Iron tailings dewatering aid and method of making same

Abstract

This invention provides a method for preparing an iron tailings dehydration aid, comprising the following steps: Step 1 involves adding saturated fatty acids and a catalyst to a first part of polyether to conduct an esterification reaction, resulting in a modified polyether after the reaction is complete; Step 2 involves adding the modified polyether to a second part of polyether, then adding deionized water and an oxidant, stirring until homogeneous, and then adding a dropwise additive, maintaining the temperature for reaction to obtain the iron tailings dehydration aid. The iron tailings dehydration aid of this invention primarily functions by adsorbing onto the tailings through electrostatic adsorption, dispersing the agglomerated tailings, and releasing free water; simultaneously, compared to hydroxyl groups, the dehydration aid introduces hydrophobic groups, which do not bind with water and confine it around the tailings particles, thereby allowing free water to be released from the system.

Description

Technical Field

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

[0002] Tailings dewatering and dry stacking is a new tailings treatment process that has emerged in the global mining industry in recent years. Especially with the tightening of safety and environmental protection policies for tailings ponds and the promotion of comprehensive tailings utilization technologies in my country, a large amount of tailings needs to be dewatered and then dry stacked or used in industries such as cement, building materials, and highway construction. Finding a suitable dewatering process and reducing tailings dewatering costs are urgent practical problems that mining companies need to solve.

[0003] Tailings dry stacking is the process by which tailings slurry discharged after mineral processing is concentrated in multiple stages and then treated by a series of high-efficiency dewatering equipment to form slag with low water content that is easy to settle, solidify, and store on site.

[0004] The drawbacks of the dry tailings process are mostly due to the difficulty in dewatering fine-grained materials in the tailings. Because fine particles have a large specific surface area, small pores between particles, strong capillary action, and poor hydrophobicity and thick hydration film on the particle surface.

[0005] Currently, flocculants are generally added to the dry discharge process to improve filtration efficiency, but their effect on reducing filter cake moisture is not ideal. Summary of the Invention

[0006] In view of this, the present invention aims to overcome the defects in the prior art and proposes an iron tailings dehydration aid and its preparation method.

[0007] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0008] A method for preparing an iron tailings dehydration aid includes the following steps:

[0009] Step 1 involves adding saturated fatty acids and a catalyst to the first part of the polyether to carry out an esterification reaction. After the reaction is completed, a modified polyether is obtained. The reaction process is shown in formula (Ⅰ).

[0010]

[0011] Step 2 involves adding the modified polyether to the second part of the polyether, then adding deionized water and an oxidant, stirring until homogeneous, then adding a dropwise additive, and maintaining the temperature for reaction to obtain the iron tailings dehydration aid.

[0012] Furthermore, in step 1, the mass ratio of the first part of polyether to lauric acid and catalyst is 60-80:2.4-5:1.3-3; the catalyst is at least one of p-toluenesulfonic acid, sulfuric acid, or phosphoric acid; the saturated fatty acid has 10 or more carbon atoms; and the saturated fatty acid is at least one of lauric acid, myristic acid, or palmitic acid.

[0013] Furthermore, the temperature of the esterification reaction in step 1 is 90-120℃.

[0014] Furthermore, the molecular weight of the first polyether in step 1 is 5000-6000.

[0015] Furthermore, in step 2, the mass ratio of the second part of polyether to modified polyether, deionized water, oxidant, and drop solution is 40-60:20-40:60-80:1.5-5:20-40.

[0016] Furthermore, the 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%.

[0017] 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.

[0018] Furthermore, the drop solution in step 2 is prepared by a method comprising the following steps: adding deionized water, a reducing agent and a chain transfer agent to acrylic acid, mixing them evenly to obtain the drop solution.

[0019] 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.

[0020] A dehydration aid for iron tailings prepared using the preparation method described above.

[0021] Because tailings are prone to agglomeration due to charge, a lot of water is trapped between the tailings particles. The dehydration aid mainly works by adsorbing the tailings through electrostatic adsorption, dispersing the agglomerated tailings and releasing free water. At the same time, compared with hydroxyl groups, the dehydration aid introduces hydrophobic groups, which do not combine with water and trap it around the tailings particles, thereby allowing free water to be released from the system.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] The iron tailings dehydration aid described in this invention fully disperses the particles, releasing the encapsulated water. At the same time, it modifies the terminal hydroxyl portion of the long side chain in the structure into a hydrophobic group, so that the water cannot bind with the dispersant and is released from the system. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the dehydration mechanism of the dehydration aid described in Example 1 of the present invention;

[0025] Figure 2 This is a schematic diagram showing the dehydration results of the dehydration aid described in Comparative Example 1 of the present invention. Detailed Implementation

[0026] 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.

[0027] The present invention will be described in detail below with reference to the embodiments.

[0028] Example 1

[0029] A method for preparing an iron tailings dehydration aid includes the following steps:

[0030] (1) Add 2.4g of lauric acid and 1.3g of catalyst to 60g of polyether and carry out esterification reaction at 90℃. After the reaction is completed, modified polyether is obtained.

[0031] (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;

[0032] (3) Add 20g of modified polyether to 40g of polyether, then add 60g of deionized water and 1.5g of hydrogen peroxide (35% concentration), stir evenly, add the dropwise solution, add dropwise at 20-30℃ for 2 hours, and keep warm for 3 hours to obtain the iron tailings dehydration aid.

[0033] Comparative Example 1

[0034] A method for preparing an iron tailings dehydration aid includes the following steps:

[0035] (1) 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;

[0036] (2) Add 60g of deionized water and 1.5g of hydrogen peroxide (35% concentration) to 60g of polyether, stir evenly, add the dropwise solution dropwise, add dropwise at 20-30℃ for 2 hours, and keep warm for 3 hours to obtain the iron tailings dehydration aid.

[0037] Comparative Example 2

[0038] A method for preparing an iron tailings dehydration aid includes the following steps:

[0039] (1) Add 2.4g of lauric acid and 1.3g of catalyst to 60g of polyether and carry out esterification reaction at 90℃. After the reaction is completed, modified polyether is obtained.

[0040] (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;

[0041] (3) Add 60g of deionized water and 1.5g of hydrogen peroxide (35% concentration) to 60g of modified polyether, stir evenly, add the dropwise solution dropwise, add dropwise at 20-30℃ for 2 hours, and keep warm for 3 hours to obtain the iron tailings dehydration aid.

[0042] The dehydration aids obtained in Example 1 and Comparative Examples 1-2 were tested, and the results are shown in Table 1.

[0043] Test method: Add 3g of dehydration aid to 100g of tailings with a moisture content of 40%, filter it using a vacuum filtration device, and weigh the mass M after filtration.

[0044] Dehydration rate = (10³ - M) / 10³ * 100%

[0045] Table 1 Test Results

[0046] category Dehydration rate / % Example 1 12 Comparative Example 1 1 Comparative Example 2 This product is insoluble in water and has no effect.

[0047] As shown in Table 1, in Example 1, due to the modification of the terminal hydroxyl groups of the long side chains to hydrophobic -CH3, water is released after dispersion, and water can also be removed from the system, such as... Figure 1 As shown; in Comparative Example 1, when the substitution rate of the modified polyether is 0 (i.e., no modified polyether is used), because the tail end of the long side chain is a hydroxyl group, it will combine with water to form hydrogen bonds, causing water to be released but still unable to escape from the system, such as... Figure 2 As shown; when the modified polyether substitution rate of Comparative Example 2 is 100%, the product after the reaction is completed presents as a blocky substance that is insoluble in water, and the tailings cannot be dispersed.

[0048] 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 dewatering aid, characterized in that: Includes the following steps: Step 1 involves adding saturated fatty acids and a catalyst to the first part of the polyether to carry out an esterification reaction, and obtaining the modified polyether after the reaction is complete. Step 2 involves adding the modified polyether to the second part of the polyether, then adding deionized water and an oxidant, stirring until homogeneous, then adding a dropwise additive, and maintaining the temperature for reaction to obtain the iron tailings dehydration aid. The drop solution in step 2 is prepared by a method including the following steps: adding deionized water, reducing agent and chain transfer agent to acrylic acid, mixing them evenly to obtain the drop solution.

2. The method for preparing the iron tailings dewatering aid according to claim 1, characterized in that: In step 1, the mass ratio of the first part of polyether to saturated fatty acid and catalyst is 60-80:2.4-5:1.3-3; the catalyst is at least one of p-toluenesulfonic acid, sulfuric acid or phosphoric acid; the saturated fatty acid has 10 or more carbon atoms; and the saturated fatty acid is at least one of lauric acid, myristic acid or palmitic acid.

3. The method for preparing the iron tailings dewatering aid according to claim 1, characterized in that: The temperature of the esterification reaction in step 1 is 90-120℃.

4. The method for preparing the iron tailings dewatering aid according to claim 1, characterized in that: The molecular weight of the first polyether in step 1 is 5000-6000.

5. The method for preparing the iron tailings dewatering aid according to claim 1, characterized in that: In step 2, the mass ratio of the second part of polyether to modified polyether, deionized water, oxidant, and drop solution is 40-60:20-40:60-80:1.5-5:20-40.

6. The method for preparing the iron tailings dewatering aid according to claim 1, characterized in that: The 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%.

7. The method for preparing the iron tailings dewatering aid 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.

8. The method for preparing the iron tailings dewatering aid according to claim 1, characterized in that: 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.

9. An iron tailings dehydration aid prepared by the preparation method according to any one of claims 1-8.

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