A scale inhibitor for soda ash mother liquor and its preparation method

Abstract

This invention relates to the field of scale inhibition technology, and proposes a scale inhibitor for soda ash mother liquor and its preparation method. The scale inhibitor for soda ash mother liquor comprises the following components by weight: 50-75 parts polyacrylic acid, 30-50 parts polyepoxysuccinic acid, 5-12 parts surfactant, 2-16 parts sodium gallate, 1-10 parts sodium lactate, 1-7 parts stabilizer, 0.5-4.5 parts dispersant, and 30-50 parts water. This technical solution solves the problem of low scale inhibition rate in existing soda ash mother liquor scale inhibitors.

Description

Technical Field

[0001] This invention relates to the field of scale inhibition technology, specifically to a scale inhibitor for soda ash mother liquor and its preparation method. Background Technology

[0002] Soda ash, as an important basic chemical raw material, is widely used in many fields such as glass, chemical industry, and metallurgy. Its production process involves complex technological steps. In the soda ash production process, soda ash mother liquor plays a key role. However, the mother liquor system is prone to scaling problems, which brings many troubles to soda ash production and has also spurred the research and application of scale inhibitors for soda ash mother liquor.

[0003] From the perspective of soda ash production processes, the ammonia-soda process or the combined alkali process is commonly used. Taking the ammonia-soda process as an example, limestone is calcined to produce quicklime and carbon dioxide. The quicklime is then slaked to obtain hydrated lime, which reacts with a mother liquor containing ammonium chloride to produce calcium hydroxide and ammonium chloride. In subsequent steps, carbon dioxide reacts with ammonia brine to produce sodium bicarbonate, which is then calcined to obtain soda ash. In this series of conversions, the mother liquor is continuously recycled and is rich in calcium and magnesium ions, as well as anions such as carbonate and sulfate. As the mother liquor circulates, the concentration of these ions gradually accumulates. When a certain saturation level is reached, they combine to form insoluble precipitates such as calcium carbonate, magnesium carbonate, and calcium sulfate, which adhere to the inner walls of equipment and pipes, forming a scale layer.

[0004] Scaling has serious consequences for soda ash production. On the one hand, thicker scale layers significantly reduce the heat transfer efficiency of equipment, preventing the timely transfer of heat required for the reaction, resulting in a slower reaction rate, longer production cycles, and consequently reduced production efficiency. On the other hand, scale layers increase fluid resistance in pipelines, reduce the cross-sectional area for fluid flow, making it difficult to transport mother liquor, increasing pump energy consumption, and potentially causing pipeline blockages, leading to production interruptions and high maintenance costs.

[0005] Traditional descaling methods, such as mechanical cleaning and chemical cleaning, have significant limitations. Mechanical cleaning is time-consuming and labor-intensive, requiring production shutdowns, during which companies face substantial economic losses. While chemical cleaning does not require production shutdowns, the cleaning agents used are often corrosive, easily causing secondary damage to equipment. Furthermore, the disposal of waste liquid after cleaning is a major challenge, potentially leading to environmental pollution. Faced with these difficulties, developing highly efficient scale inhibitors for soda ash mother liquor has become an urgent priority.

[0006] The scale inhibition rate of existing scale inhibitors for soda ash mother liquor is still relatively low. Therefore, it is crucial to develop a scale inhibitor for soda ash mother liquor with a high scale inhibition rate. Summary of the Invention

[0007] This invention proposes a scale inhibitor for soda ash mother liquor and its preparation method, which solves the problem of low scale inhibition rate of scale inhibitors for soda ash mother liquor in related technologies.

[0008] This invention proposes a scale inhibitor for soda ash mother liquor, the raw materials comprising the following components by weight: 50-75 parts polyacrylic acid, 30-50 parts polyepoxysuccinic acid, 5-12 parts surfactant, 2-16 parts sodium gallate, 1-10 parts sodium lactate, 1-7 parts stabilizer, 0.5-4.5 parts dispersant, and 30-50 parts water.

[0009] As a further technical solution, the mass ratio of sodium gallate to sodium lactate is 2~4:1.

[0010] As a further technical solution, the mass ratio of sodium gallate to sodium lactate is 3:1.

[0011] As a further technical solution, the surfactant includes one or more of dodecyl dimethyl betaine, sodium dodecyl sulfonate, and sodium lauroyl amphoteric acetate; the stabilizer includes sodium alginate; and the dispersant includes isopropanolamine.

[0012] As a further technical solution, the polyepoxysuccinic acid is a modified polyepoxysuccinic acid, and the raw materials of the modified polyepoxysuccinic acid include polyepoxysuccinic acid and pent-4-ene-1-amine.

[0013] In this invention, pent-4-ene-1-amine is used to modify polyepoxysuccinic acid, which further improves the scale inhibition rate of scale inhibitors for soda ash mother liquor.

[0014] As a further technical solution, the preparation process of the modified polyepoxysuccinic acid includes the following steps: adding the polyepoxysuccinic acid to water, adding an initiator in an inert gas atmosphere, mixing, adding pent-4-en-1-amine, reacting, concentrating, and drying to obtain the modified polyepoxysuccinic acid.

[0015] The mass ratio of the polyepoxysuccinic acid to water is 1:3~5.

[0016] As a further technical solution, the mass ratio of the polyepoxysuccinic acid to the pent-4-ene-1-amine is 20:1~3.

[0017] In this invention, by adjusting the mass ratio of polyepoxysuccinic acid to pent-4-ene-1-amine to 20:1~3, the scale inhibition rate of the scale inhibitor for soda ash mother liquor is further improved.

[0018] As a further technical solution, the initiator includes one of sodium persulfate and ammonium persulfate, and the mass ratio of polyepoxysuccinic acid to the initiator is 30:0.5~1.5.

[0019] As a further technical solution, the reaction temperature is 25~45℃ and the time is 2~4h.

[0020] The present invention also proposes a method for preparing a scale inhibitor for soda ash mother liquor, comprising the following steps: mixing the raw material components evenly to obtain the scale inhibitor for soda ash mother liquor.

[0021] The working principle and beneficial effects of this invention are as follows:

[0022] In this invention, the polyepoxysuccinic acid molecule is rich in two characteristic functional groups: carboxyl groups and ether bonds. When polyepoxysuccinic acid dissolves in water, it ionizes to release carboxyl anions. As the alkalinity of the solution increases, the chain structure of the molecule extends from a curved shape to a straight chain, exposing more negatively charged groups. If scale forms, the straight chain structure adsorbs scale microcrystals and incorporates them into the chain, forming coordinate bonds through micro-chelation and generating soluble chelates. Therefore, polyepoxysuccinic acid exhibits excellent scale inhibition effects in highly alkaline environments, with a higher scale inhibition rate. The lone pairs of electrons in the carboxyl, hydroxyl, and ether bonds of the polyepoxysuccinic acid molecule can form coordinate bonds with the empty orbitals of iron atoms, thus playing a role in corrosion inhibition. Sodium gallate and sodium lactate chelate with metal ions, and the synergistic effect of sodium gallate and sodium lactate improves the scale inhibition rate of the scale inhibitor for soda ash mother liquor. Detailed Implementation

[0023] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0024] In the following examples and comparative examples, the weight-average molecular weight of polyacrylic acid is 2000; the polyepoxysuccinic acid is PESA-L.

[0025] Example 1

[0026] A scale inhibitor for soda ash mother liquor, comprising the following components by weight: 75 parts polyacrylic acid, 50 parts polyepoxysuccinic acid, 12 parts sodium lauroyl amphoteric acetate, 16 parts sodium gallate, 1 part sodium lactate, 7 parts sodium alginate, 4.5 parts isopropanolamine, and 50 parts water.

[0027] Its preparation method includes the following steps:

[0028] Mix all components of the raw materials evenly to obtain a scale inhibitor for soda ash mother liquor.

[0029] Example 2

[0030] A scale inhibitor for soda ash mother liquor, comprising the following components by weight: 50 parts polyacrylic acid, 30 parts polyepoxysuccinic acid, 5 parts sodium dodecyl sulfonate, 2 parts sodium gallate, 10 parts sodium lactate, 1 part sodium alginate, 0.5 parts isopropanolamine, and 30 parts water.

[0031] Its preparation method includes the following steps:

[0032] Mix all components of the raw materials evenly to obtain a scale inhibitor for soda ash mother liquor.

[0033] Example 3

[0034] A scale inhibitor for soda ash mother liquor, comprising the following components by weight: 65 parts polyacrylic acid, 40 parts polyepoxysuccinic acid, 8 parts dodecyl dimethyl betaine, 10 parts sodium gallate, 2 parts sodium lactate, 5 parts sodium alginate, 3.5 parts isopropanolamine, and 40 parts water.

[0035] Its preparation method includes the following steps:

[0036] Mix all components of the raw materials evenly to obtain a scale inhibitor for soda ash mother liquor.

[0037] Example 4

[0038] The only difference between this embodiment and Example 3 is that the raw materials in this embodiment include the following components by weight: 65 parts polyacrylic acid, 40 parts polyepoxysuccinic acid, 8 parts dodecyl dimethyl betaine, 3 parts sodium gallate, 9 parts sodium lactate, 5 parts sodium alginate, 3.5 parts isopropanolamine, and 40 parts water.

[0039] Example 5

[0040] The only difference between this embodiment and Embodiment 3 is that the raw materials in this embodiment include the following components by weight: 65 parts polyacrylic acid, 40 parts polyepoxysuccinic acid, 8 parts dodecyl dimethyl betaine, 8 parts sodium gallate, 4 parts sodium lactate, 5 parts sodium alginate, 3.5 parts isopropanolamine, and 40 parts water.

[0041] Example 6

[0042] The only difference between this embodiment and Embodiment 3 is that the raw materials in this embodiment include the following components by weight: 65 parts polyacrylic acid, 40 parts polyepoxysuccinic acid, 8 parts dodecyl dimethyl betaine, 9 parts sodium gallate, 3 parts sodium lactate, 5 parts sodium alginate, 3.5 parts isopropanolamine, and 40 parts water.

[0043] Example 7

[0044] The only difference between this embodiment and Embodiment 3 is that the raw materials in this embodiment include the following components by weight: 65 parts polyacrylic acid, 40 parts polyepoxysuccinic acid, 8 parts dodecyl dimethyl betaine, 9.6 parts sodium gallate, 2.4 parts sodium lactate, 5 parts sodium alginate, 3.5 parts isopropanolamine, and 40 parts water.

[0045] Example 8

[0046] The only difference between this embodiment and Example 6 is that the raw materials in this embodiment include the following components by weight: 65 parts polyacrylic acid, 40 parts modified polyepoxysuccinic acid, 8 parts dodecyl dimethyl betaine, 9 parts sodium gallate, 3 parts sodium lactate, 5 parts sodium alginate, 3.5 parts isopropanolamine, and 40 parts water.

[0047] The preparation process of modified polyepoxysuccinic acid includes the following steps: 30 parts of polyepoxysuccinic acid are added to 120 parts of water, 1 part of sodium persulfate is added in an inert gas atmosphere, the mixture is added, pent-4-en-1-amine is added, the reaction is carried out at 35°C for 3 hours, the mixture is concentrated and dried to obtain modified polyepoxysuccinic acid.

[0048] The mass ratio of polyepoxysuccinic acid to pent-4-ene-1-amine is 5:1.

[0049] Example 9

[0050] The only difference between this embodiment and Example 8 is that the mass ratio of polyepoxysuccinic acid to pent-4-ene-1-amine in this embodiment is 30:1.

[0051] Example 10

[0052] The only difference between this embodiment and Example 8 is that the mass ratio of polyepoxysuccinic acid to pent-4-ene-1-amine in this embodiment is 20:1.

[0053] Example 11

[0054] The only difference between this embodiment and Example 8 is that the mass ratio of polyepoxysuccinic acid to pent-4-ene-1-amine in this embodiment is 10:1.

[0055] Example 12

[0056] The only difference between this embodiment and Example 8 is that the mass ratio of polyepoxysuccinic acid to pent-4-ene-1-amine in this embodiment is 20:3.

[0057] Comparative Example 1

[0058] The only difference between this comparative example and Example 2 is that the raw materials in this comparative example include the following components by weight: 50 parts polyacrylic acid, 30 parts polyepoxysuccinic acid, 5 parts sodium dodecyl sulfonate, 12 parts sodium gallate, 1 part sodium alginate, 0.5 parts isopropanolamine, and 30 parts water.

[0059] Comparative Example 2

[0060] The only difference between this comparative example and Example 2 is that the raw materials in this comparative example include the following components by weight: 50 parts polyacrylic acid, 30 parts polyepoxysuccinic acid, 5 parts sodium dodecyl sulfonate, 12 parts sodium lactate, 1 part sodium alginate, 0.5 parts isopropanolamine, and 30 parts water.

[0061] Comparative Example 3

[0062] The only difference between this comparative example and Example 2 is that the raw materials in this comparative example include the following components by weight: 50 parts polyacrylic acid, 30 parts polyepoxysuccinic acid, 5 parts sodium dodecyl sulfonate, 2 parts sodium gallate, 10 parts sodium citrate, 1 part sodium alginate, 0.5 parts isopropanolamine, and 30 parts water.

[0063] Comparative Example 4

[0064] The only difference between this comparative example and Example 2 is that the raw materials in this comparative example include the following components by weight: 50 parts polyacrylic acid, 30 parts polyepoxysuccinic acid, 5 parts sodium dodecyl sulfonate, 1 part sodium alginate, 0.5 parts isopropanolamine, and 30 parts water.

[0065] Test case

[0066] The scale inhibitors used in the soda ash mother liquor prepared in Examples 1-12 and Comparative Examples 1-4 of the present invention were tested according to the following method:

[0067] The scale inhibition performance of the water treatment agent was determined according to GB / T 16632-2019, "Determination of Scale Inhibition Performance of Water Treatment - Calcium Carbonate Deposition Method". A test solution was prepared using formulated water containing a certain amount of bicarbonate and calcium ions, and a water treatment agent. Under heating conditions, calcium bicarbonate was accelerated to decompose into calcium carbonate. After equilibrium was reached, the calcium ion concentration in the test solution was measured. The scale inhibition performance η of the scale inhibitor was expressed as a percentage and calculated using the following formula:

[0068] η=(ρ4-ρ3)×100 / (ρ-ρ3)

[0069] ρ4 represents the calcium ions (Ca) in the test solution after adding water treatment agent. 2+ The mass concentration is expressed in milligrams per milliliter (mg / mL).

[0070] ρ3 represents the calcium ions (Ca) in the blank solution without added water treatment agent after the test. 2+ The mass concentration is expressed in milligrams per milliliter (mg / mL).

[0071] ρ represents the calcium ions (Ca) in the water. 2+ The mass concentration is expressed in milligrams per milliliter (mg / mL).

[0072] Water treatment agent test solution: 1.0 mL contains 0.500 mg of scale inhibitor for the preparation of soda ash mother liquor; the amount of water treatment agent added in each test solution is 12 mL / L.

[0073] Preparation of water: Add 250 mL of water to a 500 mL volumetric flask. Using a burette, add a specific volume of calcium chloride standard solution to bring the calcium ion concentration to 120 mg. Using a pipette, add the water treatment agent sample solution at a concentration of 12 mL / L and mix well. Then add 20 mL of borax buffer solution and mix well. Slowly add a specific volume of sodium bicarbonate standard solution using a burette (while shaking) to bring the bicarbonate ion concentration to 366 mg. Dilute with water to the mark and mix well.

[0074] The experimental results are shown in Table 1.

[0075]

[0076] Comparing Example 2 with Comparative Examples 1-4, it is shown that sodium gallate and sodium lactate have a synergistic effect in the present invention, which improves the scale inhibition rate of the scale inhibitor for soda ash mother liquor.

[0077] Comparing Examples 5-7 with Examples 3-4, it is shown that by adjusting the mass ratio of sodium gallate to sodium lactate to 2-4:1, the scale inhibition rate of the scale inhibitor for soda ash mother liquor is improved in this invention. Comparing Example 6 with Examples 5 and 7, it is shown that adjusting the mass ratio of sodium gallate to sodium lactate to 3:1 results in an even better improvement. Comparing Examples 8-12 with Example 6, it is shown that the modification of polyepoxysuccinic acid with pent-4-en-1-amine in this invention further improves the scale inhibition rate of the scale inhibitor for soda ash mother liquor. Comparing Examples 10-12 with Examples 8-9, it is shown that adjusting the mass ratio of polyepoxysuccinic acid to pent-4-en-1-amine to 20:1-3 in this invention further improves the scale inhibition rate of the scale inhibitor for soda ash mother liquor. Comparing Example 11 with Examples 10 and 12, it is shown that the best effect in improving the scale inhibition rate of the scale inhibitor for soda ash mother liquor is achieved when the mass ratio of polyepoxysuccinic acid to pent-4-en-1-amine is 10:1.

[0078] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A scale inhibitor for soda ash mother liquor, characterized in that, The raw materials are composed of the following components by weight: 50-75 parts polyacrylic acid, 30-50 parts polyepoxysuccinic acid, 5-12 parts surfactant, 2-16 parts sodium gallate, 1-10 parts sodium lactate, 1-7 parts stabilizer, 0.5-4.5 parts dispersant, and 30-50 parts water; the stabilizer includes sodium alginate.

2. The scale inhibitor for soda ash mother liquor according to claim 1, characterized in that, The mass ratio of sodium gallate to sodium lactate is 2~4:

1.

3. The scale inhibitor for soda ash mother liquor according to claim 2, characterized in that, The mass ratio of sodium gallate to sodium lactate is 3:

1.

4. The scale inhibitor for soda ash mother liquor according to claim 1, characterized in that, The surfactant includes one or more of dodecyl dimethyl betaine, sodium dodecyl sulfonate, and sodium lauroyl amphoteric acetate; the dispersant includes isopropanolamine.

5. The scale inhibitor for soda ash mother liquor according to claim 1, characterized in that, The polyepoxysuccinic acid is a modified polyepoxysuccinic acid, and the raw materials for the modified polyepoxysuccinic acid include polyepoxysuccinic acid and pent-4-en-1-amine.

6. The scale inhibitor for soda ash mother liquor according to claim 5, characterized in that, The preparation process of the modified polyepoxysuccinic acid includes the following steps: adding the polyepoxysuccinic acid to water, adding an initiator in an inert gas atmosphere, mixing, adding pent-4-en-1-amine, reacting, concentrating, and drying to obtain the modified polyepoxysuccinic acid. The mass ratio of the polyepoxysuccinic acid to water is 1:3~5.

7. The scale inhibitor for soda ash mother liquor according to claim 6, characterized in that, The mass ratio of the polyepoxysuccinic acid to the pent-4-ene-1-amine is 20:1~3.

8. The scale inhibitor for soda ash mother liquor according to claim 6, characterized in that, The initiator includes one of sodium persulfate and ammonium persulfate, and the mass ratio of polyepoxysuccinic acid to the initiator is 30:0.5~1.

5.

9. A scale inhibitor for soda ash mother liquor according to claim 6, characterized in that, The reaction is carried out at a temperature of 25-45°C for 2-4 hours.

10. A method for preparing a scale inhibitor for soda ash mother liquor according to any one of claims 1 to 9, characterized in that, The process includes the following steps: mixing the raw material components evenly to obtain the scale inhibitor for soda ash mother liquor.

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