Inhibitor stock solution for marble cutting saw blade, preparation method and application of inhibitor

Abstract

The present invention discloses a corrosion inhibitor stock solution for marble cutting saw blades, a preparation method and application of the corrosion inhibitor. The corrosion inhibitor is composed of benzotriazole, sodium nitrite, sodium molybdate, sodium silicate, triethanolamine and sodium benzoate which are mixed in proportion. The preparation method is to first dissolve sodium silicate, triethanolamine and sodium benzoate in water and heat, then add benzotriazole, sodium nitrite and sodium molybdate, continuously heat and stir until completely dissolved, and then dilute with water to obtain the compound corrosion inhibitor. The compound corrosion inhibitor of the present invention has excellent corrosion inhibition performance, has a simple preparation process, low cost, convenient use, easy control, and can extend the service life of the saw blade.

Description

Technical Field

[0001] The present invention belongs to the field of corrosion inhibitors, and particularly relates to a corrosion inhibitor stock solution for marble cutting saw blades, a preparation method and application of the corrosion inhibitor. Background Art

[0002] During the stone processing, a saw blade is used to cut the stone. A large amount of heat is dissipated during the cutting process of the saw blade. Therefore, an open-circuit circulating cooling water system is adopted to cool down the saw blade. Stone wastewater mainly comes from the cooling water during the cutting process of the saw blade, which contains a large amount of suspended solids, anions and cations, continuously corrodes the saw blade, shortens the equipment life, and causes huge economic losses and environmental risks.

[0003] By adopting the method of adding a corrosion inhibitor, the corrosion rate of the saw blade can be reduced, the anodic or cathodic reaction can be inhibited, delayed or even completely prevented, and the environmental hazards caused by corrosion can be avoided. At present, most commercially available corrosion inhibitors, such as carboxylic acid organic corrosion inhibitors, are relatively cheap in price, but their corrosion inhibition performance is weak. Most traditional corrosion inhibitors contain organic phosphoric acid. A large amount of untreated phosphorus-containing water discharged will cause a large number of algae to grow, cause water eutrophication, endanger the water environment, and increase the water treatment cost.

[0004] Therefore, it is of great significance to develop a corrosion inhibitor with low price, excellent performance and suitable for large-scale use in stone factories. Summary of the Invention

[0005] The present invention is proposed to solve the problems of complex process and high price of existing corrosion inhibitors, and its purpose is to provide a corrosion inhibitor stock solution for marble cutting saw blades, a preparation method and application of the corrosion inhibitor.

[0006] The present invention is achieved through the following technical solutions:

[0007] A corrosion inhibitor stock solution for marble cutting saw blades, characterized in that the components of the corrosion inhibitor stock solution and the mass parts of each component are as follows:

[0008]

[0009] In the above technical solution, the components of the corrosion inhibitor stock solution and the mass parts of each component are as follows:

[0010]

[0011]

[0012] In the above technical solution, the components of the corrosion inhibitor stock solution and the mass parts of each component are as follows:

[0013]

[0014] Preparation method of special corrosion inhibitor for marble cutting saw blade, comprising the following steps:

[0015] (ⅰ) Weigh 5 - 30 parts by mass of sodium silicate, 5 - 50 parts of triethanolamine and 10 - 80 parts of sodium benzoate in proportion, mix evenly and transfer to a round-bottom flask;

[0016] (ⅱ) Wash the mixture obtained in step (ⅰ) with 50 mL - 150 mL of deionized water, stir at 30°C - 40°C for 10 min to obtain a mixed solution;

[0017] (ⅲ) Weigh 0.5 - 1.5 parts by mass of benzotriazole, 50 - 100 parts of sodium nitrite, 10 - 30 parts of sodium molybdate in proportion, add to the mixed solution obtained in step (ⅱ), stir evenly at 30°C - 40°C to obtain the original corrosion inhibitor solution;

[0018] (ⅳ) Cool the original corrosion inhibitor solution obtained in step (ⅲ) to room temperature, add deionized water to the original corrosion inhibitor solution according to the ratio of original corrosion inhibitor solution:deionized water = 1:2, stir for 5 min to obtain the corrosion inhibitor.

[0019] In the above technical solution, the purity of the triethanolamine is at least 99%, the purity of the sodium benzoate is at least 99%, and the purity of the sodium nitrite is at least 99%.

[0020] In the above technical solution, the stirring speed in step (ⅱ) is 300 - 400 rpm, preferably 300 rpm.

[0021] In the above technical solution, the stirring speed in step (ⅳ) is 500 - 800 rpm, preferably 600 rpm.

[0022] Application of special corrosion inhibitor for marble cutting saw blade, adding the corrosion inhibitor to the corrosive medium, and adding 10 mL - 50 mL of the corrosion inhibitor to each 1 L of the corrosive medium.

[0023] In the above technical solution, the corrosive medium is stone wastewater.

[0024] Evaluation method for corrosion inhibition performance of corrosion inhibitor for marble saw blade in stone wastewater, comprising the following steps:

[0025] (ⅰ) Measure 10 - 50 mL of the corrosion inhibitor and mix it in 1 L of the corrosive medium to obtain a corrosive solution;

[0026] (ⅱ) At room temperature, conduct a dynamic weight loss experiment in the corrosive solution obtained in step (ⅰ) to evaluate the corrosion inhibition performance;

[0027] (ⅲ) At room temperature, use an exposed surface area of 1 cm 2A carbon steel sample was used as the working electrode for electrochemical tests. The Tafel polarization curves and electrochemical impedance data of the carbon steel electrode in the corrosive medium before and after adding the corrosion inhibitor were measured to evaluate the corrosion inhibition performance.

[0028] In the above technical solution, before the dynamic weight loss experiment in step (ii), the carbon steel sample was immersed in the corrosion inhibitor solution for 3 min to 5 min, which was more conducive to preventing corrosion.

[0029] In the above technical solution, the stirring speed of the dynamic weight loss experiment in step (ii) was 250 rpm.

[0030] In the above technical solution, the room temperature in steps (ii) and (iii) was 30 °C.

[0031] The beneficial effects of the present invention are as follows:

[0032] The present invention provides a special corrosion inhibitor stock solution for marble cutting saw blades and a preparation method thereof. The corrosion inhibitor has stable corrosion inhibition performance, can effectively inhibit the corrosion of the metal matrix in stone wastewater, has the characteristics of less dosage and obvious effect, and there is a certain synergistic effect among the chemical components of the corrosion inhibitor. Its production process is simple, the manufacturing cost is low, and it has strong market competitiveness. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is the Tafel polarization curve atlas of carbon steel adding different concentrations of corrosion inhibitor in 1 L of stone wastewater;

[0034] Figure 2 It is the Nyquist diagram of carbon steel adding different concentrations of corrosion inhibitor in 1 L of stone wastewater;

[0035] Figure 3 It is the Bode diagram of carbon steel adding different concentrations of corrosion inhibitor in 1 L of stone wastewater;

[0036] Figure 4 It is the scanning electron microscope image of carbon steel adding different concentrations of corrosion inhibitor and immersed in 1 L of stone wastewater for 7 d.

[0037] For those of ordinary skill in the art, without creative efforts, other related drawings can be obtained according to the above drawings. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention will be further described below with reference to the drawings in the specification and through specific embodiments.

[0039] Example 1

[0040] A preparation method of a special corrosion inhibitor for marble cutting saw blades includes the following steps:

[0041] (i) Weigh 15 parts by mass of sodium silicate, 20 parts of triethanolamine with a purity greater than 99%, and 50 parts of sodium benzoate with a purity greater than 99% proportionally. After mixing evenly, transfer them to a round-bottom flask.

[0042] (ii) Wash the mixture obtained in step (i) with 50 mL of deionized water, stir at 40 °C for 10 min with a stirring speed of 300 rpm to obtain a mixed solution.

[0043] (iii) Weigh 1 part by mass of benzotriazole, 75 parts of sodium nitrite with a purity greater than 99%, and 15 parts of sodium molybdate proportionally, add them to the mixed solution obtained in step (ii), and stir evenly at 30 °C - 40 °C to obtain the original inhibitor solution.

[0044] (iv) Cool the original inhibitor solution obtained in step (iii) to room temperature, add deionized water to the original inhibitor solution according to the volume ratio of the original inhibitor solution to deionized water of 1:2, stir for 5 min with a stirring speed of 600 rpm to obtain the inhibitor.

[0045] Example 2

[0046] Evaluation method for the corrosion inhibition performance of the corrosion inhibitor for marble saw blades in stone waste water - Dynamic weight loss experiment:

[0047] (1) Prepare the test solutions

[0048] Prepare the test solutions according to the volume ratios of stone waste water to the inhibitor of 1 L:0 mL, 1 L:10 mL, 1 L:20 mL, 1 L:30 mL, and 1 L:40 mL respectively.

[0049] (2) Grind carbon steel with a specification of 50×25×2 mm step by step with 240#, 400#, 1000#, 1200#, and 1500# sandpapers, then ultrasonically clean with acetone and ethanol for 10 min, air-dry naturally, put it into the inhibitor and soak for 3 - 5 min and then take it out, hang it and place it to dry under the condition of room temperature without corrosive atmosphere. At room temperature, put the carbon steel after the same treatment into different test solutions for dynamic weight loss tests. After 7 d, take out the carbon steel, remove the corrosion products on the surface of the carbon steel, clean and dry it, and weigh it. Calculate the corrosion rate according to the formula v = (W0 - W1) / (S t), where W0 is the mass of the coupon before corrosion; W1 is the mass of the coupon after corrosion; S is the surface area of the coupon; t is the time. Calculate the inhibition efficiency according to the formula η = (v1 - v0) / v0, where v0 is the corrosion rate of the coupon in the stone waste water containing the inhibitor; v1 is the corrosion rate of the coupon in the stone waste water without the inhibitor.

[0050] Table 1 Results of the inhibition efficiency of carbon steel in stone waste water containing different concentrations of the inhibitor

[0051] Inhibitor concentration (mL / L) <![CDATA[Corrosion rate (g·cm -2 h -1 )]]> Inhibition efficiency (%) 0 0.5833 — 10 0.3024 48.16 20 0.1429 75.51 30 0.0738 87.35 40 0.0095 98.37

[0052] As can be seen from the data in Table 1, as the concentration of the corrosion inhibitor increases, the corrosion inhibition efficiency continuously increases. When the concentration reaches 40 mL / L, the corrosion inhibition efficiency reaches 98.37%, indicating that this corrosion inhibitor can effectively inhibit the corrosion of carbon steel in stone waste water.

[0053] Example 3

[0054] Evaluation method for corrosion inhibition performance of marble saw blade corrosion inhibitor in stone waste water - Chemical test

[0055] (1) Prepare test solutions

[0056] Prepare 150 mL of test solutions according to the volume ratios of stone waste water to corrosion inhibitor of 1 L:0 mL, 1 L:10 mL, 1 L:20 mL, 1 L:30 mL, and 1 L:40 mL respectively.

[0057] (2) Use carbon steel with a test area of 1 cm 2 as the working electrode, Ag / AgCl electrode as the reference electrode, and platinum electrode as the auxiliary electrode. Use a CS120 electrochemical workstation to measure the potentiodynamic polarization curve in a three - electrode system. Pre - scan the open - circuit potential for 0.5 h until it is stable before testing, with a scan rate of 5 mV / s and a scan range of E±0.5 V.

[0058] From Figure 1 the Tafel polarization curve patterns of carbon steel in stone waste water with different concentrations of corrosion inhibitor added, it can be seen that as the concentration of the corrosion inhibitor increases, the self - corrosion potential of the polarization curve moves towards the positive potential direction, and at the same time, the polarization curve also moves towards the direction with a lower current density. From Figure 2 and Figure 3 it can be seen that the impedance spectrum is semi - circular. The larger the dosage of the corrosion inhibitor, the larger the diameter of the capacitive reactance arc; the larger the dosage of the corrosion inhibitor, the continuously increasing impedance modulus. The results of electrochemical impedance are consistent with the results of the polarization curve, indicating that the corrosion inhibitor has good corrosion inhibition performance.

[0059] Example 4

[0060] Evaluation method for corrosion inhibition performance of marble saw blade corrosion inhibitor in stone waste water - Corrosion test

[0061] (1) Prepare test solutions

[0062] Prepare test solutions according to the volume ratios of stone waste water to corrosion inhibitor of 1 L:0 mL, 1 L:20 mL, and 1 L:40 mL respectively.

[0063] (2) Carbon steel with a specification of 50×25×2mm was polished step by step with 240#, 400#, 1000#, 1200#, and 1500# sandpaper, and then ultrasonically treated with acetone and ethanol for 10 minutes. After natural air drying, it was immersed in a corrosion inhibitor for 3 to 5 minutes and then taken out and hung to dry at room temperature without a corrosive atmosphere. The carbon steel that had undergone the same treatment was placed in different test solutions for corrosion tests at room temperature. After 7 days, the surface morphology of the polished carbon steel and the corroded carbon steel was tested.

[0064] Depend on Figure 4 It can be seen that the surface of polished carbon steel is flat, with deep and clear lines; the carbon steel in stone wastewater without corrosion inhibitor is seriously corroded, with a thick layer of corrosion products covering the surface, which is uneven; when the corrosion inhibitor is added at a dosage of 20mL / L, the surface lines disappear and become flat, but corrosion still occurs in some parts; when the corrosion inhibitor dosage reaches 40mL / L, there is no significant difference between the carbon steel surface and the polished carbon steel. This shows that the corrosion inhibitor can effectively inhibit the corrosion of carbon steel in stone wastewater. The results are consistent with the electrochemical test results.

[0065] Benzotriazole in the special corrosion inhibitor for marble cutting saw blades is an effective organic metal corrosion inhibitor, but the corrosion inhibition effect of single benzotriazole is poor and it is expensive; molybdate has low toxicity and low environmental pollution, and is generally used in conjunction with corrosion inhibitors such as benzotriazole; silicate is a green corrosion inhibitor and also a co-solvent, with the advantages of being non-toxic and inexpensive, and is usually used in conjunction with organic corrosion inhibitors to accelerate the film formation rate; nitrite is an effective metal corrosion inhibitor, usually used in conjunction with other corrosion inhibitors such as sodium benzoate, showing excellent corrosion inhibition effect, and can form an oxide film on the metal surface. In order to further illustrate the synergistic effect between the various chemical components of the special corrosion inhibitor for marble cutting saw blades, comparative examples 1 to 4 are set:

[0066] Comparative Example 1

[0067] (i) Add 0.008 g / L benzotriazole into the corrosive medium to obtain a corrosive solution.

[0068] (ii) A dynamic weight loss experiment was conducted at room temperature in the corrosion solution of step (i), and the corrosion inhibition efficiency was measured to be 7.13%.

[0069] Comparative Example 2

[0070] (i) Add 0.008 g / L benzotriazole and 0.1 g / L sodium silicate into a corrosive medium to obtain a corrosive solution.

[0071] (ii) A dynamic weight loss experiment was conducted at room temperature in the corrosion solution of step (i), and the corrosion inhibition efficiency was measured to be 45.56%.

[0072] Comparative Example 3

[0073] (ⅰ) Add 0.008 g / L of benzotriazole, 0.1 g / L of sodium silicate, and 0.1 g / L of sodium molybdate to the corrosion medium to obtain a corrosion solution.

[0074] (ⅱ) At room temperature, conduct a dynamic weight loss experiment in the corrosion solution obtained in step (ⅰ), and the measured corrosion inhibition efficiency is 59.63%.

[0075] Comparative Example 4

[0076] (ⅰ) Add 0.008 g / L of benzotriazole, 0.1 g / L of sodium silicate, 0.1 g / L of sodium molybdate, and 0.15 g / L of triethanolamine to the corrosion medium to obtain a corrosion solution.

[0077] (ⅱ) At room temperature, conduct a dynamic weight loss experiment in the corrosion solution obtained in step (ⅰ), and the measured corrosion inhibition efficiency is 67.14%.

[0078] From the corrosion inhibition efficiencies of Comparative Examples 1 - 4 and the results of Example 2, it can be seen that as the types of corrosion inhibitors added increase, the corrosion inhibition efficiency also continuously improves; there is a synergistic effect between sodium benzoate and sodium nitrite. They all belong to anodic corrosion inhibitors and can inhibit the oxygen absorption corrosion of the metal anode; benzotriazole, triethanolamine, and sodium benzoate all belong to organic corrosion inhibitors and form a protective film on the metal surface through adsorption; sodium silicate, sodium nitrite, and sodium molybdate all belong to inorganic corrosion inhibitors and inhibit the progress of the corrosion reaction by forming an oxide film or a precipitation film on the metal surface. Only the special corrosion inhibitor for marble cutting saw blades with the complete components in Example 1 can achieve excellent corrosion inhibition effects.

[0079] The applicant declares that the above - mentioned is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by any person skilled in the art within the technical scope disclosed by the present invention fall within the protection scope and the disclosure scope of the present invention.

Claims

1. An inhibitor stock solution for marble cutting saw blades, characterized in that: The components of the corrosion inhibitor stock solution and the mass parts of each component are as follows: Benzotriazole 0.5 - 1.5; Sodium nitrite 50 - 100; Sodium molybdate 10 - 30; Sodium silicate 5 - 30; Triethanolamine 5 - 50; Sodium benzoate 10 - 80.

2. The inhibitor stock solution for marble cutting saw blades according to claim 1, characterized in that: The components of the corrosion inhibitor stock solution and the mass parts of each component are as follows: Benzotriazole 0.9 - 1.2; Sodium nitrite 73 - 76; Sodium molybdate 13 - 16; Sodium silicate 12 - 16; Triethanolamine 18 - 21; Sodium benzoate 48 - 51.

3. The inhibitor stock solution for marble cutting saw blade according to claim 1, characterized in that: The components of the corrosion inhibitor stock solution and the mass parts of each component are as follows: Benzotriazole 1; Sodium nitrite 75; Sodium molybdate 15; Sodium silicate 15; Triethanolamine 20; Sodium benzoate 50.

4. A method for preparing a corrosion inhibitor for a marble cutting saw blade according to any one of claims 1 to 3, characterized in that: It includes the following steps: (ⅰ) Mix sodium silicate, triethanolamine and sodium benzoate to obtain a mixture; (ⅱ) Wash the mixture obtained in step (ⅰ) with deionized water and stir to obtain a mixed solution; (ⅲ) Add benzotriazole, sodium nitrite, and sodium molybdate to the mixed solution in step (ⅱ) and stir evenly to obtain the corrosion inhibitor stock solution; (ⅳ) Cool the corrosion inhibitor stock solution obtained in step (ⅲ) to room temperature, add deionized water to the corrosion inhibitor stock solution and stir to obtain the corrosion inhibitor.

5. The preparation method of the corrosion inhibitor for marble cutting saw blades according to claim 4, characterized in that: The mass parts of the sodium silicate, triethanolamine, sodium benzoate, triazole, sodium nitrite and sodium molybdate are as described in any one of claims 1 to 3.

6. The preparation method of the corrosion inhibitor for marble cutting saw blades according to claim 4, characterized in that: The stirring temperature in steps (ⅱ) and (ⅲ) is 30°C - 40°C, the stirring time in step (ⅱ) is 10 min; the stirring time in step (ⅳ) is 5 min; the stirring speed in step (ⅱ) is 300 - 400 rpm, and the stirring speed in step (ⅳ) is 500 - 800 rpm.

7. The preparation method of the corrosion inhibitor for marble cutting saw blades according to claim 4, characterized in that: In step (ⅱ), the mass ratio of deionized water to the mixture is 25:1; in step (ⅳ), the volume ratio of the corrosion inhibitor stock solution to deionized water is 1:2.

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