Multi-element waste residue cementing material and preparation method thereof

Abstract

The invention discloses a multi-element waste residue cementing material and a preparation method thereof. The multi-element waste residue cementing material provided by the invention comprises the following raw materials in parts by weight: 5-20 parts of an alkaline activator, 3-9 parts of a retarder, 71-92 parts of a soil reinforcing agent and 20-30 parts of water. The alkaline activator comprises at least one of red mud, carbide slag and coal gangue, the retarder is preferably desulfurized gypsum, and the soil reinforcing agent comprises at least one of slag and steel slag. The multi-element waste residue cementing material provided by the invention adopts a full solid waste ratio, provides a new method for solving the problem of industrial waste residue accumulation and environmental pollution, and is beneficial to reducing environmental hazards caused by cement production; according to the ratio provided by the invention, the cementing material has good hydration activity and pavement performance at the same time, and has great significance in resource utilization of industrial solid wastes in building materials. The invention also provides a preparation method of the multi-element waste residue cementing material.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of cementitious materials, and particularly relates to a multi-element waste residue cementitious material and a preparation method thereof. BACKGROUND

[0002] The total amount of industrial waste residues in China is huge. According to statistical data, by the end of 2022, it has exceeded 30 billion tons, with an annual increase of about 4.14 billion tons. Among them, large industrial waste residues such as slag, steel slag, fly ash, desulfurization gypsum and calcium carbide slag account for a significant proportion. Large-scale storage not only occupies land but also poses an environmental pollution risk. Such waste residues generally have potential hydration activity and can be used to replace part of cement or aggregate. At present, the common method is to activate the cementitious properties of industrial waste residues by adding alkali activators (such as lime, caustic soda, water glass, etc.), but these activators have high production cost and high price, which limits their large-scale application.

[0003] In recent years, the technology of promoting the resource utilization of industrial solid waste in road materials has developed rapidly. For example, phosphogypsum, steel slag and slag are used for road base, roadbed filler and cementitious materials. However, in actual engineering applications, there is still a lack of cementitious material formulations and technologies that can simultaneously meet the requirements of mechanical properties, construction feasibility and environmental friendliness. Therefore, it is urgent to develop a waste residue cementitious material with good hydration activity and road performance suitable for road base. SUMMARY

[0004] In view of the above problems, the application provides a multi-element waste residue cementitious material and a preparation method thereof. The cementitious material uses solid waste as raw material, realizes the transformation of waste into treasure, has strong social and environmental benefits, and has good hydration activity and road performance. The application also provides a preparation method of the cementitious material.

[0005] To solve the above problems, the technical scheme provided by the application is as follows: A multi-element waste residue cementitious material, comprising the following component raw materials in parts by weight: 5-20 parts of an alkali activator, 3-9 parts of a retarder, 71-92 parts of a soil body reinforcing agent and 20-30 parts of water.

[0006] The alkali activator can be selected from at least one of red mud, calcium carbide slag and coal gangue.

[0007] The retarder is preferably desulfurization gypsum.

[0008] The soil body reinforcing agent can be selected from at least one of slag and steel slag.

[0009] A preparation method of a multi-element waste residue cementitious material, comprising the following steps: S1, dehydrating, drying, crushing, grinding and screening the alkali activator, the retarder and the soil body reinforcing agent, and uniformly mixing them according to a predetermined proportion as raw materials; S2, the raw materials are put into a blender at a low speed of 120-150 r / min for 1-2 min to obtain a preliminary mixture; S3, the blender is kept at a low speed of 120-150 r / min for 3-4 min, and water is added in two times, each time adding half of it, to obtain a preliminary mixed slurry; S4, the speed of the blender is increased to a high speed of 260-300 r / min, and stirring is performed for 4-5 min to obtain a slurry with uniform mixing and good fluidity; S5, poured into any mold and placed in a standard curing chamber for curing for 12-24 h, the temperature is controlled at 20±2℃, and the humidity is ≥95%, so that the raw materials fully undergo hydration reaction.

[0010] Beneficial effects: The application develops a new multi-waste residue cementing material, which can not only effectively replace traditional cementing materials, reduce production cost and energy consumption, but also has good hydration activity and road performance, and is suitable for road base stabilizing material. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 Figure of the multi-waste residue cementing material mortar sample prepared in Example 1 of the application. DETAILED DESCRIPTION

[0012] The application will be further described in detail below in combination with specific preferred embodiments. Obviously, the described embodiments are only a part of the embodiments of the application, rather than all the embodiments; based on the embodiments in the application, all other embodiments obtained by a person of ordinary skill in the art without creative labor fall within the protection scope of the application.

[0013] Example 1 The embodiment provides a multi-waste residue cementing material, which comprises the following components by weight: 10 parts of an alkaline activator, 3 parts of a retarder, 87 parts of a soil body reinforcing agent, and 20 parts of water. The alkaline activator is carbide slag, the retarder is desulfurized gypsum, and the soil body reinforcing agent is slag.

[0014] The embodiment also provides a preparation method of the multi-waste residue cementing material, which comprises the following steps: S1, the alkaline activator, the retarder and the soil body reinforcing agent are subjected to dehydration drying, crushing, grinding and screening treatment, and are uniformly mixed according to the above-mentioned ratio as raw materials; S2, the raw materials are put into a blender at a low speed of 150 r / min for 1 min to obtain a preliminary mixture; S3, the blender is kept at a low speed of 150 r / min for 3 min, and water is added in two times, each time adding half of it, to obtain a preliminary mixed slurry; S4, increase the stirring speed to 260 r / min, stir for 5 min, to obtain a slurry with good fluidity and uniform mixing; S5, pour into any mold, put into a standard curing chamber for 24 h, control the temperature at 20±2℃, humidity ≥95%, so that the raw materials fully hydrate.

[0015] Example 2 A multi-waste residue cementing material, comprising the following components by weight: 20 parts of alkaline activator, 3 parts of retarder, 77 parts of soil enhancer, and 30 parts of water. The alkaline activator is carbide slag, the retarder is desulfurized gypsum, and the soil enhancer is slag.

[0016] A preparation method of a multi-waste residue cementing material, comprising the following steps: S1, dehydrate, dry, crush, grind, and sieve the alkaline activator, retarder, and soil enhancer, and mix them uniformly according to a predetermined ratio as raw materials; S2, put the raw materials into a stirrer at a low speed of 120 r / min and stir for 2 min to obtain a preliminary mixture; S3, keep the stirrer at a low speed of 120 r / min and stir for 4 min, add water in two times, each time adding half of the water, to obtain a preliminary mixed slurry; S4, increase the stirring speed to a high speed of 300 r / min, stir for 4 min, to obtain a slurry with good fluidity and uniform mixing; S5, pour into any mold, put into a standard curing chamber for 24 h, control the temperature at 20±2℃, humidity ≥95%, so that the raw materials fully hydrate.

[0017] Example 3 A multi-waste residue cementing material, comprising the following components by weight: 10 parts of alkaline activator, 6 parts of retarder, 84 parts of soil enhancer, and 20 parts of water. The alkaline activator is carbide slag, the retarder is desulfurized gypsum, and the soil enhancer is slag.

[0018] A preparation method of a multi-waste residue cementing material, comprising the following steps: S1, dehydrate, dry, crush, grind, and sieve the alkaline activator, retarder, and soil enhancer, and mix them uniformly according to a predetermined ratio as raw materials; S2, put the raw materials into a stirrer at a low speed of 150 r / min and stir for 1 min to obtain a preliminary mixture; S3, keep the stirrer at a low speed of 150 r / min and stir for 3 min, add water in two times, each time adding half of the water, to obtain a preliminary mixed slurry; S4, increase the stirring speed to a high speed of 260 r / min, stir for 5 min, to obtain a slurry with good fluidity and uniform mixing; S5, pour into any mold into the standard curing room curing 24h, control temperature 20±2℃, humidity≥95%, so that the raw materials fully occur hydration reaction.

[0019] Example 4 A multi-waste residue cementing material, comprising the following components by weight: 10 parts of alkaline activator, 9 parts of retarder, 81 parts of soil enhancer, and 30 parts of water. The alkaline activator is carbide slag, the retarder is desulfurized gypsum, and the soil enhancer is slag.

[0020] A preparation method of a multi-waste residue cementing material, comprising the following steps: S1, the alkaline activator, the retarder, and the soil enhancer are dehydrated, dried, crushed, ground, and sieved, and then mixed uniformly according to a predetermined proportion as raw materials; S2, the raw materials are placed into a stirrer and stirred at a low speed of 120r / min for 2min to obtain a preliminary mixture; S3, the stirrer is kept at a low speed of 120r / min for 4min, and water is added twice, each time adding half of it, to obtain a preliminary mixed slurry; S4, the stirring speed of the stirrer is increased to a high speed of 300r / min, and stirring is performed for 4min to obtain a slurry with good mixing uniformity and fluidity; S5, pour into any mold into the standard curing room curing 24h, control temperature 20±2℃, humidity≥95%, so that the raw materials fully occur hydration reaction.

[0021] Example 5 A multi-waste residue cementing material, comprising the following components by weight: 20 parts of alkaline activator, 9 parts of retarder, 71 parts of soil enhancer, and 30 parts of water. The alkaline activator is a mixture of carbide slag and coal gangue in a weight ratio of 1:1, the retarder is desulfurized gypsum, and the soil enhancer is a mixture of slag and steel slag in a weight ratio of 2:1.

[0022] A preparation method of a multi-waste residue cementing material, comprising the following steps: S1, the alkaline activator, the retarder, and the soil enhancer are dehydrated, dried, crushed, ground, and sieved, and then mixed uniformly according to a predetermined proportion as raw materials; S2, the raw materials are placed into a stirrer and stirred at a low speed of 150r / min for 1min to obtain a preliminary mixture; S3, the stirrer is kept at a low speed of 150r / min for 3min, and water is added twice, each time adding half of it, to obtain a preliminary mixed slurry; S4, the stirring speed of the stirrer is increased to a high speed of 260r / min, and stirring is performed for 5min to obtain a slurry with good mixing uniformity and fluidity; S5, pour into any mold, put into standard curing room curing 24h, control temperature 20±2℃, humidity≥95%, so that the raw materials fully occur hydration reaction.

[0023] Comparative Example 1 The comparative example uses 32.5 grade cement, according to the ratio of cement: ISO standard sand: water = 1:3:0.5, to make unconfined compressive strength test block for testing.

[0024] Comparative Example 2 The difference between the comparative example and example 2 is that the components are different, specifically including the following components: 20 parts of alkaline activator, 80 parts of soil body enhancer, and 20 parts of water. The rest of the components and preparation steps are the same as example 2.

[0025] Comparative Example 3 The difference between the comparative example and example 2 is that the weight of the components is different, specifically including the following components: 20 parts of alkaline activator, 12 parts of retarder, 68 parts of soil body enhancer, and 20 parts of water. The rest of the components and preparation steps are the same as example 2.

[0026] Comparative Example 4 The difference between the comparative example and example 3 is that the components are different, specifically using quicklime instead of carbide slag as alkaline activator, and the rest of the components and preparation steps are the same as example 3.

[0027] The materials prepared in the above examples and comparative examples were tested for compressive strength, and the test results are shown in Table 1 below: Table 1 is the mortar compressive strength of the multi-waste residue cementitious material in examples 1-5 and comparative examples 1-3 The results of Table 1 show that: The multi-waste residue cementing material has the characteristics of high early strength and the 28d mortar compressive strength is equivalent to that of the cement with the strength grade of 32.5. The compressive strength of comparative example 2 relative to example 2 is reduced by 29% at 7d and 28d, which shows that the retarder is important in the application and can effectively improve the compressive strength of the cementing material while delaying the setting time. The compressive strength of comparative example 3 relative to example 2 is reduced by 14% at 7d and 21% at 28d, which shows that the weight of the components in the application is optimal. The compressive strength of comparative example 4 relative to example 3 is reduced by 26% at 7d and 24% at 28d, which shows that the selected components in the application are optimal. It can be seen that the multi-waste residue cementing material can meet the compressive strength requirement of the cementing material under the condition of full solid waste ratio and without using additional chemical additives.

Claims

1. A multi-element waste residue cementitious material, characterized by, The component raw materials include the following components by weight: 5-20 parts of an alkaline activator, 3-9 parts of a retarder, 71-92 parts of a soil body reinforcing agent, and 20-30 parts of water.

2. The multi- waste aggregate cementitious material of claim 1, wherein, The alkaline activator is selected from any one or several of red mud, carbide slag, and coal gangue.

3. The multi- waste aggregate cementitious material of claim 1, wherein: The retarder is desulfurized gypsum.

4. The multi- waste aggregate cementitious material of claim 1, wherein: The soil body reinforcing agent is selected from any one or several of slag and steel slag.

5. The method of producing a multiplexed waste cementitious material according to any one of claims 1 to 4, characterized in that: The method includes the following steps: S1. Dehydrate, dry, crush, grind, and sieve the alkaline activator, the retarder, and the soil body reinforcing agent, and uniformly mix them according to a proportion to obtain a raw material; S2. Put the raw material into a stirrer and stir at a low speed of 120-150 r / min for 1-2 min to obtain a preliminary mixture; S3. Keep stirring at the low speed of 120-150 r / min for 3-4 min, and add water twice, each time adding half of the water, to obtain a preliminary mixed slurry; S4. Increase the stirring speed to a high speed of 260-300 r / min, and stir for 4-5 min to obtain a slurry that is uniformly mixed and has good fluidity; S5. Pour the slurry into any mold, and place it in a standard curing chamber for curing for 12-24 h, with a temperature of 20±2 ℃ and a humidity of ≥95%, so that the raw material fully undergoes a hydration reaction.

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