Red mud based foamed concrete and method of making the same

Abstract

The application discloses a kind of red mud-based foamed concrete and preparation method thereof, including the following ingredients by weight parts count: red mud 100-160 parts;Calcium chloride waste liquid 5-13 parts;Fly ash 20-49 parts;Gypsum gel 30-50 parts;Gypsum activator 3-6 parts;Cement clinker 15-45 parts;Water 50-150 parts;Fine sand with a diameter of 1-4mm 10-30 parts;Polypropylene fiber 5-15 parts;Foaming agent 1-10 parts;Waterproof agent 1-4 parts;Rust inhibitor 1-3 parts.The application has the advantages of high strength, solves the existing red mud-based foamed concrete in the process of use, only by red mud instead of cement as gel material, prone to low strength and low consistency of concrete, the problem that the inside of concrete is not provided with fine sand with a diameter of 1-4mm, easy to crack and damage when bearing excessive pressure.

Description

Technical Field

[0001] This invention relates to the field of building materials, specifically to a red mud-based foamed concrete and its preparation method. Background Technology

[0002] Red mud-based foamed concrete is a type of building material, primarily used in construction. The strength of concrete is crucial to the safety of buildings. Red mud is a solid waste produced during the alumina production process, and it has a high alkali content, which can pollute the environment if left on the ground. Therefore, using red mud to manufacture concrete allows for the secondary utilization of waste. Red mud-based foamed concrete is a type of foamed concrete, filled with numerous air bubbles, giving it thermal insulation properties.

[0003] Chinese Patent Publication No. CN104193274B discloses an alkaline slag foamed concrete, comprising slag and an alkaline activator, wherein the alkaline activator is sodium hydroxide or water glass. When the alkaline activator is sodium hydroxide, the alkaline slag foamed concrete is composed of the following components by weight: slag: 59-65 parts; NaOH: 5-6 parts; water: 23-26 parts; foaming agent: 4.8-12.2 parts. When the alkaline activator is water glass, the alkaline slag foamed concrete is composed of the following components by weight: slag: 56-61 parts; water glass: 9-11 parts; water: 21-25 parts; foaming agent: 5.0-12.2 parts. The bulk density of the foamed concrete is 290-610 kg / m³. 3 The alkali slag foamed concrete of this invention has a short setting speed, rapid strength development, and high later strength. It also has excellent water resistance and weather resistance, and can be used for a long time. However, it is prone to cracking during actual use because it does not contain internal reinforcing materials.

[0004] Chinese patent publication number CN102584319 discloses a multifunctional foamed concrete. The aggregate of this foamed concrete contains diatomaceous earth. Because diatomaceous earth has thermal insulation and sound insulation properties, the aggregate and closed pores of the foamed concrete of this invention also have thermal insulation and sound insulation properties. This allows the foamed concrete to maintain high strength while having good thermal insulation and sound insulation properties. However, this invention does not have waterproof and rust-resistant functions, and it contains less adhesive, making it inconvenient to process.

[0005] Chinese patent CN112500187B discloses a foamed concrete production process. Using water, cement, and sand as raw materials, a composite foaming agent (black bean foaming agent A and hydrogen peroxide foaming agent B) is used for foaming. Calcium lignosulfonate is added to enhance mechanical properties, and finally, the concrete is steam-cured in an autoclave to obtain foamed concrete. This invention's foamed concrete production process uses a composite foaming agent, which has good foaming performance, strong stability, simple preparation, and strong practicality. Concrete prepared using this process has advantages such as light weight, high strength, more uniform and dense porosity, and low thermal conductivity. However, during the preparation process, the raw materials are not uniformly stirred, which can easily lead to uneven and messy concrete, affecting the strength and performance of the foamed concrete.

[0006] In the current use of red mud-based foamed concrete, red mud is used instead of cement as a gelling agent, which easily leads to low concrete strength and low consistency. Since no aggregate is set inside the concrete, it is prone to cracking and damage when subjected to excessive pressure. Summary of the Invention

[0007] The purpose of this invention is to provide a red mud-based foamed concrete and its preparation method, which has the advantage of high strength. It solves the problems of existing red mud-based foamed concrete, which simply uses red mud instead of cement as a gelling agent, resulting in low strength and low consistency of the concrete. Furthermore, the concrete does not contain fine sand with a diameter of 1-4 mm, making it prone to cracking and damage under excessive pressure.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a red mud-based foamed concrete, comprising the following components by weight:

[0009] Red mud 100-160 parts; calcium chloride waste liquid 5-13 parts; fly ash 20-49 parts; gypsum gel 30-50 parts; gypsum activator 3-6 parts; cement clinker 15-45 parts; water 50-150 parts; fine sand with a diameter of 1-4 mm 10-30 parts; polypropylene fiber 5-15 parts; foaming agent 1-10 parts; waterproofing agent 1-4 parts; rust inhibitor 1-3 parts; glass fiber 10-50 parts; silicon carbide micro powder 10-50 parts; nanomaterials 5-10 parts.

[0010] Preferably, the nanomaterials in the calcium chloride waste liquid glass fiber are one of nano-alumina and nano-calcium silicate.

[0011] Preferably, the foaming agent is one of rosin foaming agent and waste animal hair foaming agent.

[0012] Preferably, the diameter of the red mud is 0.088-0.25 mm.

[0013] A method for preparing red mud-based foamed concrete specifically includes the following steps:

[0014] 1) Mix 100-160 parts of red mud with 5-13 parts of calcium chloride waste liquid, add 50-150 parts of water and stir to make a red mud-calcium chloride waste liquid mixture slurry. Use the calcium chloride waste liquid to dealkalize the red mud and reduce its alkali content. The sodium in the red mud and the calcium in the calcium chloride waste liquid undergo ion exchange to reduce the alkali content in the red mud. After dealkalization, dry and break up the red mud.

[0015] 2) Pour 20-49 parts fly ash, 15-45 parts cement clinker, 10-30 parts fine sand with a diameter of 1-4 mm, 5-15 parts polypropylene fiber, 10-50 parts glass fiber, 10-50 parts silicon carbide micro powder, 5-10 parts nanomaterials and the red mud-calcium chloride waste liquid mixture obtained in step 1) into a mixer. The mixing speed is 10-20 r / min. The mixer mixes the raw materials for 10-15 min.

[0016] 3) After mixing, pour 30-50 parts of gypsum gel and 3-6 parts of gypsum activator into the mixer and continue mixing for 3-5 minutes at a speed of 8-15 r / min.

[0017] 4) Add 1-4 parts waterproofing agent and 1-3 parts rust inhibitor to the mixer to modify the concrete. The mixing time is 3-6 minutes and the mixing speed is 8-15 r / min.

[0018] 5) After mixing, use an ultrasonic stirrer to ultrasonically vibrate the mixture inside the mixer for 10-15 minutes at an ultrasonic frequency of 20kHz-100kHz to promote the synergistic effect between material particles and enhance the mixing effect, thereby improving uniformity and stability.

[0019] 6) After modification, 1-10 parts of foaming agent are fully foamed mechanically through the foaming system of the foaming machine, and the foam is put into the mixer for uniform mixing with the previously mixed materials. Then, it is poured or molded through the pumping system of the foaming machine.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] 1. This invention uses calcium chloride waste liquid to dealkalize red mud, reducing the alkali content in the red mud to 0.13, which meets the requirements for concrete use, realizes the recycling of red mud, and reduces the degree of environmental pollution.

[0022] 2. This invention can supplement red mud by adding fly ash, gypsum gel and cement clinker to increase the strength of concrete and make it easier to combine multiple materials. Adding gypsum activator can activate gypsum gel materials and improve their performance.

[0023] 3. By adding fine sand with a diameter of 1-4mm and polypropylene fibers, this invention can improve the strength of concrete, prevent it from cracking and being damaged under excessive pressure, and increase the strength and performance of concrete.

[0024] 4. By setting a foaming agent, the present invention can foam concrete, generating a large number of uniform air bubbles inside, reducing the strength of concrete, and providing local thermal insulation and noise reduction effects.

[0025] 5. By adding waterproofing agents and rust inhibitors, this invention can modify concrete, making its exterior waterproof and preventing moisture from penetrating into the interior of the concrete and causing internal corrosion and damage. The rust inhibitor can protect the steel bars inside the concrete, preventing them from rusting and being damaged, thus affecting the service life of the building.

[0026] 6. By incorporating glass fiber and silicon carbide micropowder, this invention can enhance the thermal insulation effect of foamed concrete, enabling it to maintain a constant internal temperature when applied to buildings. The silicon carbide micropowder also increases the sound absorption effect of foamed concrete, reducing the decibel level of external noise transmitted into the building. Furthermore, the inclusion of nanomaterials improves the mechanical properties and durability of red mud-based foamed concrete, while also reducing its weight, making it lighter and thus reducing the load on the building structure. Detailed Implementation

[0027] Example 1

[0028] A red mud-based foamed concrete comprises the following components by weight:

[0029] 100 parts red mud, with a diameter of 0.088-0.25 mm; 5 parts calcium chloride waste liquid; 20 parts fly ash; 30 parts gypsum gel; 3 parts gypsum activator; 15 parts cement clinker; 50 parts water; 10 parts fine sand with a diameter of 1-4 mm; 5 parts polypropylene fiber; 1 part foaming agent, which is rosin foaming agent; 1 part waterproofing agent; 1 part rust inhibitor; 10 parts glass fiber; 10 parts silicon carbide micro powder; 5 parts nanomaterials, which are nano alumina.

[0030] The preparation method of red mud-based foamed concrete involved in this embodiment specifically includes the following steps:

[0031] 1) Mix the above-mentioned red mud and calcium chloride waste liquid, add water and stir to make a red mud-calcium chloride waste liquid mixture slurry. Use calcium chloride waste liquid to dealkalize the red mud and reduce the alkali content of the red mud. The sodium in the red mud and the calcium chloride in the calcium chloride waste liquid undergo ion exchange to reduce the alkali content in the red mud. After the dealkalization is completed, dry and break up the red mud.

[0032] 2) The above-mentioned parts by weight of fly ash, cement clinker, fine sand with a diameter of 1-4 mm, polypropylene fiber, glass fiber, silicon carbide micro powder, nanomaterials and the red mud-calcium chloride waste liquid mixture obtained in step 1) are poured into a mixer. The mixing speed is 10-20 r / min. The mixer mixes the raw materials for 10-15 min.

[0033] 3) After mixing, pour the above-mentioned weight parts of gypsum gel and gypsum activator into the mixer and continue mixing for a second time. The mixing time is 3-5 minutes and the mixing speed is 8-15 r / min.

[0034] 4) Add the above-mentioned parts by weight of waterproofing agent and rust inhibitor into the mixer to modify the concrete. The mixing time is 3-6 minutes and the mixing speed is 8-15 r / min.

[0035] 5) After mixing, use an ultrasonic stirrer to ultrasonically vibrate the mixture inside the mixer for 10-15 minutes at an ultrasonic frequency of 20kHz-100kHz to promote the synergistic effect between material particles and enhance the mixing effect, thereby improving uniformity and stability.

[0036] 6) After modification, the foaming agent of the above weight parts is fully foamed mechanically through the foaming system of the foaming machine, and the foam is put into the mixer for uniform mixing with the previously mixed materials. Then, it is poured or molded through the pumping system of the foaming machine.

[0037] The construction method of red mud-based foamed concrete involved in this embodiment includes the following steps:

[0038] 1) Inspection: Before construction, the quality of the red mud-based foamed concrete needs to be inspected. Construction can only proceed after the density, moisture content, strength and other indicators meet the standard requirements.

[0039] 2) Preparation: Before construction, it is necessary to prepare appropriate templates, tools and safety equipment, select a good construction site, and remove debris and dust to ensure construction quality.

[0040] 3) Construction method: The construction method of red mud-based foamed concrete is similar to that of ordinary concrete, and can be carried out by pouring or vertical pouring. Before construction, apply a release agent to the surface of the pouring area, add appropriate position support before filling, inject foaming agent into the concrete and add an appropriate amount of cement according to the construction method, mix evenly and pour into the formwork. After the concrete has completely cured, the formwork can be removed.

[0041] 4) Requirements: During the construction of red mud-based foamed concrete, care should be taken to keep the construction site clean, avoiding excessive moisture, exposed reinforcing bars, and external corners, etc. Strengthening measures such as wire mesh and reinforcing bars should be adopted to enhance the strength and stability of the concrete.

[0042] 5) Finishing: Various coatings or decorative materials can be applied to the surface of red mud-based foamed concrete to achieve the desired decorative effect. Maintenance should be strengthened in a timely manner according to different conditions.

[0043] Example 2

[0044] A red mud-based foamed concrete comprises the following components by weight:

[0045] 160 parts red mud, with a diameter of 0.088-0.25 mm; 13 parts calcium chloride waste liquid; 49 parts fly ash; 50 parts gypsum gel; 6 parts gypsum activator; 45 parts cement clinker; 150 parts water; 30 parts fine sand with a diameter of 1-4 mm; 15 parts polypropylene fiber; 10 parts foaming agent, which is rosin foaming agent; 4 parts waterproofing agent; 3 parts rust inhibitor; 50 parts glass fiber; 50 parts silicon carbide micro powder; 10 parts nanomaterials, which is nano alumina.

[0046] The preparation and construction methods of the red mud-based foamed concrete involved in this embodiment are the same as those in Embodiment 1.

[0047] Example 3

[0048] A red mud-based foamed concrete comprises the following components by weight:

[0049] 120 parts red mud, with a diameter of 0.088-0.25 mm; 8 parts calcium chloride waste liquid; 35 parts fly ash; 40 parts gypsum gel; 5 parts gypsum activator; 25 parts cement clinker; 80 parts water; 20 parts fine sand with a diameter of 1-4 mm; 8 parts polypropylene fiber; 6 parts foaming agent, which is rosin foaming agent; 2 parts waterproofing agent; 2 parts rust inhibitor; 25 parts glass fiber; 25 parts silicon carbide micro powder; 6 parts nanomaterials, which are nano alumina.

[0050] The preparation and construction methods of the red mud-based foamed concrete involved in this embodiment are the same as those in Embodiment 1.

[0051] The parameters of the red mud-based foamed concrete prepared in Examples 1-3 are compared with those of ordinary foamed concrete. The comparison table is as follows:

[0052]

[0053]

[0054] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A red mud-based foamed concrete, characterized in that, The ingredients, when counted by weight, include the following: Red mud 100-160 parts; calcium chloride waste liquid 5-13 parts; fly ash 20-49 parts; gypsum gel 30-50 parts; gypsum activator 3-6 parts; cement clinker 15-45 parts; water 50-150 parts; fine sand with a diameter of 1-4 mm 10-30 parts; polypropylene fiber 5-15 parts; foaming agent 1-10 parts; waterproofing agent 1-4 parts; rust inhibitor 1-3 parts; glass fiber 10-50 parts; silicon carbide micro powder 10-50 parts; nanomaterials 5-10 parts; wherein the nanomaterials are one of nano-alumina and nano-calcium silicate.

2. The red mud-based foamed concrete according to claim 1, characterized in that, The foaming agent is one of rosin foaming agent and waste animal hair foaming agent.

3. The red mud-based foamed concrete according to claim 1, characterized in that, The diameter of the red mud is 0.088-0.25 mm.

4. A method for preparing red mud-based foamed concrete according to claim 1, characterized in that, Specifically, the following steps are included: 1) Mix 100-160 parts of red mud with 5-13 parts of calcium chloride waste liquid, add 50-150 parts of water and stir to make a red mud-calcium chloride waste liquid mixed slurry; 2) Pour 20-49 parts fly ash, 15-45 parts cement clinker, 10-30 parts fine sand with a diameter of 1-4 mm, 5-15 parts polypropylene fiber, 10-50 parts glass fiber, 10-50 parts silicon carbide micro powder, 5-10 parts nanomaterials, and the red mud-calcium chloride waste liquid mixture obtained in step 1) into a mixer. The mixing speed is 10-20 r / min. The mixer mixes the raw materials for 10-15 min. 3) After mixing, pour 30-50 parts of gypsum gel and 3-6 parts of gypsum activator into the mixer and continue mixing for 3-5 minutes at a speed of 8-15 r / min. 4) Add 1-4 parts waterproofing agent and 1-3 parts rust inhibitor to the mixer to modify the concrete. The mixing time is 3-6 minutes and the mixing speed is 8-15 r / min. 5) After mixing, use an ultrasonic mixer to ultrasonically vibrate the mixture inside the mixer for 10-15 minutes at an ultrasonic frequency of 20kHz-100kHz. 6) After modification, 1-10 parts of foaming agent are fully foamed mechanically through the foaming system of the foaming machine, and the foam is put into the mixer for uniform mixing with the previously mixed materials. Then, it is poured on-site or molded through the pumping system of the foaming machine.

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