Composite flotation inhibitor based on sodium lignin sulfonate and preparation process of composite flotation inhibitor

Abstract

The invention provides a composite flotation inhibitor based on sodium lignin sulfonate and a preparation technology of the composite flotation inhibitor, and belongs to the technical field of flotation inhibitor preparation. The preparation process comprises the following steps: preparing modified sodium lignin sulfonate; preparing modified carboxymethyl cellulose; and preparing the composite flotation inhibitor. The modified sodium lignin sulfonate and the modified carboxymethyl cellulose are compounded, and the prepared composite flotation inhibitor can effectively improve the lepidolite flotation concentrate grade and the recovery rate.

Description

Technical Field

[0001] The present invention relates to the technical field of flotation inhibitors, and particularly relates to a composite flotation inhibitor based on sodium lignosulfonate and a preparation process thereof. Background Art

[0002] Lithium, as an important strategic metal, is widely used in new energy batteries, aerospace and other fields, and lepidolite ore is one of the important sources for extracting lithium resources. With the rapid growth of global demand for lithium, the efficient development and utilization of lepidolite ore is imminent. However, lepidolite ore is often closely associated with gangue minerals such as quartz, feldspar, and clay, and the surface properties of lepidolite are complex, with small differences in floatability, resulting in difficult flotation separation. Traditional flotation processes and inhibitors are difficult to achieve efficient separation of lepidolite from gangue minerals, and there are problems such as low concentrate grade, low recovery rate, and high reagent consumption.

[0003] Sodium lignosulfonate is a natural polymer surfactant. Due to its wide source, low price, and certain inhibitory properties, it has attracted attention in mineral flotation. The active groups in its molecular structure can interact with the mineral surface and change the mineral surface properties through adsorption, complexation, etc., thereby affecting the floatability of minerals. In some mineral flotation studies, it has been found that sodium lignosulfonate has a certain inhibitory effect on some gangue minerals. However, in the field of lepidolite ore flotation, there is currently little research on the application of sodium lignosulfonate. The few existing attempts show that it is difficult to effectively inhibit the key gangue minerals in lepidolite ore flotation by using sodium lignosulfonate alone, and its stability and selectivity in a complex pulp environment are poor, unable to meet the requirements of efficient flotation separation of lepidolite ore, and the concentrate grade and recovery rate are difficult to reach ideal levels.

[0004] Therefore, we propose a composite flotation inhibitor based on sodium lignosulfonate and a preparation process thereof. Summary of the Invention

[0005] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a composite flotation inhibitor based on sodium lignosulfonate and a preparation process thereof.

[0006] A preparation process of a composite flotation inhibitor based on sodium lignosulfonate includes the following steps: S1: Preparation of modified sodium lignosulfonate React sodium lignosulfonate with sodium hydroxide and hydrogen peroxide, and then add sulfuric acid to obtain modified sodium lignosulfonate; S2: Preparation of modified carboxymethyl cellulose React carboxymethyl cellulose with sodium hydroxide and chloroacetic acid to prepare modified carboxymethyl cellulose; S3: Preparation of composite flotation inhibitor Prepare a composite flotation inhibitor by compounding modified sodium lignosulfonate, modified carboxymethyl cellulose and sodium silicate.

[0007] Furthermore, the preparation of the modified sodium lignosulfonate in step S1 specifically includes the following steps: S1.1: Add 10 - 12 parts by weight of sodium lignosulfonate to 100 - 125 parts by weight of a sodium hydroxide solution with a mass fraction of 5 - 10%, stir for 20 - 30 min, then add a hydrogen peroxide solution with a mass fraction of 30 - 32%, and react at 60 - 80 °C for 2 - 4 h to obtain a reaction solution; S1.2: Add a sulfuric acid solution with a mass fraction of 2 - 5% to the reaction solution to adjust the pH to neutral, then filter, concentrate the filtrate under reduced pressure, and then dry in a vacuum drying oven at 50 - 60 °C to obtain modified sodium lignosulfonate.

[0008] Furthermore, the preparation of the modified carboxymethyl cellulose in step S2 specifically includes the following steps: S2.1: Add 10 - 12 parts by weight of carboxymethyl cellulose to 200 - 300 parts by weight of an ethanol - water solution with a mass fraction of 70 - 80%, then add 20 - 30 parts by weight of a sodium hydroxide solution with a mass fraction of 40% and stir for 20 - 30 min to obtain a mixed system; S2.2: Add 12 - 15 parts by weight of chloroacetic acid to the mixed system, then react at 70 - 72 °C for 2 - 3 h. After the reaction is completed, adjust the pH to neutral, and finally wash and dry to obtain modified carboxymethyl cellulose.

[0009] Furthermore, the preparation of the composite flotation inhibitor in step S3 specifically includes the following steps: Mix the modified sodium lignosulfonate and the modified carboxymethyl cellulose evenly to obtain a mixed system, and then add sodium silicate to the mixed system and stir - mix for 20 - 30 min to obtain a composite flotation inhibitor.

[0010] Furthermore, in step S1.1, the mass ratio of hydrogen peroxide to sodium lignosulfonate is 1:5 - 1:8.

[0011] Furthermore, in step S3, the modified sodium lignosulfonate and the modified carboxymethyl cellulose are mixed in a mass ratio of 3 - 4:1.

[0012] Furthermore, the addition amount of sodium silicate in step S3 is 20 - 30 wt% of the mixed system.

[0013] A composite flotation inhibitor based on sodium lignosulfonate, which is prepared by the preparation process of the composite flotation inhibitor based on sodium lignosulfonate described above.

[0014] Compared with the prior art, the present invention has at least the following beneficial effects: 1. In the present invention, more active groups are introduced into the modified sodium lignosulfonate, which can be more precisely adsorbed on the surface of gangue minerals, hindering the combination of gangue minerals and collectors; through further modification, more hydrophilic functional groups such as carboxyl groups and hydroxyl groups are introduced into the modified carboxymethyl cellulose, which is preferentially adsorbed on the surface of gangue, preventing the adsorption of collectors, and realizing the efficient inhibition of gangue. The synergistic effect of the two can effectively inhibit gangue minerals such as feldspar and quartz associated with lepidolite, improve the selectivity of lepidolite flotation, and significantly improve the grade of lithium concentrate.

[0015] 2. The modified carboxymethyl cellulose added in the present invention can adjust the stability and viscosity of the flotation foam. Appropriately stable foam is beneficial to the attachment and floating of lepidolite, avoiding the re-sedimentation of lepidolite particles caused by the too-fast rupture of the foam; at the same time, the appropriate foam viscosity can prevent excessive adhesion of the foam, ensure the fluidity of the foam, make the flotation process smoother, and further improve the flotation index. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings incorporated herein and constituting a part of the specification illustrate embodiments of the present invention and, together with the specification, are further used to explain the principles of the present invention and enable those skilled in the relevant art to implement and use the present invention.

[0017] Figure 1 It is a process flow chart of the preparation of a composite flotation inhibitor based on sodium lignosulfonate adopted in the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] The following describes in detail the preparation process of a composite flotation inhibitor based on sodium lignosulfonate provided by the present invention with reference to the accompanying drawings and specific embodiments. At the same time, it is noted here that in order to make the embodiments more detailed, the following embodiments are the best and preferred embodiments. For some well-known technologies, those skilled in the art can also adopt other alternative methods for implementation; moreover, the accompanying drawings are only for more specific description of the embodiments and are not intended to specifically limit the present invention.

[0019] Example 1: A preparation process of a composite flotation inhibitor based on sodium lignosulfonate, as Figure 1 shown, includes the following steps: S1: Preparation of modified sodium lignosulfonate S1.1: Add 10 parts by weight of sodium lignosulfonate to 100 parts by weight of a sodium hydroxide solution with a mass fraction of 5%, stir for 20 min, then add a hydrogen peroxide solution with a mass fraction of 30%. The mass ratio of hydrogen peroxide to sodium lignosulfonate is 1:5, and react at 60 - 80 °C for 2 h to obtain a reaction solution; S1.2: Add a sulfuric acid solution with a mass fraction of 2% to the reaction solution, adjust the pH to neutral, then filter, concentrate the filtrate under reduced pressure, and then dry it in a vacuum drying oven at 50 °C to obtain modified sodium lignosulfonate; S2: Preparation of modified carboxymethyl cellulose S2.1: Add 10 parts by weight of carboxymethyl cellulose to 200 parts by weight of an aqueous ethanol solution with a mass fraction of 70%, then add 20 parts by weight of a sodium hydroxide solution with a mass fraction of 40% and stir for 20 min to obtain a mixed system; S2.2: Add 12 parts by weight of chloroacetic acid to the mixed system, then react at 70 °C for 2 h. After the reaction is completed, adjust the pH to neutral, and finally wash and dry to obtain modified carboxymethyl cellulose; S3: Preparation of composite flotation inhibitor Mix the modified sodium lignosulfonate and modified carboxymethyl cellulose evenly according to a mass ratio of 3:1 to obtain a mixed system, and then add 20 wt% sodium silicate to the mixed system and stir and mix for 20 min to obtain a composite flotation inhibitor.

[0020] Example 2: A preparation process of a composite flotation inhibitor based on sodium lignosulfonate, as Figure 1 shown, includes the following steps: S1: Preparation of modified sodium lignosulfonate S1.1: Add 10 parts by weight of sodium lignosulfonate to 100 parts by weight of a sodium hydroxide solution with a mass fraction of 5%, then stir for 30 min, and then add a hydrogen peroxide solution with a mass fraction of 30%. The mass ratio of hydrogen peroxide to sodium lignosulfonate is 1:5, and react at 80 °C for 4 h to obtain a reaction solution; S1.2: Add a sulfuric acid solution with a mass fraction of 2% to the reaction solution, adjust the pH to neutral, then filter, concentrate the filtrate under reduced pressure, and then dry it in a vacuum drying oven at 60 °C to obtain modified sodium lignosulfonate; S2: Preparation of modified carboxymethyl cellulose S2.1: Add 10 parts by weight of carboxymethyl cellulose to 200 parts by weight of an aqueous ethanol solution with a mass fraction of 70%, then add 20 parts by weight of a sodium hydroxide solution with a mass fraction of 40% and stir for 30 min to obtain a mixed system; S2.2: Add 12 parts by weight of chloroacetic acid to the mixed system, then react at 72 °C for 3 h. After the reaction is completed, adjust the pH to neutral, and finally wash and dry to obtain modified carboxymethyl cellulose; S3: Preparation of composite flotation inhibitor Mix sodium lignosulfonate and carboxymethyl cellulose in a mass ratio of 3:1 evenly to obtain a mixed system. Then, add 20wt% sodium silicate to the mixed system and stir for 30 minutes to obtain a composite flotation inhibitor.

[0021] Example 3: A preparation process of a composite flotation inhibitor based on sodium lignosulfonate, as Figure 1 shown, includes the following steps: S1: Preparation of modified sodium lignosulfonate S1.1: Add 12 parts by weight of sodium lignosulfonate to 125 parts by weight of a sodium hydroxide solution with a mass fraction of 10%. Then stir for 20 minutes, and then add a hydrogen peroxide solution with a mass fraction of 32%. The mass ratio of hydrogen peroxide to sodium lignosulfonate is 1:8, and react at 60 - 80°C for 2 hours to obtain a reaction solution; S1.2: Add a sulfuric acid solution with a mass fraction of 5% to the reaction solution to adjust the pH to neutral. Then filter, concentrate the filtrate under reduced pressure, and then dry in a vacuum drying oven at 50°C to obtain modified sodium lignosulfonate; S2: Preparation of modified carboxymethyl cellulose S2.1: Add 12 parts by weight of carboxymethyl cellulose to 300 parts by weight of an ethanol - aqueous solution with a mass fraction of 80%. Then add 30 parts by weight of a sodium hydroxide solution with a mass fraction of 40% and stir for 20 minutes to obtain a mixed system; S2.2: Add 15 parts by weight of chloroacetic acid to the mixed system, and then react at 70°C for 2 hours. After the reaction is completed, adjust the pH to neutral, and finally wash and dry to obtain modified carboxymethyl cellulose; S3: Preparation of the composite flotation inhibitor Mix modified sodium lignosulfonate and modified carboxymethyl cellulose in a mass ratio of 4:1 evenly to obtain a mixed system. Then, add 30wt% sodium silicate to the mixed system and stir for 20 minutes to obtain a composite flotation inhibitor.

[0022] Comparative Example 1: Compared with Example 1, the difference in Comparative Example 1 is that in Comparative Example 1, step S1 is removed, and the modified sodium lignosulfonate in step S3 is replaced with sodium lignosulfonate, and the other steps remain unchanged to prepare the composite flotation inhibitor, denoted as Comparative Example 1.

[0023] Comparative Example 2: Compared with Example 1, the difference in Comparative Example 2 is that in Comparative Example 2, step S2 is removed, and the modified carboxymethyl cellulose in S3 is replaced with carboxymethyl cellulose, and the other steps remain unchanged to prepare the composite flotation inhibitor, denoted as Comparative Example 2.

[0024] Comparative Example 3: Compared with Example 1, the difference in Comparative Example 3 is that in Comparative Example 3, step S1 is removed, and the modified sodium lignosulfonate in step S3 is replaced with modified carboxymethyl cellulose, and the remaining steps remain unchanged to prepare a composite flotation inhibitor, denoted as Comparative Example 3.

[0025] Comparative Example 4: Compared with Example 1, the difference in Comparative Example 4 is that in Comparative Example 4, step S2 is removed, and the modified carboxymethyl cellulose in S3 is replaced with modified lignosulfonic acid, and the remaining steps remain unchanged to prepare a composite flotation inhibitor, denoted as Comparative Example 4.

[0026] The composite flotation inhibitors prepared in Examples 1-3 and Comparative Examples 1-4 were used for flotation tests under the condition of a dosage of 500 g / t, and the test results are shown in Table 1 for reference.

[0027] Table 1. Test Results of Flotation Tests for Examples 1-3 and Comparative Examples 1-2 <![CDATA[Grade of Li2O in Lepidolite Concentrate / %]]> <![CDATA[Recovery rate of Li2O in lepidolite concentrate / %]]> Example 1 4.12 62.32 Example 2 4.09 61.59 Example 3 4.11 61.82 Comparative Example 1 2.36 46.53 Comparative Example 2 2.78 52.32 Comparative Example 3 3.44 56.84 Comparative Example 4 3.62 57.32 It can be seen from the data in Table 1 that the data of Comparative Examples 1-2 are significantly lower than those of Examples 1-3, indicating that the modified sodium lignosulfonate and the modified carboxymethyl cellulose can significantly improve the flotation inhibition effect. It can be seen from the data of Comparative Examples 3-4 that the synergistic effect of the modified sodium lignosulfonate and the modified carboxymethyl cellulose effectively improves the selectivity of spodumene flotation, significantly improves the grade of spodumene concentrate, and reduces the loss of spodumene in the flotation process, thereby improving the recovery rate of spodumene.

[0028] The above examples are only illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above examples without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. Preparation process of a composite flotation inhibitor based on sodium lignosulfonate, characterized in that, It includes the following steps: S1: Preparation of modified sodium lignosulfonate React sodium hydroxide, hydrogen peroxide with sodium lignosulfonate, and then add sulfuric acid to obtain modified sodium lignosulfonate; S2: Preparation of modified carboxymethyl cellulose React sodium hydroxide and chloroacetic acid with carboxymethyl cellulose to prepare modified carboxymethyl cellulose; S3: Preparation of composite flotation inhibitor Compound modified sodium lignosulfonate, modified carboxymethyl cellulose and sodium silicate to prepare a composite flotation inhibitor.

2. The preparation process of a composite flotation inhibitor based on sodium lignosulfonate according to claim 1, characterized in that, The preparation of modified sodium lignosulfonate in step S1 specifically includes the following steps: S1.1: Add 10 - 12 parts by weight of sodium lignosulfonate to 100 - 125 parts by weight of sodium hydroxide solution with a mass fraction of 5 - 10%, stir for 20 - 30 min, then add a hydrogen peroxide solution with a mass fraction of 30 - 32%, and react at 60 - 80 °C for 2 - 4 h to obtain a reaction solution; S1.2: Add a sulfuric acid solution with a mass fraction of 2 - 5% to the reaction solution, adjust the pH to neutral, then filter, concentrate the filtrate under reduced pressure, and then dry it in a vacuum drying oven at 50 - 60 °C to obtain modified sodium lignosulfonate.

3. The preparation process of a composite flotation inhibitor based on sodium lignosulfonate according to claim 2, characterized in that, The preparation of modified carboxymethyl cellulose in step S2 specifically includes the following steps: S2.1: Add 10 - 12 parts by weight of carboxymethyl cellulose to 200 - 300 parts by weight of an ethanol - water solution with a mass fraction of 70 - 80%, then add 20 - 30 parts by weight of a sodium hydroxide solution with a mass fraction of 40% and stir for 20 - 30 min to obtain a mixed system; S2.2: Add 12 - 15 parts by weight of chloroacetic acid to the mixed system, then react at 70 - 72 °C for 2 - 3 h, adjust the pH to neutral after the reaction is completed, and finally wash and dry to obtain modified carboxymethyl cellulose.

4. The composite flotation inhibitor based on sodium lignosulfonate and its preparation process according to claim 3, characterized in that, The preparation of the composite flotation inhibitor in step S3 specifically includes the following steps: Mix modified sodium lignosulfonate and modified carboxymethyl cellulose evenly to obtain a mixed system, then add sodium silicate to the mixed system and stir and mix for 20 - 30 min to obtain a composite flotation inhibitor.

5. The preparation process of a composite flotation inhibitor based on sodium lignosulfonate according to claim 2, characterized in that, In step S1.1, the mass ratio of hydrogen peroxide to sodium lignosulfonate is 1:5 - 1:

8.

6. The preparation process of a composite flotation inhibitor based on sodium lignosulfonate according to claim 4, characterized in that, In step S3, modified sodium lignosulfonate and modified carboxymethyl cellulose are mixed in a mass ratio of 3 - 4:

1.

7. The preparation process of a composite flotation inhibitor based on sodium lignosulfonate according to claim 4, characterized in that, In step S3, the addition amount of sodium silicate is 20 - 30 wt% of the mixed system.

8. A composite flotation inhibitor based on sodium lignosulfonate, characterized in that, It is prepared by the preparation process of a composite flotation inhibitor based on sodium lignosulfonate described in claims 1 - 7.

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