Color-adjustable red mud-regenerated mixture environment-friendly sound barrier and preparation method thereof

Abstract

The invention discloses a color-adjustable red mud-regenerated mixture environment-friendly sound barrier and a preparation method thereof. A regenerated mixture is used as a basic material, an alkali activator is added to excite potential gelation activity of red mud, a foaming agent is added to form a porous structure, and a proper amount of cement is matched to form the environment-friendly sound barrier. According to the recycled mixture, screening treatment of coarse and fine aggregates can be avoided, so that the production cost is reduced; based on the characteristic that the red mud is red, the color of the sound barrier can be changed between red and gray by adjusting the mixing amount of the red mud, and visual fatigue of a driver is helped to be relieved; acid gas components in the tail gas can be absorbed and neutralized by utilizing residual alkalinity of the red mud and the alkali activator, so that the pollution to the environment is reduced. According to the sound barrier prepared by the method, recycling of waste resources can be realized, energy consumption and carbon emission in the production and use processes of the sound barrier are reduced, the recycling level of wastes is improved, and environmental protection and sustainable development in the field of sound barriers are promoted.

Description

Technical Field

[0001] The invention belongs to the field of sound barriers, and specifically is an environmentally friendly sound barrier of red mud-recycled mixture with adjustable color and a preparation method thereof. Background Art

[0002] Red mud is the waste residue produced during the production of alumina. It is red because it contains a large amount of iron oxide, so it is called red mud. Due to the difference in ore grade, production method and technical level, most production plants produce 1 to 2 tons of red mud for every ton of alumina produced. Red mud is a solid residue of iron, calcium, aluminum and other compounds and silicon dioxide, with the characteristics of strong alkalinity and high salinity. At present, most alumina plants at home and abroad transport red mud to storage yards and store it by wet damming. This method easily causes a large amount of waste alkali liquid to penetrate into the nearby soil, causing soil alkalization. Red mud has potential gelling activity, and alkaline chemicals (such as sodium hydroxide, sodium silicate, etc.) can be used to stimulate the potential active components in red mud, thereby preparing materials with certain gelling properties.

[0003] Recycled aggregate refers to the aggregate obtained by crushing, screening, cleaning and other processes of waste concrete, which contains coarse aggregate and fine aggregate. For concrete components that do not require high aggregates, the recycled aggregate can be directly used in the production of building products without distinguishing between coarse and fine aggregates, saving the cost of aggregate screening and processing and realizing the recycling of resources. With the advancement of technology and the improvement of environmental awareness, the application of recycled aggregate in concrete is becoming more and more extensive.

[0004] A sound barrier is an acoustic barrier between the noise source and the receiving point. It is mainly used to reduce the impact of noise on the receiving point. It is widely used on both sides of highways, expressways, railways and other traffic arteries. Concrete sound barriers are widely used due to their low cost, good durability and high strength.

[0005] The present invention utilizes the comprehensive resources of red mud and recycled mixture in the field of sound barriers. Firstly, the alkaline property of red mud can be used to absorb and neutralize the acidic gas components in the exhaust gas, thereby reducing pollution to the environment. Secondly, the reddish color of red mud can be used to produce sound barriers of different colors to avoid visual fatigue for drivers. Finally, combining the two solid wastes can reduce energy consumption and carbon emissions during the production and use of sound barriers, improve the level of waste recycling, and promote environmental protection and sustainable development. Summary of the invention

[0006] The purpose of the present invention is to provide a color-adjustable red mud-recycled mixture environmentally friendly sound barrier and a preparation method thereof, thereby realizing the resource utilization of red mud and recycled mixture.

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] A color-adjustable red mud-recycled mixture environmentally friendly sound barrier, the raw materials of which include, by weight: 100-500 parts of red mud, 500-800 parts of recycled mixture, 50-200 parts of cement, 50-100 parts of alkali activator, 10-50 parts of foaming agent, and 200-400 parts of water;

[0009] Taking recycled mixture as the basic material, alkali activator is added to stimulate the potential gelling activity of red mud, foaming agent is added to form a porous structure, and cement is combined to form a color-adjustable red mud-recycled mixture environmentally friendly sound barrier; by adjusting the red mud dosage, the color of the sound barrier can be changed between red and gray.

[0010] Furthermore, the red mud is industrial solid waste from the Bayer process for producing alumina, which is dried and ground to a particle size of 8-10 μm.

[0011] Furthermore, the recycled mixture is the aggregate obtained by crushing and screening the waste concrete, including coarse aggregate and fine aggregate, which are not further distinguished, and the particle size distribution is 0.15-50mm.

[0012] Furthermore, the cement is ordinary Portland cement.

[0013] Furthermore, the alkaline activator is sodium hydroxide.

[0014] Furthermore, the foaming agent is a protein foaming agent or a rosin resin foaming agent.

[0015] The present invention also provides a method for preparing the color-adjustable red mud-recycled mixture environmentally friendly sound barrier, comprising the following steps:

[0016] (1) Select a suitable mold according to the size of the sound barrier, and select different rubber sound-absorbing hole pads according to the different sound-absorbing hole shapes and size requirements to install on the mold panel, and evenly apply a release agent on all surfaces inside the mold;

[0017] (2) mixing red mud, recycled mixture, alkali activator, cement and water in proportion to obtain slurry;

[0018] (3) mixing a blowing agent and water to foam;

[0019] (4) Evenly mix the foam and the mixture, pour them into the mold and vibrate them to make them dense;

[0020] (5) Transporting the waste to a maintenance site for natural curing to obtain a color-adjustable red mud-recycled mixture environmentally friendly sound barrier.

[0021] The advantages of the present invention are as follows:

[0022] 1. The main materials are industrial solid waste red mud and construction solid waste recycled mixture, and there is no need to screen coarse aggregate and fine aggregate, which reduces production costs, realizes the resource utilization of solid waste, and reduces the exploitation of natural resources.

[0023] 2. By stimulating the potential gelling activity of red mud through alkali activation technology, the amount of cement used can be reduced, and energy consumption and carbon dioxide emissions can be reduced.

[0024] 3. The residual alkalinity of red mud and alkaline activator can be used to absorb and neutralize the acidic gas components in automobile exhaust, thereby reducing pollution to the environment.

[0025] 4. Taking advantage of the red color of red mud and adjusting the amount of red mud added, the color of the sound barrier can be changed between red and gray, helping to reduce the driver's visual fatigue. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The invention discloses a recycled mixture with adjustable color used in a red mud-recycled mixture environment-friendly sound barrier. DETAILED DESCRIPTION

[0027] The specific embodiments of the present invention are described in detail below.

[0028] The invention uses recycled mixture as the basic material, adds an alkali activator to activate the potential gelling activity of red mud, adds a foaming agent to form a porous structure, and combines with an appropriate amount of cement to form a color-adjustable red mud-recycled mixture environmentally friendly sound barrier. By adjusting the amount of red mud, the color of the sound barrier can be changed between red and gray, helping to reduce the visual fatigue of the driver. The residual alkalinity of the red mud and the alkali activator in the sound barrier can absorb the acidic gas in the exhaust gas of the car.

[0029] The red mud used in the following Examples 1-8 is industrial solid waste from the Bayer process for producing alumina, which is dried and ground to a particle size of 8-10 μm; the recycled mixture used is the aggregate obtained by crushing and screening waste concrete, including coarse aggregate and fine aggregate, which are not further distinguished, and the particle size distribution is 0.15-50 mm; the cement used is ordinary Portland cement.

[0030] Example 1

[0031] A method for preparing a color-adjustable red mud-recycled mixture environmentally friendly sound barrier is completed by the following steps:

[0032] 1. Select a suitable mold, install the sound-absorbing hole pad, select the raw materials according to the components, and take 100 parts of red mud, 500 parts of recycled mixture, 140 parts of cement, 50 parts of sodium hydroxide, 20 parts of protein foaming agent and 200 parts of water;

[0033] 2. Mix red mud, recycled mixture, sodium hydroxide, cement and water in proportion to obtain slurry;

[0034] 3. Mix the foaming agent and water and mix them evenly with the slurry. Pour them into the mold and vibrate them to make them dense. Transport them to the curing site and cure them naturally for 28 days to produce an environmentally friendly sound barrier. Test the various properties of the cured sound barrier.

[0035] Example 2

[0036] A method for preparing a color-adjustable red mud-recycled mixture environmentally friendly sound barrier is completed by the following steps:

[0037] 1. Select a suitable mold, install the sound-absorbing hole pad, select the raw materials according to the components, and take 200 parts of red mud, 500 parts of recycled mixture, 120 parts of cement, 60 parts of sodium hydroxide, 20 parts of protein foaming agent and 250 parts of water;

[0038] 2. Mix red mud, recycled mixture, sodium hydroxide, cement and water in proportion to obtain slurry;

[0039] 3. Mix the foaming agent and water and mix them evenly with the slurry. Pour them into the mold and vibrate them to make them dense. Transport them to the curing site and cure them naturally for 28 days to produce an environmentally friendly sound barrier. Test the various properties of the cured sound barrier.

[0040] Example 3

[0041] A method for preparing a color-adjustable red mud-recycled mixture environmentally friendly sound barrier is completed by the following steps:

[0042] 1. Select a suitable mold, install the sound-absorbing hole pad, select the raw materials according to the components, and take 300 parts of red mud, 500 parts of recycled mixture, 100 parts of cement, 80 parts of sodium hydroxide, 20 parts of protein foaming agent and 300 parts of water;

[0043] 2. Mix red mud, recycled mixture, sodium hydroxide, cement and water in proportion to obtain slurry;

[0044] 3. Mix the foaming agent and water and mix them evenly with the slurry. Pour them into the mold and vibrate them to make them dense. Transport them to the curing site and cure them naturally for 28 days to produce an environmentally friendly sound barrier. Test the various properties of the cured sound barrier.

[0045] Example 4

[0046] A method for preparing a color-adjustable red mud-recycled mixture environmentally friendly sound barrier is completed by the following steps:

[0047] 1. Select a suitable mold, install the sound-absorbing hole pad, select the raw materials according to the components, and take 400 parts of red mud, 500 parts of recycled mixture, 80 parts of cement, 90 parts of sodium hydroxide, 20 parts of protein foaming agent and 350 parts of water;

[0048] 2. Mix red mud, recycled mixture, sodium hydroxide, cement and water in proportion to obtain slurry;

[0049] 3. Mix the foaming agent and water and mix them evenly with the slurry. Pour them into the mold and vibrate them to make them dense. Transport them to the curing site and cure them naturally for 28 days to produce an environmentally friendly sound barrier. Test the various properties of the cured sound barrier.

[0050] Example 5

[0051] A method for preparing a color-adjustable red mud-recycled mixture environmentally friendly sound barrier is completed by the following steps:

[0052] 1. Select a suitable mold, install the sound-absorbing hole pad, select the raw materials according to the components, and take 500 parts of red mud, 500 parts of recycled mixture, 50 parts of cement, 100 parts of sodium hydroxide, 20 parts of protein foaming agent and 400 parts of water.

[0053] 2. Mix red mud, recycled mixture, sodium hydroxide, cement and water in proportion to obtain slurry;

[0054] 3. Mix the foaming agent and water and mix them evenly with the slurry. Pour them into the mold and vibrate them to make them dense. Transport them to the curing site and cure them naturally for 28 days to produce an environmentally friendly sound barrier. Test the various properties of the cured sound barrier.

[0055] Example 6

[0056] A method for preparing a color-adjustable red mud-recycled mixture environmentally friendly sound barrier is completed by the following steps:

[0057] 1. Select a suitable mold, install the sound-absorbing hole pad, select the raw materials according to the components, and take 100 parts of red mud, 600 parts of recycled mixture, 160 parts of cement, 50 parts of sodium hydroxide, 30 parts of protein foaming agent and 250 parts of water;

[0058] 2. Mix red mud, recycled mixture, sodium hydroxide, cement and water in proportion to obtain slurry;

[0059] 3. Mix the foaming agent and water and mix them evenly with the slurry. Pour them into the mold and vibrate them to make them dense. Transport them to the curing site and cure them naturally for 28 days to produce an environmentally friendly sound barrier. Test the various properties of the cured sound barrier.

[0060] Example 7

[0061] A method for preparing a color-adjustable red mud-recycled mixture environmentally friendly sound barrier is completed by the following steps:

[0062] 1. Select a suitable mold, install the sound-absorbing hole pad, select the raw materials according to the components, and take 100 parts of red mud, 700 parts of recycled mixture, 180 parts of cement, 50 parts of sodium hydroxide, 40 parts of protein foaming agent and 300 parts of water;

[0063] 2. Mix red mud, recycled mixture, sodium hydroxide, cement and water in proportion to obtain slurry;

[0064] 3. Mix the foaming agent and water and mix them evenly with the slurry. Pour them into the mold and vibrate them to make them dense. Transport them to the curing site and cure them naturally for 28 days to produce an environmentally friendly sound barrier. Test the various properties of the cured sound barrier.

[0065] Example 8

[0066] A method for preparing a color-adjustable red mud-recycled mixture environmentally friendly sound barrier is completed by the following steps:

[0067] 1. Select a suitable mold, install the sound-absorbing hole pad, select the raw materials according to the components, and take 100 parts of red mud, 800 parts of recycled mixture, 200 parts of cement, 50 parts of sodium hydroxide, 50 parts of protein foaming agent and 350 parts of water;

[0068] 2. Mix red mud, recycled mixture, sodium hydroxide, cement and water in proportion to obtain slurry;

[0069] 3. Mix the foaming agent and water and mix them evenly with the slurry. Pour them into the mold and vibrate them to make them dense. Transport them to the curing site and cure them naturally for 28 days to produce an environmentally friendly sound barrier. Test the various properties of the cured sound barrier.

[0070] Compare the appearance color of the sound barrier after maintenance with the RAL standard color to determine the color of the sound barrier.

[0071] A quantitative amount of humid sulfur dioxide gas and the prepared sound barrier are placed in a closed container. A fan is used to fully mix the gas and the sound barrier. After contacting for 2 hours, the gas in the closed container is discharged, the change in the sulfur dioxide gas content is detected, and the sulfur dioxide absorption rate is calculated.

[0072] The noise reduction effect of the samples was tested in accordance with Part 5: Noise Reduction Effect Test Method in JT / T 646.5-2017 "Highway Sound Barriers".

[0073] The compressive strength of the samples was tested in accordance with GB / T 50081-2019 "Standard for Test Methods for Physical and Mechanical Properties of Concrete".

[0074] Table 1 Test results of environmentally friendly sound barrier performance of color-adjustable red mud-recycled mixture

[0075] Group No. 28d compressive strength / MPa WEB standard colors Sound insulation / dB Sulfur dioxide absorption rate / % Example 1 18.8 Earthy brown 32.6 34.1 Example 2 17.5 Reddish brown 32.7 39.3 Example 3 17.0 Light red 35.5 44.8 Example 4 16.1 Coral Red 35.3 50.8 Example 5 15.3 Purple 37.0 57.4 Example 6 18.6 Earthy brown 36.3 36.9 Example 7 19.6 Earthy gray 35.9 32.5 Example 8 20.1 Earthy gray 34.2 33.7

[0076] As can be seen from Table 1, the average compressive strength of the sound barrier samples is higher than 15.0MPa, which meets the C15 concrete strength standard. The appearance color of the sound barrier changes significantly with the amount of red mud added. It is purple-red when the red mud content is high and yellow-gray when the red mud content is low. The red mud content can be changed according to demand to produce sound barriers of different colors. The sound insulation of the sound barrier is higher than 30dB, which meets the requirements of JT / T 646.5-2017 "Highway Sound Barrier" for sound insulation performance. The sulfur dioxide absorption rate of the sound barrier changes with the red mud content. When the red mud content is high, the absorption rate exceeds 50%, and the lower red mud content also has an absorption rate of more than 30%. The color-adjustable red mud-recycled mixture environmentally friendly sound barrier prepared by the present invention provides a new idea for the resource utilization of red mud and recycled mixture, and has significant advantages such as color controllable, strength pass, acid gas absorption and low production cost.

[0077] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A color-adjustable red mud-recycled mixture environmentally friendly sound barrier, characterized in that: The raw materials include, by weight: 100-500 parts of red mud, 500-800 parts of recycled mixed materials, 50-200 parts of cement, 50-100 parts of alkali activator, 10-50 parts of foaming agent, and 200-400 parts of water; Taking recycled mixture as the basic material, alkali activator is added to stimulate the potential gelling activity of red mud, foaming agent is added to form a porous structure, and cement is combined to form a color-adjustable red mud-recycled mixture environmentally friendly sound barrier; by adjusting the red mud dosage, the color of the sound barrier can be changed between red and gray.

2. The color-adjustable red mud-recycled mixture environmentally friendly sound barrier according to claim 1, characterized in that: The red mud is industrial solid waste from the Bayer process of producing alumina, which is dried and ground to a particle size of 8-10 μm.

3. The color-adjustable red mud-recycled mixture environmentally friendly sound barrier according to claim 1, characterized in that: The recycled mixture is the aggregate obtained after crushing and screening of waste concrete, including coarse aggregate and fine aggregate, which are not further distinguished, and the particle size distribution is 0.15-50mm.

4. The color-adjustable red mud-recycled mixture environmentally friendly sound barrier according to claim 1, characterized in that: The cement is ordinary Portland cement.

5. The color-adjustable red mud-recycled mixture environmentally friendly sound barrier according to claim 1, characterized in that: The alkaline activator is sodium hydroxide.

6. The color-adjustable red mud-recycled mixture environmentally friendly sound barrier according to claim 1, characterized in that: The foaming agent is a protein foaming agent or a rosin resin foaming agent.

7. A method for preparing a color-adjustable red mud-recycled mixture environmentally friendly sound barrier according to any one of claims 1 to 6, characterized in that: The following steps are involved: (1) Select a suitable mold according to the size of the sound barrier, and select different rubber sound-absorbing hole pads according to the different sound-absorbing hole shapes and size requirements to install on the mold panel, and evenly apply a release agent on all surfaces inside the mold; (2) mixing red mud, recycled mixture, alkali activator, cement and water in proportion to obtain slurry; (3) mixing a blowing agent and water to foam; (4) Evenly mix the foam and the mixture, pour them into the mold and vibrate them to make them dense; (5) Transporting the waste to a maintenance site for natural curing to obtain a color-adjustable red mud-recycled mixture environmentally friendly sound barrier.

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