Preparation method of temperature-resistant high-hydrogen-inhibiting polymer inhibitor for wet dust removal system and application thereof

Abstract

The present application relates to the hydrogen explosion prevention and treatment field of wet dust removal system, especially to the hydrogen production inhibition technology field of polishing and grinding aluminum alloy dust in wet dust removal system, in particular to a preparation method of a temperature-resistant high-hydrogen-inhibiting polymer inhibitor for a wet dust removal system and application thereof.The inhibitor is a polymer obtained by ion reaction after chitosan and sodium alginate are compounded.The preparation steps include: preparing a chitosan acetic acid solution;preparing a sodium alginate solution, adding sodium chloride to the sodium alginate solution;pouring the chitosan solution into the sodium alginate solution, stirring and mixing to obtain a chitosan and sodium alginate composite gel solution;adding excess ethanol to the composite gel solution for precipitation, separating the precipitate, drying, and grinding to obtain the product.The inhibitor significantly improves the hydrogen inhibition effect on aluminum alloy dust, enhances the hydrogen inhibition stability in a high-temperature environment, and efficiently, quickly and stably adsorbs aluminum alloy dust.

Description

Technical Field

[0001] The present invention relates to the field of explosion prevention and control of metal hydrogen production in wet dust removal systems, in particular to the technical field of hydrogen production suppression in polishing and grinding aluminum alloy dust in wet dust removal systems, and specifically to a preparation method and application of a temperature-resistant and highly hydrogen-suppressing polymer inhibitor for wet dust removal systems. Background Art

[0002] Aluminum alloy is a lightweight, high-strength material that is widely used in aerospace, automobile manufacturing, and other fields, and has a high practical value. With the advancement and development of science and technology and technology, the demand for aluminum alloys in various fields has gradually increased. However, during the mechanical processing of aluminum alloys, a large amount of scrap alloy dust is generated. Scrap aluminum alloy powder is a hazardous waste material, and strict control measures need to be taken during its collection, storage, and utilization. Currently, dry and wet dust collectors are two collection and treatment systems for scrap aluminum alloy powder produced during mechanical processing. Dry dust collectors are prone to aluminum dust explosion accidents, while wet dust collectors can prevent dust explosions to a certain extent and are being widely used to collect scrap alloy powder.

[0003] However, when aluminum alloy scrap powder comes into contact with water in a wet dust collector, it undergoes a hydrolysis reaction, generating hydrogen. This poses a risk of hydrogen explosions in wet dust collection systems. This is primarily due to the hydrogen produced by the hydrolysis of aluminum alloy scrap powder. The accumulation of hydrogen, combined with static electricity and machine impact, can cause explosions. While hydrogen accumulation is prevented by installing hydrogen detection alarms and continuously running fans to remove hydrogen, these safety measures cannot fundamentally eliminate hydrogen production, and the risk of hydrogen explosions caused by system or equipment failures remains. Furthermore, the risk of hydrogen generation and accumulation explosions persists during the subsequent storage and utilization of waste residues.

[0004] Adding inhibitors to the liquid environment of wet dust collectors is the most convenient, economical, and effective method for addressing hydrogen production. Traditional inorganic and organic inhibitors, such as chromates and dichromates, and benzimidazoles, pose environmental risks and biodegradation challenges. Therefore, based on the concept of green chemistry, developing safe, non-toxic, highly effective, sustainable, and environmentally friendly green inhibitors based on traditional inhibitors is a key research direction. Summary of the Invention

[0005] In order to solve the problem of certain environmental pollution caused by inorganic and organic hydrogen inhibitors in traditional wet dust collectors and the challenges they bring to biodegradation, the present invention provides a method for preparing a high-temperature-resistant and high-hydrogen-suppression polymer inhibitor for a wet dust removal system and its application. A high-temperature-resistant and high-hydrogen-suppression polymer inhibitor is obtained by conducting an ion reaction between the biomass material chitosan and sodium alginate. The high-temperature-resistant and high-hydrogen-suppression polymer inhibitor contains polar groups such as amino, carboxyl, carbonyl and hydroxyl groups, which contain electron-rich heteroatoms such as oxygen and nitrogen atoms, and their lone pairs of electrons form coordination bonds with aluminum atoms on the surface of aluminum alloy powder; the -COO- groups on the high-temperature-resistant and high-hydrogen-suppression polymer inhibitor molecules undergo a chelating reaction with the metal ions dissolved in the aluminum alloy powder, so that the inhibitor molecules can be firmly adsorbed on the surface of the aluminum alloy waste dust, thereby self-assembling between water molecules and the aluminum alloy waste dust to form a dense and complete physical barrier film; it can block the contact between water molecules and aluminum alloy waste dust, thereby avoiding the reaction of aluminum and water to generate hydrogen, thereby realizing the essential safety production of the wet dust removal system.

[0006] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0007] The invention provides an inhibitor, which is a polymer obtained by compounding chitosan and sodium alginate and then subjecting them to ion reaction.

[0008] In the above technical solution, further, the preparation method of the inhibitor comprises the following steps:

[0009] (1) preparing chitosan acetic acid solution;

[0010] (2) preparing a sodium alginate solution by adding sodium chloride to the sodium alginate solution;

[0011] (3) pouring the chitosan solution into the sodium alginate solution, stirring and mixing to obtain a chitosan and sodium alginate composite gel solution;

[0012] (4) Adding excess ethanol to the composite gel solution described in step (3) to precipitate, separating the precipitate, drying, and grinding to obtain the composite gel solution.

[0013] In the above technical solution, further, the concentration of the chitosan acetic acid solution is 1-3wt%, and the concentration of the sodium alginate solution is 1-3wt%; preferably, the concentration of the chitosan acetic acid solution is 2wt%, and the concentration of the sodium alginate solution is 2wt%;

[0014] In the above technical solution, further, the mass ratio of the chitosan solution to the sodium alginate solution is: 1:0.5-1.5; preferably, the mass ratio of the chitosan solution to the sodium alginate solution is 1:1.

[0015] In the technical solution, further, the mass ratio of sodium alginate and sodium chloride in the step (2) is 1:8-9.5; preferably, the mass ratio of sodium alginate and sodium chloride in the step (2) is 1:8.8.

[0016] In the technical solution, further, the stirring speed in the step (2) is greater than 3000rmp.

[0017] In the technical solution, further, the deacetylation degree of the chitosan is greater than or equal to 95%, and the viscosity is 100-200mpa.s; the concentration of acetic acid used is 1%; the sodium alginate is 90% pure, and the sodium alginate is analytically pure.

[0018] In the technical solution, further, the ethanol in the step (4) is anhydrous ethanol; the separation and precipitation are filtered by a funnel, and the precipitate is washed; the drying is performed at 60-80 DEG C for 48-96h; and the grinding mode is ball milling.

[0019] The application also provides the foregoing inhibitor for inhibiting hydrogen production of aluminum alloy dust when meeting water.

[0020] In the technical solution, further, the application is to configure the inhibitor into a suspension by adding water, and then mix the suspension with aluminum alloy dust; preferably, the concentration of the suspension is 0.1-0.6wt%, and the mixing ratio of aluminum alloy dust and the suspension is 1.5g:200ml; preferably, the aluminum alloy dust comprises, by mass percentage, aluminum 80.09%, lithium 0.91%, zinc 5.7%, magnesium 3.2%, and copper 10.1%.

[0021] Compared with the prior art, the application has the following beneficial effects:

[0022] The application uses the environment-friendly and economically efficient biomass materials chitosan and sodium alginate as raw materials to synthesize a green, environmentally friendly and efficient hydrogen inhibitor. Chitosan and sodium alginate are typical marine biomass materials, which can be extracted from marine organisms such as crabs and shrimp shells. Sodium alginate can be extracted from marine plants such as kelp and sargassum. Both are green and environmentally friendly raw materials, and have the advantages of biodegradability, non-toxicity, and renewability. The synthesis process of the inhibitor is simple, the reaction conditions are mild, the hydrogen inhibition effect on aluminum alloy dust is significantly improved, the hydrogen inhibition stability in a high-temperature environment is enhanced, and the aluminum alloy dust is efficiently, quickly and stably adsorbed. It is of great significance to inhibit the explosion risk caused by hydrogen production of aluminum alloy polishing dust in a wet dust removal system. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The reaction mechanism diagram of the temperature-resistant high-hydrogen-inhibiting polymer inhibitor of the application;

[0024] Figure 2These are the SEM and EDS images of the temperature-resistant high hydrogen inhibition polymer inhibitor powder obtained in Examples 2-4 of the present invention and chitosan and sodium alginate after hydrogen inhibition.

[0025] Figure 3 This is the XPS spectrum of the hydrogen suppression product of the temperature-resistant and highly hydrogen suppression polymer inhibitor obtained in Example 1 of the present invention.

[0026] Figure 4 This is the infrared spectrum of the temperature-resistant and highly hydrogen-suppressive polymer inhibitor powder obtained in Example 1 of the present invention. DETAILED DESCRIPTION

[0027] In order to make the purpose, 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 in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention.

[0028] Example 1

[0029] Add 50 ml of 1% acetic acid and 1 g of chitosan to beaker 1, and stir at 650 rpm for 0.5 h at 30° C. using a magnetic stirrer to prepare a 2 wt % chitosan solution; the chitosan has a deacetylation degree of ≥95% and a viscosity of 100-200 mPa.s.

[0030] Add 50 ml of deionized water and 1 g of sodium alginate to beaker 2, and stir at 650 rpm using a magnetic stirrer at 30°C for 0.5 h to prepare a 2 wt% sodium alginate solution. Add 8.8 g of sodium chloride to the sodium alginate solution and stir thoroughly. The addition of sodium chloride can serve as a stabilizer and enhancer for the chitosan and sodium alginate solution system.

[0031] Slowly pour the chitosan solution into the sodium alginate solution at a mass ratio of 1:1, and rapidly stir the mixed solution to form a chitosan and sodium alginate composite gel solution; the stirring speed is greater than 3000 rpm;

[0032] Excess ethanol was added to precipitate the viscous solution, and the precipitated polymer was separated using a filter funnel, washed 2-3 times with deionized water, and then dried at 80°C for 48 h.

[0033] The precipitate was ground using a grinder, with the rotation speed set to 30,000 r / min and the time set to 10 minutes, to finally obtain a temperature-resistant and highly hydrogen-suppressive polymer inhibitor powder.

[0034] Example 2

[0035] The heat-resistant, highly hydrogen-suppressive polymer inhibitor powder prepared in Example 1 was added to 200 ml of deionized water to create a suspension with a concentration of 0.1-0.6 wt% (in 0.1 wt% increments). 1.5 g of Al-Li alloy powder was weighed. The aluminum alloy powder used in this example consisted of the following mass percentages: 80.09% aluminum, 0.91% lithium, 5.7% zinc, 3.2% magnesium, and 10.1% copper. The powder and suspension were placed in varying proportions in a testing system (the tester described in patent CN106153831B), set to 60°C and 100 kPa. The pressure change was recorded continuously for 12 hours.

[0036] Example 3

[0037] Chitosan powder was added to 200ml of deionized water to create a suspension with a concentration of 0.1-0.6wt% (in 0.1wt% increments). 1.5g of Al-Li alloy powder was weighed. The powder and suspension were placed in a test system set to 60°C and 100kPa. The pressure change was recorded continuously for 12 hours.

[0038] Example 4

[0039] Sodium alginate powder was added to 200ml of deionized water to prepare solutions with concentrations of 0.05wt%, 0.1wt%, 0.2wt%, 0.3wt%, 0.4wt%, and 0.5wt%. 1.5g of Al-Li alloy powder was weighed. The powder and suspension were placed in a test system set to 60°C and 100kPa. The pressure change was recorded continuously for 12 hours.

[0040] Example 5

[0041] To meet the temperature requirements of wet dust removal systems at industrial sites, this study investigated the temperature effects of 0.4 wt% heat-resistant, highly hydrogen-suppressing polymer powder, with the temperature set at 40-60° C. Other parameters were consistent with those in Example 2.

[0042] In order to quantify the reaction progress of metal hydrolysis and the amount of hydrogen produced, this study used the ideal state equation to calculate the hydrogen conversion rate α based on the pressure change of the test system.

[0043]

[0044] In the formula, P and P0 represent the pressure at the end of hydrolysis and the initial pressure, kPa; V and V0 represent the volume of the system container and the volume of the solution, mL; n represents the amount of substance of hydrogen gas theoretically generated by complete hydrolysis of the metal powder, mol, and the n value of the alloy powder used in Example 2 is 0.0835; R represents the ideal gas constant, 8.314 J / (mol·K), and T represents the hydrolysis experiment temperature, K.

[0045] The hydrogen inhibition efficiency σ of the temperature-resistant high-hydrogen-inhibition polymer inhibitor of different concentrations in Examples 2-4, chitosan and sodium alginate was calculated according to formula (2), and see Table 1.

[0046]

[0047] In the formula, α Black : the hydrogen conversion rate of the 12h blank solution; α Inhibitor : the hydrogen conversion rate under the 12h inhibitor solution.

[0048] Table 1 Hydrogen inhibition efficiency under different inhibitor concentrations

[0049]

[0050] The highest hydrogen inhibition efficiency of the temperature-resistant high-hydrogen-inhibition polymer inhibitor prepared in Example 1 is 96.14%, the highest hydrogen inhibition efficiency of chitosan in Example 2 is 30.49%, and the highest hydrogen inhibition efficiency of sodium alginate in Example 4 is 80.05%. This shows that the temperature-resistant high-hydrogen-inhibition polymer inhibitor modified by chitosan and sodium alginate can better inhibit the hydrogen generation behavior of aluminum alloy dust.

[0051] As Figure 2 shown, the SEM and EDS diagrams of the temperature-resistant high-hydrogen-inhibition polymer inhibitor powder (0.60wt%) and chitosan (0.50wt%) and sodium alginate (0.10wt%) with the highest hydrogen inhibition efficiency in Table 1 after hydrogen inhibition are shown. After adding chitosan and sodium alginate, the surface of the dust becomes rough and presents petal-shaped outward diffusion. At the same time, it can be observed that there are holes, so that water molecules can continue to diffuse to the inside and react. When the temperature-resistant high-hydrogen-inhibition polymer inhibitor powder is added, the surface of the aluminum alloy dust is smoother and denser than the reaction product dust of chitosan and sodium alginate, which shows that the temperature-resistant high-hydrogen-inhibition polymer inhibitor powder is adsorbed on the surface of the alloy powder to form a smooth and complete protective film. The content of Al and O elements shows that the hydrogen inhibition effect of the temperature-resistant high-hydrogen-inhibition polymer inhibitor powder, sodium alginate and chitosan is weakened in turn, which further verifies the hydrogen inhibition effect of the temperature-resistant high-hydrogen-inhibition polymer inhibitor powder on the aluminum alloy powder.

[0052] Table 2 shows the hydrogen suppression efficiency of a 0.4wt% heat-resistant, highly hydrogen-suppressive polymer inhibitor at different temperatures. As the temperature increases from 30°C to 60°C, the hydrogen conversion rate gradually decreases. This indicates that the heat-resistant, highly hydrogen-suppressive polymer inhibitor powder molecules desorb from the metal surface, demonstrating the presence of a physical interaction between the heat-resistant, highly hydrogen-suppressive polymer inhibitor powder molecules and the aluminum alloy powder during adsorption. Overall, the 0.4wt% heat-resistant, highly hydrogen-suppressive polymer inhibitor powder maintains a hydrogen suppression efficiency exceeding 90% even at an extreme temperature of 60°C, demonstrating its suitability for use in on-site industrial wet dust removal systems and its reliable hydrogen suppression effectiveness.

[0053] Table 2 Hydrogen inhibition efficiency of 0.4 wt% temperature-resistant high hydrogen inhibition polymer inhibitor at different temperatures

[0054]

[0055] like Figure 3 The following is the XPS spectrum of the hydrogen suppression product of the heat-resistant, highly hydrogen-suppressive polymer inhibitor obtained in Example 1. The hydrogen suppression product is obtained by reacting aluminum alloy powder with the inhibitor solution for 12 hours, filtering the reacted aluminum alloy powder, and drying it at 60°C for 12 hours. The spectrum shows peaks for Na1s, N1s, and Al2p in the product. This indicates that the heat-resistant, highly hydrogen-suppressive polymer inhibitor successfully contains sodium and nitrogen, indicating that chitosan and sodium alginate are successfully composited.

[0056] like Figure 4 The infrared spectrum of the high temperature resistant and highly hydrogen inhibiting polymer inhibitor obtained in Example 1 is shown below. For CS, 3200-3657 cm -1 It is formed by the overlapping of the stretching vibration absorption peaks of the OH bond and the -NH2 group; 2875cm -1 The absorption peak belongs to the stretching vibration of -CH2; 1650cm -1 It is the result of NH bond bending vibration; 1602cm -1 It is caused by the angular vibration of -NH2 group. For SA, 3200-3657cm -1 It is the result of OH bond stretching vibration; the characteristic peak at 2927cm-1 corresponds to the stretching vibration of -CH2; 1622cm -1 and 1415cm -1 They are -COO - The asymmetric and symmetric stretching vibration absorption peaks of the base; compared with the infrared spectra of CS and SA, CS / SA has a peak at 3200-3657cm -1 The characteristic peak at 1650 cm shifts to the left and the intensity of the peak weakens, which indicates that there is a hydrogen bond or electrostatic interaction between CS and SA. -1 and 1602cm -1The (CS) absorption peak disappears, probably because -NH2 is protonated to -NH3 + CS / SA absorption peak 1622cm -1 and 1415cm -1 The intensity of -NH3 is weaker than that of SA, which indicates that + and -COO - Ionic interactions occur. This electrostatic interaction between polyions of opposite charges has a strong cross-linking ability, allowing CS and SA to form a stable cross-linked polyelectrolyte complex without a cross-linking agent. In addition, at 418-569 cm -1 At 947 cm, CS / SA shows the same absorption peak as CS. -1 The absorption peak is attributed to the uronic acid residue of SA. The above information proves that the synthesis of the temperature-resistant and highly hydrogen-suppressive polymer inhibitor obtained in Example 1 is successful.

Claims

1. An inhibitor, characterized in that The inhibitor is a polymer obtained by ionic reaction of chitosan and sodium alginate; The preparation method of the inhibitor comprises the following steps: (1) preparing chitosan acetic acid solution; (2) preparing a sodium alginate solution by adding sodium chloride to the sodium alginate solution; (3) pouring the chitosan solution into the sodium alginate solution, stirring and mixing to obtain a chitosan and sodium alginate composite gel solution; (4) Adding excess ethanol to the composite gel solution described in step (3) to precipitate, separating the precipitate, drying, and grinding to obtain the composite gel solution.

2. The inhibitor according to claim 1, characterized in that The concentration of the chitosan acetic acid solution is 1-3 wt %, and the concentration of the sodium alginate solution is 1-3 wt %.

3. The inhibitor according to claim 1, characterized in that The mass ratio of chitosan solution to sodium alginate solution is 1:0.5-1.

5.

4. The inhibitor according to claim 1, characterized in that The mass ratio of sodium alginate to sodium chloride in step (2) is 1:8-9.

5.

5. The inhibitor according to claim 1, characterized in that The stirring speed in step (2) is greater than 3000 rpm.

6. The inhibitor according to claim 1, characterized in that The chitosan has a deacetylation degree of ≥95% and a viscosity of 100-200 mPa.s; the concentration of the acetic acid used is 1%; and the sodium alginate has a purity of 90% and is analytically pure sodium alginate.

7. The inhibitor according to claim 1, characterized in that The ethanol in step (4) is anhydrous ethanol; the separated precipitate is filtered with a funnel and washed; the drying temperature is 60-80° C. for 48-96 hours; and the grinding method is ball milling.

8. Use of the inhibitor according to any one of claims 1 to 7 in inhibiting hydrogen generation when aluminum alloy dust comes into contact with water.

9. The use according to claim 8, characterized in that The application comprises adding water to the inhibitor to form a suspension, and then mixing the suspension with aluminum alloy dust; the concentration of the suspension is 0.1-0.6wt%, and the mixing ratio of the aluminum alloy dust and the suspension is 1.5g:200ml; the aluminum alloy dust comprises, by mass percentage, 80.09% aluminum, 0.91% lithium, 5.7% zinc, 3.2% magnesium, and 10.1% copper.

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