Equipment and method for real-time evaluation of mine water corrosion behavior and screening of corrosion inhibitors

Abstract

Equipment for real-time evaluation of the corrosion behavior of mine water and screening of corrosion inhibitors, which consists of a feeding system, a testing system, and a data acquisition and processing system; the feeding system consists of a feed flow path and a flow control flow path formed by sequentially connecting a water chiller, a jacketed water bath constant temperature storage water tank, a delivery pump, a first stop valve, and a first flowmeter through pipe fittings; the testing system is mainly composed of a rectangular annular pipe and a first elbow sampling point, a second elbow sampling point respectively arranged along two top corners of the rectangular annular pipe, and a first straight pipe sampling point and a second straight pipe sampling point arranged on two parallel pipes; the data acquisition and processing system consists of a multi-channel electrochemical workstation and a computer. Through the above equipment, the condition of the sheet-like test material under the dynamic corrosion of mine water and the dynamic corrosion condition of the mine water with different corrosion inhibitors added to the sheet-like test material can be obtained, providing a basis for selecting materials and corresponding corrosion inhibitors for the mine water conveying pipelines and equipment under actual working conditions.

Description

Technical Field

[0001] The invention belongs to the technical field of evaluation of the corrosion behavior of mine water and screening of corrosion inhibitors, and relates to equipment and a use method for evaluating the corrosion behavior of mine water and screening corrosion inhibitors. Background Art

[0002] China's energy structure has enabled the rapid development of the coal chemical industry. However, a large amount of mine water is generated during the mining process. Mine water is characterized by high salt content, large discharge volume, and complex composition. Therefore, direct discharge will cause serious pollution to the surrounding water bodies and soil environment, and at the same time, the corrosion of equipment and pipelines for transporting mine water is very serious. In order to slow down the corrosion of equipment and pipelines during the flow of mine water, the measure of adding corrosion inhibitors to the pipeline is usually adopted. However, selecting an effective corrosion inhibitor is crucial for extending the service life of chemical equipment and reducing the corrosion cost of equipment and pipelines.

[0003] Regarding the evaluation and screening of corrosion inhibitors, devices are indispensable. However, the content disclosed in the prior art does not have a device for evaluating corrosion inhibitors by simulating the actual working conditions of pipelines. Commonly used corrosion inhibitor evaluation methods include static coupon test method, high-temperature and high-pressure dynamic method, electrochemical test method, etc. Among them, the static coupon test method is to suspend and immerse the sheet-like test material in a beaker filled with mine water simulation liquid or mine water simulation liquid containing corrosion inhibitor, and conduct static corrosion and measure the mass change of the sheet-like test material before and after corrosion. Although the static coupon test method can obtain the average corrosion inhibition efficiency within a certain test period, it cannot obtain the erosion-corrosion situation in the pipeline under actual working conditions, cannot evaluate the corrosion inhibition effect of the corrosion inhibitor at different positions of the pipeline, and has a long test period and cumbersome operation; the high-temperature and high-pressure dynamic method is to reach high-temperature and high-pressure conditions by pressurization and heating in a sealed environment, and use linear polarization resistance probe technology to monitor the corrosion rate. The problems of the high-temperature and high-pressure dynamic method are that the requirements for experimental conditions are too high, the accuracy is poor, and it cannot be used for a long period; the electrochemical test method uses an electrochemical workstation to monitor the corrosion rate in real time and can quickly evaluate the corrosion inhibition efficiency of the corrosion inhibitor. However, the problem still exists that it cannot obtain the erosion-corrosion situation in the pipeline under actual working conditions and cannot evaluate the corrosion inhibition effect of the corrosion inhibitor at different positions of the pipeline. Summary of the Invention

[0004] The purpose of the invention is to overcome the deficiencies of the prior art and provide a device and a use method for real-time evaluation of the corrosion behavior of mine water and screening of corrosion inhibitors, so as to be able to obtain the dynamic corrosion situation of mine water or mine water containing corrosion agents at different positions of the pipeline in real time and accurately, and screen out corrosion inhibitors that meet the actual working conditions.

[0005] The equipment for real-time evaluation of the corrosion behavior of mine water and screening of corrosion inhibitors according to the present invention is composed of a feeding system, a testing system, and a data acquisition and processing system; the feeding system is composed of a feeding flow path and a flow control flow path which are sequentially connected by a water chiller, a jacketed water bath constant temperature storage tank, a delivery pump, a first stop valve, and a first flowmeter through pipe fittings. The flow control flow path is composed of a bypass valve and connecting pipe fittings. The liquid inlet end of the flow control flow path is connected to the pipe fitting between the delivery pump and the first stop valve, and the liquid outlet end is connected to the jacketed water bath constant temperature storage tank; the testing system is composed of a rectangular annular pipe, a first elbow sampling point and a second elbow sampling point respectively arranged at two top corners of the rectangular annular pipe, a first straight pipe sampling point and a second straight pipe sampling point arranged on two parallel pipes, a liquid inlet and a liquid outlet respectively arranged on the two parallel pipes without sampling points, and a second stop valve, a third stop valve, a second flowmeter, and a third flowmeter respectively arranged on the pipe fittings on both sides of the liquid inlet. The liquid inlet is connected to the outlet of the first flowmeter in the feeding flow path through pipe fittings, and the liquid outlet is connected to the jacketed water bath constant temperature storage tank in the feeding flow path through pipe fittings; the data acquisition and processing system is composed of a multi-channel electrochemical workstation and a computer. The multi-channel electrochemical workstation is used to collect information of each sampling point arranged on the rectangular annular pipe in the testing system and transmit the collected information to the computer. The computer processes the information from the multi-channel electrochemical workstation, displays the results, and stores them.

[0006] In the above-mentioned equipment for real-time evaluation of the corrosion behavior of mine water and screening of corrosion inhibitors, at least three through holes for installing sheet-like test materials are arranged at the first elbow sampling point and the second elbow sampling point, one or two through holes for installing sheet-like test materials are arranged at the first straight pipe sampling point and the second straight pipe sampling point, and the diameter of the through hole - the diameter of the sheet-like test material ≤ 0.1 mm.

[0007] In the above-mentioned equipment for real-time evaluation of the corrosion behavior of mine water and screening of corrosion inhibitors, the rectangular annular pipe in the testing system is formed by connecting four straight pipes and four "right-angled" or "arc-shaped" elbows through threads.

[0008] In the above-mentioned equipment for real-time evaluation of the corrosion behavior of mine water and screening of corrosion inhibitors, the delivery pump is a centrifugal pump, the first flowmeter is a rotameter, and the second flowmeter and the third flowmeter are ultrasonic flowmeters.

[0009] The usage method of the equipment for real-time evaluation of the corrosion behavior of mine water and screening of corrosion inhibitors according to the present invention is as follows in the operation steps:

[0010] Step 1: Grind and polish the sheet-shaped test material, then connect the sheet-shaped test material to a wire. Next, embed the sheet-shaped test material into at least one through-hole set at the first elbow sampling point, the second elbow sampling point, the first straight pipe sampling point, and the second straight pipe sampling point of the rectangular ring-shaped pipe, and make the side of the sheet-shaped test material facing the inner wall of the elbow or the straight pipe flush with the inner wall of the elbow or the straight pipe at the through-hole. Then, use hot melt adhesive to bond and fix each sheet-shaped test material at the through-hole and fill the gap between the sheet-shaped test material and the through-hole. The wires connected to the sheet-shaped test materials bonded at each sampling point are pulled out from the through-hole and connected to a multi-channel electrochemical workstation. The through-holes at each sampling point without bonded sheet-shaped test materials are blocked with plugs.

[0011] Step 2: Install a calomel reference electrode and a platinum sheet electrode near the sheet-shaped test materials bonded at the first elbow sampling point, the second elbow sampling point, the first straight pipe sampling point, and the second straight pipe sampling point of the rectangular ring-shaped pipe, and connect the calomel reference electrodes and platinum sheet electrodes installed at each sampling point to the multi-channel electrochemical workstation through wires.

[0012] Step 3: Add mine water or mine water containing an inhibitor to the water cooler. Cool the mine water or mine water containing an inhibitor to the feed water temperature through the water cooler and then inject it into the jacket water bath storage tank. Then, open the first stop valve, the second stop valve, and the third stop valve, adjust the mine water or mine water containing an inhibitor to the required flow rate through the bypass valve, and then start the delivery pump to transport the mine water or mine water containing an inhibitor in the jacket water bath storage tank to the rectangular ring-shaped pipe through pipe fittings. The mine water or mine water containing an inhibitor flowing out of the rectangular ring-shaped pipe returns to the jacket water bath storage tank, forming a circulating flow of mine water or mine water containing an inhibitor.

[0013] Step 4: After the mine water or mine water containing an inhibitor circulates for at least 4 hours, test the polarization curve information and impedance spectrum information of the sheet-shaped test material through the multi-channel electrochemical workstation, and transmit the collected information to a computer. After being processed by the computer, the results are displayed and stored.

[0014] Using the equipment of the present invention and through the method of the present invention, the condition of the sheet-shaped test material under the dynamic corrosion of mine water and the dynamic corrosion condition of the mine water with different inhibitors added to the sheet-shaped test material can be obtained, providing a basis in line with the actual working conditions for the selection of manufacturing materials for mine water transportation pipelines and equipment and the corresponding inhibitor selection.

[0015] After the above Step 4 is completed, the sheet-shaped test materials corroded by mine water at each test point can be subjected to characterization and analysis such as SEM, XPS, and EDS, so as to obtain more morphologies of the surface of the sheet-shaped test material after corrosion and corrosion products, providing more data for studying the corrosion behavior of mine water.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] (1) Since the device for real-time evaluating the corrosion behavior of mine water and screening corrosion inhibitors according to the present invention is composed of a feeding system, a testing system, and a data acquisition and processing system, and the feeding system and the testing system can form a circulating flow of mine water or mine water containing corrosion inhibitors, the data acquisition and processing system obtains the condition of the sheet-like test material under dynamic corrosion of mine water, and the dynamic corrosion condition of the mine water with different corrosion inhibitors added to the sheet-like test material, providing a basis for selecting materials and corresponding corrosion inhibitors for the mine water conveying pipelines and equipment under actual working conditions.

[0018] (2) Since the main body of the testing system of the device according to the present invention is a rectangular ring-shaped pipe, and a first elbow sampling point, a second elbow sampling point are arranged at two top corners of the rectangular ring-shaped pipe, and a first straight pipe sampling point and a second straight pipe sampling point are arranged on two parallel pipes, two groups of detection data on the parallel pipes and two groups of detection data on the elbows can be obtained simultaneously, facilitating comparative evaluation of the corrosion of mine water and the selection of corrosion inhibitors.

[0019] (3) Since the rectangular ring-shaped pipe in the testing system of the device according to the present invention is formed by connecting four straight pipes and four "right-angled" or "arc-shaped" elbows through threads, it is convenient for disassembly and combination, and for pasting the sheet-like test material on the inner walls of each sampling point and taking it out from each sampling point.

[0020] (4) The device according to the present invention has a simple structure, a simple operation method, and is easy to master, so it is conducive to popularization and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic structural diagram of the device for real-time evaluating the corrosion behavior of mine water and screening corrosion inhibitors according to the present invention;

[0022] Figure 2 is a schematic diagram of the outer side of the right-angled elbow forming the rectangular ring-shaped pipe and a schematic diagram of the through hole provided on the right-angled elbow for installing the sheet-like test material;

[0023] Figure 3 is a schematic diagram of the inner side of the right-angled elbow forming the rectangular ring-shaped pipe and a schematic diagram of the through hole provided on the right-angled elbow for installing the sheet-like test material;

[0024] Figure 4 is a schematic diagram of the outer side of the arc-shaped elbow forming the rectangular ring-shaped pipe and a schematic diagram of the through hole provided on the arc-shaped elbow for installing the sheet-like test material;

[0025] Figure 5Schematic diagram of the inner side of the arc-shaped elbow that forms a rectangular annular pipe and a schematic diagram of the through-hole provided on the arc-shaped elbow for installing the sheet-like material to be tested;

[0026] Figure 6 Schematic diagram of the installation methods of the sheet-like material to be tested, the calomel reference electrode, and the platinum sheet electrode at each sampling point and their connection to a multi-channel electrochemical workstation through wires;

[0027] Figure 7 Is the polarization curve of the 304 stainless steel sheet pasted at the sampling point of the first straight pipe in Example 2;

[0028] Figure 8 Is the impedance spectrum of the 304 stainless steel sheet pasted at the sampling point of the first straight pipe in Example 2;

[0029] Figure 9 Is the polarization curve of the 304 stainless steel sheet pasted at the sampling point of the second straight pipe in Example 2;

[0030] Figure 10 Is the impedance spectrum of the 304 stainless steel sheet pasted at the sampling point of the second straight pipe in Example 2;

[0031] Figure 11 Is the polarization curve of the 304 stainless steel sheet pasted at the sampling point of the first elbow in Example 2;

[0032] Figure 12 Is the impedance spectrum of the 304 stainless steel sheet pasted at the sampling point of the first elbow in Example 2;

[0033] Figure 13 Is the polarization curve of the 304 stainless steel sheet pasted at the sampling point of the second elbow in Example 2;

[0034] Figure 14 Is the impedance spectrum of the 304 stainless steel sheet pasted at the sampling point of the second elbow in Example 2.

[0035] In the figure, 1 - water chiller, 2 - jacket water bath constant temperature storage tank, 3 - transfer pump, 4 - bypass valve, 5 - first stop valve, 6 - first flow meter, 7 - second stop valve, 8 - second flow meter, 9 - first elbow sampling point, 9-1 - through-hole provided at the first elbow sampling point, 10 - first straight pipe sampling point, 11 - third stop valve, 12 - third flow meter, 13 - second elbow sampling point, 13-1 - through-hole provided at the second elbow sampling point, 14 - second straight pipe sampling point, 15 - multi-channel electrochemical workstation, 16 - computer, 17 - liquid inlet, 18 - liquid outlet, 19 - calomel reference electrode, 20 - platinum sheet electrode, 21 - sheet-like material to be tested, 22 - wire. Specific implementation mode

[0036] The following further illustrates the equipment and its usage method for real-time evaluation of the corrosion behavior of mine water and screening of corrosion inhibitors according to the present invention through embodiments in conjunction with the accompanying drawings.

[0037] Example 1

[0038] In this example, the equipment for real-time evaluation of the corrosion behavior of mine water and screening of corrosion inhibitors is as Figure 1 shown, and it consists of a feeding system, a testing system, and a data acquisition and processing system.

[0039] The feeding system consists of a feeding flow path and a flow control flow path that are sequentially connected by a water chiller 1, a jacketed water bath constant temperature storage tank 2, a delivery pump 3, a first stop valve 5, and a first flowmeter 6 through pipe fittings. The flow control flow path is composed of a bypass valve 4 and connecting pipe fittings. The liquid inlet end of the flow control flow path is connected to the pipe fitting between the delivery pump 3 and the first stop valve 5, and the liquid outlet end is connected to the jacketed water bath constant temperature storage tank 2. In this feeding system, the delivery pump 3 is a centrifugal pump with model MP-70R, and the first flowmeter 6 is a rotameter with model LZB-15.

[0040] The testing system consists of a rectangular annular pipe, a first elbow sampling point 9 and a second elbow sampling point 13 respectively arranged at the upper and lower two top corners on the right side of the rectangular annular pipe, a first straight pipe sampling point 10 and a second straight pipe sampling point 14 arranged on the upper and lower two parallel pipes, a liquid inlet 17 and a liquid outlet 18 respectively arranged on the left and right two parallel pipes without sampling points, a second stop valve 7, a third stop valve 11, a second flowmeter 8, and a third flowmeter 12 respectively arranged on the pipe fittings on both sides of the liquid inlet. The liquid inlet 17 is connected to the outlet of the first flowmeter 6 in the feeding flow path through pipe fittings, and the liquid outlet 18 is connected to the jacketed water bath constant temperature storage tank 2 in the feeding flow path through pipe fittings. In this testing system, the rectangular annular pipe is formed by connecting four straight pipes and four "arc-shaped" elbows through threads. The first elbow sampling point 9 and the second elbow sampling point 13 are provided with 7 through holes for installing sheet-like test materials. The 7 through holes for installing sheet-like test materials are distributed on the "arc-shaped" elbow at 0°, 15°, 30°, 45°, 60°, 75°, and 90°, as Figure 4 、 Figure 5 shown. The first straight pipe sampling point 10 and the second straight pipe sampling point 14 are provided with one through hole for installing sheet-like test materials. The center lines of the through holes on the two straight pipe sampling points coincide on a straight line. The aperture of the through holes at each sampling point is 6.6 mm. The second flowmeter 8 and the third flowmeter 12 are ultrasonic flowmeters.

[0041] The data acquisition and processing system consists of a multi-channel electrochemical workstation 15 and a computer 16. The multi-channel electrochemical workstation 15 is used to collect information of each sampling point set on the rectangular annular tube in the test system, and transmit the collected information to the computer 16. The computer 16 processes the information from the multi-channel electrochemical workstation 15, displays the results and stores them. In this data acquisition and processing system, the model of the multi-channel electrochemical workstation 15 is CS3008, and the CSstudio software is installed in the computer 16.

[0042] In this embodiment, the rectangular annular tube, the connecting pipe fittings in the feeding system and the test system are all made of polyvinyl chloride (PVC).

[0043] Embodiment 2

[0044] In this embodiment, the equipment described in Embodiment 1 is used to test the corrosion of mine water on 304 stainless steel in real time and screen the corrosion inhibitors used for 304 stainless steel.

[0045] In this embodiment, the components contained in the mine water are shown in Table 1 below.

[0046] Table 1 Components Contained in Mine Water

[0047]

[0048]

[0049] In this embodiment, the corrosion inhibitors used are tannic acid TA, sodium molybdate SM, and the composition of tannic acid TA and sodium molybdate SM. When the corrosion inhibitor is tannic acid TA, the addition amount is 3 g per liter of mineral water, that is, 3 g / L TA. When the corrosion inhibitor is sodium molybdate SM, the addition amount is 0.04 mol per liter of mineral water, that is, 0.04 mol / L SM. When the corrosion inhibitor is the composition of tannic acid TA and sodium molybdate SM, there are the following four addition amounts: 3 g / L TA + 0.05 g / L SM (add 3 g TA and 0.05 g SM per liter of mineral water), 3 g / L TA + 0.1 g / L SM (add 3 g TA and 0.1 g SM per liter of mineral water), 3 g / L TA + 0.15 g / L SM (add 3 g TA and 0.15 g SM per liter of mineral water), 3 g / L TA + 0.2 g / L SM (add 3 g TA and 0.2 g SM per liter of mineral water).

[0050] In this embodiment, the feeding temperature of the mine water and the mine water containing the corrosion inhibitor is 25 ± 1 °C, the operating pressure is atmospheric pressure, pH = 7 ± 0.2, and the feeding flow rate is controlled at 12 L / min.

[0051] In this embodiment, the steps for testing the corrosion of mine water on 304 stainless steel are as follows:

[0052] Step 1: Polish the 304 stainless steel sheet (diameter 6.5 mm, thickness 3 mm) with 600# and 3000# sandpapers, then connect the 304 stainless steel sheet with a copper wire. Next, embed the 304 stainless steel sheet into one through-hole respectively set at the first elbow sampling point 9, the second elbow sampling point 13, the first straight pipe sampling point 10 and the second straight pipe sampling point 14 of the rectangular annular pipe, and make the side of the 304 stainless steel sheet facing the inner wall of the elbow or straight pipe flush with the inner wall of the elbow or straight pipe at the through-hole. Then, use hot melt adhesive to bond and fix each 304 stainless steel sheet at the through-hole and fill the micro-gap between the 304 stainless steel sheet and the through-hole. The copper wires connected to the 304 stainless steel sheets bonded at each sampling point are pulled out from the through-hole and connected to the multi-channel electrochemical workstation 15, and the through-holes without 304 stainless steel sheets bonded at each sampling point are blocked with plugs;

[0053] Step 2: Install a calomel reference electrode 19 and a platinum sheet electrode 20 respectively near the 304 stainless steel sheets bonded at the first elbow sampling point 9, the second elbow sampling point 13, the first straight pipe sampling point 10 and the second straight pipe sampling point 14 of the rectangular annular pipe, and connect the calomel reference electrodes and platinum sheet electrodes installed at each sampling point to the multi-channel electrochemical workstation 15 through copper wires; The loop formed by connecting the 304 stainless steel sheets bonded at each sampling point, the calomel reference electrode 19 and the platinum sheet electrode 20 installed is as Figure 6 shown;

[0054] Step 3: Add mine water to the water cooler 1, cool the mine water to 25 ± 1 °C by the water cooler 1 and then inject it into the jacketed water bath storage tank 2. Then, open the first stop valve 5, the second stop valve 7, and the third stop valve 11, adjust the mine water to the required flow rate of 12 L / min through the bypass valve 4, and then start the delivery pump 3 to transport the mine water in the jacketed water bath storage tank 2 to the rectangular annular pipe through the pipe fittings. The mine water flowing out of the rectangular annular pipe returns to the jacketed water bath storage tank 2 to form a circulating flow of the mine water;

[0055] Step 4: After the mine water circulates for 6 h, test the polarization curve information and impedance spectrum information of the 304 stainless steel sheet through the multi-channel electrochemical workstation 15, and transmit the collected information to the computer 16. After being processed by the computer 16, display the results and store them.

[0056] In this embodiment, the steps for testing the corrosion of 304 stainless steel by mine water containing corrosion inhibitor are the same as those for testing the corrosion of 304 stainless steel by mine water above.

[0057] The test results of the corrosion of 304 stainless steel by mine water and 6 kinds of mine water containing corrosion inhibitors are as follows:

[0058] (1) Test results of the 304 stainless steel sheet bonded at the sampling point of the first straight pipe

[0059] The polarization curve of the 304 stainless steel sheet bonded at the sampling point of the first straight pipe is shown in Figure 7 , and the impedance spectrum is shown in Figure 8 . The fitting data of the polarization curve are shown in Table 2 below.

[0060] Table 2 Fitting data of the polarization curve of the 304 stainless steel sheet at the sampling point of the first straight pipe

[0061]

[0062] (2) Test results of the 304 stainless steel sheet bonded at the sampling point of the second straight pipe

[0063] The polarization curve of the 304 stainless steel sheet bonded at the sampling point of the second straight pipe is shown in Figure 9 , and the impedance spectrum is shown in Figure 10 . The fitting data of the polarization curve are shown in Table 3 below.

[0064] Table 3 Fitting data of the polarization curve of the 304 stainless steel sheet at the sampling point of the second straight pipe

[0065]

[0066] (3) Test results of the 304 stainless steel sheet bonded at the sampling point of the first elbow

[0067] The polarization curve of the 304 stainless steel sheet bonded at the sampling point of the first elbow is shown in Figure 11 , and the impedance spectrum is shown in Figure 12 . The fitting data of the polarization curve are shown in Table 4 below.

[0068] Table 4 Fitting data of the polarization curve of the 304 stainless steel sheet at the sampling point of the first elbow

[0069]

[0070] (4) Test results of the 304 stainless steel sheet bonded at the sampling point of the second elbow

[0071] The polarization curve of the 304 stainless steel sheet bonded at the sampling point of the second elbow is shown in Figure 13 , and the impedance spectrum is shown in Figure 14 . The fitting data of the polarization curve are shown in Table 5 below.

[0072] Table 5 Fitting data of the polarization curve of the 304 stainless steel sheet at the sampling point of the second elbow

[0073]

[0074] It can be seen from the above test results that the test results at each sampling point are different. However, the test results at each sampling point show that for the mine water with tannic acid added alone, its self-corrosion current density is increased or decreased compared with that of the mine water, indicating that its corrosion inhibition effect is unstable. For the mine water with sodium molybdate added alone, its self-corrosion current density is decreased compared with that of the mine water, indicating that adding sodium molybdate alone has a corrosion inhibition effect. The tannic acid-sodium molybdate compound corrosion inhibitor composed of tannic acid and sodium molybdate in a certain proportion has the best corrosion inhibition effect for the compound corrosion inhibitor of 3g / L TA + 0.05g / L SM. It is not only superior to the tannic acid corrosion inhibitor and sodium molybdate corrosion inhibitor alone, but also superior to the tannic acid-sodium molybdate compound corrosion inhibitors in other proportions. Because Tables 2, 3, 4, and 5 show that the mine water with the compound corrosion inhibitor of 3g / L TA + 0.05g / L SM added has the smallest self-corrosion current density and the smallest corrosion rate. From Figure 8 , Figure 10 , Figure 12 and Figure 14 , it can be seen that the mine water with the compound corrosion inhibitor of 3g / L TA + 0.05g / L SM added has the largest charge transfer resistance radius, which is consistent with the results of the polarization curve. Therefore, for 304 stainless steel, adding the compound corrosion inhibitor composed of 3g TA and 0.05g SM per liter of mine water can minimize the corrosion.

Claims

1. Equipment for real-time evaluation of the corrosion behavior of mine water and screening of corrosion inhibitors, characterized in that The device consists of a feeding system, a testing system, and a data acquisition and processing system; the feeding system consists of a feeding flow path and a flow control flow path formed by sequentially connecting a water chiller (1), a jacketed water bath constant temperature storage tank (2), a delivery pump (3), a first stop valve (5), and a first flowmeter (6) through pipe fittings. The flow control flow path is composed of a bypass valve (4) and connecting pipe fittings. The liquid inlet end of the flow control flow path is connected to the pipe fitting between the delivery pump (3) and the first stop valve (5), and the liquid outlet end is connected to the jacketed water bath constant temperature storage tank (2); the testing system consists of a rectangular annular pipe, a first elbow sampling point (9) and a second elbow sampling point (13) respectively arranged at two top corners of the rectangular annular pipe, and a first straight pipe sampling point (10) and a second straight pipe sampling point (14) arranged on two parallel pipes of the rectangular annular pipe. An inlet (17) and an outlet (18) are respectively arranged on the two parallel pipes of the rectangular annular pipe without sampling points, and a second stop valve (7), a third stop valve (11), a second flowmeter (8), and a third flowmeter (12) are respectively arranged on the pipe fittings on both sides of the inlet. The inlet (17) is connected to the outlet of the first flowmeter (6) in the feeding flow path through pipe fittings, and the outlet (18) is connected to the jacketed water bath constant temperature storage tank (2) in the feeding flow path through pipe fittings; the data acquisition and processing system consists of a multi-channel electrochemical workstation (15) and a computer (16). The multi-channel electrochemical workstation (15) is used to collect information of each sampling point arranged on the rectangular annular pipe in the testing system and transmit the collected information to the computer (16). The computer (16) processes the information from the multi-channel electrochemical workstation (15) and then displays the results and stores them.

2. The device for real-time evaluating the corrosion behavior of mine water and screening corrosion inhibitors according to claim 1, wherein At least three through holes for installing sheet-like test materials are provided at the first elbow sampling point (9) and the second elbow sampling point (13), and one or two through holes for installing sheet-like test materials are provided at the first straight pipe sampling point (10) and the second straight pipe sampling point (14).

3. The device for real-time evaluation of the corrosion behavior of mine water and screening of corrosion inhibitors according to claim 1 or 2, characterized in that The rectangular annular pipe in the testing system is formed by threadedly connecting four straight pipes and four "right-angled" or "arc-shaped" elbows.

4. The device for real-time evaluating the corrosion behavior of mine water and screening corrosion inhibitors according to claim 1 or 2, characterized in that The delivery pump (3) is a centrifugal pump, the first flowmeter (6) is a rotameter, and the second flowmeter (8) and the third flowmeter (12) are ultrasonic flowmeters.

5. The device for real-time evaluating the corrosion behavior of mine water and screening corrosion inhibitors according to claim 3, wherein The delivery pump (3) is a centrifugal pump, the first flowmeter (6) is a rotameter, and the second flowmeter (8) and the third flowmeter (12) are ultrasonic flowmeters.

6. The method of using the device for real-time evaluating the corrosion behavior of mine water and screening corrosion inhibitors according to any one of claims 1 to 5, characterized in that The operation steps are as follows: Step 1: Grind and polish the sheet-shaped test material, then connect the sheet-shaped test material to a wire. Next, embed the sheet-shaped test material into at least one through-hole provided at the first elbow sampling point (9), the second elbow sampling point (13), the first straight pipe sampling point (10), and the second straight pipe sampling point (14) of the rectangular annular pipe, and make the side of the sheet-shaped test material facing the inner wall of the elbow or straight pipe flush with the inner wall of the elbow or straight pipe at the through-hole. Then, use hot melt adhesive to bond and fix each sheet-shaped test material at the through-hole and fill the gap between the sheet-shaped test material and the through-hole. Pull out the wires connected to the sheet-shaped test materials bonded at each sampling point from the through-hole and connect them to the multi-channel electrochemical workstation (15). Plug the through-holes at each sampling point where no sheet-shaped test material is bonded with plugs. Step 2: Install a calomel reference electrode (19) and a platinum sheet electrode (20) near the sheet-shaped test materials bonded at the first elbow sampling point (9), the second elbow sampling point (13), the first straight pipe sampling point (10), and the second straight pipe sampling point (14) of the rectangular annular pipe, and connect the calomel reference electrodes and platinum sheet electrodes installed at each sampling point to the multi-channel electrochemical workstation (15) through wires. Step 3: Add mine water or mine water containing an inhibitor to the water cooler (1). Cool the mine water or mine water containing an inhibitor to the feed water temperature through the water cooler (1) and then inject it into the jacketed water bath constant temperature storage tank (2). Then, open the first stop valve (5), the second stop valve (7), and the third stop valve (11). Adjust the mine water or mine water containing an inhibitor to the required flow rate through the bypass valve (4). Then, start the delivery pump (3) to transport the mine water or mine water containing an inhibitor in the jacketed water bath constant temperature storage tank (2) to the rectangular annular pipe through pipe fittings. The mine water or mine water containing an inhibitor flowing out of the rectangular annular pipe returns to the jacketed water bath constant temperature storage tank (2) to form a circulating flow of the mine water or mine water containing an inhibitor. Step 4: After the mine water or mine water containing an inhibitor circulates for at least 4 hours, test the polarization curve information and impedance spectrum information of the sheet-shaped test material through the multi-channel electrochemical workstation (15), and transmit the collected information to the computer (16). After being processed by the computer (16), display the results and store them.

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