7. The method for determining the particle size distribution of solid sodium methoxide according to claim 1 or 6, characterized in that, A fourth mesh sieve is set between the sieve bottom and the first mesh sieve, and the fourth mesh number of the fourth mesh sieve is greater than the first mesh number of the first mesh sieve; or a fourth mesh sieve is set between the third mesh sieve and the sieve cover, and the fourth mesh number of the fourth mesh sieve is less than the third mesh number of the third mesh sieve.

8. The method for measuring the particle size distribution of solid sodium methoxide according to claim 1 or 6, characterized in that The process of the particle size distribution measurement is carried out in a glove box or a fume hood protected by dry inert gas, and the duration of the particle size distribution measurement process does not exceed 15 minutes; the standard test sieve is dried in an oven before the particle size distribution measurement.

9. The method for measuring the particle size distribution of solid sodium methoxide according to claim 1 or 6, characterized in that The vibration is carried out manually or with a vibrating sieve machine; the duration of each vibration does not exceed 30 seconds.

10. The method for determining the particle size distribution of solid sodium methoxide according to claim 1 or 6, characterized in that The standard test sieve is made of stainless steel or PVC plastic; among them, when it is made of PVC plastic, the drying temperature of the corresponding standard test sieve does not exceed 60 °C.

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