A fast-setting early-strength inorganic material, a preparation method and application thereof

Abstract

The application provides a fast-setting early-strength inorganic material and a preparation method and application thereof. The inorganic material mainly comprises the following raw material components in parts by weight: 10-60 parts by weight of aluminate cement, 15-50 parts by weight of high calcium mineral, 15-40 parts by weight of gasification slag, 10-35 parts by weight of bauxite slag, 0.06-0.5 parts by weight of retarder; wherein the content of free calcium oxide in the high calcium mineral is 2-40%, the retarder is an organic acid containing carboxylate, and the weight ratio of the aluminate cement to the high calcium mineral is 1:(0.5-4). The preparation method comprises the following steps: mixing the aluminate cement, the high calcium mineral, the gasification slag, the bauxite slag, the retarder and a plasticizer to obtain a solid masterbatch; mixing the solid masterbatch with water, with a liquid-solid ratio of 0.1-0.8, and stirring uniformly to prepare the fast-setting early-strength inorganic material. By controlling the adding proportion of the high calcium mineral, the aluminate cement and the retarder, the setting time of the cementing material is shortened, and the early strength is high.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mining engineering, in particular to a fast-setting early-strength inorganic material and a preparation method and application thereof. BACKGROUND

[0002] With the increase of coal mining amount and mining range, the goaf and underground cavity pose a great threat to the safety production of surface buildings and bridges and roads. At present, the measures adopted in China are to grout and reinforce the goaf and underground cavity, and the grouting mostly uses Portland cement as raw material to prepare cement slurry by adding water, and then the cement slurry is used for grouting and filling reinforcement, but the cost of cement grouting is high.

[0003] At present, the commonly used cementing material is mainly Portland cement, but due to the long setting time of Portland cement, which is usually 7-8 hours for initial setting, and the low 1d strength, the filling mining efficiency is low, which cannot meet the requirements of coal mining and filling simultaneously. SUMMARY

[0004] In order to overcome the deficiencies in the prior art, the present application controls the proportion of high-calcium minerals and aluminate cement, and compounding an additive containing carboxylate, which effectively improves the early strength and controls the setting time of the inorganic material.

[0005] In order to achieve the purpose of the present application, the following technical solutions are adopted:

[0006] The present application provides a fast-setting early-strength inorganic material in the first aspect, which mainly comprises the following raw material components by weight:

[0007]

[0008] The content of free calcium oxide in the high-calcium mineral is 2% to 40%, the retarder is an organic acid containing carboxylate, and the weight ratio of the aluminate cement to the high-calcium mineral is 1:(0.5-4).

[0009] At present, the addition of a retarder in a conventional cement-based material can prolong the setting time, but the early strength of the material will be greatly reduced, and the present inventors have found that the addition of a retarder containing carboxylate under the synergistic action of aluminate cement and high-calcium minerals can adjust the setting time of the material and further improve the early strength.

[0010] The high calcium mineral in the present application refers to a mineral with a high content of free calcium oxide. Although the content of calcium oxide in the fly ash of a pulverized coal furnace is more than 5% or even more than 10%, it cannot achieve the synergistic effect with the aluminate cement. The reason is that the calcium oxide in the fly ash of the pulverized coal furnace is mainly inert calcium oxide, and the content of free calcium oxide is only 0.15%. However, the calcium oxide in the fly ash of the circulating fluidized bed mainly exists in the form of free calcium oxide (more than 2%), which can achieve the above-mentioned ternary synergistic effect with the aluminate cement in the raw material and the carboxylate-containing retarder, so as to adjust the setting time of the material and further improve the early strength. In some specific embodiments, the high calcium mineral used in the present application is selected from one or more of tourmaline slag, fly ash, gypsum or limestone; wherein the fly ash is selected from the fly ash of the circulating fluidized bed with a high content of free calcium oxide.

[0011] In the present application, the gasification slag refers to the waste slag generated in the production process of a gasification furnace. As known by those skilled in the art, the gasification slag can be further divided into a gasification fine slag which is washed out of the gasification process with the synthesis gas into a scrubbing tower and a gasification coarse slag which is discharged from the bottom of the gasification furnace and formed after cooling. In the present application, the gasification fine slag and the gasification coarse slag can both be used as the gasification slag without distinction. The bauxite slag refers to a large amount of slag generated in the mining process of bauxite, which can be used in the present application after crushing and screening. The aluminate cement can be obtained from the market, for example, the aluminate cement with the brand CA50 produced by Zhengzhou Jianai in Henan.

[0012] In some preferred technical solutions, the inorganic material mainly comprises the following raw material components by weight:

[0013]

[0014]

[0015] In some specific embodiments, the content of free calcium oxide in the high calcium mineral is 5% to 20%, such as 10%, 12%, 15% or 18%.

[0016] In some specific embodiments, the inorganic material in the present application further comprises 0.02 to 2 parts by weight of a plasticizer, and the plasticizer is selected from hydroxypropyl methyl cellulose and / or latex powder.

[0017] In some specific embodiments, the retarder in the present application is selected from tartaric acid, citric acid or salicylic acid.

[0018] In some specific embodiments of the inorganic material provided in the present application, the raw material components of the inorganic material are composed of the aluminate cement, the high calcium mineral, the gasification slag, the bauxite slag, the retarder and the plasticizer.

[0019] The present application provides, in a second aspect, a preparation method of the inorganic material with fast setting and early strength, the preparation method comprising:

[0020] mixing aluminate cement, high calcium mineral, gasification slag, bauxite slag, setting retarder and plasticizer to obtain a solid masterbatch;

[0021] mixing the solid masterbatch with water, the liquid-solid ratio of the water to the solid masterbatch being 0.1-0.8, and stirring uniformly to prepare the inorganic material with fast setting and early strength.

[0022] The present application provides, in a third aspect, an application of the inorganic material with fast setting and early strength or the inorganic material prepared by the preparation method, for example, the inorganic material is used as 3D printing, mine sealing wall material, guniting or floor material.

[0023] In some specific application modes, the initial setting time of the inorganic material is ≤60 min, and the final setting time is ≤120 min.

[0024] In some specific application modes, the 2h compressive strength of the inorganic material is ≥6 MPa, and the 28d compressive strength is >25 MPa; in some preferred embodiments, the 2h compressive strength of the inorganic material is ≥10 MPa, and the 28d compressive strength is >30 MPa.

[0025] The technical scheme has the following technical effects:

[0026] The inorganic material provided by the present application can exhibit excellent fast setting and early strength and the like through the synergistic effect of the aluminate cement, the high calcium mineral containing a high content of free calcium oxide and the additive containing carboxylate, without adding early strength agent; and the addition of the plasticizer can ensure continuous extrusion of the embryo, so that the material has constructability and extrudability. DETAILED DESCRIPTION

[0027] In order to better understand the technical scheme of the present application, the content of the present application will be further described below in combination with examples, but the content of the present application is not limited to the following examples only.

[0028] The raw materials used in the following examples and comparative examples of the present application are as follows:

[0029] Aluminate cement: aluminate cement with a brand of CA50;

[0030] High calcium mineral: high calcium fly ash, in which the content of free calcium oxide is as high as 2% or more;

[0031] Gasification slag: gasification slag produced in the production process of the gasification furnace of Yuanyanghu power plant;

[0032] Bauxite residue: the residue produced in the process of bauxite mining, which is crushed and sieved to a particle size of less than or equal to 4.75 mm;

[0033] Retarder: tartaric acid, L + Model;

[0034] Plasticizer: hydroxypropyl methylcellulose (HPMC) with a molecular weight of 10,000.

[0035] The test methods used in the following examples and comparative examples of the present application are as follows:

[0036] (1) Initial setting time: tested according to GBT 50080-2016 “Standard Test Methods for Properties of Fresh Ordinary Concrete”;

[0037] (2) Final setting time: tested according to GBT 50080-2016 “Standard Test Methods for Properties of Fresh Ordinary Concrete”;

[0038] (3) 2h and 28d compressive strength: tested according to GBT 50081-2019 “Standard Test Methods for Physical and Mechanical Properties of Concrete”;

[0039] (4) Detection method of free calcium oxide in high-calcium mineral: tested according to GB / T 176-2017 “Methods of Chemical Analysis of Cement”.

[0040] Example 1

[0041] (1) 10 parts by weight of aluminate cement, 40 parts by weight of high-calcium mineral (free calcium oxide content of 5%), 30 parts by weight of gasification slag, 20 parts by weight of bauxite residue, 0.2 parts by weight of tartaric acid, and 0.5 parts by weight of plasticizer were mixed to obtain a solid masterbatch;

[0042] (2) The above solid masterbatch was mixed with water at a liquid-solid ratio of 0.5 to obtain a fast-setting and early-strength inorganic material.

[0043] Example 2

[0044] (1) 60 parts by weight of aluminate cement, 50 parts by weight of high-calcium mineral (free calcium oxide content of 12%), 15 parts by weight of gasification slag, 10 parts by weight of bauxite residue, 0.5 parts by weight of tartaric acid, and 2 parts by weight of plasticizer were mixed to obtain a solid masterbatch;

[0045] (2) The above solid masterbatch was mixed with water at a liquid-solid ratio of 0.5 to obtain a fast-setting and early-strength inorganic material.

[0046] Example 3

[0047] (1) 20 parts by weight of aluminate cement, 30 parts by weight of high calcium mineral (free calcium oxide content of 20%), 30 parts by weight of fumed slag, 20 parts by weight of bauxite slag, 0.2 parts by weight of tartaric acid, and 0.5 parts by weight of plasticizer are mixed to obtain a solid masterbatch;

[0048] (2) The solid masterbatch is mixed with water at a liquid-to-solid ratio of 0.5, and stirred evenly to form a fast-setting and early-strength inorganic material.

[0049] Example 4

[0050] (1) 10 parts by weight of aluminate cement, 50 parts by weight of high calcium mineral (free calcium oxide content of 30%), 40 parts by weight of fumed slag, 10 parts by weight of bauxite slag, 0.2 parts by weight of tartaric acid, and 1 part by weight of plasticizer are mixed to obtain a solid masterbatch;

[0051] (2) The solid masterbatch is mixed with water at a liquid-to-solid ratio of 0.5, and stirred evenly to form a fast-setting and early-strength inorganic material.

[0052] Example 5

[0053] (1) 40 parts by weight of aluminate cement, 20 parts by weight of high calcium mineral (free calcium oxide content of 10%), 20 parts by weight of fumed slag, 30 parts by weight of bauxite slag, 0.2 parts by weight of tartaric acid, and 0.5 parts by weight of plasticizer are mixed to obtain a solid masterbatch;

[0054] (2) The solid masterbatch is mixed with water at a liquid-to-solid ratio of 0.5, and stirred evenly to form a fast-setting and early-strength inorganic material.

[0055] Example 6

[0056] (1) 20 parts by weight of aluminate cement, 40 parts by weight of high calcium mineral (free calcium oxide content of 40%), 30 parts by weight of fumed slag, 10 parts by weight of bauxite slag, 0.2 parts by weight of tartaric acid, and 1 part by weight of plasticizer are mixed to obtain a solid masterbatch;

[0057] (2) The solid masterbatch is mixed with water at a liquid-to-solid ratio of 0.5, and stirred evenly to form a fast-setting and early-strength inorganic material.

[0058] Comparative Example 1

[0059] (1) 10 parts by weight of aluminate cement, 60 parts by weight of high calcium mineral (free calcium oxide content of 12%), 20 parts by weight of fumed slag, 10 parts by weight of bauxite slag, 0.28 parts by weight of tartaric acid, and 0.5 parts by weight of plasticizer are mixed to obtain a solid masterbatch;

[0060] (2) The above solid material is mixed with water in a liquid-solid ratio of 0.5 between water and the solid material, and stirred uniformly to produce the inorganic material of fast-setting and early-strength type.

[0061] Comparative Example 2

[0062] (1) 20 parts by weight of aluminate cement, 5 parts by weight of high calcium mineral (free calcium oxide content of 12%), 50 parts by weight of gasification slag, 25 parts by weight of bauxite slag, 0.12 part by weight of tartaric acid, and 1 part by weight of plasticizer are mixed to obtain a solid material;

[0063] (2) The above solid material is mixed with water in a liquid-solid ratio of 0.5 between water and the solid material, and stirred uniformly to produce the inorganic material of fast-setting and early-strength type.

[0064] Comparative Example 3

[0065] (1) 20 parts by weight of aluminate cement, 30 parts by weight of high calcium mineral (free calcium oxide content of 0.15%), 30 parts by weight of gasification slag, 20 parts by weight of bauxite slag, 0.2 part by weight of boric acid, and 0.5 part by weight of plasticizer are mixed to obtain a solid material;

[0066] (2) The above solid material is mixed with water in a liquid-solid ratio of 0.5 between water and the solid material, and stirred uniformly to produce the inorganic material of fast-setting and early-strength type.

[0067] The inorganic material of fast-setting and early-strength type is subjected to performance test, and the test results are shown in Table 1 below:

[0068] Table 1

[0069]

Claims

1. A fast-setting and early-strength inorganic material, characterized in that: The inorganic material mainly includes the following raw material components in parts by weight: The content of free calcium oxide in the high-calcium mineral is 5% to 40%, the retarder is an organic acid containing a carboxylate radical, and the weight ratio of the aluminate cement to the high-calcium mineral is 1:(0.5 to 4).

2. The inorganic material according to claim 1, characterized in that The inorganic material mainly includes the following raw material components in parts by weight:

3. The inorganic material according to claim 1 or 2, characterized in that The content of free calcium oxide in the high-calcium mineral is 5% to 20%.

4. The inorganic material according to claim 3, characterized in that The plasticizer is selected from hydroxypropyl methylcellulose and / or latex powder.

5. The inorganic material according to claim 4, characterized in that The high-calcium mineral is selected from fly ash; wherein, the fly ash is selected from circulating fluidized bed fly ash.

6. The inorganic material according to claim 5, characterized in that The retarder is tartaric acid, citric acid or salicylic acid.

7. A method for preparing the fast-setting and early-strength inorganic material according to any one of claims 1 to 6, characterized in that: The preparation method comprises: Aluminate cement, high calcium mineral, fumed slag, bauxite slag, retarder and plasticizer are mixed to obtain a solid masterbatch; The solid masterbatch is mixed with water, wherein the liquid-to-solid ratio of the water to the solid masterbatch is 0.1 to 0.8, and stirred evenly to prepare a fast-setting and early-strength inorganic material.

8. Use of the fast-setting, early-strength inorganic material according to any one of claims 1 to 6 or the fast-setting, early-strength inorganic material prepared by the preparation method according to claim 7.

9. The use according to claim 8, characterized in that The inorganic material is used as 3D printing, mine sealing wall material, spraying or floor material.

10. The use according to claim 8, characterized in that During the application of the inorganic material, the initial setting time of the inorganic material is ≤60 min, and the final setting time is ≤120 min.

11. The use according to any one of claims 8 to 10, characterized in that: The 2h compressive strength of the inorganic material is ≥6MPa, and the 28d compressive strength of the inorganic material is >25MPa.

12. The use according to claim 11, characterized in that The inorganic material has a 2h compressive strength of ≥10MPa and a 28d compressive strength of >30MPa.

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