Iron tailings dispersant and method for preparing the same

Abstract

This invention provides a method for preparing an iron tailings dispersant, comprising the following steps: Step 1 involves adding a first oxidant to a first portion of terminal hydroxyl polyether and reacting it under heating conditions. After the reaction is complete, a second oxidant is added dropwise, resulting in a terminal carboxyl polyether. Step 2 involves adding the terminal carboxyl polyether to a second portion of terminal hydroxyl polyether, then adding deionized water and a third oxidant, stirring until homogeneous, and then adding a dropwise additive. After maintaining the temperature and reacting, the iron tailings dispersant is obtained. The iron tailings dispersant of this invention introduces a terminal carboxyl polyether (as shown in Figure 1) on the basis of a long-side-chain (high steric hindrance) iron tailings dispersant (as shown in Figure 2), which allows the long side chains to extend and better promotes the dispersion of iron tailings particles.

Description

Technical Field

[0001] This invention belongs to the field of iron tailings processing, and in particular relates to an iron tailings dispersant and its preparation method. Background Technology

[0002] With the continuous development of mining and the steel industry, the amount of tailings, as waste after mineral processing, is also increasing. Statistics show that my country's annual tailings production is approximately 1.272 billion tons. Improving the resource utilization rate of tailings is of great significance for reducing the pressure on existing mineral resources, turning waste into treasure, promoting national economic development, ensuring iron resource supply, and protecting the environment.

[0003] Iron tailings powder, due to its main mineral composition being similar to that of natural sand, can be used as fine aggregate or micro-aggregate in concrete. However, the particle size of iron tailings powder is between 0.04-0.15mm, and its specific surface area is too large. When preparing concrete, it will have a large water absorption, and the amount of admixtures will need to be increased several times, which greatly increases the cost and brings great difficulties to the promotion and application of iron tailings. Summary of the Invention

[0004] In view of this, the present invention aims to overcome the defects in the prior art and proposes an iron tailings dispersant and its preparation method.

[0005] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0006] A method for preparing an iron tailings dispersant includes the following steps:

[0007] Step 1 involves adding a first oxidizing agent to the first hydroxyl-terminated polyether and reacting it under heating conditions. After the reaction is complete, a second oxidizing agent is added dropwise. After the reaction is complete, a carboxyl-terminated polyether is obtained. The reaction process is shown in formula (Ⅰ).

[0008]

[0009] Step 2 involves adding the terminal carboxyl polyether to the second part of the terminal hydroxyl polyether, then adding deionized water and a third oxidizing agent, stirring until homogeneous, then adding a dropwise additive, and maintaining the temperature for reaction to obtain the iron tailings dispersant.

[0010] Furthermore, in step 1, the mass ratio of the first hydroxyl-terminated polyether to the first oxidant and the second oxidant is 50-80:2-4:1-3; the first oxidant is copper oxide; and the second oxidant is hydrogen peroxide with a mass concentration of 35%.

[0011] Furthermore, the heating temperature in step 1 is 90-120℃; the reaction time for adding the first oxidant in step 1 is 3-5 hours.

[0012] Furthermore, in step 2, the mass ratio of the second part of the hydroxyl-terminated polyether to the carboxyl-terminated polyether, deionized water, the third oxidant, and the dropper is 60-100:20-50:60-80:1.5-2.5:20-40.

[0013] Furthermore, the molecular weight of the second hydroxyl-terminated polyether is 5000-6000.

[0014] Furthermore, the third oxidant in step 2 is at least one of hydrogen peroxide, potassium persulfate, or ammonium persulfate; the mass concentration of the hydrogen peroxide is 35%.

[0015] Furthermore, the temperature of the dropwise addition step in step 2 is 20-30℃, and the time is 2 hours; the time for the heat preservation reaction in step 2 is 3 hours.

[0016] Furthermore, the drop solution in step 2 is prepared by a method comprising the following steps: adding deionized water, reducing agent and mercaptoethanol to acrylic acid, mixing them evenly to obtain the drop solution.

[0017] Furthermore, the mass ratio of acrylic acid, deionized water, reducing agent, and chain transfer agent is 6-10:20-30:0.15-0.5:0.32-0.5; the reducing agent is at least one of vitamin C, sodium bisulfite, or ferrous sulfate; and the chain transfer agent is at least one of mercaptoethanol, mercaptoacetic acid, or sodium hypophosphite.

[0018] An iron tailings dispersant prepared using the preparation method described above.

[0019] The dispersion of tailings depends on electrostatic repulsion and high steric hindrance. Commonly used dispersants that meet this dispersion effect are polycarboxylic acid structures. This invention further improves the steric hindrance effect on the basis of conventional polycarboxylic acid, which is beneficial to the further dispersion of tailings. However, the introduction of high steric hindrance can easily lead to the entanglement of long side chains, thereby reducing the dispersion performance of polycarboxylic acid.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] The iron tailings dispersant of this invention is used in iron tailings dispersants with long side chains (high steric hindrance) (such as...). Figure 2 Based on the above, carboxyl-terminated polyethers (such as shown) were introduced. Figure 1 As shown in the figure, this allows the long side chains to extend, which better promotes the dispersion of iron tailings particles. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the iron tailings dispersant described in Embodiment 1 of the present invention;

[0023] Figure 2 This is a schematic diagram of the original iron tailings dispersant. Detailed Implementation

[0024] Unless otherwise defined, the technical terms used in the following embodiments have the same meanings as commonly understood by those skilled in the art. Unless otherwise specified, the experimental reagents used in the following embodiments are conventional biochemical reagents; and the experimental methods described are conventional methods.

[0025] The present invention will be described in detail below with reference to the embodiments.

[0026] Example 1

[0027] A method for preparing an iron tailings dispersant includes the following steps:

[0028] (1) Add 2g of copper oxide to 50g of hydroxyl-terminated polyether and react at 90℃ for 3h until the liquid turns red. Add 1g of 35% hydrogen peroxide to it. After the reaction is complete, carboxyl-terminated polyether is obtained.

[0029] (2) Add 20g of deionized water, 0.15g of vitamin C and 0.32g of mercaptoethanol to 6g of acrylic acid and stir until homogeneous to obtain a dropping solution;

[0030] (3) Add 20g of carboxyl-terminated polyether prepared above to 60g of hydroxyl-terminated polyether, then add 60g of deionized water and 1.5g of 35% hydrogen peroxide, stir evenly, and add dropwise solution for 2h at 20-30℃. After keeping warm for 3h, the iron tailings dispersant is obtained.

[0031] Comparative Example 1

[0032] A method for preparing an iron tailings dispersant includes the following steps:

[0033] (1) Add 2g of copper oxide to 50g of hydroxyl-terminated polyether and react at 90℃ for 3h until the liquid turns red. Add 1g of 35% hydrogen peroxide to it. After the reaction is complete, carboxyl-terminated polyether is obtained.

[0034] (2) Add 20g of deionized water, 0.15g of vitamin C and 0.32g of mercaptoethanol to 6g of acrylic acid and stir until homogeneous to obtain a dropping solution;

[0035] (3) Add 60g of deionized water and 1.5g of 35% hydrogen peroxide to the carboxyl-terminated polyether prepared above, stir evenly, and add dropwise solution for 2h at 20-30℃. After keeping warm for 3h, the iron tailings dispersant is obtained.

[0036] Comparative Example 2

[0037] A method for preparing an iron tailings dispersant includes the following steps:

[0038] (1) Add 2g of copper oxide to 50g of hydroxyl-terminated polyether and react at 90℃ for 3h until the liquid turns red. Add 1g of 35% hydrogen peroxide to it. After the reaction is complete, carboxyl-terminated polyether is obtained.

[0039] (2) Add 20g of deionized water, 0.15g of vitamin C and 0.32g of mercaptoethanol to 6g of acrylic acid and stir until homogeneous to obtain a dropping solution;

[0040] (3) Add the above 20g of end-carboxyl polyether to 60g of conventional end-carboxyl polyether, then add 60g of deionized water and 1.5g of 35% hydrogen peroxide, stir evenly, and add the dropwise solution for 2h at 20-30℃. After keeping warm for 3h, the iron tailings dispersant is obtained.

[0041] The dispersants obtained in Example 1 and Comparative Examples 1-2 were tested, and the results are shown in Table 1.

[0042] Test method: Take 300g of iron tailings powder, add 3g of iron tailings dispersant, add 84g of water, and test its flowability using a truncated cone mold.

[0043] Table 1 Test Results

[0044] project Tailings Flowability / mm Example 1 180 Comparative Example 1 120 Comparative Example 2 illiquid

[0045] As shown in Table 1, the fluidity of Comparative Example 1 is reduced compared to Example 1. This is because the high steric hindrance dispersant can improve the fluidity of tailings, but it is a flexible side chain that is very easy to entangle together, thereby reducing the dispersion effect. Comparative Example 2 has no fluidity because the tail ends of the side chains are all carboxyl groups, which are all negatively charged. Although they spread out better, the side chains are very easy to be adsorbed on the surface of the tailings due to the charge, resulting in the failure of the steric hindrance effect.

[0046] The above description is only a preferred embodiment of the present invention and is 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 method for preparing an iron tailings dispersant, characterized in that: Includes the following steps: Step 1 involves adding a first oxidant to the first part of the hydroxyl-terminated polyether and reacting it under heating conditions. After the reaction is complete, a second oxidant is added dropwise to obtain the carboxyl-terminated polyether. Step 2 involves adding the terminal carboxyl polyether to the second part of the terminal hydroxyl polyether, then adding deionized water and a third oxidant, stirring until homogeneous, then adding a dropwise solution, and maintaining the temperature for reaction to obtain the iron tailings dispersant. The first oxidizing agent is copper oxide; the second oxidizing agent is hydrogen peroxide with a mass concentration of 35%. The molecular weight of the second hydroxyl-terminated polyether is 5000-6000; The drop solution in step 2 is prepared by a method including the following steps: adding deionized water, reducing agent and mercaptoethanol to acrylic acid, mixing evenly to obtain the drop solution; the mass ratio of acrylic acid, deionized water, reducing agent and mercaptoethanol is 6-10:20-30:0.15-0.5:0.32-0.

5.

2. The method for preparing the iron tailings dispersant according to claim 1, characterized in that: In step 1, the mass ratio of the first hydroxyl-terminated polyether to the first oxidant and the second oxidant is 50-80:2-4:1-3.

3. The method for preparing the iron tailings dispersant according to claim 1, characterized in that: The heating temperature in step 1 is 90-120℃; the reaction time for adding the first oxidant in step 1 is 3-5 hours.

4. The method for preparing the iron tailings dispersant according to claim 1, characterized in that: In step 2, the mass ratio of the second part of the hydroxyl-terminated polyether to the carboxyl-terminated polyether, deionized water, the third oxidant, and the drop solution is 60-100:20-50:60-80:1.5-2.5:20-40.

5. The method for preparing the iron tailings dispersant according to claim 1, characterized in that: The third oxidant in step 2 is at least one of hydrogen peroxide, potassium persulfate, or ammonium persulfate; the mass concentration of the hydrogen peroxide is 35%.

6. The method for preparing the iron tailings dispersant according to claim 1, characterized in that: The temperature of the dropwise addition step in step 2 is 20-30℃, and the time is 2 hours; the time for the heat preservation reaction in step 2 is 3 hours.

7. The method for preparing the iron tailings dispersant according to claim 1, characterized in that: The reducing agent is at least one of vitamin C, sodium bisulfite, or ferrous sulfate.

8. An iron tailings dispersant prepared using the preparation method according to any one of claims 1-7.

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