Preparation method of Bayer process red mud-based polymer material system

Abstract

The present invention discloses a preparation method for a Bayer red mud-based polymer material system, belonging to the field of material preparation technology. S1: sorting plastic waste from domestic waste, then crushing and shearing it, and then refining it at high temperature; S2: after pre-treating the red mud, adding slag powder, cement, water, and the refined plastic waste to mix them to obtain a first mixed material; S3: continuing to add a curing agent, fine sand, and water glass to the first mixed material, and continuing to mix to obtain a finished product. The present invention uses Bayer red mud as a geopolymer material, which not only effectively utilizes its high alkalinity and reduces the cost of the activator, but also achieves the goal of solidifying alkali metal cations, ensuring the long-term stability of the hardened slurry and meeting environmental standards.

Description

Technical Field

[0001] The invention belongs to the technical field of material preparation, and in particular relates to a method for preparing a Bayer process red mud-based polymer material system. Background Art

[0002] Red mud refers to the polluted waste residue produced when alumina is produced in the aluminum industry. It is reddish-brown in color because it contains a large amount of hematite, so it is called red mud.

[0003] Moreover, most of this red mud is Bayer red mud, which is characterized by high alkalinity and low activity, making it difficult to use directly in the cement industry, and its comprehensive utilization is severely limited. Therefore, finding a large-scale, safe, and economical way to utilize it is the key to solving the large-scale accumulation of Bayer red mud.

[0004] The modern social environment is developing rapidly, cities are getting bigger and bigger, and the population is getting bigger and bigger, which inevitably generates a lot of domestic waste. Some of this domestic waste will be treated harmlessly by sanitary landfill, incineration, composting, etc., while other rural waste is not properly handled and is often simply piled up or buried, leading to the spread of odor, and in serious cases, it will also pollute the soil and groundwater. Summary of the Invention

[0005] In view of this, the object of the present invention is to provide a method for preparing a Bayer process red mud-based polymer material system.

[0006] To achieve the above object, the present invention provides the following technical solution: a method for preparing a Bayer process red mud-based polymer material system, the method comprising the following steps:

[0007] S1. Sorting the plastic waste from domestic waste, then crushing and shearing it, and then refining it at high temperature;

[0008] S2, after the red mud is pretreated, slag powder, cement, water, and refined plastic waste are added and mixed to obtain a first mixed material;

[0009] S3. Continue to add internal curing agent, fine sand and water glass to the first mixture and continue mixing to obtain the finished product.

[0010] Furthermore, in parts by weight, the plastic waste is 80-100 parts, red mud is 150-190 parts, slag powder is 30-40 parts, cement is 50-65 parts, internal curing agent is 15-20 parts, fine sand is 20-35 parts, water glass is 10-20 parts, and water is 80-100 parts.

[0011] Furthermore, the plastic waste is 90 parts, red mud is 170 parts, slag powder is 35 parts, cement is 58 parts, internal curing agent is 18 parts, fine sand is 30 parts, water glass is 15 parts, and water is 90 parts.

[0012] Furthermore, the water content of the red mud is 1-4%, the particle size of the red mud is 0.1-5 μm; the content of aluminum oxide in the red mud is greater than 20%, and the content of iron oxide is greater than 13%.

[0013] Furthermore, the stirring rate of step S2 and step S3 is 15-23 rpm / min.

[0014] Furthermore, in step S2, the temperature of the sheared plastic waste during mixing is 90-110 degrees Celsius.

[0015] Furthermore, the calcium oxide content in the slag powder is greater than 35%, the silicon dioxide content is greater than 30%, the aluminum oxide content is greater than 10%, and the magnesium oxide content is greater than 8%; the calcium oxide content in the cement is greater than 60%, and the silicon dioxide content is greater than 20%.

[0016] Furthermore, the water glass is composed of silicon dioxide, sodium oxide and water in a mass ratio of 29.2:12.8:58.

[0017] Furthermore, the internal curing agent is composed of sodium hydroxide, water, acrylic acid, deionized water, acrylamide, ammonium persulfate, N,N'-methylenebisacrylamide, and anhydrous ethanol in a mass ratio of 2:10:8:9:1:1.5:0.7:10.

[0018] Furthermore, the plastic waste is PET, HDPE, PVC, PP, LDPE, PS, the refining temperature of the plastic waste is 200-250 degrees Celsius, and the water used in step 2 is purified water when refining the plastic waste.

[0019] The beneficial effects of the present invention are:

[0020] 1. The present invention uses Bayer red mud as geopolymer material, which not only effectively utilizes its high alkalinity and reduces the cost of the activator, but also achieves the goal of solidifying alkali metal cations, ensuring the long-term stability of the hardened slurry and compliance with environmental protection standards.

[0021] 2. The Bayer red mud of the present invention can be used in a large amount in a geopolymer system. The high alkalinity of the Bayer red mud can be used to reduce the consumption of activators, thereby significantly reducing material costs. The alkali metal cations in the Bayer red mud participate in the reaction, thereby achieving the effect of solidifying the alkali metal cations and meeting environmental protection requirements.

[0022] 3. The present invention refines plastic waste in daily life, such as plastic bags, mineral water bottles, medicine packaging bottles and other plastic production areas that are inconvenient to recycle, at high temperature, and then cools it to 100 degrees Celsius and mixes it with red mud, cement, slag powder, etc. During mixing, the plastic waste can wrap the mixture to enhance its adhesion; at the same time, the recycling of plastic waste is in line with the purpose of green environmental protection.

[0023] 4. During the preparation of the present invention, an internal curing agent is added. The internal curing agent is a porous super absorbent resin powder material (SAP), which can absorb several times or even hundreds of times its own weight of water. Therefore, after being added, the internal curing effect can be achieved during the preparation process. In combination with other components, the adhesion of the finished product can be made denser, reducing the possibility of cracking of the finished geopolymer.

[0024] Other advantages, objectives and features of the present invention will be described in the following description and will be apparent to those skilled in the art to some extent, or those skilled in the art can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to make the purpose, technical solutions and beneficial effects of the invention clearer, the present invention is described with the following drawings:

[0026] Figure 1 A flow chart of the preparation of the invention; DETAILED DESCRIPTION

[0027] A method for preparing a Bayer process red mud-based polymer material system.

[0028] Example 1

[0029] S1. 90 pieces of plastic waste were sorted and then cut into 5 cm blocks in a crusher, and then heated at 210 degrees Celsius for 5 minutes;

[0030] S2. After preliminarily dehydrating 170 parts of red mud, 35 parts of slag powder, 60 parts of cement, 90 parts of water, and refined plastic waste were added and mixed to obtain a first mixture;

[0031] S3. Continue to add 18 parts of internal curing agent, 30 parts of fine sand, and 15 parts of water glass to the first mixture, and continue mixing to obtain the finished product.

[0032] Example 2

[0033] S1. 80 pieces of plastic waste were sorted and then cut into 5 cm blocks in a crusher, and then heated at 200 degrees Celsius for 5 minutes;

[0034] S2. After preliminarily dehydrating 190 parts of red mud, 40 parts of slag powder, 50 parts of cement, 100 parts of water, and refined plastic waste were added and mixed to obtain a first mixture;

[0035] S3. Continue to add 20 parts of internal curing agent, 35 parts of fine sand, and 10 parts of water glass to the first mixture, and continue mixing to obtain a finished product.

[0036] Example 3

[0037] S1. 90 pieces of plastic waste were sorted and then cut into 5 cm blocks in a crusher, and then heated at 240 degrees Celsius for 5 minutes;

[0038] S2. After preliminarily dehydrating 150 parts of red mud, 30 parts of slag powder, 65 parts of cement, 80 parts of water, and refined plastic waste were added and mixed to obtain a first mixture;

[0039] S3. Continue to add 15 parts of internal curing agent, 20 parts of fine sand, and 20 parts of water glass to the first mixture, and continue mixing to obtain a finished product.

[0040] In order to demonstrate the superiority of the raw materials and method of the present invention, comparative examples 1 to 3 are set up here.

[0041] Comparative Example 1

[0042] S1. 90 pieces of plastic waste were sorted and then cut into 5 cm blocks in a crusher, and then heated at 210 degrees Celsius for 5 minutes;

[0043] S2. After preliminary dehydration, 170 parts of red mud are mixed with the sheared plastic waste to obtain a finished product.

[0044] Comparative Example 2

[0045] S1. 70 pieces of plastic waste were sorted and then cut into 5 cm blocks in a crusher, and then heated at 210 degrees Celsius for 5 minutes;

[0046] S2. After preliminarily dehydrating 140 parts of red mud, 20 parts of slag powder, 80 parts of cement, 120 parts of water, and refined plastic waste were added and mixed to obtain a first mixture;

[0047] S3. Continue to add 10 parts of internal curing agent, 40 parts of fine sand, and 20 parts of water glass to the first mixture, and continue mixing to obtain a finished product.

[0048] Comparative Example 3

[0049] S1. 120 pieces of plastic waste were sorted and then cut into 5 cm blocks in a crusher, and then heated at 210 degrees Celsius for 5 minutes;

[0050] S2. After preliminarily dehydrating 200 parts of red mud, 45 parts of slag powder, 40 parts of cement, 50 parts of water, and refined plastic waste were added and mixed to obtain a first mixture;

[0051] S3, continue to add 22 parts of internal curing agent, 15 parts of fine sand, and 25 parts of water glass to the first mixture, continue mixing, and obtain the finished product

[0052] Comparative Example 1 differs from the preparation method of the present application, and Comparative Examples 2-3 differ from the raw material ratios of the present application. Mechanical property tests were conducted on the finished products prepared in Examples 1-3 and Comparative Examples 1-3. The mechanical property tests of the specimens were conducted in accordance with the "Test Method for Strength of Cement Mortar" (GB / T 17671-1999). The compressive strength of the specimens at specified ages (7 days and 28 days) was measured. The results are shown in the following table:

[0053]

[0054] As can be seen from the table above, the compressive strength of the geopolymer materials prepared in Examples 1-3 of the present application is superior to that of the comparative materials prepared in Comparative Examples 1-3. Comparative Example 1 directly mixes plastic waste with red mud without adding other materials, resulting in an uneven mixture and little practical application. Comparative Examples 2 and 3 use different raw materials than the present application, resulting in inferior finished products and less practicality. By controlling the materials and proportions, the present application produces a finished geopolymer that is both practical and environmentally friendly.

[0055] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A method for preparing a Bayer process red mud-based polymer material system, characterized in that: The method comprises the following steps, S1. Sorting the plastic waste from domestic waste, then crushing and shearing it, and then refining it at high temperature; S2, after the red mud is pretreated, slag powder, cement, water, and refined plastic waste are added and mixed to obtain a first mixed material; S3. Continue to add internal curing agent, fine sand, and water glass to the first mixture and continue mixing to obtain a finished product; By weight, the plastic waste is 80-100 parts, red mud is 150-190 parts, slag powder is 30-40 parts, cement is 50-65 parts, internal curing agent is 15-20 parts, fine sand is 20-35 parts, water glass is 10-20 parts, and water is 80-100 parts; In step S2, the temperature of the sheared plastic waste when mixed is 90-110 degrees Celsius.

2. The method for preparing a Bayer process red mud-based polymer material system according to claim 1, characterized in that: The plastic waste is 90 parts, red mud is 170 parts, slag powder is 35 parts, cement is 58 parts, internal curing agent is 18 parts, fine sand is 30 parts, water glass is 15 parts, and water is 90 parts.

3. The method for preparing a Bayer process red mud-based polymer material system according to claim 1, characterized in that: The red mud has a moisture content of 1-4% and a particle size of 0.1-5 μm; the red mud contains more than 20% aluminum oxide and more than 13% iron oxide.

4. The method for preparing a Bayer process red mud-based polymer material system according to claim 1, characterized in that: The stirring rate of step S2 and step S3 is 20-28 rpm.

5. The method for preparing a Bayer process red mud-based polymer material system according to claim 1, characterized in that: The slag powder has a calcium oxide content greater than 35%, a silicon dioxide content greater than 30%, an aluminum oxide content greater than 10%, and a magnesium oxide content greater than 8%; the cement has a calcium oxide content greater than 60%, and a silicon dioxide content greater than 20%.

6. The method for preparing a Bayer process red mud-based polymer material system according to claim 1, characterized in that: The water glass is composed of silicon dioxide, sodium oxide and water in a mass ratio of 29.2:12.8:

58.

7. The method for preparing a Bayer process red mud-based polymer material system according to claim 1, characterized in that: The internal curing agent comprises sodium hydroxide, water, acrylic acid, deionized water, acrylamide, ammonium persulfate, N,N'-methylenebisacrylamide and anhydrous ethanol in a mass ratio of 2:10:8:9:1:1.5:0.7:

10.

8. The method for preparing a Bayer process red mud-based polymer material system according to claim 1, characterized in that: The plastic waste is PET, HDPE, PVC, PP, LDPE, and PS. The refining temperature of the plastic waste is 200-250 degrees Celsius. The water used in step S2 is purified water used in refining the plastic waste.

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