Concrete based on iron ore tailings and preparation method thereof

Abstract

The invention relates to concrete based on iron ore tailings and a preparation method thereof, and belongs to the technical field of application of iron ore tailings, the concrete is prepared from the following raw materials: iron ore tailings, river sand, Portland cement, tap water, a bonding solution and a water reducing agent; wherein the bonding liquid is prepared from the following raw materials in parts by weight: 20 to 30 parts of polyacrylamide solution, 3 to 6 parts of magnesium oxide powder, 5 to 10 parts of resin, 20 to 25 parts of polypropylene fiber, 10 to 18 parts of antioxidant and 5 to 12 parts of cellulose acetate butyrate powder; the water reducing agent is prepared from the following raw materials in parts by weight: 6-10 parts of montmorillonite powder, 10-15 parts of ferric oxide powder and 3-8 parts of corn starch. The compressive strength and the breaking strength can be reduced when iron ore tailings are added into existing concrete, however, the iron ore tailings, a polyacrylamide solution, magnesium oxide powder and cellulose acetate butyrate powder in the concrete cooperate with one another, the influence of the iron ore tailings on the compressive strength and the breaking strength of the concrete is reduced, the content of the iron ore tailings in the concrete is increased, and the service life of the concrete is prolonged. And the consumption of iron ore tailings is increased.

Description

Technical Field

[0001] The present invention belongs to the technical field of the application of iron ore tailings, and particularly relates to a concrete based on iron ore tailings and a preparation method thereof. Background Art

[0002] Iron ore tailings refer to the waste residues left after the beneficiation of iron ore, which contain both beneficial components and harmful components in the iron ore. Due to ore mining, a large amount of iron ore tailings have been stockpiled. Long-term storage will pollute the environment, and they are usually used to prepare concrete.

[0003] However, when configuring concrete, the proportion of iron ore tailings added has an inverse relationship with the strength of the concrete. That is to say, the higher the proportion of iron ore tailings added to the concrete, the lower the strength of the concrete. Therefore, in order to increase the strength of the concrete, it is necessary to reduce the addition of iron ore tailings, which will cause a large amount of iron ore tailings to be difficult to consume. Summary of the Invention

[0004] The purpose of the present invention is to provide a concrete based on iron ore tailings and a preparation method thereof in order to solve the above problems.

[0005] The present invention realizes the above purpose through the following technical solutions:

[0006] The present invention provides a concrete based on iron ore tailings, and the concrete includes iron ore tailings, river sand, portland cement, tap water, adhesive liquid and water reducing agent;

[0007] Among them, by weight, the raw materials for preparing the adhesive liquid are: 20 - 30 parts of polyacrylamide solution, 3 - 6 parts of magnesium oxide powder, 5 - 10 parts of resin, 20 - 25 parts of polypropylene fiber, 10 - 18 parts of antioxidant and 5 - 12 parts of cellulose acetate butyrate powder; the raw materials for preparing the water reducing agent are: 6 - 10 parts of montmorillonite powder, 10 - 15 parts of iron oxide powder, 3 - 8 parts of corn starch.

[0008] As a further optimized scheme of the present invention, by weight, the raw materials for preparing the concrete are: 20 - 35 parts of iron ore tailings, 10 - 15 parts of river sand, 35 - 45 parts of portland cement, 60 - 80 parts of tap water, 5 - 10 parts of adhesive liquid and 8 - 15 parts of water reducing agent.

[0009] As a further optimized scheme of the present invention, the preparation process of the polyacrylamide solution is: putting the polyacrylamide colloid into a container and stirring for 30 - 45 min, adding pure water to it during the stirring process, and obtaining the polyacrylamide solution after full mixing. The stirring speed is 60 rpm.

[0010] As a further optimized scheme of the present invention, the mass ratio of the polyacrylamide colloid to pure water is 1:5.

[0011] As a further optimization scheme of the present invention, the preparation process of the resin is as follows: heating and fusing furfuryl alcohol resin and rosin to obtain the resin; the preparation process of the antioxidant is as follows: mixing palmitic acid, magnesium stearate, and glycerol, and then adding distilled water and heating to 80 - 120 °C to obtain the antioxidant.

[0012] As a further optimization scheme of the present invention, by weight, the raw materials for preparing the resin are: 30 - 45 parts of furfuryl alcohol resin and 10 - 20 parts of rosin; the raw materials for preparing the antioxidant are: 20 - 35 parts of palmitic acid, 6 - 10 parts of magnesium stearate, 10 - 20 parts of glycerol, and 50 - 60 parts of distilled water.

[0013] The present invention also provides a method for preparing concrete based on iron ore tailings, comprising the following steps:

[0014] S1, heating the polyacrylamide solution to 100 - 120 °C, stirring when the temperature reaches, with a stirring speed of 80 rpm, stirring for 45 - 60 min, adding magnesium oxide powder and polypropylene fiber at the 10th minute of stirring, adding the resin and cellulose acetate butyrate powder at the 20th minute of stirring, and finally adding the antioxidant at the 30th minute of stirring to obtain the adhesive liquid;

[0015] S2, mixing montmorillonite powder, iron oxide powder, and corn starch, and grinding them to 10 - 15 nm through a grinding process to obtain the water reducing agent;

[0016] S3, adding the adhesive liquid to tap water, mixing evenly to obtain a mixture, and putting the mixture into a cement mixer;

[0017] S4, putting iron ore tailings, river sand, and Portland cement into the cement mixer containing the mixture in step S3, stirring, and adding the water reducing agent during stirring, and mixing evenly to obtain the concrete.

[0018] As a further optimization scheme of the present invention, the stirring duration in step S4 is 20 - 35 min, and the stirring speed is 60 rpm.

[0019] The beneficial effects of the present invention are as follows: adding iron ore tailings to the existing concrete will cause a decrease in compressive strength and flexural strength, while in this application, the iron ore tailings cooperate with the polyacrylamide solution, magnesium oxide powder, and cellulose acetate butyrate powder, reducing the influence of iron ore tailings on the compressive strength and flexural strength of the concrete, increasing the content of iron ore tailings in the concrete, and increasing the consumption of iron ore tailings. Detailed Embodiments

[0020] The present application is described in further detail below. It is necessary to point out that the following specific implementation methods are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Technicians in this field can make some non-essential improvements and adjustments to the present application based on the above application content.

[0021] Example 1

[0022] The concrete of this embodiment is prepared by:

[0023] Put the polyacrylamide colloid into a container and stir for 30 minutes. During the stirring process, add pure water to mix with it. After sufficient mixing, a polyacrylamide solution is obtained. The stirring speed is 60 rpm, and the mass ratio of the polyacrylamide colloid to the pure water is 1:5.

[0024] 30 parts of furfuryl alcohol resin and 10 parts of rosin are heated and melted to obtain resin; 20 parts of palmitic acid, 6 parts of magnesium stearate and 10 parts of glycerol are mixed, and then 50 parts of distilled water are added, and heated to 80° C. to obtain an antioxidant;

[0025] 20 parts of polyacrylamide solution were heated to 100°C, stirred at a speed of 80 rpm for 45 minutes, 3 parts of magnesium oxide powder and 20 parts of polypropylene fiber were added at the 10th minute of stirring, 5 parts of resin and 5 parts of cellulose acetate butyrate powder were added at the 20th minute of stirring, and finally 10 parts of antioxidant were added at the 30th minute of stirring to obtain a bonding solution;

[0026] 6 parts of montmorillonite powder, 10 parts of iron oxide powder and 3 parts of corn starch are mixed and ground to 10 nm by a grinding process to obtain a water reducing agent;

[0027] Add 5 parts of adhesive liquid to 60 parts of tap water, mix well to obtain a mixture, and put the mixture into a cement mixer;

[0028] 20 parts of iron ore tailings, 10 parts of river sand, and 35 parts of Portland cement were put into a cement mixer containing the mixture and stirred (stirring time was 20 minutes and stirring speed was 60 rpm). During the stirring period, 8 parts of water reducing agent were added and mixed evenly to obtain concrete.

[0029] Example 2

[0030] The concrete of this embodiment is prepared by:

[0031] Put the polyacrylamide colloid into a container and stir for 35 minutes. During the stirring process, add pure water to mix with it. After sufficient mixing, a polyacrylamide solution is obtained. The stirring speed is 60 rpm, and the mass ratio of the polyacrylamide colloid to the pure water is 1:5.

[0032] 35 parts of furfuryl alcohol resin and 15 parts of rosin are heated and melted to obtain resin; 28 parts of palmitic acid, 8 parts of magnesium stearate and 15 parts of glycerol are mixed, and then 55 parts of distilled water are added, and heated to 100° C. to obtain an antioxidant;

[0033] 25 parts of polyacrylamide solution were heated to 110°C, stirred at a speed of 80 rpm for 50 minutes, 5 parts of magnesium oxide powder and 22 parts of polypropylene fiber were added at the 10th minute of stirring, 8 parts of resin and 8 parts of cellulose acetate butyrate powder were added at the 20th minute of stirring, and finally 14 parts of antioxidant were added at the 30th minute of stirring to obtain a bonding solution;

[0034] 8 parts of montmorillonite powder, 12 parts of iron oxide powder, and 6 parts of corn starch are mixed and ground to 13 nm by a grinding process to obtain a water reducing agent;

[0035] Add 8 parts of adhesive liquid to 70 parts of tap water, mix well to obtain a mixture, and put the mixture into a cement mixer;

[0036] 30 parts of iron ore tailings, 12 parts of river sand, and 40 parts of Portland cement were put into a cement mixer containing the mixture and stirred (stirring time was 30 minutes and stirring speed was 60 rpm). During the stirring period, 10 parts of water reducing agent were added and mixed evenly to obtain concrete.

[0037] Example 3

[0038] The concrete of this embodiment is prepared by:

[0039] Put the polyacrylamide colloid into a container and stir for 45 minutes. During the stirring process, add pure water to mix with it. After sufficient mixing, a polyacrylamide solution is obtained. The stirring speed is 60 rpm, and the mass ratio of the polyacrylamide colloid to the pure water is 1:5.

[0040] 45 parts of furfuryl alcohol resin and 20 parts of rosin are heated and melted to obtain resin; 35 parts of palmitic acid, 10 parts of magnesium stearate and 20 parts of glycerol are mixed, and then 60 parts of distilled water are added, and heated to 120° C. to obtain an antioxidant;

[0041] 30 parts of polyacrylamide solution were heated to 120°C, stirred at a speed of 80 rpm for 60 minutes, 6 parts of magnesium oxide powder and 25 parts of polypropylene fiber were added at the 10th minute of stirring, 10 parts of resin and 12 parts of cellulose acetate butyrate powder were added at the 20th minute of stirring, and finally 18 parts of antioxidant were added at the 30th minute of stirring to obtain a bonding solution;

[0042] 10 parts of montmorillonite powder, 15 parts of iron oxide powder, and 8 parts of corn starch are mixed and ground to 15 nm by a grinding process to obtain a water reducing agent;

[0043] Add 10 parts of adhesive liquid to 80 parts of tap water, mix well to obtain a mixture, and put the mixture into a cement mixer;

[0044] 35 parts of iron ore tailings, 15 parts of river sand, and 45 parts of Portland cement were put into a cement mixer containing the mixture and stirred (stirring time was 35 minutes and stirring speed was 60 rpm). 15 parts of water reducer were added during stirring and mixed evenly to obtain concrete.

[0045] Comparative Example 1

[0046] The concrete of this comparative example is prepared by:

[0047] Put the epoxy resin colloid into a container and stir for 35 minutes. During the stirring process, add pure water and mix with it. After fully mixing, an epoxy resin solution is obtained. The stirring speed is 60 rpm, and the mass ratio of the epoxy resin colloid to pure water is 1:5.

[0048] 35 parts of furfuryl alcohol resin and 15 parts of rosin are heated and melted to obtain resin; 28 parts of palmitic acid, 8 parts of magnesium stearate and 15 parts of glycerol are mixed, and then 55 parts of distilled water are added, and heated to 100° C. to obtain an antioxidant;

[0049] 25 parts of epoxy resin solution were heated to 110°C, stirred at a speed of 80 rpm for 50 minutes, 5 parts of magnesium oxide powder and 22 parts of polypropylene fiber were added at the 10th minute of stirring, 8 parts of resin and 8 parts of cellulose acetate butyrate powder were added at the 20th minute of stirring, and finally 14 parts of antioxidant were added at the 30th minute of stirring to obtain an adhesive solution;

[0050] 8 parts of montmorillonite powder, 12 parts of iron oxide powder, and 6 parts of corn starch are mixed and ground to 13 nm by a grinding process to obtain a water reducing agent;

[0051] Add 8 parts of adhesive liquid to 70 parts of tap water, mix well to obtain a mixture, and put the mixture into a cement mixer;

[0052] 30 parts of iron ore tailings, 12 parts of river sand, and 40 parts of Portland cement were put into a cement mixer containing the mixture and stirred (stirring time was 30 minutes and stirring speed was 60 rpm). During the stirring period, 10 parts of water reducing agent were added and mixed evenly to obtain concrete.

[0053] Comparative Example 2

[0054] The concrete of this comparative example is prepared by:

[0055] Put the polyacrylamide colloid into a container and stir for 35 min. During the stirring process, add pure water and mix it with the colloid. After thorough mixing, a polyacrylamide solution is obtained. The stirring speed is 60 rpm, and the mass ratio of polyacrylamide colloid to pure water is 1:5.

[0056] Heat and fuse 35 parts of furfuryl alcohol resin and 15 parts of rosin to obtain a resin; mix 28 parts of palmitic acid, 8 parts of magnesium stearate, and 15 parts of glycerol, then add 55 parts of distilled water and heat to 100 °C to obtain an antioxidant.

[0057] Heat 26.6 parts of the polyacrylamide solution to 110 °C. When the temperature reaches, start stirring at a speed of 80 rpm for 50 min. Add 24.5 parts of polypropylene fiber at the 10th minute of stirring, add 8.5 parts of resin and 8.5 parts of cellulose acetate butyrate powder at the 20th minute of stirring, and finally add 16 parts of antioxidant at the 30th minute of stirring to obtain an adhesive liquid.

[0058] Mix 8 parts of montmorillonite powder, 12 parts of iron oxide powder, and 6 parts of corn starch, and grind them to 13 nm through a grinding process to obtain a water reducing agent.

[0059] Add 8 parts of the adhesive liquid to 70 parts of tap water, mix evenly to obtain a mixture, and put the mixture into a cement mixer.

[0060] Put 30 parts of iron ore tailings, 12 parts of river sand, and 40 parts of portland cement into the cement mixer containing the mixture, and stir (the stirring duration is 30 min, and the stirring speed is 60 rpm). Add 10 parts of the water reducing agent during the stirring process, and mix evenly to obtain concrete.

[0061] Comparative Example 3

[0062] For the concrete of this comparative example, the preparation method is as follows:

[0063] Put the polyacrylamide colloid into a container and stir for 35 min. During the stirring process, add pure water and mix it with the colloid. After thorough mixing, a polyacrylamide solution is obtained. The stirring speed is 60 rpm, and the mass ratio of polyacrylamide colloid to pure water is 1:5.

[0064] Heat and fuse 35 parts of furfuryl alcohol resin and 15 parts of rosin to obtain a resin; mix 28 parts of palmitic acid, 8 parts of magnesium stearate, and 15 parts of glycerol, then add 55 parts of distilled water and heat to 100 °C to obtain an antioxidant.

[0065] Heat 27.6 parts of polyacrylamide solution to 110 °C. After the temperature reaches, stir at a speed of 80 rpm for 50 min. Add 5.6 parts of magnesium oxide powder and 24.3 parts of polypropylene fiber at the 10th minute of stirring, add 9 parts of resin at the 20th minute of stirring, and finally add 15.5 parts of antioxidant at the 30th minute of stirring to obtain an adhesive liquid;

[0066] Mix 8 parts of montmorillonite powder, 12 parts of iron oxide powder, and 6 parts of corn starch, and grind them to 13 nm through a grinding process to obtain a water reducing agent;

[0067] Add 8 parts of the adhesive liquid to 70 parts of tap water, mix evenly to obtain a mixture, and put the mixture into a cement mixer;

[0068] Put 30 parts of iron ore tailings, 12 parts of river sand, and 40 parts of portland cement into the cement mixer containing the mixture, and stir (the stirring duration is 30 min, and the stirring speed is 60 rpm). Add 10 parts of the water reducing agent during stirring, and mix evenly to obtain concrete.

[0069] Comparative Example 4

[0070] For the concrete of this comparative example, the preparation method is as follows:

[0071] Mix 8 parts of montmorillonite powder, 12 parts of iron oxide powder, and 6 parts of corn starch, and grind them to 13 nm through a grinding process to obtain a water reducing agent;

[0072] Add 8 parts of the adhesive liquid to 70 parts of tap water, mix evenly to obtain a mixture, and put the mixture into a cement mixer;

[0073] Put 12 parts of river sand and 40 parts of portland cement into the cement mixer containing the mixture, and stir (the stirring duration is 30 min, and the stirring speed is 60 rpm). Add 10 parts of the water reducing agent during stirring, and mix evenly to obtain concrete.

[0074] Comparative Example 5

[0075] For the concrete of this comparative example, the preparation method is as follows:

[0076] Mix 8 parts of montmorillonite powder, 12 parts of iron oxide powder, and 6 parts of corn starch, and grind them to 13 nm through a grinding process to obtain a water reducing agent;

[0077] Put 30 parts of iron ore tailings, 12 parts of river sand, and 40 parts of portland cement into the cement mixer containing the mixture, and stir (the stirring duration is 30 min, and the stirring speed is 60 rpm). Add 10 parts of the water reducing agent during stirring, and mix evenly to obtain concrete.

[0078] (I) Performance Test

[0079] 1.1. Take the concrete samples prepared in Examples 1-3 and Comparative Examples 1-5, and conduct compressive strength and flexural strength performance tests according to the "Standard for Inspection and Evaluation of Concrete Strength" GB / T50107-2010 at the ages of 3d and 28d. The Portland cement for the test (purchased from Wuxi Jianghuai Building Materials Technology Co., Ltd.), river sand (selected ISO standard sand), and iron ore tailings (meeting GB / T31288-2014, extra fine sand with a fineness modulus of 1.5-0.7) are used.

[0080] Table 1 Product Performance Test

[0081]

[0082]

[0083] The test results are shown in Table 1 above. By comparing Examples 1-3, it is found that the concrete prepared with the weight ratio in Example 2 is the best in both compressive strength and flexural strength. By comparing Comparative Example 1 with Example 2, it is found that the difference between Comparative Example 1 and Example 2 is that in Comparative Example 1, the polyacrylamide solution is changed to an epoxy resin solution, and after the change, the compressive strength and flexural strength of Comparative Example 1 are not as good as those of Example 2. By comparing Comparative Example 2 with Example 2, it is found that the difference between Comparative Example 2 and Example 2 is that Comparative Example 2 does not add magnesium oxide powder, so the compressive strength and flexural strength of Comparative Example 2 are not as good as those of Example 2. By comparing Comparative Example 3 with Example 2, it is found that the difference between Comparative Example 3 and Example 2 is that Comparative Example 3 lacks cellulose acetate butyrate powder, so the compressive strength and flexural strength of Comparative Example 3 are not as good as those of Example 2. By comparing Comparative Example 4 with Example 2, it is found that the difference between Comparative Example 4 and Example 2 is that Comparative Example 4 lacks iron ore tailings and adhesive liquid. As a result, the compressive strength and flexural strength of Comparative Example 4 at 3d are better than those of Example 2, but after 28d, the compressive strength and flexural strength of Comparative Example 4 are slightly lower than those of Example 2. By comparing Comparative Example 5 with Example 2, it is found that the difference between Comparative Example 5 and Example 2 is that Comparative Example 5 lacks adhesive liquid, so the compressive strength and flexural strength of Comparative Example 5 at 3d and 28d are not as good as those of Example 2.

[0084] In summary, there are many factors affecting the compressive strength and flexural strength of concrete. Among them, adding polyacrylamide solution, magnesium oxide powder, cellulose acetate butyrate powder, iron oxide powder and antioxidant to concrete has a greater impact on the compressive strength and flexural strength of concrete. And adding iron ore tailings to existing concrete will cause the compressive strength and flexural strength to decrease. However, in this application, the iron ore tailings synergize with polyacrylamide solution, magnesium oxide powder and cellulose acetate butyrate powder, so that the compressive strength and flexural strength of the concrete in Example 2 at the 28th day are higher than those of the concrete in Comparative Example 4 without adding iron ore tailings.

[0085] 1.2. Take the concrete samples prepared in Examples 1-3 and Comparative Examples 1-5, place them in containers respectively, and use a Vicat apparatus to detect the initial setting time and final setting time of the concrete samples prepared in Examples 1-3 and Comparative Examples 1-4 in an environment of -5°C.

[0086] Table 2 Product Performance Test

[0087] Group Initial setting time / min Final setting time / min Example 1 50 155 Example 2 45 150 Example 3 48 150 Comparative Example 1 56 240 Comparative Example 2 65 245 Comparative Example 3 60 240 Comparative Example 4 45 160 Comparative Example 5 63 180

[0088] The test results are shown in Table 2 above. Through comparison, it can be seen that the initial setting time of the concrete prepared by the method of Example 2 is the same as that of Comparative Example 4, but the final setting time is longer than that used in Example 2. This shows that not adding iron ore tailings will not affect the initial setting time of concrete but will affect the final setting time of concrete. And the polyacrylamide solution, magnesium oxide powder and cellulose acetate butyrate powder added in Example 2 synergize with the iron ore tailings, which can help the concrete shorten the final setting time.

[0089] The above-described embodiments merely represent several implementation manners of the present invention. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. A concrete based on iron ore tailings, characterized in that: The raw materials for preparing the concrete include iron ore tailings, river sand, silicate cement, tap water, adhesive and water reducing agent; Among them, the raw materials for preparing the adhesive are, by weight: 20-30 parts of polyacrylamide solution, 3-6 parts of magnesium oxide powder, 5-10 parts of resin, 20-25 parts of polypropylene fiber, 10-18 parts of antioxidant and 5-12 parts of cellulose acetate butyrate powder; the raw materials for preparing the water reducing agent are: 6-10 parts of montmorillonite powder, 10-15 parts of iron oxide powder, and 3-8 parts of corn starch.

2. The concrete based on iron ore tailings according to claim 1, characterized in that: The raw materials for preparing the concrete are, by weight, 20-35 parts of iron ore tailings, 10-15 parts of river sand, 35-45 parts of Portland cement, 60-80 parts of tap water, 5-10 parts of adhesive and 8-15 parts of water reducing agent.

3. The concrete based on iron ore tailings according to claim 2, characterized in that: The preparation process of the polyacrylamide solution is as follows: putting polyacrylamide colloid into a container and stirring for 30-45 minutes, adding pure water to mix with it during the stirring process, and obtaining the polyacrylamide solution after sufficient mixing, and the stirring speed is 60 rpm.

4. The concrete based on iron ore tailings according to claim 3, characterized in that: The mass ratio of the polyacrylamide colloid to pure water is 1:

5.

5. The concrete based on iron ore tailings according to claim 1, characterized in that: The preparation process of the resin is: heating and fusing furfuryl alcohol resin and rosin to obtain the resin; the preparation process of the antioxidant is: mixing palmitic acid, magnesium stearate and glycerin, then adding distilled water, heating to 80-120° C. to obtain the antioxidant.

6. The iron ore tailings-based concrete according to claim 5, characterized in that: By weight, the raw materials for preparing the resin are: 30-45 parts of furfuryl alcohol resin and 10-20 parts of rosin; the raw materials for preparing the antioxidant are: 20-35 parts of palmitic acid, 6-10 parts of magnesium stearate, 10-20 parts of glycerin and 50-60 parts of distilled water.

7. A method for preparing concrete based on iron ore tailings according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1, heating the polyacrylamide solution to 100-120°C, stirring at a speed of 80 rpm for 45-60 minutes when the temperature reaches the target, adding magnesium oxide powder and polypropylene fiber at the 10th minute of stirring, adding resin and cellulose acetate butyrate powder at the 20th minute of stirring, and finally adding an antioxidant at the 30th minute of stirring to obtain a bonding solution; S2, mixing montmorillonite powder, iron oxide powder and corn starch, and grinding them to 10-15 nm by a grinding process to obtain a water reducing agent; S3, adding the adhesive liquid to tap water, mixing them evenly to obtain a mixture, and putting the mixture into a cement mixer; S4, putting the iron ore tailings, river sand and acid salt cement into the cement mixer containing the mixture in step S3, stirring, adding a water reducing agent during the stirring, and mixing evenly to obtain concrete.

8. The method for preparing concrete based on iron ore tailings according to claim 7, characterized in that: The stirring time in step S4 is 20-35 min, and the stirring speed is 60 rpm.

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