Device and method for automatically detecting hydrolysis degree of anionic polyacrylamide

Abstract

The invention discloses a device for automatically detecting the hydrolysis degree of anionic polyacrylamide, which comprises a liquid storage bottle, a liquid distribution pipe, a digital display operation screen, a burette, a single magnetic stirrer, a titration pump, a pH meter, a control circuit and a power supply, the magnetic stirrer is located below the burette, the digital display operation screen is respectively and electrically connected with the magnetic stirrer, the titration pump and the pH meter through the control circuit, and the digital display operation screen, the magnetic stirrer, the titration pump, the pH meter and the control circuit are respectively connected with the power supply. The invention also provides a method for automatically detecting the hydrolysis degree of anionic polyacrylamide by using the device. According to the detection device and method, the hydrolysis degree of the anionic polyacrylamide can be rapidly, accurately and automatically detected.

Description

Technical Field

[0001] The invention belongs to the field of chemical detection, and in particular relates to a device and a method for automatically detecting the hydrolysis degree of anionic polyacrylamide. Background Art

[0002] Anionic polyacrylamide is a widely used polymer flocculant. It plays an important role in oilfield chemical additives, production and domestic sewage treatment additives, mineral processing and other fields. Its performance is closely related to the degree of hydrolysis. Therefore, the degree of hydrolysis has become one of the important detection indicators of the performance of anionic polyacrylamide.

[0003] The degree of hydrolysis refers to the proportion of amide groups in polyacrylamide molecules converted to carboxyl groups. If the hydrolysis degree is too low, the adsorption and bridging ability of polyacrylamide is weak, and it cannot effectively condense suspended particles in the water, resulting in poor flocculation effect. Excessive hydrolysis will lead to enhanced anionicity of polyacrylamide, increase the repulsive force with negatively charged suspended particles, and reduce the flocculation effect. A moderate degree of hydrolysis (usually around 20%) can properly stretch the molecular chain of polyacrylamide, increase its adsorption surface area and bridging ability, and thus improve the flocculation effect.

[0004] Common methods for detecting the degree of hydrolysis include chemical titration, potentiometric titration, infrared spectroscopy, etc. At present, the methods for detecting the degree of hydrolysis of anionic polyacrylamide generally take a long time to detect, and manual titration readings are prone to inaccuracies, and even affect the final calculation results. Therefore, it is necessary to realize automatic detection of the degree of hydrolysis. Summary of the invention

[0005] The purpose of the present invention is to provide a device capable of quickly and accurately automatically detecting the hydrolysis degree of anionic polyacrylamide in view of the above technical problems to be solved.

[0006] In order to achieve the above invention objectives, the present invention provides a device for automatically detecting the hydrolysis degree of anionic polyacrylamide, which includes a liquid storage bottle, a liquid dispensing tube, a digital display operation screen, a burette, a single magnetic stirrer, a titration pump, a pH meter, a control circuit and a power supply, wherein the liquid storage bottle is connected to the titration pump through the liquid dispensing tube, the titration pump is further connected to the burette, the magnetic stirrer is located below the burette, the digital display operation screen is electrically connected to the magnetic stirrer, the titration pump, and the pH meter through the control circuit, and the digital display operation screen, the magnetic stirrer, the titration pump, the pH meter, and the control circuit are respectively connected to the power supply.

[0007] According to the device of the present invention, preferably, the digital display operation screen is a touch screen.

[0008] According to the device of the present invention, preferably, the digital display operation screen controls the titration rate and automatically discharges the air bubbles in the burette and the dispensing tube by touch screen mode.

[0009] According to the device of the present invention, preferably, the titration pump is arranged on the back of the digital display operation screen.

[0010] According to the device of the present invention, preferably, the control circuit receives input from the digital display operation screen, and controls the magnetic stirrer, the titration pump, and the pH meter according to the user input.

[0011] According to the device of the present invention, preferably, the magnetic stirrer 4 is a single magnetic stirrer.

[0012] According to the device of the present invention, preferably, the digital display operation screen includes a user operation menu, and various parameters of titration, calibration, pH and rotation speed are set through the operation menu.

[0013] On the other hand, the present invention also provides a method for automatically detecting the hydrolysis degree of anionic polyacrylamide using the device, which comprises the following steps:

[0014] (1) Exhaust and calibrate the device;

[0015] (2) Place the aqueous solution of anionic polyacrylamide on a magnetic stirrer, adjust the speed through the digital display operation screen to stir and dissolve, add a titration indicator and stir evenly, start the titration pump 6, titrate the aqueous solution of anionic polyacrylamide with the titration solution, record the volume of the titration solution consumed and the pH value, and calculate the hydrolysis degree of the anionic polyacrylamide.

[0016] Compared with the prior art, the detection device and method of the present invention can realize rapid, accurate and automated detection of the hydrolysis degree of anionic polyacrylamide, with higher precision and faster efficiency. In addition, the device can be integrated, and a titration pump, a single magnetic stirrer and a pH meter can be synchronously operated through a digital display operation screen, which optimizes space costs and labor costs. The device is also easy to carry and has an integrated design. It is not restricted by the location and can be placed and used in any place. The automated detection method using the device does not only judge the end point by color, but also judges the end point based on the change in pH. The titration end point is determined by the double data results, which effectively improves the accuracy of the detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The schematic diagram of the structure of the device for automatically detecting the hydrolysis degree of anionic polyacrylamide of the present invention is shown.

[0018] Figure 2 A schematic diagram of the connection structure between the titration pump, the dispensing tube and the burette is shown. DETAILED DESCRIPTION

[0019] The present invention will be further described below in conjunction with specific examples. It should be understood that the following examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. Unless otherwise specified, the experimental reagents and instruments used in the examples of the present invention are all reagents and instruments known in the art.

[0020] The invention provides a device for automatically detecting the hydrolysis degree of anionic polyacrylamide. Figure 1 The schematic diagram of the structure of the device for automatically detecting the hydrolysis degree of anionic polyacrylamide is shown. Figure 2 A schematic diagram of the connection structure between the titration pump, the dispensing tube and the burette is shown.

[0021] like Figure 1 and Figure 2 As shown, the device includes a liquid storage bottle 1, a liquid dispensing tube 2, a digital display operation screen 3, a burette 4, a magnetic stirrer 5, a titration pump 6, a pH meter 7, a control circuit and a power supply.

[0022] The liquid storage bottle 1 is used to contain a reagent solution for pH titration, namely a titration solution, such as but not limited to a standard hydrochloric acid solution or a standard alkali solution.

[0023] The liquid storage bottle 1 is connected to the titration pump 6 through the liquid dispensing tube 2, and the titration pump 6 is connected to the burette 4. The magnetic stirrer 5 is located below the burette 4 (refer to Figure 1 direction shown).

[0024] The magnetic stirrer 5 is used to stir the sample solution to be tested. During testing, the sample solution to be tested can be placed on the magnetic stirrer 5 to achieve stirring and titration.

[0025] The digital display operation screen 3 is electrically connected to the titration pump 6 , the magnetic stirrer 5 , and the pH meter 7 through the control circuit, thereby realizing electrical control of the titration pump 6 , the magnetic stirrer 5 , and the pH meter 7 .

[0026] The digital display operation screen 3, the magnetic stirrer 5, the titration pump 6, the pH meter 7 and the control circuit are respectively connected to the power supply.

[0027] The digital display operation screen 3 can control the titration rate and automatically discharge the air bubbles in the burette 4 and the dispensing tube 2 by touch screen mode.

[0028] The titration pump 6 can be arranged on the back side of the digital display operation screen 3 (ie, the other side opposite to the display surface), and the titration pump 6 is connected to the dispensing tube 2 and the burette 4 respectively.

[0029] The digital display operation screen 3 may be a touch screen to achieve more friendly human-computer interaction, but is not limited thereto.

[0030] The control circuit can receive input from the digital display operation screen 3 and control the magnetic stirrer 5, the titration pump 6 and the pH meter 7 according to the user input.

[0031] The diameter of the burette is preferably 1 cm.

[0032] The magnetic stirrer 4 is preferably a single magnetic stirrer.

[0033] Those skilled in the art are familiar with the operations of the pH meter 7, the magnetic stirrer 5, the titration pump 6, etc., and therefore, they will not be described in detail in this embodiment.

[0034] The digital display operation screen 3 can display a user menu, which can be accessed by the user by clicking / touching the operation menu icon on the screen. The operation menu includes but is not limited to the following operation functions: titration, calibration, pH, and speed. The various parameters of titration, calibration, pH, and speed can be set through the operation menu.

[0035] For "titration", the titration pump 6 can be started by clicking the "titration start" button to absorb the sample solution in the liquid storage bottle 1, and the roller can push the flow of the liquid in the tube by alternately squeezing and relaxing the elastic hose. The titration speed can be adjusted according to actual needs.

[0036] "Calibration" can be divided into titration calibration and pH calibration.

[0037] Titration calibration: Set the "titration pump stroke" to 50 times, place a 5mL small measuring cylinder under the burette, press the "titration pump calibration" button to start the titration pump 6, and after 50 strokes, check the volume in the measuring cylinder, which is usually within the range of 2.3-2.8mL. Compare this range with the value displayed on the screen. If they do not match, you can manually change the value on the screen and save to complete the calibration. Titration calibration is a key step to ensure the accuracy of titration analysis.

[0038] pH calibration: Before measuring the pH value of the solution, use pH buffer solution to calibrate the pH meter to ensure the accuracy of the measurement results. Prepare pH buffer solution in advance, press the pH calibration button, and follow the on-screen prompts to place buffer solutions of different pH values ​​for automatic calibration.

[0039] For "pH", rinse the pH electrode with deionized water, place the pH electrode in the solution to be tested, and wait for the screen value to stabilize.

[0040] As for the "rotation speed", the rotation speed range of the magnetic stirrer 5 can be adjusted to be 0-1500 r / min.

[0041] The degree of hydrolysis of anionic polyacrylamide can be detected by the above-mentioned automated device.

[0042] The method for detecting the hydrolysis degree of anionic polyacrylamide comprises the following steps: firstly, venting and calibrating the device, then weighing 0.03g of anionic polyacrylamide into a 200mL beaker, adding 100mL of water to dissolve, placing the beaker containing the solution on a single magnetic stirrer 5, adjusting the rotation speed to 400-450r / min through a digital display operation screen 3, stirring, after the dissolution is completed, adding 1 drop of methyl orange indicator and 1 drop of sodium indigo disulfonate indicator, stirring evenly, starting a titration pump 6, titrating the anionic polyacrylamide solution of the sample to be tested with a 0.1mol / L hydrochloric acid standard solution, stopping the titration when the solution changes from emerald green to light gray and does not fade for half a minute, recording the volume and pH of the hydrochloric acid standard solution consumed in the titration, and obtaining the hydrolysis degree of the anionic polyacrylamide sample to be tested by calculation.

[0043] Degree of hydrolysis n The value is expressed as % by mass and the degree of hydrolysis is calculated according to the following equation:

[0044]

[0045] V——The volume of the hydrochloric acid standard titration solution consumed in the titration, in milliliters (mL);

[0046] c——The accurate value of the actual concentration of the hydrochloric acid standard titration solution, in moles per liter (mol / L);

[0047] M1——the numerical value of the molar mass of acrylamide in grams per mole (g / mol) (M3=71.07);

[0048] M2——the numerical value of the molar mass of sodium acrylate in grams per mole (g / mol) (M=94.04);

[0049] m——the numerical value of the sample mass, in grams (g);

[0050] w1——mass fraction of solid content of the sample, expressed in %.

[0051] The device was used to detect the hydrolysis degree of the same anionic polyacrylamide sample 10 times, and the results were 10.13, 10.14, 10.08, 10.12, 10.15, 10.09, 10.11, 10.13, 10.12, and 10.11, respectively. The standard deviation of these 10 sets of data was 0.02%, the relative standard deviation was 0.21%, and the relative average deviation was 0.16%, indicating that the device has high precision and good repeatability.

[0052] By using the device method to detect anionic polyacrylamide samples with a hydrolysis degree of 15%, 10 groups were tested and the results were 15.05, 14.99, 15.00, 15.03, 15.03, 14.99, 15.06, 14.99, 15.03, and 15.05. The standard deviation of these 10 groups of data was 0.03%, the relative standard deviation was 0.18%, and the relative average deviation was 0.16%, indicating that the detection method has high accuracy, fast efficiency, and more precise results.

[0053] It can be seen from the experimental results that the detection device and method of the present invention can realize rapid, accurate and automated detection of the hydrolysis degree of anionic polyacrylamide.

Claims

1. A device for automatically detecting the hydrolysis degree of anionic polyacrylamide, characterized in that The invention comprises a liquid storage bottle, a liquid dispensing tube, a digital display operation screen, a burette, a single magnetic stirrer, a titration pump, a pH meter, a control circuit and a power supply, wherein the liquid storage bottle is connected to the titration pump through the liquid dispensing tube, the titration pump is further connected to the burette, the magnetic stirrer is located below the burette, the digital display operation screen is electrically connected to the magnetic stirrer, the titration pump and the pH meter through the control circuit, and the digital display operation screen, the magnetic stirrer, the titration pump, the pH meter and the control circuit are respectively connected to the power supply.

2. The device according to claim 1, characterized in that The digital display operation screen is a touch screen.

3. The device according to claim 1, characterized in that The digital display operation screen controls the titration rate by touch screen mode and automatically discharges the air bubbles in the burette and the dispensing tube.

4. The device according to claim 1, characterized in that The titration pump is arranged on the back of the digital display operation screen.

5. The device according to claim 1, characterized in that The control circuit receives input from the digital display operation screen, and controls the magnetic stirrer, the titration pump, and the pH meter according to the user input.

6. The device according to claim 1, characterized in that The magnetic stirrer 4 is a single magnetic stirrer.

7. The device according to claim 1, characterized in that The digital display operation screen includes a user operation menu, through which various parameters of titration, calibration, pH and rotation speed are set.

8. A method for automatically detecting the degree of hydrolysis of anionic polyacrylamide using the device described in any one of claims 1 to 7, characterized in that The following steps are involved: (1) exhausting and calibrating the device; (2) placing the aqueous solution of anionic polyacrylamide on the magnetic stirrer, adjusting the speed through the digital display operation screen to stir and dissolve, adding a titration indicator and stirring evenly, turning on the titration pump, titrating the aqueous solution of anionic polyacrylamide with the titration solution, recording the volume of the titration solution consumed and the pH value, and calculating the hydrolysis degree of the anionic polyacrylamide.

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