Clinker-free slag cement and preparation method thereof

Abstract

The invention belongs to the technical field of preparation of building materials, and particularly relates to clinker-free slag cement and a preparation method thereof. The clinker-free slag cement is prepared from the following raw materials in parts by weight: 8-15 parts of industrial solid waste fluorgypsum; 1-3 parts of sodium hydroxide; 10 to 20 parts of fly ash; 5 to 20 parts of lithium slag powder; 10 to 20 parts of slag; 45 to 65 parts of mineral powder; 0.5 to 2 parts of quick lime; and 1-2 parts of sodium silicate. According to the cement disclosed by the invention, by limiting the ratio of the raw materials and matching the components with one another, the prepared cement meets the technical requirements of P.S.A42.5-grade cement.

Description

Technical Field

[0001] The present invention belongs to the technical field of the preparation of building materials, and particularly relates to clinker-free slag cement and a preparation method thereof. Background Art

[0002] Clinker-free slag cement is a new type of cement variety. Its emergence is mainly to solve the problems of high energy consumption and high pollution in the traditional cement production process. In the traditional cement production process, raw materials such as limestone and clay need to be calcined at high temperature to produce clinker, and then gypsum, slag and other raw materials are added for grinding and processing to finally obtain cement. This production method requires a large amount of energy and resources, and at the same time, it will also generate a large amount of waste gas, waste water and waste residue, causing great pollution to the environment. In addition, a large amount of raw materials such as limestone and clay are required in the traditional cement production process, and the mining of these resources will also have a certain impact on the environment.

[0003] To solve these problems, people began to study the production method of clinker-free cement. Clinker-free slag cement is a new type of cement variety produced from raw materials such as lime, gypsum and slag. Its production process does not require high-temperature calcination, so it does not consume a large amount of energy and resources, and at the same time, it will not generate a large amount of waste gas, waste water and waste residue, and has good environmental protection performance. In addition, the raw materials used in the production process of clinker-free slag cement can also be industrial waste residues, waste gases and other wastes, which can effectively utilize waste resources and further reduce the impact on the environment.

[0004] Patent application CN102557496A, with a publication date of July 1, 2012, discloses a clinker-free slag cement manufactured mainly from industrial slag. This cement can meet the performance indicators of slag Portland cement PS32.5, and is composed of slag, gypsum, limestone, slaked lime, water glass and alum. In the clinker-free slag cement of the present invention, the alkaline activator is composed of water glass, slaked lime and alum. This alkaline activator can effectively activate the gelling activity of slag, release Ca 2+ , generate more C-S-H gels and AFt crystals, and a large number of hydration products are intertwined, thereby reducing the porosity of the cement stone and decreasing the pore size. However, it needs to additionally add water glass, slaked lime and alum as alkaline activators, which undoubtedly greatly increases the production cost and is not conducive to industrial production. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the above-mentioned defects existing in the prior art, and provide a clinker-free slag cement. By limiting the raw material ratio and the mutual cooperation between components, the prepared cement meets the technical requirements of P.S.A42.5 grade cement.

[0006] Another object of the present invention is to provide a method for preparing clinker-free slag cement, which is simple to prepare, does not require high-temperature roasting, and is conducive to industrial production.

[0007] The technical solution adopted by the present invention is as follows:

[0008] The clinker-free slag cement described above is composed of the following raw materials in parts by weight: industrial solid waste fluorogypsum: 8-15 parts; sodium hydroxide: 1-3 parts; fly ash: 10-20 parts; lithium slag powder: 5-20 parts; slag: 10-20 parts; mineral powder: 45-65 parts; quicklime: 0.5-2 parts; sodium silicate: 1-2 parts.

[0009] The weight percentage content of calcium sulfate in the industrial solid waste fluorogypsum is 82%-87%.

[0010] The weight percentage content of free calcium oxide in the quicklime is 25%-30%.

[0011] The fly ash described above is composed of the following raw materials in parts by weight: SiO 2 : 40-60 parts; Al 2 O 3 : 20-30 parts; Fe 2 O 3 : 1-5 parts; CaO: 10-15 parts.

[0012] The lithium slag powder described above is composed of the following raw materials in parts by weight: SiO 2 : 21-25 parts; Al2O3: 60-65 parts; CaO: 5-10 parts; SO 3 : 3-5 parts; Li2O: 0.5-3 parts.

[0013] The slag described above is composed of the following raw materials in parts by weight: CaO: 35-42 parts; SiO2: 32-48 parts; Al2O3: 23-28 parts.

[0014] The specific surface area of the mineral powder is 451m 2 / g, and the fineness is 0.048mm.

[0015] The method for preparing the clinker-free slag cement described above includes the following steps: weighing industrial solid waste fluorogypsum, sodium hydroxide, fly ash, lithium slag powder, slag, mineral powder, quicklime, and sodium silicate according to the mass ratio, then conveying them by belt to the grinding process, and adding a liquid grinding aid, and grinding to a specific surface area of 500m 2 / g to obtain the clinker-free slag cement.

[0016] The liquid grinding aid is triethanolamine, and the addition amount of the liquid grinding aid is 3-5% of the total mass of the raw materials.

[0017] The principle of the present invention is as follows:

[0018] During the use of the clinker - free slag cement, water needs to be added for mixing. The water reacts with free calcium oxide in quicklime, releasing a large amount of OH - , and reacts with sulfate radicals in fluorogypsum to form ettringite. Ettringite is fibrous crystal with relatively high strength, which can fill pores. Lithium oxide in lithium slag reacts with water to produce lithium hydroxide, or reacts with titanium dioxide and water to produce lithium carbonate. Lithium hydroxide and lithium carbonate, together with the hydrate of sodium silicate, jointly regulate the setting and enhance the strength of the whole system. Iron can enhance the tensile strength of concrete, and calcium and potassium can promote the solidification and hardening of concrete materials, making the prepared clinker - free slag cement have the advantages of high early strength, ultra - high late strength, small shrinkage and good carbonation resistance.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] By using the clinker - free slag cement of the present invention, through the interaction of lithium slag powder, quicklime and sodium silicate, the prepared clinker - free slag cement has the advantages of high early strength, ultra - high late strength, small shrinkage and good carbonation resistance, meeting the technical requirements of P.S.A42.5 grade cement. Specific Embodiments

[0021] The present invention will be further described below in conjunction with specific embodiments.

[0022] The specific surface area of the slag powder used below is 451 m 2 / g, and the fineness is 0.048 mm.

[0023] Example 1

[0024] The clinker - free slag cement described above is composed of raw materials in the following weight parts: industrial solid waste fluorogypsum: 12 parts; sodium hydroxide: 2 parts; fly ash: 15 parts; lithium slag powder: 12 parts; slag: 15 parts; slag powder: 55 parts; quicklime: 1 part; sodium silicate: 1 part.

[0025] The weight percentage of calcium sulfate in the industrial solid waste fluorogypsum is 85%.

[0026] The weight percentage of free calcium oxide in the quicklime is 28%.

[0027] The fly ash is composed of raw materials in the following weight parts: SiO 2 : 50 parts; Al 2 O 3 : 25 parts; Fe 2 O 3 : 3 parts; CaO: 12 parts.

[0028] The described lithium slag powder is composed of the following raw materials in parts by weight: SiO 2 : 13 parts; Al2O3: 63 parts; CaO: 8 parts; SO 3 : 4 parts; Li2O: 2 parts.

[0029] The described slag is composed of the following raw materials in parts by weight: CaO: 38 parts; SiO2: 40 parts; Al2O3: 25 parts.

[0030] The above raw materials are conveyed by belt to the grinding process, and 4% of triethanolamine based on the total mass of the raw materials is added, and ground to a specific surface area of 500 m 2 / g to obtain clinker-free slag cement.

[0031] Example 2

[0032] The described clinker-free slag cement is composed of the following raw materials in parts by weight: industrial solid waste fluorogypsum: 8 parts; sodium hydroxide: 1 part; fly ash: 10 parts; lithium slag powder: 5 parts; slag: 10 parts; mineral powder: 45 parts; quicklime: 0.5 part; sodium silicate: 1 part.

[0033] The weight percentage of calcium sulfate in the described industrial solid waste fluorogypsum is 82%.

[0034] The weight percentage of free calcium oxide in the described quicklime is 25%.

[0035] The described fly ash is composed of the following raw materials in parts by weight: SiO 2 : 40 parts; Al 2 O 3 : 20 parts; Fe 2 O 3 : 1 part; CaO: 10 parts.

[0036] The described lithium slag powder is composed of the following raw materials in parts by weight: SiO 2 : 21 parts; Al2O3: 60 parts; CaO: 5 parts; SO 3 : 3 parts; Li2O: 0.5 part.

[0037] The described slag is composed of the following raw materials in parts by weight: CaO: 35 parts; SiO2: 32 parts; Al2O3: 23 parts.

[0038] The above raw materials are conveyed by belt to the grinding process, and 3% of triethanolamine based on the total mass of the raw materials is added, and ground to a specific surface area of 500 m 2 / g to obtain clinker-free slag cement.

[0039] Example 3

[0040] The described clinker-free slag cement is composed of raw materials in the following weight parts: industrial solid waste fluorogypsum: 15 parts; sodium hydroxide: 3 parts; fly ash: 20 parts; lithium slag powder: 20 parts; slag: 20 parts; mineral powder: 65 parts; quicklime: 2 parts; sodium silicate: 2 parts.

[0041] The weight percentage of calcium sulfate in the described industrial solid waste fluorogypsum is 87%.

[0042] The weight percentage of free calcium oxide in the described quicklime is 30%.

[0043] The fly ash described is composed of raw materials in the following weight parts: SiO 2 : 60 parts; Al 2 O 3 : 30 parts; Fe 2 O 3 : 5 parts; CaO: 15 parts.

[0044] The lithium slag powder described is composed of raw materials in the following weight parts: SiO 2 : 25 parts; Al2O3: 65 parts; CaO: 10 parts; SO 3 : 5 parts; Li2O: 3 parts.

[0045] The slag described is composed of raw materials in the following weight parts: CaO: 42 parts; SiO2: 48 parts; Al2O3: 28 parts.

[0046] The above raw materials are conveyed by belt to the grinding process, and 5% of the total mass of the raw materials of triethanolamine is added, and ground to a specific surface area of 500 m 2 / g to obtain the clinker-free slag cement.

[0047] Example 4

[0048] The described clinker-free slag cement is composed of raw materials in the following weight parts: industrial solid waste fluorogypsum: 10 parts; sodium hydroxide: 1 part; fly ash: 13 parts; lithium slag powder: 8 parts; slag: 12 parts; mineral powder: 50 parts; quicklime: 1 part; sodium silicate: 1 part.

[0049] The weight percentage of calcium sulfate in the described industrial solid waste fluorogypsum is 83%.

[0050] The weight percentage of free calcium oxide in the described quicklime is 26%.

[0051] The fly ash described is composed of raw materials in the following weight parts: SiO 2 : 45 parts; Al 2 O 3 : 23 parts; Fe 2 O 3 : 2 parts; CaO: 12 parts.

[0052] The described lithium slag powder is composed of raw materials in the following parts by weight: SiO 2 : 22 parts; Al2O3: 62 parts; CaO: 6 parts; SO 3 : 3 parts; Li2O: 1 part.

[0053] The described slag is composed of raw materials in the following parts by weight: CaO: 28 parts; SiO2: 38 parts; Al2O3: 24 parts.

[0054] The above raw materials are conveyed by belt to the powder grinding process, and 4% of triethanolamine based on the total mass of the raw materials is added, and the powder is ground to a specific surface area of 500 m 2 / g to obtain clinker-free slag cement.

[0055] Example 5

[0056] The described clinker-free slag cement is composed of raw materials in the following parts by weight: industrial solid waste fluorogypsum: 12 parts; sodium hydroxide: 3 parts; fly ash: 18 parts; lithium slag powder: 18 parts; slag: 18 parts; mineral powder: 60 parts; quicklime: 1.5 parts; sodium silicate: 2 parts.

[0057] The weight percentage of calcium sulfate in the described industrial solid waste fluorogypsum is 86%.

[0058] The weight percentage of free calcium oxide in the described quicklime is 28%.

[0059] The described fly ash is composed of raw materials in the following parts by weight: SiO 2 : 55 parts; Al 2 O 3 : 28 parts; Fe 2 O 3 : 4 parts; CaO: 14 parts.

[0060] The described lithium slag powder is composed of raw materials in the following parts by weight: SiO 2 : 24 parts; Al2O3: 64 parts; CaO: 8 parts; SO 3 : 4 parts; Li2O: 2 parts.

[0061] The described slag is composed of raw materials in the following parts by weight: CaO: 40 parts; SiO2: 45 parts; Al2O3: 26 parts.

[0062] The above raw materials are conveyed by belt to the powder grinding process, and 5% of triethanolamine based on the total mass of the raw materials is added, and the powder is ground to a specific surface area of 500 m 2 / g to obtain clinker-free slag cement.

[0063] Comparative Example 1

[0064] The described clinker-free slag cement is composed of raw materials in the following parts by weight: industrial solid waste fluorogypsum: 12 parts; sodium hydroxide: 2 parts; fly ash: 15 parts; slag: 15 parts; mineral powder: 55 parts; quicklime: 1 part; sodium silicate: 1 part.

[0065] The weight percentage of calcium sulfate in the described industrial solid waste fluorogypsum is 85%.

[0066] The weight percentage of free calcium oxide in the described quicklime is 28%.

[0067] The described fly ash is composed of raw materials in the following parts by weight: SiO 2 : 50 parts; Al 2 O 3 : 25 parts; Fe 2 O 3 : 3 parts; CaO: 12 parts.

[0068] The described slag is composed of raw materials in the following parts by weight: CaO: 38 parts; SiO2: 40 parts; Al2O3: 25 parts.

[0069] The above raw materials are conveyed by belt to the grinding process, and 4% of the total mass of the raw materials of triethanolamine is added, and ground to a specific surface area of 500 m 2 / g to obtain the clinker-free slag cement.

[0070] Comparative Example 2

[0071] The described clinker-free slag cement is composed of raw materials in the following parts by weight: industrial solid waste fluorogypsum: 8 parts; sodium hydroxide: 1 part; fly ash: 10 parts; lithium slag powder: 5 parts; slag: 10 parts; mineral powder: 45 parts; sodium silicate: 1 part.

[0072] The weight percentage of calcium sulfate in the described industrial solid waste fluorogypsum is 82%.

[0073] The described fly ash is composed of raw materials in the following parts by weight: SiO 2 : 40 parts; Al 2 O 3 : 20 parts; Fe 2 O 3 : 1 part; CaO: 10 parts.

[0074] The described lithium slag powder is composed of raw materials in the following parts by weight: SiO 2 : 21 parts; Al2O3: 60 parts; CaO: 5 parts; SO 3 : 3 parts; Li2O: 0.5 part.

[0075] The described slag is composed of raw materials in the following parts by weight: CaO: 35 parts; SiO2: 32 parts; Al2O3: 23 parts.

[0076] The above raw materials are conveyed by a belt to the powder grinding process, and 3% of triethanolamine based on the total mass of the raw materials is added, and the powder is ground to a specific surface area of 500 m 2 / g to obtain clinker-free slag cement.

[0077] Comparative Example 3

[0078] The clinker-free slag cement described above is composed of the following raw materials in parts by weight: industrial solid waste fluorogypsum: 15 parts; sodium hydroxide: 3 parts; fly ash: 20 parts; lithium slag powder: 20 parts; slag: 20 parts; mineral powder: 65 parts; quicklime: 2 parts.

[0079] The weight percentage of calcium sulfate in the industrial solid waste fluorogypsum is 87%.

[0080] The weight percentage of free calcium oxide in the quicklime is 30%.

[0081] The fly ash described above is composed of the following raw materials in parts by weight: SiO 2 : 60 parts; Al 2 O 3 : 30 parts; Fe 2 O 3 : 5 parts; CaO: 15 parts.

[0082] The lithium slag powder described above is composed of the following raw materials in parts by weight: SiO 2 : 25 parts; Al2O3: 65 parts; CaO: 10 parts; SO 3 : 5 parts; Li2O: 3 parts.

[0083] The slag described above is composed of the following raw materials in parts by weight: CaO: 42 parts; SiO2: 48 parts; Al2O3: 28 parts.

[0084] The above raw materials are conveyed by a belt to the powder grinding process, and 5% of triethanolamine based on the total mass of the raw materials is added, and the powder is ground to a specific surface area of 500 m 2 / g to obtain clinker-free slag cement.

[0085] The clinker-free slag cements prepared in the above Examples 1-5 were tested, and according to the technical requirements of national standard P.S.A 42.5 grade cement, the test results are shown in Table 1.

[0086] Table 1 Test results of the clinker-free slag cement prepared in Examples 1-5

[0087]

[0088] The clinker-free slag cement prepared in Comparative Examples 1-3 above was tested. According to the technical requirements of national standard P.S.A 42.5 grade cement, the test results are shown in Table 2.

[0089] Table 2 Test results of the clinker-free slag cement prepared in Comparative Examples 1-3

[0090]

[0091] It can be seen from the above that the clinker-free slag cement prepared by the present invention using industrial solid waste as the raw material formula meets the requirements of national standard 42.5 grade cement and can be used for building blocks and walls in the construction market.

[0092] Of course, the above content is only the preferred embodiment of the present invention and cannot be considered as limiting the scope of the embodiments of the present invention. The present invention is not limited to the above examples, and all equivalent changes and improvements made by those of ordinary skill in the art within the scope of the essence of the present invention shall fall within the scope covered by the patent of the present invention.

Claims

1. A clinker-free slag cement, characterized in that, it is composed of the following raw materials in parts by weight: industrial solid waste fluorogypsum: 8 - 15 parts; sodium hydroxide: 1 - 3 parts; fly ash: 10 - 20 parts; lithium slag powder: 5 - 20 parts; slag: 10 - 20 parts; mineral powder: 45 - 65 parts; quicklime: 0.5 - 2 parts; sodium silicate: 1 - 2 parts.

2. The clinker-free slag cement according to claim 1, characterized in that, the weight percentage content of calcium sulfate in the industrial solid waste fluorogypsum is 82% - 87%.

3. The clinker-free slag cement according to claim 1, characterized in that, the weight percentage content of free calcium oxide in the quicklime is 25% - 30%.

4. The clinker-free slag cement according to claim 1, characterized in that, The fly ash described is composed of raw materials in the following parts by weight: SiO 2 : 40 - 60 parts; Al 2 O 3 : 20 - 30 parts; Fe 2 O 3 : 1 - 5 parts; CaO: 10 - 15 parts.

5. The clinker-free slag cement according to claim 1, characterized in that, The lithium slag powder described above is composed of raw materials in the following weight parts: SiO 2 : 21-25 parts; Al2O3: 60-65 parts; CaO: 5-10 parts; SO 3 : 3-5 parts; Li2O: 0.5-3 parts.

6. The clinker-free slag cement according to claim 1, characterized in that, the slag is composed of the following raw materials in parts by weight: CaO: 35 - 42 parts; SiO2: 32 - 48 parts; Al2O3: 23 - 28 parts.

7. The clinker-free slag cement according to claim 1, characterized in that, The specific surface area of the mineral powder is 451 m 2 / g, and the fineness is 0.048 mm.

8. A preparation method of the clinker-free slag cement according to any one of claims 1 - 7, characterized in that, it includes the following steps: Weigh industrial solid waste fluorogypsum, sodium hydroxide, fly ash, lithium slag powder, slag, ore powder, quicklime, and sodium silicate according to the mass ratio, then convey them to the grinding process by belt, and add a liquid grinding aid, grind them to a specific surface area of 500 m 2 / g to obtain clinker-free slag cement.

9. The preparation method of the clinker-free slag cement according to claim 8, characterized in that, the liquid grinding aid is triethanolamine, and the addition amount of the liquid grinding aid is 3 - 5% of the total mass of the raw materials.

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