Manganese slag water-permeable pavement base material and preparation method thereof

Abstract

The application discloses a manganese slag water-permeable pavement base material and a preparation method thereof. In the manganese slag water-permeable pavement base material, 10-40 wt% of coarse aggregate is modified coarse manganese slag; and 5-10 wt% of cement is replaced by manganese slag powder. The application maximizes the use of manganese slag to prepare the water-permeable pavement base material, so that the resource value of the manganese slag is better exploited, and a broader idea is provided for the resource utilization of the manganese slag.

Description

Technical Field

[0001] Technical Field This invention relates to the field of harmless treatment of manganese slag, and in particular to a permeable pavement base material made of manganese slag and its preparation method. Background Technology

[0002] my country is a major global producer of electrolytic manganese metal, electrolytic manganese dioxide, and high-purity manganese sulfate, and a core supply region for the world's manganese-related new energy and metallurgical industries. However, the average grade of manganese ore in my country is relatively low, and the production of 1 ton of metallic manganese generates approximately 8-10 tons of manganese slag. Therefore, the total amount of newly generated manganese slag each year is enormous, and the large stockpiles of manganese slag have become a core environmental bottleneck restricting the high-quality development of the manganese industry.

[0003] At present, most manganese slag is stored in stockpiles with the construction of anti-seepage stockpiles for temporary storage. This method has some drawbacks, such as: (1) it occupies a large amount of land resources and long-term stockpiling greatly reduces the available space around the industry; (2) the simple stockpiling model cannot realize the resource value of manganese slag at all, and a large amount of valuable elements such as manganese, silicon, and calcium remaining in the slag are completely wasted, which does not meet the requirements of circular economy development.

[0004] Therefore, it is essential to find an effective way to utilize manganese slag. Summary of the Invention

[0005] This invention discloses a manganese slag permeable pavement base material and its preparation method. By replacing crushed stone with manganese slag as coarse aggregate, it has excellent porosity and good permeability, and can achieve good compressive strength, which is conducive to realizing the value of manganese slag resources.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows:

[0007] The first aspect of this invention provides a manganese slag permeable pavement base material, wherein 10-40 wt% of the coarse aggregate is modified coarse manganese slag; and 5-10 wt% of the cement is replaced with manganese slag powder.

[0008] The preparation method of the modified crude manganese slag includes the following steps: A1. Take crude manganese slag, calcine it at 600-800℃ for 2-4 hours, and after calcination, screen out crude manganese slag with a particle size of 8-18mm to obtain calcined crude manganese slag; A2. Dissolve tetraethyl orthosilicate in an alcohol-water mixed solvent, heat to 50-70℃, add the calcined crude manganese slag, and then add dilute sulfuric acid until the initial pH of the reaction system is 2.5-3.0. After silica sol is formed, stir and let stand, then separate the solid, and dry it to a moisture content of 3-5% to obtain pre-modified crude manganese slag; A3. Take the pre-modified crude manganese slag, spray it with a mixed modifier of lignin, isobutyltriethoxysilane, and titanate coupling agent, and dry it to obtain modified crude manganese slag;

[0009] The manganese slag powder is pretreated before being mixed with cement. The pretreatment includes the following steps: B1. Take fine manganese slag with a particle size of less than 1 mm, calcine it at 600-800℃ for 1-3 hours, crush it after calcination, and sieve it to obtain manganese slag powder with a particle size of less than 45 μm; B2. Mix silane coupling agent, alkylphenol polyethylene ether, sodium fluorosilicate, potassium hydroxide, phenolic resin and water, heat to 60-70℃, add manganese slag powder, stir evenly, and complete the pretreatment of manganese slag powder.

[0010] Preferably, in step A2, the mass ratio of tetraethyl orthosilicate, alcohol and water is 1-3:5-9:5-15, and the mass ratio of alcohol-water mixed solvent to crude manganese slag is 30-50:1.

[0011] Stirring time is 20-30 minutes, and standing time is 4-10 hours.

[0012] Preferably, in step A3, the weight ratio of lignin, isobutyltriethoxysilane, and titanate coupling agent is 1-3:0.5-1:0.5-1, and the mass ratio of mixed modifier to preliminarily modified crude manganese slag is 0.5-2:100.

[0013] Preferably, in step A2, the temperature of the preliminarily modified crude manganese slag is maintained at 50-70℃;

[0014] In step A3, the mixed modifier is pre-diluted in a solvent at a concentration of 40-50 wt%, and the solvent is an alcohol solvent.

[0015] Preferably, in the modified crude manganese slag, 20-30 wt% of the modified crude manganese slag has a particle size of 8-12 mm, and the remainder has a particle size of 12-18 mm.

[0016] Preferably, in step B2, the weight ratio of silane coupling agent, alkylphenol polyvinyl ether, sodium fluorosilicate, potassium hydroxide, phenolic resin, and manganese slag powder is 0.5-2:0.1-0.2:0.1-0.3:0.3-0.6:4-5:100-120.

[0017] Preferably, the titanate coupling agent is one or both of bis(dioctyloxypyrophosphate) ethylene titanate and isopropyltris(dioctylphosphoyloxy) titanate.

[0018] Preferably, the silane coupling agent is one or both of γ-aminopropyltriethoxysilane and N-β-aminoethyl-γ-aminopropyltrimethoxysilane.

[0019] Another aspect of the present invention provides a method for preparing the above-mentioned manganese slag permeable pavement base material, comprising the following steps:

[0020] (1) Weigh the raw materials for preparing the base concrete, which also include cement, coarse aggregate, water-reducing agent and water. The cement, coarse aggregate and modified coarse manganese slag are pre-mixed and stirred to obtain solid material;

[0021] (2) The manganese slag powder is pretreated, wherein the water used for pretreatment is 1 / 5 to 1 / 4 of the water in step (1) to obtain pretreated manganese slag powder premix;

[0022] (3) Take 1 / 3 to 1 / 2 of the water from step (1), mix it with the solid material and stir it evenly, add the pre-treated manganese slag powder premix, add the remaining water, add the water-reducing agent, stir and mix evenly to obtain the manganese slag permeable pavement base material.

[0023] The manganese slag permeable pavement base material and its preparation method described above have the following advantages:

[0024] (1) In this invention, modified coarse manganese slag is introduced as coarse aggregate. Impurities such as ammonia nitrogen and free water in the manganese slag can be removed by calcination in advance, and its porosity can be reduced. Then, the high porosity caused by the natural precipitation of silica is used to further change the defect of insufficient mechanical properties. Then, the bonding force between it and concrete is improved by lignin and coupling agent, thereby improving the structural strength of the concrete base layer and ensuring that the concrete base layer still has a certain porosity, thus optimizing its continuous permeability.

[0025] (2) In this invention, pretreated manganese slag powder is used to replace part of the cement. The manganese slag powder is first activated by calcination to enhance its gelling activity, and then modified by adding silane coupling agent, alkylphenol polyethylene ether, sodium fluorosilicate and phenolic resin. This forms a stronger chemical bond between the manganese slag powder, cement and coarse aggregate, thereby effectively constructing the strength skeleton of the concrete base layer and ensuring the overall strength of the concrete.

[0026] (3) By adjusting the coarse aggregate and cement admixture, this invention maximizes the use of manganese slag to prepare permeable pavement base material, thereby better realizing the resource value of manganese slag and providing a broader idea for the resource utilization of manganese slag. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0028] Example 1

[0029] The raw materials for preparing each cubic meter of base concrete include: 342 kg of P.O42.5 grade cement, 18 kg of manganese slag powder, 1350 kg of crushed stone (particle size 5-10 mm), 150 kg of modified coarse manganese slag, 110 kg of water, and 1.5 kg of water-reducing agent.

[0030] The preparation method of modified crude manganese slag includes the following steps: A1. Take crude manganese slag, calcine it at 750℃ for 2.5h, and after calcination, screen out crude manganese slag with a particle size of 8-18mm to obtain calcined crude manganese slag; A2. Dissolve tetraethyl orthosilicate in an ethanol-water mixed solvent, heat to 70℃, add the calcined crude manganese slag, the mass ratio of tetraethyl orthosilicate, ethanol and water is 1:6:10, the mass ratio of ethanol-water mixed solvent to crude manganese slag is 35:1, then add dilute sulfuric acid until the initial pH of the reaction system is 2.8, after silica sol is formed, stir for 25min and let stand for 5h, then separate the solid, dry it to a moisture content of 3-5%, to obtain preliminarily modified crude manganese slag, and keep the temperature of the preliminarily modified crude manganese slag at 70℃; A3. A preliminarily modified crude manganese slag was sprayed into a mixed modifier consisting of lignin, isobutyltriethoxysilane, and bis(dioctyloxypyrophosphate)ethylene titanate, heated to 80°C. The weight ratio of lignin, isobutyltriethoxysilane, and bis(dioctyloxypyrophosphate)ethylene titanate was 2:0.8:0.8. The mixture was pre-diluted in isopropanol to a concentration of 45 wt%. The mass ratio of the mixed modifier to the preliminarily modified crude manganese slag was 1:100. After drying, modified crude manganese slag was obtained.

[0031] In the modified coarse manganese slag, 20-30 wt% are taken from particles with a diameter of 8-12 mm (excluding 12 mm), and the rest are taken from particles with a diameter of 12-18 mm.

[0032] Before mixing with cement, manganese slag powder undergoes pretreatment, which includes the following steps: B1. Take fine manganese slag with a particle size of less than 1 mm, calcine it at 750℃ for 1.5 h, pulverize it after calcination, and sieve it to obtain manganese slag powder with a particle size of less than 45 μm; B2. Mix N-β-aminoethyl-γ-aminopropyltrimethoxysilane, alkylphenol polyethylene ether, sodium fluorosilicate, potassium hydroxide, phenolic resin and water. The weight ratio of N-β-aminoethyl-γ-aminopropyltrimethoxysilane, alkylphenol polyethylene ether, sodium fluorosilicate, potassium hydroxide, phenolic resin and manganese slag powder is 1:0.2:0.2:0.5:4.5:100. Heat to 70℃, add manganese slag powder, and stir evenly for 1 h to complete the pretreatment of manganese slag powder.

[0033] The preparation method of manganese slag permeable pavement base material includes the following steps:

[0034] (1) Weigh the raw materials for the preparation of the base concrete according to the above formula, and mix the cement, crushed stone and modified coarse manganese slag in advance to obtain solid material;

[0035] (2) The manganese slag powder is pretreated, wherein the water used for pretreatment is 1 / 5 of the water in step (1) to obtain pretreated manganese slag powder premix;

[0036] (3) Take half of the water from step (1), mix it with the solid material and stir it evenly, add the pretreated manganese slag powder premix, add the remaining water, add the water-reducing agent, stir and mix evenly to obtain the manganese slag permeable pavement base material.

[0037] Example 2

[0038] The raw materials for preparing each cubic meter of base concrete include: 324 kg of P.O42.5 grade cement, 36 kg of manganese slag powder, 1350 kg of crushed stone (particle size 5-10 mm), 150 kg of modified coarse manganese slag, 110 kg of water, and 1.5 kg of water-reducing agent.

[0039] The preparation methods of modified coarse manganese slag, the pretreatment methods of manganese slag powder, and the preparation methods of manganese slag permeable pavement base materials are all based on Example 1.

[0040] Example 3

[0041] The raw materials for preparing each cubic meter of base concrete include: 342 kg of P.O42.5 grade cement, 18 kg of manganese slag powder, 900 kg of crushed stone (particle size 5-10 mm), 600 kg of modified coarse manganese slag, 110 kg of water, and 1.5 kg of water-reducing agent.

[0042] The preparation methods of modified coarse manganese slag, the pretreatment methods of manganese slag powder, and the preparation methods of manganese slag permeable pavement base materials are all based on Example 1.

[0043] Example 4

[0044] The preparation method of modified crude manganese slag is basically the same as in Example 1, but includes the following steps: A1. Take crude manganese slag, calcine it at 750℃ for 3 hours, and after calcination, screen out crude manganese slag with a particle size of 8-18 mm to obtain calcined crude manganese slag; A2. Dissolve tetraethyl orthosilicate in an ethanol-water mixed solvent, heat to 70℃, add the calcined crude manganese slag, the mass ratio of tetraethyl orthosilicate, ethanol and water is 1.5:6:10, the mass ratio of ethanol-water mixed solvent to crude manganese slag is 40:1, then add dilute sulfuric acid until the initial pH of the reaction system is 2.8, after silica sol is formed, stir for 25 minutes and let stand for 5 hours, then separate the solid, dry it to a moisture content of 3-5%, and obtain preliminarily modified crude manganese slag, keeping the temperature of the preliminarily modified crude manganese slag at 70℃; A3. A preliminarily modified crude manganese slag is sprayed into a mixed modifier consisting of lignin, isobutyltriethoxysilane, and isopropyltris(dioctylphosphoyloxy)titanate heated to 75°C. The weight ratio of lignin, isobutyltriethoxysilane, and isopropyltris(dioctylphosphoyloxy)titanate is 2:1:1. The mixture is pre-diluted in isopropanol to a concentration of 45 wt%. The mass ratio of the mixed modifier to the preliminarily modified crude manganese slag is 1:100. After drying, modified crude manganese slag is obtained.

[0045] Example 5

[0046] The process is basically the same as in Example 1, but the pretreatment of manganese slag powder includes the following steps: B1. Take fine manganese slag with a particle size of less than 1 mm, calcine it at 750°C for 2 hours, crush it after calcination, and sieve it to obtain manganese slag powder with a particle size of less than 45 μm; B2. Mix γ-aminopropyltriethoxysilane, alkylphenol polyethylene ether, sodium fluorosilicate, potassium hydroxide, phenolic resin and water. The weight ratio of γ-aminopropyltriethoxysilane, alkylphenol polyethylene ether, sodium fluorosilicate, potassium hydroxide, phenolic resin and manganese slag powder is 0.5:0.2:0.2:0.5:5:100. Heat to 70°C, add manganese slag powder, stir evenly for 1 hour to complete the pretreatment of manganese slag powder.

[0047] Comparative Example 1

[0048] The raw materials for preparing each cubic meter of base concrete include: 360 kg of P.O4 2.5 grade cement, 1500 kg of crushed stone (particle size 5-10 mm), 110 kg of water, and 1.5 kg of water-reducing agent.

[0049] The preparation method includes the following steps:

[0050] (1) Weigh the raw materials for the preparation of the base concrete according to the above formula, and mix the cement and crushed stone in advance to obtain solid material;

[0051] (2) Take half of the water from step (1), mix it with the solid material and stir it evenly, then add the remaining water, stir for 3 minutes and then add the water-reducing agent, stir and mix evenly to obtain the manganese slag permeable pavement base material.

[0052] Comparative Example 2

[0053] The raw materials for preparing each cubic meter of base concrete include: 360 kg of P.O4 2.5 grade cement, 1350 kg of crushed stone (particle size 5-10 mm), 150 kg of coarse manganese slag, 110 kg of water, and 1.5 kg of water-reducing agent.

[0054] The crude manganese slag is pre-calcined at 750℃ for 2.5 hours. 20-30 wt% of the slag is selected from particles with a diameter of 8-12 mm (excluding 12 mm), and the remainder is selected from particles with a diameter of 12-18 mm.

[0055] The preparation method includes the following steps:

[0056] (1) Weigh the raw materials for the preparation of the base concrete according to the above formula, and mix the cement, coarse manganese slag and crushed stone in advance to obtain solid material;

[0057] (2) Take half of the water from step (1), mix it with the solid material and stir it evenly, then add the remaining water, stir for 3 minutes and then add the water-reducing agent, stir and mix evenly to obtain the manganese slag permeable pavement base material.

[0058] Comparative Example 3

[0059] The raw materials for preparing each cubic meter of base concrete include: 342 kg of P.O42.5 grade cement, 18 kg of manganese slag powder, 1500 kg of crushed stone (particle size 5-10 mm), 110 kg of water, and 1.5 kg of water-reducing agent.

[0060] The specific process for processing manganese slag powder is as follows: fine manganese slag with a particle size of less than 1 mm is taken, calcined at 750℃ for 1.5 h, crushed after calcination, and then sieved to obtain manganese slag powder with a particle size of less than 45 μm.

[0061] The preparation method includes the following steps:

[0062] (1) Weigh the raw materials for the preparation of the base concrete according to the above formula, and mix the cement, manganese slag powder and crushed stone in advance to obtain solid material;

[0063] (2) Take half of the water from step (1), mix it with the solid material and stir it evenly, then add the remaining water, stir for 3 minutes and then add the water-reducing agent, stir and mix evenly to obtain the manganese slag permeable pavement base material.

[0064] The compressive strength, flexural strength, permeability coefficient, and continuous porosity of the permeable pavement base materials of Examples 1-5 and Comparative Examples 1-3 were tested after 28 days. The compressive strength was determined according to the "Standard for Testing and Evaluation of Concrete Strength" (GB / T 50107-2010), and the permeability coefficient was determined according to the "Technical Specification for Permeable Cement Concrete Pavement" (CJJ / T135-2009). The results are shown in Table 1.

[0065] Table 1

[0066]

[0067] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A manganese slag permeable pavement base material, characterized in that: 10-40wt% of coarse aggregate is made from modified coarse manganese slag; 5-10 wt% of cement is replaced with manganese slag powder; The preparation method of the modified crude manganese slag includes the following steps: A1. Take crude manganese slag, calcine it at 600-800℃ for 2-4 hours, and after calcination, screen out crude manganese slag with a particle size of 8-18mm to obtain calcined crude manganese slag; A2. Dissolve tetraethyl orthosilicate in an alcohol-water mixed solvent, heat to 50-70℃, add the calcined crude manganese slag, and then add dilute sulfuric acid until the initial pH of the reaction system is 2.5-3.

0. After silica sol is formed, stir and let stand, then separate the solid, and dry it to a moisture content of 3-5% to obtain pre-modified crude manganese slag; A3. Take the pre-modified crude manganese slag, spray it with a mixed modifier of lignin, isobutyltriethoxysilane, and titanate coupling agent, and dry it to obtain modified crude manganese slag; The manganese slag powder is pretreated before being mixed with cement. The pretreatment includes the following steps: B1. Take fine manganese slag with a particle size of less than 1 mm, calcine it at 600-800℃ for 1-3 hours, crush it after calcination, and sieve it to obtain manganese slag powder with a particle size of less than 45 μm; B2. Mix silane coupling agent, alkylphenol polyethylene ether, sodium fluorosilicate, potassium hydroxide, phenolic resin and water, heat to 60-70℃, add manganese slag powder, stir evenly, and complete the pretreatment of manganese slag powder.

2. The manganese slag permeable pavement base material according to claim 1, characterized in that: In step A2, the mass ratio of tetraethyl orthosilicate, alcohol and water is 1-3:5-9:5-15, and the mass ratio of alcohol-water mixed solvent to crude manganese slag is 30-50:

1. Stirring time is 20-30 minutes, and standing time is 4-10 hours.

3. The manganese slag permeable pavement base material according to claim 1, characterized in that: In step A3, the weight ratio of lignin, isobutyltriethoxysilane, and titanate coupling agent is 1-3:0.5-1:0.5-1, and the mass ratio of mixed modifier to preliminarily modified crude manganese slag is 0.5-2:

100.

4. The manganese slag permeable pavement base material according to claim 3, characterized in that: In step A2, the temperature of the preliminarily modified crude manganese slag is maintained at 50-70℃; In step A3, the mixed modifier is pre-diluted in a solvent at a concentration of 40-50 wt%, the solvent being an alcohol solvent, and heated to 70-80°C.

5. The manganese slag permeable pavement base material according to claim 1, characterized in that: Of the modified crude manganese slag, 20-30 wt% consists of modified crude manganese slag with a particle size of 8-12 mm, and the remainder consists of crude manganese slag with a particle size of 12-18 mm.

6. The manganese slag permeable pavement base material according to claim 1, characterized in that: In step B2, the weight ratio of silane coupling agent, alkylphenol polyethylene ether, sodium fluorosilicate, potassium hydroxide, phenolic resin, and manganese slag powder is 0.5-2:0.1-0.2:0.1-0.3:0.3-0.6:4-5:100-120.

7. The manganese slag permeable pavement base material according to claim 1, characterized in that: The titanate coupling agent is one or both of bis(dioctyloxypyrophosphate) ethylene titanate and isopropyltris(dioctylphosphoyloxy) titanate.

8. The manganese slag permeable pavement base material according to claim 1, characterized in that: The silane coupling agent is one or both of γ-aminopropyltriethoxysilane and N-β-aminoethyl-γ-aminopropyltrimethoxysilane.

9. The method for preparing the manganese slag permeable pavement base material according to any one of claims 1-8, characterized in that... Includes the following steps: (1) Weigh the raw materials for preparing the base concrete, which also include cement, coarse aggregate, water-reducing agent and water. The cement, coarse aggregate and modified coarse manganese slag are pre-mixed and stirred to obtain solid material; (2) The manganese slag powder is pretreated, wherein the water used for pretreatment is 1 / 5 to 1 / 4 of the water in step (1) to obtain pretreated manganese slag powder premix; (3) Take 1 / 3 to 1 / 2 of the water from step (1), mix it with the solid material and stir it evenly, add the pre-treated manganese slag powder premix, add the remaining water, add the water-reducing agent, stir and mix evenly to obtain the manganese slag permeable pavement base material.

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