A low-carbon cementitious material and its preparation method and application

Abstract

The present invention provides a low-carbon cementitious material and a preparation method and application thereof, belonging to the technical field of cementitious materials. The low-carbon cementitious material comprises the following raw materials in parts by weight: 60-90 parts of limestone, 5-20 parts of perlite, 0.1-1 parts of diaspore and 5-30 parts of attapulgite. The low-carbon cementitious material provided by the present invention can be used to replace cement, and has a negative carbon emission value, which is more environmentally friendly.

Description

Technical Field

[0001] The invention belongs to the technical field of cementitious materials, and in particular relates to a low-carbon cementitious material and a preparation method and application thereof. Background Art

[0002] As a basic raw material industry, the cement industry plays an important role in the development of the global economy, but it also produces huge carbon dioxide emissions. According to research, every ton of cement produced is equivalent to 819 kilograms of carbon dioxide emissions. Therefore, the development and application of low-carbon materials has become urgent. Summary of the invention

[0003] The present invention provides a low-carbon cementitious material and a preparation method and application thereof. The low-carbon cementitious material provided by the present invention can replace cement, has a negative carbon emission, and is more environmentally friendly.

[0004] The invention provides a low-carbon cementitious material, comprising the following raw materials in parts by weight: 60-90 parts of limestone, 5-20 parts of perlite, 0.1-1 parts of diaspore and 5-30 parts of attapulgite.

[0005] Preferably, the calcium oxide content in the limestone is greater than 30% by weight.

[0006] Preferably, the particle size of the limestone, perlite and diaspore is less than 100 mm.

[0007] Preferably, by weight percentage, the calcium oxide content in the low-carbon cementitious material is 45% to 65%, the silicon dioxide content is 10% to 30%, the aluminum oxide content is 1% to 20%, the iron oxide content is 3% to 10%, and the trace element content is 0.1% to 3%.

[0008] Preferably, the mortar strength of the low-carbon cementitious material after being cured for 28 days is greater than 17 MPa; the mortar strength after being cured for 60 days is greater than 20 MPa.

[0009] The present invention provides a method for preparing any one of the above-mentioned low-carbon cementitious materials, comprising the following steps:

[0010] 1) mixing limestone, perlite, diaspore and attapulgite to obtain a mixture;

[0011] 2) subjecting the obtained mixture to oxygen calcination to obtain a calcined product;

[0012] 3) Add water to the obtained calcined product for digestion and differentiation, dry and grind to obtain a low-carbon gelling material. The plate is cured and trimmed to obtain a low-carbon gelling material.

[0013] Preferably, in step 2), the temperature of aerobic calcination is 900-1100° C. and the time is 6-12 hours.

[0014] Preferably, in step 3), the temperature during digestion and differentiation is 100-300°C.

[0015] Preferably, in the step 3), the mesh size achieved after grinding is 400-1200 meshes.

[0016] The present invention provides an application of the low-carbon cementitious material described in the above scheme as cement in construction.

[0017] Compared with the prior art, the advantages and positive effects of the present invention are:

[0018] The main raw material of the low-carbon cementitious material provided by the present invention is limestone. By adding perlite, diaspore and attapulgite to adjust the ratio of calcium oxide to silicon oxide and control the content of aluminum oxide, the bonding strength of the obtained cementitious material can be equivalent to that of cement, and it can replace cement and be applied in the fields of civil engineering, transportation and other infrastructure. In addition, the carbon emission of the entire cementitious material during the preparation process is less than the carbon absorption during the curing process, which is a negative value as a whole, which can achieve the purpose of carbon reduction and is more environmentally friendly. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] The invention provides a low-carbon cementitious material, comprising the following raw materials in parts by weight: 60-90 parts of limestone, 5-20 parts of perlite, 0.1-1 parts of diaspore and 5-30 parts of attapulgite.

[0021] The low-carbon cementitious material provided by the present invention includes raw material limestone, which includes 60-90 parts by weight, preferably 70-80 parts. In the present invention, the content of calcium oxide in the limestone is preferably greater than 30% by weight, and more preferably 35% to 50%. In the present invention, by using limestone with a calcium oxide content greater than 30%, lean ore can be used as a raw material to prepare low-carbon cementitious material without purification, thereby reducing costs. In the present invention, the particle size of the limestone is preferably less than 100 mm, and more preferably 50 mm.

[0022] The low-carbon cementitious material provided by the present invention includes raw material perlite, which includes 5-20 parts by weight, preferably 10-15 parts. In the present invention, the perlite is used as a raw material, mainly as one of the sources of silicon oxide and iron oxide, and the raw material price is low. In the present invention, the particle size of the perlite is preferably less than 100 mm, more preferably 50 mm.

[0023] The low-carbon cementitious material provided by the present invention comprises raw material diaspore, which comprises 0.1-1 parts by weight, preferably 0.5-0.8 parts by weight. In the present invention, the diaspore is used as the main source of alumina. In the present invention, the particle size of the diaspore is preferably less than 100 mm, more preferably 50 mm.

[0024] The low-carbon gelling material provided by the present invention comprises attapulgite as a raw material, which comprises 5-30 parts by weight, preferably 1-20 parts by weight. In the present invention, the attapulgite is used as the main source of magnesium oxide, and the raw material price is low.

[0025] The present invention has no special limitation on the sources of the limestone, perlite, diaspore and attapulgite, and conventional commercial products in the art may be used.

[0026] The low-carbon cementitious material in the present invention refers to a material that has lower carbon emissions during the entire production process compared to traditional cement-based cementitious materials.

[0027] In the present invention, the main raw material of the low-carbon cementitious material provided by the present invention is limestone. By adding perlite, diaspore and attapulgite to adjust the ratio of calcium oxide to silicon oxide and control the content of aluminum oxide, the bonding strength of the obtained cementitious material can be equivalent to that of cement, and it can replace cement and be applied in the fields of civil engineering, transportation and other infrastructure. Lean ore limestone with a calcium oxide content greater than 30% and not higher than 50% is used as a raw material, and carbon emission is reduced in the raw material step. Perlite, diaspore and attapulgite, which are easily available raw materials, are used as iron sources, aluminum sources and magnesium sources respectively. Compared with the production of traditional cement-based cementitious materials, the carbon emission of producing 1 ton of low-carbon cementitious materials is at least about 500 kg, while the carbon emission of producing 1 ton of cement is at least 800 kg.

[0028] The present invention provides a method for preparing any one of the above-mentioned low-carbon cementitious materials, comprising the following steps:

[0029] 1) mixing limestone, perlite, diaspore and attapulgite to obtain a mixture;

[0030] 2) subjecting the obtained mixture to oxygen calcination to obtain a calcined product;

[0031] 3) Add water to the obtained calcined product for digestion and differentiation, dry and grind to obtain a low-carbon gelling material. The plate is cured and trimmed to obtain a low-carbon gelling material.

[0032] The present invention mixes limestone, perlite, diaspore and attapulgite to obtain a mixture. In the present invention, the mixing method is preferably stirring, and the stirring time is preferably 10-30 minutes.

[0033] After obtaining the mixture, the present invention performs aerobic calcination on the obtained mixture to obtain a calcined product. In the present invention, the temperature of the aerobic calcination is preferably 900-1100°C, more preferably 950-1050°C; the time of the aerobic calcination is preferably 6-12h, more preferably 8-10h.

[0034] After obtaining the calcined material, the present invention adds water to the obtained calcined material for digestion and differentiation, and dry and grind to obtain a low-carbon cementitious material. The plate is cured and trimmed to obtain a low-carbon cementitious material. In the present invention, the amount of water added is preferably 25-40 parts. In the present invention, the temperature during the digestion and differentiation is preferably 100-300°C, more preferably 150-250°C. In the present invention, the drying is preferably carried out at room temperature. The mesh number achieved after the grinding is preferably 400-1200 mesh.

[0035] In the present invention, the prepared low-carbon cementitious material has a calcium oxide content of 45% to 65%, a silicon dioxide content of 10% to 30%, an aluminum oxide content of 1% to 20%, a iron oxide content of 3% to 10%, and a trace element content of 0.1% to 3% by weight.

[0036] The present invention provides an application of the low-carbon cementitious material described in the above scheme as cement in construction.

[0037] In order to further illustrate the present invention, the technical solutions provided by the present invention are described in detail below in conjunction with embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0038] Example 1

[0039] The raw material components are: 60 parts of limestone (calcium oxide content 30%), 20 parts of perlite, 0.1 parts of diaspore, 25 parts of attapulgite

[0040] The preparation method is:

[0041] Limestone, perlite and diaspore were crushed to a particle size of less than 80 mm, then attapulgite was added and mixed for 20 minutes, and aerobically calcined at 1000°C for 6 hours in a container. When the temperature dropped to 120°C, 25 parts of water were added to vaporize and powderize the calcined material, and then dried and ground at room temperature for 1 hour to obtain a 600-mesh cementitious material.

[0042] Example 2

[0043] The raw material components are: 70 parts of limestone (calcium oxide content 40%), 10 parts of perlite, 0.2 parts of diaspore, 20 parts of attapulgite

[0044] The preparation method is:

[0045] Limestone, perlite and diaspore were crushed to a particle size of less than 60 mm, then attapulgite was added and mixed for 15 minutes, and aerobically calcined at 900°C for 6 hours in a container. When the temperature dropped to 150°C, 30 parts of water were added to vaporize and atomize the calcined material into powder, and then dried and ground at room temperature for 2 hours to obtain a 1000-mesh cementitious material.

[0046] Example 3

[0047] The raw material components are: 80 parts of limestone (calcium oxide content 50%), 5 parts of perlite, 0.5 parts of diaspore, 15 parts of attapulgite

[0048] The preparation method is:

[0049] Limestone, perlite and diaspore were crushed to a particle size of less than 60 mm, then added with attapulgite and mixed for 20 minutes, calcined in a container at 950°C for 6 hours, and when the temperature dropped to 150°C, 35 parts of water were added to vaporize and atomize the calcined material into powder, and then dried and ground at room temperature for 1 hour to obtain a cementitious material with a mesh size of 800.

[0050] Example 4

[0051] The raw material components are: 90 parts of limestone (calcium oxide content 60%), 5 parts of perlite, 1 part of diaspore, 5 parts of attapulgite

[0052] The preparation method is:

[0053] Limestone, perlite and diaspore were crushed to a particle size of less than 50 mm, then added with attapulgite and mixed for 15 minutes, calcined in a container at 950°C for 6 hours, and when the temperature dropped to 130°C, 40 parts of water were added to vaporize and powderize the calcined material, and then dried and ground at room temperature for 4 hours to obtain a 1200 mesh cementitious material.

[0054] Comparative Example 1

[0055] Except that the amount of perlite is 2 parts, the others are exactly the same as in Example 1.

[0056] Comparative Example 2

[0057] Except that the amount of limestone is 30 parts, the other steps are exactly the same as those in Example 1.

[0058] Performance Testing

[0059] The properties of the gelling materials prepared in Examples 1 to 4 and Comparative Examples 1 to 2 were measured, and the specific results are shown in Table 1:

[0060] Table 1 Performance parameters of cementitious materials

[0061]

[0062] It can be seen from Table 1 that the cementitious material mortar prepared by the present invention has good strength, can be used instead of cement, and is more environmentally friendly.

[0063] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A low-carbon cementitious material, characterized in that: The invention is prepared from the following raw materials in parts by weight: 60-90 parts of limestone, 5-20 parts of perlite, 0.1-1 parts of diaspore and 5-30 parts of attapulgite; The low-carbon cementitious material has a calcium oxide content of 45% to 65%, a silicon dioxide content of 10% to 30%, an aluminum oxide content of 1% to 20%, an iron oxide content of 3% to 10%, and a trace element content of 0.1% to 3%.

2. The low-carbon cementitious material according to claim 1, characterized in that: Measured by weight percentage, the content of calcium oxide in the limestone is greater than 30%.

3. The low-carbon cementitious material according to claim 1, characterized in that: The particle sizes of the limestone, perlite and diaspore are less than 100 mm.

4. The low-carbon cementitious material according to claim 1, characterized in that: The mortar strength of the low-carbon cementitious material after curing for 28 days is greater than 17 MPa; the mortar strength after curing for 60 days is greater than 20 MPa.

5. The method for preparing the low-carbon cementitious material according to any one of claims 1 to 4, characterized in that: The steps include: 1) mixing limestone, perlite, diaspore and attapulgite to obtain a mixture; 2) subjecting the obtained mixture to oxygen calcination to obtain a calcined product; 3) adding water to the obtained calcined product for digestion and differentiation, drying and grinding to obtain a low-carbon gelling material.

6. The preparation method according to claim 5, characterized in that: In the step 2), the temperature of aerobic calcination is 900-1100° C. and the time is 6-12 hours.

7. The preparation method according to claim 5, characterized in that: In the step 3), the temperature during digestion and differentiation is 100-300° C., and the mesh size achieved after grinding is 400-1200 mesh.

8. Use of the low-carbon cementitious material according to any one of claims 1 to 4 as cement in construction.

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