Preparation method and application of high-agglomeration and flame-retardant magnesium powder dust suppressant

Abstract

The present invention belongs to the technical field of dust suppressants, and specifically discloses a preparation method and application of a magnesium powder dust suppressant with high agglomeration and flame retardancy, including the following components: 1-ethyl-3-methylimidazolium ethyl sulfate, 1-butyl-3-methylimidazolium trifluoromethanesulfonate, N-butyl imidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 1-butyl-3-methylimidazolium bromide, plant glycosides, sodium sulfate, magnesium chloride, and the remainder is water; the weight percentage of the water to all the above components is 60-80%. The present invention adopts the preparation method and application of the above-mentioned magnesium powder dust suppressant with high agglomeration and flame retardancy, solves the problem that a single-component metal magnesium dust suppressant in the prior art cannot meet the current metal magnesium production dust prevention demand, and has effective explosion suppression capability to ensure the safety of the staff and the factory during the metal magnesium processing.

Description

Technical Field

[0001] The invention relates to the technical field of dust suppressants, in particular to a preparation method and application of a magnesium powder dust suppressant with high agglomeration and flame retardancy. Background Art

[0002] In recent years, with the continuous advancement of industrialization, magnesium dust generated by magnesium processing, welding, cutting and other process activities has become a major hidden danger to human-machine safety and environmental pollution. Magnesium dust not only poses a potential hazard to the health of workers, but also has a high activity. The metal dust cloud it forms is very likely to cause explosion accidents when encountering an ignition source, causing immeasurable losses to society and the country.

[0003] The minimum explosive concentration of magnesium dust in air is 10g / m 3 Without taking any measures, the dust concentration in the magnesium metal processing working surface far exceeds its minimum explosion concentration value. In addition, since magnesium powder is a light metal, its density is relatively low (about 1.738g / m 3 ), which means that the weight of magnesium powder is lighter in the same volume. In addition, the specific surface area of ​​magnesium powder in the dust state is significantly increased. Once it encounters an ignition source, it will produce a high-temperature and high-pressure shock wave and dazzling light.

[0004] In the existing technology, most factories in my country use water-added wet dust collectors to treat magnesium powder generated during processing, and collect dust through inertial sedimentation, collision and particle adhesion to improve the efficiency of dust removal. However, with the continuous deepening of industrialization, especially for light metal dust, a single component (water) as a dust collector is difficult to meet the actual dust reduction needs of magnesium metal dust.

[0005] Therefore, there is an urgent need for a multi-component dust suppressant with high dust removal efficiency and effective explosion suppression to solve the above problems. Summary of the invention

[0006] The purpose of the present invention is to provide a preparation method and application of a highly agglomerated and flame-retardant magnesium powder dust suppressant, which solves the problem that a single-component magnesium powder dust suppressant in the prior art cannot meet the current dust prevention needs of magnesium metal production, and at the same time has effective explosion suppression capability to ensure the safety of workers and factories during magnesium metal processing.

[0007] To achieve the above object, the present invention provides a method for preparing a magnesium powder dust suppressant with high agglomeration and flame retardancy, comprising the following components in weight percentage:

[0008] 1-Ethyl-3-methylimidazolium ethyl sulfate 1%~4%, 1-butyl-3-methylimidazolium trifluoromethanesulfonate 2%~10%, N-butylimidazolium tetrafluoroborate 1%~6%, 1-butyl-3-methylimidazolium tetrafluoroborate 2%~8%, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate 3%~6%, 1-butyl-3-methylimidazolium bromide 1%~2%, plant glycoside 0.1%~1%, sodium sulfate 0.1%~1%, magnesium chloride 0.1%~1%, and the balance is water;

[0009] The weight percentage of water in all the above components is 60-80%;

[0010] The preparation method comprises the following steps:

[0011] According to weight percentage, 1-ethyl-3-methylimidazolium ethyl sulfate, 1-butyl-3-methylimidazolium trifluoromethanesulfonate, N-butylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 1-butyl-3-methylimidazolium bromide, plant glycoside, sodium sulfate and magnesium chloride are added into water in sequence and stirred until completely dissolved to obtain a dust suppressant without stratification and precipitation.

[0012] Preferably, the following components are included in weight percentage:

[0013] 1-Ethyl-3-methylimidazole ethyl sulfate 2%~4%;

[0014] 1-Butyl-3-methylimidazolium trifluoromethanesulfonate 4%~10%;

[0015] N-butyl imidazole tetrafluoroborate 2%~6%;

[0016] 1-Butyl-3-methylimidazolium tetrafluoroborate 4%~8%;

[0017] 1-Ethyl-3-methylimidazolium trifluoromethanesulfonate 4%~6%;

[0018] 1-Butyl-3-methylimidazolium bromide 1.2%~2%;

[0019] Plant glycosides 0.3%~1%;

[0020] Sodium sulfate 0.4%~1%;

[0021] Magnesium chloride 0.5%~1%;

[0022] The balance is water.

[0023] Preferably, the following components are included in weight percentage:

[0024] 1-Ethyl-3-methylimidazole ethyl sulfate 1%~3%;

[0025] 1-Butyl-3-methylimidazolium trifluoromethanesulfonate 5%~10%;

[0026] N-butyl imidazole tetrafluoroborate 1%~4%;

[0027] 1-Butyl-3-methylimidazolium tetrafluoroborate 5%~8%;

[0028] 1-Ethyl-3-methylimidazolium trifluoromethanesulfonate 4%~6%;

[0029] 1-Butyl-3-methylimidazolium bromide 1.2%~2%;

[0030] Plant glycosides 0.1%~0.8%;

[0031] Sodium sulfate 0.6%~1%;

[0032] Magnesium chloride 0.5%~1%;

[0033] The balance is water.

[0034] Preferably, the contact angle between the dust suppressant and an equal weight portion of magnesium powder is less than 35°.

[0035] Preferably, the contact angle is measured by a sessile drop method to measure the contact angle of the dust suppressant on the surface of 0.2 g, 325 mesh magnesium powder.

[0036] Preferably, the surface tension of the dust suppressant is 35-45 mN / m.

[0037] Preferably, the surface tension is measured using a platinum plate measurement method.

[0038] To achieve the above objectives, the present invention also provides a method for preparing a magnesium powder dust suppressant with high agglomeration and flame retardancy, and the use of the prepared dust suppressant in magnesium metal processing, grinding, and cutting work surfaces.

[0039] Preferably, the magnesium metal processing working surface is provided with a spray hydraulic device using the dust suppressant, which is pressurized and formed into a spray through a nozzle and sprayed onto the dust generating points on the working surface and above the metal magnesium dust cloud.

[0040] Therefore, the present invention adopts the preparation method and application of the above-mentioned highly agglomerated and flame-retardant magnesium powder dust suppressant, and the beneficial effects are as follows:

[0041] (1) The dust suppressant of the present invention is compounded with a variety of active molecules and has good wetting properties. It can maintain a stable liquid state at a relatively high temperature. Both ends of the molecule show lipophilicity and hydrophilicity in deionized water. After adhering to the surface of magnesium metal dust, it shows strong flame retardant properties. This allows the dust layer formed after the magnesium metal dust cloud settles after the action of the dust suppressant to maintain wetness and agglomeration effects for a relatively long time under relatively high temperature conditions, thereby increasing the difficulty of combustion and explosion and secondary dust explosion.

[0042] (2) The dust suppressant of the present invention adds magnesium chloride. When magnesium chloride is sprayed on the surface of magnesium powder, it absorbs moisture in the air to form hydrates, making its mass greater than its own buoyancy, and completing the sedimentation process. The hydrate formed with water has a certain degree of adhesion, which can enhance the interaction between water molecules and the surface of metal magnesium dust, promote the adsorption and adhesion of water molecules on the surface of metal magnesium dust, and help to effectively remove metal magnesium dust from the air. It can also adhere to the ground. Magnesium chloride will form a thin film that adheres to the surface of the ground with magnesium powder, thereby preventing dust particles from being blown away by the wind. In addition, the magnesium chloride aqueous solution ionizes magnesium ions, which can inhibit the hydrogen evolution reaction between magnesium and water to a certain extent, and reduce the explosion intensity of metal magnesium dust.

[0043] (3) Sodium sulfate is added to the dust suppressant of the present invention. The sodium sulfate aqueous solution is electrolyzed to produce sodium ions and sulfate ions, which can fill the adsorption interface between the active agent molecules and the surface of the metal magnesium dust, produce a compact ion filling effect, and reduce the electrostatic repulsion of the metal magnesium dust surface to the active agent molecules, further enhancing the wetting activity of the compound dust suppressant.

[0044] (4) The dust suppressant of the present invention is added with plant glycosides, which have a certain surface activity. At a certain concentration, the plant glycosides can reduce the surface tension of water and enhance the interaction between water and metal dust, making the metal dust more easily dispersed by water.

[0045] (5) The dust suppressant of the present invention is a multi-component compounded with water, each component is non-toxic and non-polluting, and the main raw materials have environmentally friendly properties. It is an environmentally friendly, efficient and safe dust suppressant for magnesium metal dust. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a statistical diagram of the maximum explosion pressure of a preparation method and application example of a highly agglomerated and flame-retardant magnesium powder dust suppressant of the present invention. DETAILED DESCRIPTION

[0047] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0048] Unless otherwise defined, technical or scientific terms used in the present invention shall have the common meanings understood by one having ordinary skills in the field to which the present invention belongs.

[0049] In order to overcome the shortcomings of insufficient wetting activity of a single component and difficulty in effectively wetting metal magnesium dust, a high-efficiency composite dust suppressant is obtained by compounding and optimizing a variety of active agents such as 1-ethyl-3-methylimidazolium ethyl sulfate, 1-butyl-3-methylimidazolium trifluoromethanesulfonate, N-butylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 1-butyl-3-methylimidazolium bromide, plant glycosides, magnesium chloride, sodium sulfate, etc. Since the above-mentioned active molecules are lipophilic and hydrophilic, after entering the water body, the hydrophilic active groups are oriented towards the water, and the lipophilic active groups are oriented towards the air, forming a tightly arranged directional arrangement layer, which greatly improves the surface properties of the water, further reduces the surface tension of the water body, and improves its wetting performance.

[0050] The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, etc. used in the following examples can be purchased directly from the market unless otherwise specified.

[0051] Example 1

[0052] The following raw material components were weighed according to weight percentage: 1-ethyl-3-methylimidazolium ethyl sulfate 0.02kg (2%), 1-butyl-3-methylimidazolium trifluoromethanesulfonate 0.08kg (8%), N-butylimidazolium tetrafluoroborate 0.01kg (1%), 1-butyl-3-methylimidazolium tetrafluoroborate 0.04kg (4%), 1-ethyl-3-methylimidazolium trifluoromethanesulfonate 0.05kg (5%), 1-butyl-3-methylimidazolium bromide 0.01kg (1%), plant glycoside 0.005kg (0.5%), sodium sulfate 0.005kg (0.5%), magnesium chloride 0.005kg (0.5%), and the balance was water. After fully mixing, 1kg of dust suppressant for metal magnesium dust was prepared.

[0053] This ratio combination has a better effect. The contact angle measured by the sessile drop method can be reduced to below 35°, and the surface tension measured by the platinum plate measurement method is 45mN / m.

[0054] Example 2

[0055] The following raw material components were weighed according to weight percentage: 1-ethyl-3-methylimidazolium ethyl sulfate 0.03kg (3%), 1-butyl-3-methylimidazolium trifluoromethanesulfonate 0.1kg (10%), N-butylimidazolium tetrafluoroborate 0.02kg (2%), 1-butyl-3-methylimidazolium tetrafluoroborate 0.05kg (5%), 1-ethyl-3-methylimidazolium trifluoromethanesulfonate 0.06kg (6%), 1-butyl-3-methylimidazolium bromide 0.02kg (2%), plant glycoside 0.005kg (0.5%), sodium sulfate 0.005kg (0.5%), magnesium chloride 0.005kg (0.5%), and the balance was water. After fully mixing, 1kg of dust suppressant for metal magnesium dust was prepared.

[0056] This ratio combination has a better effect. The contact angle measured by the sessile drop method can be reduced to below 30°, and the surface tension measured by the platinum plate measurement method is 41mN / m.

[0057] Example 3

[0058] The following raw material components were weighed according to weight percentage: 1-ethyl-3-methylimidazolium ethyl sulfate 0.03kg (3%), 1-butyl-3-methylimidazolium trifluoromethanesulfonate 0.1kg (10%), N-butylimidazolium tetrafluoroborate 0.02kg (2%), 1-butyl-3-methylimidazolium tetrafluoroborate 0.05kg (5%), 1-ethyl-3-methylimidazolium trifluoromethanesulfonate 0.06kg (6%), 1-butyl-3-methylimidazolium bromide 0.02kg (2%), plant glycoside 0.005kg (0.5%), sodium sulfate 0.007kg (0.7%), magnesium chloride 0.008kg (0.8%), and the balance was water. After fully mixing, 1kg of dust suppressant for metal magnesium dust was prepared.

[0059] This ratio combination has the best effect. The contact angle measured by the sessile drop method can be reduced to below 20°, and the surface tension measured by the platinum plate measurement method is 37mN / m.

[0060] The dust suppressant prepared in Examples 1 to 3 was used in a self-made 20L cubic acrylic board cubic space to simulate the magnesium dust field environment with a blower, and a hydraulic sprayer was installed on the top of the cube. The ratio of the mass of the settled dust to the total mass of the dust was calculated as the experimental dust removal efficiency result. The dust removal rate and moisture retention rate were measured when the working surface did not adopt any dust prevention measures, only used water spray, and sprayed with the dust suppressant prepared in Examples 1 to 3 of the present invention, and the measurement results are shown in Table 1 below.

[0061] Table 1 Measurement results of dust removal rate and moisture retention rate

[0062] ;

[0063] It can be seen from Table 1 that after using the dust suppressant for magnesium dust of Example 1, Example 2 and Example 3, the dust suppressant for magnesium dust of five different magnesium dust concentrations (700 mg / m 3 , 900 mg / m 3 , 1100 mg / m 3 , 1300 mg / m 3 , 1500 mg / m 3 ) environment, the total dust fall rates were 72.5%, 72.0%, 73.1%, 73.6% and 74.8%; 76.7%, 77.2%, 77.8%, 79.9% and 80.3%; 80.1%, 81.3%, 82.0%, 83.7% and 84.5% respectively. The respirable dust fall rates were 79.2%, 79.5%, 81.3%, 84.5% and 85.6%; 83.5%, 84.1%, 84.9%, 85.8% and 86.2%; 86.9%, 87.1%, 87.5%, 88.3% and 88.6% respectively.

[0064] Compared with the water spray, the percentage points of total dust reduction rate of Example 1, Example 2 and Example 3 are respectively increased by 32.8%, 31.7%, 31.6%, 31.7% and 32%; 37%, 36.9%, 36.3%, 38% and 37.5%; 40.4%, 41%, 40.5%, 41.8% and 41.7%. The percentage points of respirable dust reduction rate of Example 1, Example 2 and Example 3 are respectively increased by 36.4%, 36.1%, 36.7%, 39.4% and 40.3%; 40.7%, 42.7%, 40.3%, 40.7% and 40.9%; 44.1%, 43.7%, 42.9%, 43.2% and 43.3%. Obviously, the use of dust reduction agent for magnesium dust greatly improves the dust removal effect of various dust concentrations.

[0065] In addition, compared with the mixture of clean water and magnesium powder, after the dust suppressants of Examples 1, 2 and 3 were mixed with magnesium powder, the mass loss of the mixture of dust suppressants and magnesium powder was less than that of the mixture of clean water and magnesium powder over time, indicating that the use of dust suppressants for metal magnesium dust also improves the moisturizing effect under various dust concentrations. The surface tension of the dust suppressants prepared in Examples 1, 2 and 3 gradually decreases, and magnesium powder is more likely to pass through the surface of the droplets. The dust suppressant prepared in Example 3 achieves a better wetting effect.

[0066] The dust suppressant prepared in Example 1, Example 2 and Example 3 was mixed with 325 mesh magnesium powder in a mass ratio of 1:5 and then subjected to a thermogravimetric analysis (TGA) experiment. It was found that the oxidation process of the magnesium powder was inhibited, indicating that the dust suppressant had a certain flame retardant effect on the magnesium powder.

[0067] Therefore, the dust suppressant shown in Example 3 was used to perform a 20 L explosive ball test. Since the mixture required for the explosive ball test needs to be dried in advance and the water in the dust suppressant is easy to evaporate, the magnesium powder was mixed with the dust suppressant shown in Example 3 without water in a mass ratio of 10:1, 20:1, 30:1, 40:1, and 50:1, respectively, and compared with the pure magnesium powder in the blank control group. The specific mixing steps of magnesium powder and dust suppressant are as follows:

[0068] First, 12 ml of dispersion medium (ethanol) was pre-mixed with 2.00 g, 1.00 g, 0.67 g, 0.50 g, and 0.40 g of ionic liquid (dust suppressant without water), respectively, and then mixed with 20 g of magnesium powder and placed in a three-necked flask.

[0069] Secondly, the three-necked flask was placed in a constant temperature magnetic stirrer and heated in a 70 °C water bath for 2 h. Argon gas was introduced into the three-necked flask at a flow rate of 40 ml / min and the stirring speed was 20 rpm / s, so that a mixture of ionic liquid and magnesium powder was uniformly mixed.

[0070] Finally, the mixture was placed in a vacuum drying oven at 25 °C for 48 h before being subjected to a 20 L explosive ball test. The 20 L explosive ball device was used and the dust concentration was set to 500 g / m 3 , the maximum explosion pressure of pure magnesium powder and mixed magnesium powder with different mass proportions of dust suppressant is obtained, such as Figure 1 shown.

[0071] from Figure 1It can be seen that without taking any measures, the maximum explosion pressure of magnesium powder is 0.85 MPa. The maximum explosion pressures of magnesium powder and dust suppressant mixed in mass ratios of 10:1, 20:1, 30:1, 40:1 and 50:1 are 0.14 MPa, 0.19 MPa, 0.31 MPa, 0.39 MPa and 0.56 MPa, respectively, indicating that under the action of the ignition source, magnesium powder and dust suppressant mixed in mass ratios of 10:1 and 20:1 did not explode, and magnesium powder and dust suppressant mixed in mass ratios of 30:1, 40:1 and 50:1 had a slight explosion, and the maximum explosion pressure was effectively controlled. Compared with magnesium powder without any measures, the maximum explosion pressure of magnesium powder and dust suppressant mixed in mass ratios of 10:1, 20:1, 30:1, 40:1 and 50:1 decreased by 83.53%, 77.65%, 63.53%, 54.12% and 34.12% respectively, indicating that magnesium powder and dust suppressant mixed in mass ratios of 10:1, 20:1, 30:1, 40:1 and 50:1 achieved effective explosion suppression effect.

[0072] Therefore, the present invention adopts the preparation method and application of the above-mentioned highly agglomerated and flame-retardant magnesium powder dust suppressant. The metal magnesium dust suppressant that increases the wetting and agglomeration ability of water can significantly reduce the contact angle between it and the magnesium powder and the surface tension of the water body, improve the wetting ability of the water body on the metal magnesium dust, enhance the dispersion ability of the metal magnesium dust in the liquid, and improve the moisturizing effect after sedimentation, thereby solving the technical problem that the dust at the metal magnesium processing site is difficult to wetting, and can greatly improve the metal magnesium dust capture efficiency, and has a positive promoting effect on the dust reduction efficiency of dust control means such as spray dust reduction and wet dust collector.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for preparing a highly agglomerated and flame-retardant magnesium powder dust suppressant, characterized in that: The composition includes the following weight percentages: 1-Ethyl-3-methylimidazolium ethyl sulfate 1%~4%, 1-butyl-3-methylimidazolium trifluoromethanesulfonate 2%~10%, N-butylimidazolium tetrafluoroborate 1%~6%, 1-butyl-3-methylimidazolium tetrafluoroborate 2%~8%, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate 3%~6%, 1-butyl-3-methylimidazolium bromide 1%~2%, plant glycoside 0.1%~1%, sodium sulfate 0.1%~1%, magnesium chloride 0.1%~1%, and the balance is water; The weight percentage of water in all the above components is 60-80%; The preparation method comprises the following steps: According to weight percentage, 1-ethyl-3-methylimidazolium ethyl sulfate, 1-butyl-3-methylimidazolium trifluoromethanesulfonate, N-butylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 1-butyl-3-methylimidazolium bromide, plant glycoside, sodium sulfate and magnesium chloride are added to water in sequence, and stirred until completely dissolved to obtain a dust suppressant without stratification and precipitation; The contact angle between the dust suppressant and an equal weight portion of magnesium powder is less than 35°; The surface tension of the dust suppressant is 35-45 mN / m.

2. The method for preparing a highly agglomerated and flame-retardant magnesium powder dust suppressant according to claim 1, characterized in that: The composition includes the following weight percentages: 1-Ethyl-3-methylimidazole ethyl sulfate 2%~4%; 1-Butyl-3-methylimidazolium trifluoromethanesulfonate 4%~10%; N-butyl imidazole tetrafluoroborate 2%~6%; 1-Butyl-3-methylimidazolium tetrafluoroborate 4%~8%; 1-Ethyl-3-methylimidazolium trifluoromethanesulfonate 4%~6%; 1-Butyl-3-methylimidazolium bromide 1.2%~2%; Plant glycosides 0.3%~1%; Sodium sulfate 0.4%~1%; Magnesium chloride 0.5%~1%; The balance is water.

3. The method for preparing a highly agglomerated and flame-retardant magnesium powder dust suppressant according to claim 1, characterized in that: The composition includes the following weight percentages: 1-Ethyl-3-methylimidazole ethyl sulfate 1%~3%; 1-Butyl-3-methylimidazolium trifluoromethanesulfonate 5%~10%; N-butyl imidazole tetrafluoroborate 1%~4%; 1-Butyl-3-methylimidazolium tetrafluoroborate 5%~8%; 1-Ethyl-3-methylimidazolium trifluoromethanesulfonate 4%~6%; 1-Butyl-3-methylimidazolium bromide 1.2%~2%; Plant glycosides 0.1%~0.8%; Sodium sulfate 0.6%~1%; Magnesium chloride 0.5%~1%; The balance is water.

4. The method for preparing a highly agglomerated and flame-retardant magnesium powder dust suppressant according to claim 1, characterized in that: The contact angle is measured by a sessile drop method to measure the contact angle of the dust suppressant on the surface of 0.2g, 325 mesh magnesium powder.

5. The method for preparing a highly agglomerated and flame-retardant magnesium powder dust suppressant according to claim 1, characterized in that: The surface tension is measured using a platinum plate measurement method.

6. Use of the dust suppressant prepared by the method for preparing the highly agglomerated and flame-retardant magnesium powder dust suppressant as claimed in any one of claims 1 to 5 in magnesium metal processing, grinding and cutting working surfaces.

7. The use of a highly agglomerated and flame-retardant magnesium powder dust suppressant according to claim 6, characterized in that: The magnesium metal processing working surface is provided with a spray hydraulic device using the dust suppressant, which is pressurized and formed into a spray through a nozzle and sprayed to the dust generating points on the working surface and above the metal magnesium dust cloud.

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