Method for identifying settlement height of montmorillonite

Abstract

The invention discloses an identification method for the settlement height of montmorillonite, and relates to the technical field of material detection. The sample to be detected is mixed with the acid solution, and the sample which does not generate bubbles is judged to be qualified in primary screening. And then weighing a qualified sample, preparing the qualified sample and water into a fluid montmorillonite suspension with the concentration of 0.2-0.3 g / ml, standing the suspension until the suspension reaches a stable state, and then accurately measuring the sedimentation height of the fluid montmorillonite. The method can be used for quickly and effectively identifying the quality of the montmorillonite sample according to the measurement result of the settlement height, and has the characteristics of simplicity and convenience in operation and quick identification.

Description

Technical Field

[0001] This invention relates to the field of materials testing technology, and more specifically, to a method for identifying the sedimentation height of montmorillonite. Background Technology

[0002] Montmorillonite is a fine-grained, hydrous, layered aluminosilicate mineral, a major component of bentonite, and is purified from bentonite. Powdered materials with a montmorillonite content greater than 85% are used as feed additives. Montmorillonite has excellent applications in livestock and poultry farming, especially in preventing yellow and white scours in piglets and diarrhea in rabbits. Due to its properties, montmorillonite is the preferred choice as a superior feed mycotoxin binder. As a feed additive, montmorillonite, with its natural properties and complex functions, has been widely used in livestock and poultry farming both domestically and internationally.

[0003] However, there is currently no unified testing standard for montmorillonite in China. Its quality assessment relies heavily on indicators such as blue absorption and ammonia absorption value, which are positively correlated with content. The testing of these indicators typically refers to standards for bentonite, zeolite powder, or pharmacopoeias, involving various complex techniques such as gravimetric analysis and X-ray diffraction. Existing methods are not only cumbersome and time-consuming, but also demanding in terms of personnel skills and laboratory equipment, making them difficult to implement routinely. Therefore, developing a rapid and convenient method for identifying the quality of montmorillonite has become an urgent need for industry procurement and efficient utilization.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a method for identifying the sedimentation height of montmorillonite, which combines qualitative identification with rapid expansion and stability analysis to make the test results more reliable and accurate.

[0006] This invention is implemented as follows: This invention provides a method for identifying the settling height of montmorillonite, comprising the following steps: mixing the montmorillonite sample to be tested with an acidic solution; samples that do not produce bubbles are initially screened and deemed qualified; weighing an appropriate amount of the initially screened qualified sample and mixing it with water to prepare a liquid montmorillonite suspension with a concentration of 0.2-0.3 g / ml; allowing the montmorillonite suspension to stand until it reaches a stable state; and measuring its settling height; and rapidly identifying the mass of the sample based on the measured settling height.

[0007] In some preferred embodiments, the particle size of the montmorillonite sample to be tested meets the requirement that 95% of it passes through a 100-mesh sieve.

[0008] In some preferred embodiments, the acidic solution is a hydrochloric acid solution with a concentration of 5-7 mol / L.

[0009] In some preferred embodiments, during the initial screening, if obvious bubbles are produced after the sample is mixed with the acidic solution, the sample is determined to contain carbonate substances and is therefore an unqualified sample.

[0010] In some preferred embodiments, the initial screening test of the montmorillonite sample to be tested is repeated at least twice to improve the reliability of the test.

[0011] In some preferred embodiments, the montmorillonite suspension is allowed to stand for at least 3 hours to ensure that the settling height reaches a stable state.

[0012] In some preferred embodiments, the montmorillonite suspension is allowed to stand under constant temperature conditions, wherein the constant temperature is 20-35°C.

[0013] In some preferred embodiments, the water used in the identification method is deionized water or distilled water.

[0014] In some preferred embodiments, the measured settling height is the height between the clarified suspension interface and the compacted precipitate interface.

[0015] In some preferred embodiments, the montmorillonite sample to be tested is sodium-based montmorillonite, calcium-based montmorillonite, or a modified product of both.

[0016] The present invention has the following beneficial effects: This invention effectively eliminates samples containing impurities such as carbonates through initial screening with an acidic solution. Furthermore, by measuring the settling height of suspensions at specific concentrations, it cleverly utilizes the intrinsic relationship between montmorillonite purity and its dispersibility and colloidal stability in water. The entire process requires no complex or expensive instruments and avoids the time-consuming steps of traditional chemical analysis, enabling quality assessment to be completed quickly. This provides strong technical support for the procurement, acceptance, and rapid on-site screening of montmorillonite, demonstrating significant practical value. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the montmorillonite suspension before settling in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the montmorillonite suspension after standing in Example 1 of the present invention; Figure 3 This is a schematic diagram of the montmorillonite suspension after standing in an embodiment of the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0020] The following is a detailed description of the method for identifying the sedimentation height of montmorillonite proposed in this invention.

[0021] According to existing records, the quality and content of montmorillonite in bentonite are closely related, and the blue absorption capacity and ammonia absorption value are positively correlated with the montmorillonite content. Current methods for detecting montmorillonite content include gravimetric analysis, X-ray diffraction (XRD), and electron microscopy (SEM). However, these methods are time-consuming, cumbersome, and require highly skilled personnel and advanced laboratory equipment, making them difficult to implement.

[0022] The inventors discovered that montmorillonite's crystalline structure gives it a high capacity for water absorption and swelling. Therefore, a sample will absorb water and swell in a certain amount of water, stabilizing at a certain height after settling; this is the settling height. This invention correlates the settling height of montmorillonite with its blue absorption and ammonia absorption values. Extensive experimental data has verified that the higher the settling height of montmorillonite, the higher its blue absorption and ammonia absorption values. In practical production, this method can be used to achieve rapid identification of montmorillonite quality, while providing a theoretical basis for quality control and efficient utilization of montmorillonite.

[0023] Therefore, this invention proposes a method for identifying the sedimentation height of montmorillonite, comprising the following steps: S1. Preliminary screening of montmorillonite: Mix the montmorillonite sample to be tested with an acidic solution. Samples that do not produce bubbles are qualified for preliminary screening.

[0024] In the embodiments of this application, the detailed steps include: taking 0.1~0.2g of the montmorillonite sample to be tested onto a spot plate, repeating at least 2 wells to improve the reliability of the detection, then adding 2~3 drops of hydrochloric acid solution, and observing under a microscope whether obvious bubbles are generated. If obvious bubbles are generated after the sample is mixed with the acidic solution, it is determined that the sample contains carbonate substances and is an unqualified sample; if no obvious bubbles are generated, the next test is carried out.

[0025] In some preferred embodiments, the montmorillonite sample needs to be dried and sieved, with 95% of the particle size passing through a 100-mesh sieve. Because the montmorillonite suspension is placed in a static state, over time, montmorillonite particles of different sizes will gradually stratify due to differences in settling velocity. Finer particles settle more slowly, while coarser particles settle to the bottom more quickly. Therefore, the settling height of montmorillonite is related to particle size and particle size distribution. Thus, to eliminate the influence of other factors on the results, sieving the sample first can improve the reliability of the data.

[0026] In some preferred embodiments, the acidic solution is a hydrochloric acid solution with a concentration of 5-7 mol / L.

[0027] S2. Swelling and sedimentation of montmorillonite: Weigh an appropriate amount of the initially qualified sample and mix it with water. Stir gently with a glass rod until the sample is in a liquid state, and prepare a liquid montmorillonite suspension with a concentration of 0.2-0.3 g / ml. Let the montmorillonite suspension stand until it reaches a stable state, and then measure its sedimentation height. Based on the measured sedimentation height, the quality of the sample can be quickly identified.

[0028] In some preferred embodiments, the montmorillonite suspension is allowed to stand for at least 3 hours to ensure that the settling height reaches a stable state. Only under these conditions can the measured settling height data be reliable and repeatable, avoiding misjudgments due to insufficient time. The montmorillonite suspension is allowed to stand under constant temperature conditions, specifically 20-35°C. This effectively eliminates the interference of ambient temperature fluctuations on the hydration expansion rate of montmorillonite particles, solution viscosity, and colloidal sedimentation kinetics. This ensures that test results from different batches and at different times are obtained under a unified standard, greatly improving the accuracy, comparability, and universality of the identification method in practical applications.

[0029] It should be noted that the water used in the identification method is deionized water or distilled water to prevent ions in the water from interfering with the swelling properties of montmorillonite.

[0030] In some preferred embodiments, the measured settling height is the height between the clarified suspension interface and the compacted precipitate interface.

[0031] In some preferred embodiments, the montmorillonite sample to be tested is sodium-based montmorillonite, calcium-based montmorillonite, or a modified product of both.

[0032] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0033] Example 1 This embodiment provides a method for identifying the sedimentation height of montmorillonite, which includes the following steps: S1. Preliminary screening of montmorillonite: After mixing sample A evenly, take 0.15g onto a spot plate and repeat for 3 wells. Add 2-3 drops of 6mol / L hydrochloric acid solution and observe under a microscope whether obvious bubbles are generated. If no obvious bubbles are generated, the preliminary screening is qualified and the next test can be carried out.

[0034] S2. Swelling and Sedimentation of Montmorillonite: Weigh approximately 25g of sample A, which has passed the initial sieve, into a 100mL beaker. Slowly add 90mL of distilled water at 25℃, and gently stir with a glass rod until the sample reaches a liquid state. Figure 1 As shown, rinse the glass rod again with the same distilled water and pour it into the beaker until the liquid level in the beaker reaches the 100mL mark. Then let it stand for 3 hours and observe its stable height. Figure 2 As shown, the settling height of sample A is 80.

[0035] Example 2 This embodiment provides a method for identifying the settling height of montmorillonite. The steps are the same as in Embodiment 1, except that sample B is used in this embodiment, and the settling height of sample B is 75.

[0036] Example 3 This embodiment provides a method for identifying the settling height of montmorillonite. The steps are the same as in Embodiment 1, except that sample C is used in this embodiment, and the settling height of sample C is 72.

[0037] Example 4 This embodiment provides a method for identifying the settling height of montmorillonite. The steps are the same as in Embodiment 1, except that in this embodiment, sample D is used, and the settling height of sample D is 50.

[0038] Test case The blue absorption amount and ammonia absorption value of samples A, B, C and D selected in Examples 1-4 were tested.

[0039] Blue absorption test conditions: Refer to GB / T 20973-2020 Bentonite, the test steps are as follows: (1) Weigh 0.2g±0.001g of bentonite sample that has been dried at 105℃±3℃ for 2h, place it in a 250mL conical flask pre-filled with 50mL of water, moisten it, disperse it on a magnetic stirrer for 5min, add 20mL of 1% sodium pyrophosphate solution, and continue stirring for 2min~3min. Then heat it on an electric furnace to a gentle boil for 2min, remove it and cool it to 25℃±5℃.

[0040] (2) Add methylene blue standard solution dropwise with a burette while stirring. For the first addition, add about two-thirds of the total amount of methylene blue solution and stir for 2 minutes to allow it to react fully. After that, add 1 to 2 mL each time, stir for 30 seconds, and then use a glass rod to take a drop of the solution onto medium-speed quantitative filter paper. Observe whether a light blue halo appears around the blue spot. If it does not appear, continue adding methylene blue solution.

[0041] (3) After the blue halo begins to appear, continue stirring for 2 minutes. Then, use a glass rod to take a drop of the test solution onto medium-speed quantitative filter paper and observe whether a light blue halo still appears. If the light blue halo no longer appears, continue to carefully add methylene blue solution. If a light blue halo still appears after stirring for 2 minutes, it indicates that the endpoint has been reached. Record the titration volume. The results are shown in Table 1.

[0042] Ammonia absorption value testing conditions: Refer to GB / T 21695-2008 Feed Grade Zeolite Powder, the testing steps are as follows: (1) Weigh 1.0000g of the sample and place it in a 250mL beaker. Add 50mL of 1.0mol / L ammonium chloride solution and a little pulp. Boil on a hot plate and keep warm for 30min.

[0043] (2) Remove, filter with slow filter paper, wash with boiling 1.0 mol / L ammonium chloride solution until there are no calcium or magnesium ions in the outflowing solution (test method: add a few milliliters of ammonia-ammonium chloride buffer solution and 1 drop of acid chrome blue K indicator to a small beaker, collect some filtrate, if the solution does not turn red, it means it has been washed).

[0044] (3) Wash with warm water until there are no chloride ions (test with silver nitrate solution), and rinse the end of the funnel with water to prevent a small amount of ammonium chloride from contaminating it.

[0045] (4) Replace the funnel with a clean 250mL container and add 80mL of boiled 1.0mol / L potassium chloride solution in three separate additions. After the solution in the funnel has completely flowed out, add 15mL of formaldehyde solution to a beaker and titrate with 0.1mol / L sodium hydroxide standard solution using phenolphthalein as an indicator until the solution turns red. Then, take another 1.0mol / L potassium chloride solution in the beaker. If the solution remains red for 30 seconds, the endpoint has been reached. If the red color fades, repeat the titration until a stable red color is achieved. Calculate the results based on the total volume of sodium hydroxide standard solution consumed in the three titrations. The results are shown in Table 1.

[0046] Settlement height measurement results are as follows Figure 3 As shown.

[0047] Table 1. Blue Absorption Value, Ammonia Absorption Amount, and Settlement Height Values

[0048] Analysis of the experimental results in Table 1 clearly shows a significant positive correlation between the settling height of montmorillonite and its key quality indicators, blue absorption and ammonia absorption. Specifically, sample A achieved a settling height of 80 ml, corresponding to a blue absorption of 40 g / 100 g and an ammonia absorption of 92 mmol / 100 g, both the highest values ​​among the four samples. As the settling height decreased sequentially from sample A to sample D (80 ml → 75 ml → 72 ml → 50 ml), the blue absorption (40 → 39 → 37 → 29) and ammonia absorption (92 → 90 → 78 → 66) also showed a synchronous decreasing trend. This pattern fully demonstrates that the settling height accurately reflects the intrinsic quality of montmorillonite—a higher settling height indicates higher purity and better colloidal properties of montmorillonite, resulting in higher blue absorption and ammonia absorption values.

[0049] Compared with traditional detection methods, the sedimentation height identification method provided by this invention has significant advantages. Traditional methods for detecting blue absorption and ammonia absorption are complex, requiring specialized experimental equipment and technicians, and are time-consuming. In contrast, this method only requires preparing the sample into a suspension and allowing it to stand for observation. The operation is simple and quick, requiring no complex instruments or professional training, and reliable results can be obtained within 3-5 hours, greatly improving detection efficiency. This simplicity and speed make it particularly suitable for quality acceptance at procurement or production sites, providing important theoretical basis and practical guidance for the rapid screening of montmorillonite.

[0050] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for identifying the sedimentation height of montmorillonite, characterized in that, Includes the following steps: The montmorillonite sample to be tested is mixed with an acidic solution. Samples that do not produce bubbles are initially qualified. An appropriate amount of the initially qualified sample is weighed and mixed with water to prepare a liquid montmorillonite suspension with a concentration of 0.2-0.3 g / ml. The montmorillonite suspension is allowed to stand until it reaches a stable state, and its settling height is measured. The mass of the sample is quickly identified based on the measured settling height.

2. The method for identifying the sedimentation height of montmorillonite according to claim 1, characterized in that, The particle size of the montmorillonite sample to be tested meets the requirement that 95% of it passes through a 100-mesh sieve.

3. The method for identifying the sedimentation height of montmorillonite according to claim 1, characterized in that, The acidic solution is a hydrochloric acid solution with a concentration of 5-7 mol / L.

4. The method for identifying the sedimentation height of montmorillonite according to claim 1, characterized in that, In the initial screening, if obvious bubbles are produced after the sample is mixed with the acidic solution, the sample is determined to contain carbonate substances and is therefore an unqualified sample.

5. The method for identifying the sedimentation height of montmorillonite according to claim 1, characterized in that, The initial screening test of the montmorillonite sample to be tested was repeated at least twice to improve the reliability of the test.

6. The method for identifying the sedimentation height of montmorillonite according to claim 1, characterized in that, The montmorillonite suspension is allowed to stand for at least 3 hours to ensure that the settling height reaches a stable state.

7. The method for identifying the sedimentation height of montmorillonite according to claim 1, characterized in that, The montmorillonite suspension was allowed to stand under constant temperature conditions, namely 20-35℃.

8. The method for identifying the sedimentation height of montmorillonite according to claim 1, characterized in that, The water used in the identification method is either deionized water or distilled water.

9. The method for identifying the sedimentation height of montmorillonite according to claim 1, characterized in that, The measured settling height is the height between the clarified interface of the suspension and the compacted interface of the precipitate.

10. The method for identifying the sedimentation height of montmorillonite according to claim 1, characterized in that, The montmorillonite sample to be tested is sodium-based montmorillonite, calcium-based montmorillonite, or a modified product of both.

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