Composite filling gelling material and preparation method thereof

Abstract

The present application relates to mine filling material technical field, specifically to a kind of composite filling cementitious material and preparation method thereof, composite filling cementitious material includes the following components: oil shale slag, iron ore slag, clay slag, Portland cement, composite activator, polycarboxylate water reducer;Composite activator includes the following components: water glass, sodium carbonate, metakaolin, anhydrous sodium sulfate, calcium sulphoaluminate, dolomite, silica fume, potassium feldspar, activation accelerator.The cementitious part of the present application is entirely composed of various industrial waste, easy to obtain materials, low cost, composite activator can effectively stimulate the potential activity of oil shale slag, iron ore slag and clay slag, promote its hydration reaction, and the composite filling cementitious material prepared has good wet resistance and good durability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mine filling materials, in particular to a composite filling cementitious material and a preparation method thereof. BACKGROUND

[0002] With the development of the mining industry and the continuous expansion of the scale of mines, the formation of mine tunnels and the mining of ores produce a large amount of waste, which not only occupies a large amount of land resources, but also has a certain impact on the environment. In order to solve these problems, composite filling cementitious materials are widely used in the treatment of waste in mines.

[0003] A Chinese invention with publication number CN115745444B discloses a kind of oil shale ash system full solid waste base cementitious material, which provides more reaction sites and active centers for hydration reaction by adding gypsum in the formula, so that the active ingredients in oil shale ash can react with water faster to generate more hydration products, such as ettringite and hydrated calcium silicate gel, etc. However, gypsum will introduce a large amount of sulfate ions, and if the material is in a humid environment for a long time, the sulfate ions will react with the hydration products in the steel slag and oil shale ash to form insoluble sulfates (such as calcium sulfate), which will cause the material to swell and crack under the long-term effect, affecting the durability of the material. SUMMARY

[0004] The purpose of the present application is to provide a composite filling cementitious material and a preparation method thereof to solve the problems raised in the background art.

[0005] To achieve the above-mentioned purpose, on the one hand, the present application provides the following technical solution: a composite filling cementitious material, which comprises the following components by mass fraction: 100 parts of oil shale ash, 20-30 parts of iron ore slag, 10-15 parts of clay slag, 8-10 parts of Portland cement, 6-9 parts of composite activator, and 0.1-0.5 parts of polycarboxylate superplasticizer.

[0006] The composite activator comprises the following components by mass fraction: 50 parts of water glass, 20-30 parts of sodium carbonate, 5-10 parts of metakaolin, 4-8 parts of anhydrous sodium sulfate, 2-4 parts of calcium sulfoaluminate, 1-3 parts of dolomite, 1-3 parts of silica fume, 1-3 parts of potassium feldspar, and 1-2 parts of an activation promoter.

[0007] The activation promoter is a mixture of calcium aluminate and aluminum sulfate, and the mass ratio of calcium aluminate to aluminum sulfate is (1-5):1.

[0008] Optionally, the oil shale residue has a particle size of 4-8 mm, and the chemical composition of the oil shale residue includes 59.14% of SiO2, 7.74% of Fe2O3, 16.26% of Al2O3, 9.08% of CaO, 1.20% of MgO, 2.69% of SO3, 1.73% of K2O and 2.16% of Na2O.

[0009] Optionally, the iron ore slag has a particle size of 4-6 mm, and the chemical composition of the iron ore slag includes 36.23% of SiO2, 1.89% of Fe2O3, 9.76% of Al2O3, 39.40% of CaO, 12.11% of MgO, 0.33% of K2O and 0.28% of Na2O.

[0010] Optionally, the clay ore slag has a particle size of 3-5 mm, and the chemical composition of the clay ore slag includes 45.07% of SiO2, 7.64% of Fe2O3, 30.83% of Al2O3, 13.23% of CaO, 2.16% of MgO, 0.82% of K2O and 0.25% of Na2O.

[0011] Optionally, the water glass has a molar ratio of silica to alkali metal oxide of 1.5.

[0012] In another aspect, the application also discloses a preparation method of the composite filling cementitious material.

[0013] S1, drying: the oil shale residue, the iron ore slag and the clay ore slag are respectively placed in a roller dryer, and are continuously dried at 100-110 DEG C for 20-30 min;

[0014] S2, grinding: the oil shale residue, the iron ore slag and the clay ore slag are placed in a ball mill and are ground for 20-30 min to obtain a mixed material with a particle size of 10-16 mesh;

[0015] S3, mixing: the mixed material, the portland cement, the composite activator and the polycarboxylic acid water reducing agent are stirred and mixed to obtain the composite filling cementitious material.

[0016] Compared with the prior art, the application has the following beneficial effects:

[0017] 1. The cementitious part of the application is completely composed of various industrial wastes, which is convenient to obtain and low in cost; the composite activator can effectively activate the potential activity of the oil shale residue, the iron ore slag and the clay ore slag, promote the hydration reaction thereof, and the prepared composite filling cementitious material has good wet resistance and good durability.

[0018] 2. In the present invention, dolomite can provide magnesium ions and calcium ions to assist alkaline excitation and regulate expansion. Silica fume can fill the pores of the material, enhance density, and promote the later volcanic ash reaction to improve the later strength. Potassium feldspar contains a stable silicon-aluminum structure, which can fill the pores of the material through ball milling and optimize the pore structure of the material. DETAILED DESCRIPTION

[0019] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0020] Example 1: The present invention provides a composite filling cementitious material comprising the following components by mass: 100 parts of oil shale slag, 20 parts of ironmaking slag, 10 parts of clay slag, 8 parts of Portland cement, 6 parts of a composite activator, and 0.1 parts of a polycarboxylate water reducer;

[0021] The composite activator comprises the following components by mass: 50 parts of water glass, 20 parts of sodium carbonate, 5 parts of metakaolin, 4 parts of anhydrous sodium sulfate, 2 parts of calcium sulfoaluminate, 1 part of dolomite, 1 part of silica fume, 1 part of potassium feldspar, and 1 part of activation accelerator;

[0022] The excitation accelerator is a mixture of calcium aluminate and aluminum sulfate, wherein the mass ratio of calcium aluminate to aluminum sulfate is 1:1.

[0023] The preparation method of the composite filling gelling material comprises the following preparation steps:

[0024] S1. Drying: Place the oil shale slag, ironmaking slag and clay slag in a drum dryer respectively and dry them continuously at 100°C for 20 minutes;

[0025] S2, grinding: placing the oil shale slag, ironmaking slag and clay slag in a ball mill and grinding them for 20 minutes to obtain a mixture with a particle size of 10 mesh;

[0026] S3. Mixing: stirring and mixing the mixture, silicate cement, composite activator and polycarboxylate water reducer to obtain a composite filling cementitious material.

[0027] Example 2: The present invention provides a composite filling cementitious material comprising the following components by mass: 100 parts of oil shale slag, 25 parts of ironmaking slag, 12 parts of clay slag, 8 parts of Portland cement, 7 parts of a composite activator, and 0.3 parts of a polycarboxylate water reducer;

[0028] The composite activator comprises the following components in parts by mass: 50 parts of water glass, 25 parts of sodium carbonate, 7 parts of metakaolin, 6 parts of anhydrous sodium sulfate, 3 parts of calcium sulfoaluminate, 2 parts of dolomite, 2 parts of silica fume, 2 parts of potassium feldspar, and 1 part of an activation promoter.

[0029] The activation promoter is a mixture of calcium aluminate and aluminum sulfate, and the mass ratio of calcium aluminate to aluminum sulfate is 2.5:1.

[0030] The preparation method of the composite filling cementitious material comprises the following preparation steps:

[0031] S1, drying: the oil shale residue, the iron ore slag and the clay slag are respectively placed in a roller dryer, and continuously dried at 105 DEG C for 25 min;

[0032] S2, grinding: the oil shale residue, the iron ore slag and the clay slag are placed in a ball mill and ground for 24 min to obtain a mixture with a particle size of 12 mesh;

[0033] S3, mixing: the mixture, the portland cement, the composite activator and the polycarboxylate superplasticizer are stirred and mixed to obtain the composite filling cementitious material.

[0034] Example 3: the present application provides a composite filling cementitious material, which comprises the following components in parts by mass: 100 parts of oil shale residue, 28 parts of iron ore slag, 14 parts of clay slag, 9 parts of portland cement, 8 parts of composite activator, and 0.4 parts of polycarboxylate superplasticizer.

[0035] The composite activator comprises the following components in parts by mass: 50 parts of water glass, 25 parts of sodium carbonate, 7 parts of metakaolin, 6 parts of anhydrous sodium sulfate, 3 parts of calcium sulfoaluminate, 2 parts of dolomite, 2 parts of silica fume, 2 parts of potassium feldspar, and 1 part of an activation promoter.

[0036] The activation promoter is a mixture of calcium aluminate and aluminum sulfate, and the mass ratio of calcium aluminate to aluminum sulfate is 4:1.

[0037] The preparation method of the composite filling cementitious material comprises the following preparation steps:

[0038] S1, drying: the oil shale residue, the iron ore slag and the clay slag are respectively placed in a roller dryer, and continuously dried at 108 DEG C for 28 min;

[0039] S2, grinding: the oil shale residue, the iron ore slag and the clay slag are placed in a ball mill and ground for 28 min to obtain a mixture with a particle size of 14 mesh;

[0040] S3, mixing: the mixture, the portland cement, the composite activator and the polycarboxylate superplasticizer are stirred and mixed to obtain the composite filling cementitious material.

[0041] Embodiment 4: The application provides a composite filling cementitious material, which comprises the following components in parts by mass: 100 parts of oil shale residue, 30 parts of ironmaking slag, 15 parts of clay slag, 10 parts of portland cement, 9 parts of composite activator, and 0.5 parts of polycarboxylate superplasticizer;

[0042] The composite activator comprises the following components in parts by mass: 50 parts of water glass, 30 parts of sodium carbonate, 10 parts of metakaolin, 8 parts of anhydrous sodium sulfate, 4 parts of calcium sulfoaluminate, 3 parts of dolomite, 3 parts of silica fume, 3 parts of potassium feldspar, and 2 parts of activation accelerator;

[0043] The activation accelerator is a mixture of calcium aluminate and aluminum sulfate, and the mass ratio of calcium aluminate to aluminum sulfate is 5:1.

[0044] A preparation method of the composite filling cementitious material, comprising the following preparation steps:

[0045] S1, drying: the oil shale residue, the ironmaking slag and the clay slag are respectively placed in a roller dryer, and continuously dried at 110 DEG C for 30 min;

[0046] S2, grinding: the oil shale residue, the ironmaking slag and the clay slag are placed in a ball mill and ground for 30 min to obtain a mixture with a particle size of 16 mesh;

[0047] S3, mixing: the mixture, the portland cement, the composite activator and the polycarboxylate superplasticizer are stirred and mixed to obtain the composite filling cementitious material.

[0048] In embodiments 1-4, the oil shale residue is from Datang Taizhou Thermal Power Co., Ltd., which is a waste residue generated by using a low-temperature dry distillation method to extract shale oil, and the particle size of the oil shale residue is 4-8 mm; the chemical composition of the oil shale residue includes 59.14% of SiO2, 7.74% of Fe2O3, 16.26% of Al2O3, 9.08% of CaO, 1.20% of MgO, 2.69% of SO3, 1.73% of K2O and 2.16% of Na2O in mass fraction; the ironmaking slag is from Jiangsu Changqiang Iron and Steel Co., Ltd., and the particle size of the ironmaking slag is 4-6 mm; the chemical composition of the ironmaking slag includes 36.23% of SiO2, 1.89% of Fe2O3, 9.76% of Al2O3, 39.40% of CaO, 12.11% of MgO, 0.33% of K2O and 0.28% of Na2O in mass fraction; the clay slag is from Taizhou Changrong New Wall Material Co., Ltd., and the particle size of the clay slag is 3-5 mm; the chemical composition of the clay slag includes 45.07% of SiO2, 7.64% of Fe2O3, 30.83% of Al2O3, 13.23% of CaO, 2.16% of MgO, 0.82% of K2O and 0.25% of Na2O in mass fraction; and the mole ratio of silicon dioxide to alkali metal oxide in the water glass is 1.5.

[0049] Comparative Example 1

[0050] A composite filling cementitious material comprises the following components by mass fraction: 100 parts of oil shale residue, 20 parts of iron smelting slag, 10 parts of clay slag, 8 parts of portland cement, and 6 parts of gypsum.

[0051] A preparation method of the composite filling cementitious material comprises the following preparation steps:

[0052] S1, drying: the oil shale residue, the iron smelting slag and the clay slag are respectively placed in a roller dryer, and continuously dried at 100℃ for 20 min;

[0053] S2, grinding: the oil shale residue, the iron smelting slag and the clay slag are placed in a ball mill and ground for 20 min to obtain a mixed material with a particle size of 10 mesh;

[0054] S3, mixing: the mixed material, the portland cement and the gypsum are stirred and mixed to obtain the composite filling cementitious material.

[0055] Comparative Example 2

[0056] A composite filling cementitious material comprises the following components by mass fraction: 100 parts of oil shale residue, 30 parts of iron smelting slag, 15 parts of clay slag, 10 parts of portland cement, and 9 parts of gypsum.

[0057] A preparation method of the composite filling cementitious material comprises the following preparation steps:

[0058] S1, drying: the oil shale residue, the iron smelting slag and the clay slag are respectively placed in a roller dryer, and continuously dried at 100℃ for 20 min;

[0059] S2, grinding: the oil shale residue, the iron smelting slag and the clay slag are placed in a ball mill and ground for 30 min to obtain a mixed material with a particle size of 16 mesh;

[0060] S3, mixing: the mixed material, the portland cement and the gypsum are stirred and mixed to obtain the composite filling cementitious material.

[0061] Test Example 1

[0062] Test content: 500g of the composite filling cementitious material prepared in Examples 1-4 and Comparative Examples 1-2 was weighed, and 1500g of standard sand and 200g of water were weighed respectively for six times. The six groups of composite filling cementitious material, standard sand and water were placed in a cement mortar mixer and stirred for 30 minutes to obtain a mortar. The mortar was placed in a mold with a size of 40mm x 40mm x 160mm, uniformly vibrated, wrapped with plastic film, and demolded after curing in a standard constant temperature curing room at a temperature of 25℃ and a relative humidity of 95% for 28 days to obtain a mortar specimen. The tensile strength of the mortar specimen was measured using a tensile testing machine, and the results are shown in Table 1.

[0063] Table 1

[0064] Tensile strength / MPa Example 1 49.94 Example 2 50.12 Example 3 50.67 Example 4 50.89 Comparative Example 1 46.32 Comparative Example 2 48.91

[0065] As shown in Table 1, the tensile strength of the mortar specimen based on the composite filling cementitious material prepared in Examples 1-4 is better than that of the mortar specimen based on the composite filling cementitious material prepared in Comparative Examples 1-2.

[0066] Test Example 2

[0067] Test content: The six groups of mortar specimens obtained in Test Example 1 were placed in a 25℃ constant temperature sealed environment with a relative humidity of 40%, 60% and 80% respectively for 20 days to simulate the mortar specimen in a humid environment. The tensile strength test of the cementitious material is the basis for evaluating its crack resistance, and the crack resistance of the cementitious material can be evaluated by measuring the tensile strength of the cementitious material. The tensile strength of the simulated cementitious material was measured using a tensile testing machine, and the results are shown in Table 2.

[0068] Table 2

[0069]

[0070] As shown in Table 2, the tensile strength of the mortar specimen based on Examples 1-4 is better than that of the mortar specimen based on Comparative Examples 1-2 in a humid environment. The composite filling cementitious material disclosed in the present application has good moisture resistance and good durability. The tensile strength of the mortar specimen based on the composite filling cementitious material prepared in Example 4 is the largest, and is worth popularizing and using.

[0071] Although embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and alterations can be made thereto without departing from the principles and spirit of the present application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A composite filling gelling material, characterized in that: The composite filling cementitious material comprises the following components by mass: 100 parts of oil shale slag, 20-30 parts of ironmaking slag, 10-15 parts of clay slag, 8-10 parts of Portland cement, 6-9 parts of composite activator, and 0.1-0.5 parts of polycarboxylate water reducer; The composite activator comprises the following components by mass: 50 parts of water glass, 20-30 parts of sodium carbonate, 5-10 parts of metakaolin, 4-8 parts of anhydrous sodium sulfate, 2-4 parts of calcium sulfoaluminate, 1-3 parts of dolomite, 1-3 parts of silica fume, 1-3 parts of potassium feldspar, and 1-2 parts of activation accelerator; The excitation promoter is a mixture of calcium aluminate and aluminum sulfate, wherein the mass ratio of calcium aluminate to aluminum sulfate is (1-5):

1.

2. A composite filling gelling material according to claim 1, characterized in that: The particle size of the oil shale slag is 4 to 8 mm. Calculated by mass, the chemical composition of the oil shale slag includes 59.14% SiO2, 7.74% Fe2O3, 16.26% Al2O3, 9.08% CaO, 1.20% MgO, 2.69% SO3, 1.73% K2O, and 2.16% Na2O.

3. The composite filling gelling material according to claim 1, characterized in that: The particle size of the ironmaking slag is 4 to 6 mm. Calculated by mass fraction, the chemical composition of the ironmaking slag includes 36.23% SiO2, 1.89% Fe2O3, 9.76% Al2O3, 39.40% CaO, 12.11% MgO, 0.33% K2O, and 0.28% Na2O.

4. The composite filling gelling material according to claim 1, characterized in that: The particle size of the clay slag is 3 to 5 mm. Calculated by mass fraction, the chemical composition of the clay slag includes 45.07% SiO2, 7.64% Fe2O3, 30.83% Al2O3, 13.23% CaO, 2.16% MgO, 0.82% K2O, and 0.25% Na2O.

5. The composite filling gelling material according to claim 1, characterized in that: The molar ratio of silicon dioxide to alkali metal oxide in the water glass is 1.

5.

6. A method for preparing the composite filling gelling material according to any one of claims 1 to 5, characterized in that: The method comprises the following preparation steps: S1. Drying: Place the oil shale slag, ironmaking slag and clay slag in a drum dryer respectively and dry them continuously at 100-110°C for 20-30 minutes; S2. Grinding: Grinding the oil shale slag, ironmaking slag and clay slag in a ball mill for 20 to 30 minutes to obtain a mixture with a particle size of 10 to 16 mesh; S3. Mixing: stirring and mixing the mixture, silicate cement, composite activator and polycarboxylate water reducer to obtain the composite filling cementitious material.

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