Slag filling material and application thereof

Abstract

The invention provides a slag filling material and application thereof, and belongs to the technical field of slag filling materials. The slag filling material provided by the invention comprises the following raw materials: tailings, slag, water and an alkali activator, the alkali activator comprises sodium carbonate and calcium hydroxide or carbide slag. According to the invention, sodium carbonate and calcium hydroxide or carbide slag are used as the composite alkali activator, on one hand, the calcium hydroxide or carbide slag is added to reduce the concentration of slag and tailings, and water is consumed in the reaction process, so that the water-cement ratio of the filling material is reduced, and the mechanical properties of the filling material are improved; on the other hand, the concentration of calcium ions in a reaction system is increased by adding the calcium hydroxide or the carbide slag, so that the Ca / Si ratio of the hydrated calcium silicate gel is increased, the mechanical property of the filling material is improved, meanwhile, the porosity of the filling material is reduced by calcium carbonate formed by the reaction, and the mechanical property of the filling material is further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of slag filling materials, and in particular to a slag filling material and application thereof. Background Art

[0002] With the progress of mining activities, a large amount of solid waste such as tailings and waste rock is generated, which has a negative impact on the environment. As a strategy to solve the problem of solid waste discharge, backfill mining method can not only avoid waste discharge to the surface, but also has the advantages of supporting adjacent rock mass, controlling ground subsidence, and improving the safety environment of miners underground, so it has been widely used in my country. Most traditional backfill cementitious materials use ordinary Portland cement, which is costly and does not conform to the concept of low-carbon development. Alkali-activated slag cementitious materials are considered to be potential backfill cementitious materials due to their low hydration heat, low carbon emissions, good early mechanical properties and strong resistance to chemical erosion. In the past, sodium hydroxide, sodium silicate, etc. were generally used as alkali activators to prepare slag backfill materials, but the mechanical properties of the backfill materials prepared by these alkali activators were low, which limited their promotion in practical applications. Therefore, there is an urgent need for a backfill material with excellent mechanical properties. Summary of the invention

[0003] The purpose of the present invention is to provide a slag filling material and its application. The slag filling material provided by the present invention has excellent mechanical properties.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] The invention provides a slag filling material, comprising the following raw materials: tailings, slag, water and an alkali activator; the alkali activator comprises sodium carbonate and calcium hydroxide or carbide slag.

[0006] Preferably, the mass ratio of tailings to slag is (5-7):1.

[0007] Preferably, the mass ratio of tailings to slag is 6:1.

[0008] Preferably, the ratio of the total mass of the tailings and slag to the mass of water is (70-75):(25-30).

[0009] Preferably, the mass ratio of the alkali activator to the slag is (23-46):100.

[0010] Preferably, the mass ratio of sodium carbonate to slag in the alkaline activator is (14-27):100.

[0011] Preferably, the mass ratio of calcium hydroxide or carbide slag to slag in the alkaline activator is (9-19):100.

[0012] Preferably, the particle sizes of the tailings, slag and carbide slag are independently 0 to 500 μm.

[0013] The present invention also provides the use of the slag filling material described in the above technical solution in filling mining.

[0014] The present invention provides a slag filling material, comprising the following raw materials: tailings, slag, water and an alkali activator; the alkali activator comprises sodium carbonate and calcium hydroxide or carbide slag. The present invention adopts sodium carbonate and calcium hydroxide or carbide slag as a composite alkali activator. On the one hand, the addition of calcium hydroxide or carbide slag reduces the concentration of slag and tailings, and consumes water during the reaction process, so that the water-cement ratio of the filling material decreases, and the mechanical properties of the filling material are improved; on the other hand, the addition of calcium hydroxide or carbide slag increases the concentration of calcium ions in the reaction system, thereby increasing the Ca / Si ratio of hydrated calcium silicate gel and improving the mechanical properties of the filling material. At the same time, the calcium carbonate formed by the reaction helps to reduce the porosity of the filling material, further improving the mechanical properties of the filling material. The results of the embodiment show that the slag filling material provided by the present invention has a 3d compressive strength increased by more than 26% and a 28d compressive strength increased by more than 86% compared with the filling material prepared by using a single sodium hydroxide as an alkali activator. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The XRD diagrams of slag and carbide slag in the embodiments;

[0016] Figure 2 The particle size distribution diagram of slag, tailings and carbide slag in the embodiment;

[0017] Figure 3 is the fluidity of the slag filling materials of Examples 1 to 4 and Comparative Examples 1 to 2;

[0018] Figure 4 The uniaxial compressive strength of the filling body obtained by molding and curing the slag filling materials of Examples 1 to 4 and Comparative Examples 1 to 2;

[0019] Figure 5 The thermogravimetric differential thermal analysis diagram of the filling body obtained by molding and curing the slag filling materials of Example 2, Example 4 and Comparative Example 2;

[0020] Figure 6 This is a mercury injection analysis diagram of the filling body obtained by molding and curing the slag filling materials of Example 2, Example 4 and Comparative Example 2. DETAILED DESCRIPTION

[0021] The invention provides a slag filling material, comprising the following raw materials: tailings, slag, water and an alkali activator; the alkali activator comprises sodium carbonate and calcium hydroxide or carbide slag.

[0022] Unless otherwise specified, the present invention has no particular limitation on the sources of the raw materials, and products with sources familiar to those skilled in the art may be used.

[0023] The raw material for preparing the slag filling material of the present invention includes tailings. In the present invention, the tailings are mainly used as aggregate.

[0024] In the present invention, the tailings are preferably artificial tailings with a silicon dioxide mass content greater than 99.8%. The use of tailings in the present invention can further improve the mechanical properties of the slag filling material.

[0025] In the present invention, the particle size of the tailings is preferably 0 to 500 μm. The present invention limits the particle size of the tailings to the above range, which can further improve the mechanical properties of the slag filling material.

[0026] The raw materials for preparing the slag filling material of the present invention also include slag.

[0027] The present invention has no particular limitation on the source of the slag, and slag from sources well known to those skilled in the art may be used.

[0028] In an embodiment of the present invention, the slag is preferably from a steel plant in Shandong; the slag preferably includes the following main components in percentage by mass: SiO2 35.72%, Al2O3 13.70%, CaO 40.37%, Fe2O3 0.48%, MgO 6.72%, MnO 0.24%, Na2O 0.05%, K2O 0.30%, TiO2 2.25% and SO3 0.17%. In the present invention, the slag undergoes a hydration reaction under the action of an alkali activator to generate a hydrated calcium silicate gel.

[0029] In the present invention, the particle size of the slag is preferably 0-500 μm. The present invention limits the particle size of the slag to the above range, which can further improve the mechanical properties of the slag filling material.

[0030] In the present invention, the mass ratio of tailings to slag is preferably (5-7): 1, more preferably (5.5-6.5): 1, and further preferably 6: 1. The present invention limits the mass ratio of tailings to slag within the above range, which can further improve the mechanical properties of the slag filling material.

[0031] The raw materials for preparing the slag filling material of the present invention also include water.

[0032] In the present invention, the ratio of the total mass of tailings and slag to the mass of water is preferably (70-75): (25-30), more preferably (71-74): (26-29), and further preferably (72-73): (27-28). The present invention limits the ratio of the total mass of tailings and slag to the mass of water within the above range, which can make the filling material have an appropriate water-cement ratio and further improve the mechanical properties of the slag filling material.

[0033] The raw materials for preparing the slag filling material of the present invention also include an alkali activator.

[0034] In the present invention, the alkaline activator includes sodium carbonate and calcium hydroxide or carbide slag. The present invention uses sodium carbonate and calcium hydroxide or carbide slag as a composite alkaline activator. On the one hand, the addition of calcium hydroxide or carbide slag reduces the concentration of slag and tailings, and consumes water during the reaction process, so that the water-cement ratio of the filling material decreases, and the mechanical properties of the filling material are improved; on the other hand, the addition of calcium hydroxide or carbide slag increases the concentration of calcium ions in the reaction system, thereby increasing the Ca / Si ratio of the hydrated calcium silicate gel and improving the mechanical properties of the filling material. At the same time, the calcium carbonate formed by the reaction helps to reduce the porosity of the filling material and improve the mechanical properties of the filling material; and carbide slag is a waste, and adding carbide slag as an alkaline activator can make solid waste resources and reduce production costs; in addition, the use of carbide slag can improve the fluidity of the filling material to a certain extent compared with calcium hydroxide.

[0035] The present invention has no special limitation on the source of the carbide slag, and the carbide slag of the source familiar to those skilled in the art can be used. In the embodiment of the present invention, the carbide slag is preferably purchased from a chemical plant in Zhengzhou; the carbide slag preferably includes the following main components in percentage by mass: SiO2 2.14%, Al2O3 0.77%, Ca(OH)2 96.14%, Fe2O3 0.76%, MgO 0.06%, Na2O 0.03% and SO3 0.10%.

[0036] In the present invention, the mass ratio of the alkali activator to the slag is preferably (23-46):100; the mass ratio of the sodium carbonate in the alkali activator to the slag is preferably (14-27):100; the mass ratio of the calcium hydroxide or carbide slag in the alkali activator to the slag is preferably (9-19):100. The present invention limits the amount of the alkali activator and the mass of the sodium carbonate, calcium hydroxide or carbide slag in the alkali activator to the above ranges, which can further improve the mechanical properties of the slag filling material.

[0037] The present invention adopts sodium carbonate and calcium hydroxide or carbide slag as a composite alkali activator, and controls the composition of other components and the amount of each component, thereby further improving the mechanical properties of the slag filling material; when carbide slag is used, waste resources can be utilized and costs can be reduced. Compared with calcium hydroxide, carbide slag can improve the fluidity of the slag filling material.

[0038] In the present invention, the method for preparing the slag filling material preferably comprises the following steps:

[0039] (1) mixing calcium hydroxide or carbide slag with tailings and slag to obtain a mixture;

[0040] (2) mixing sodium carbonate and water to obtain a mixed solution;

[0041] (3) mixing the mixture obtained in step (1) and the mixed solution obtained in step (2) to obtain a slag filling material;

[0042] There is no chronological order for steps (1) and (2).

[0043] The present invention preferably mixes calcium hydroxide or carbide slag with tailings and slag to obtain a mixture.

[0044] The present invention has no particular limitation on the mixing operation of the calcium hydroxide or carbide slag with the tailings and slag, and the components can be uniformly mixed using a mixing method well known to those skilled in the art.

[0045] The present invention preferably mixes sodium carbonate with water to obtain a mixed solution.

[0046] The present invention has no particular limitation on the mixing method of the sodium carbonate and water. The sodium carbonate and water can be uniformly mixed using a mixing method well known to those skilled in the art.

[0047] After obtaining the mixture and the mixed solution, the present invention preferably mixes the mixture and the mixed solution to obtain a slag filling material.

[0048] The present invention has no particular limitation on the mixing method of the mixture and the mixed solution. The raw materials can be uniformly mixed using a mixing method well known to those skilled in the art.

[0049] The preparation method of the present invention can make the raw materials mixed more uniformly and further improve the mechanical properties of the slag filling material.

[0050] The present invention also provides the use of the slag filling material described in the above technical solution in filling mining.

[0051] The present invention has no special limitation on the operation of the application, and the technical solutions of the application well known to those skilled in the art may be adopted.

[0052] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a 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.

[0053] The slag in each embodiment comes from a steel plant in Shandong, and the slag includes the following main components in percentage by mass: SiO2 35.72%, Al2O3 13.70%, CaO 40.37%, Fe2O3 0.48%, MgO 6.72%, MnO 0.24%, Na2O 0.05%, K2O 0.30%, TiO2 2.25% and SO3 0.17%;

[0054] The carbide slag in each embodiment was purchased from a chemical plant in Zhengzhou, and the carbide slag included the following main components in percentage by mass: SiO2 2.14%, Al2O3 0.77%, Ca(OH)2 96.14%, Fe2O3 0.76%, MgO 0.06%, Na2O 0.03% and SO3 0.10%;

[0055] The tailings in each embodiment are artificial tailings with a silicon dioxide mass content of more than 99.8%;

[0056] In the embodiments, the present invention calculates the amount of sodium carbonate and calcium hydroxide according to the amount of sodium hydroxide in formula II:

[0057] Na2CO3+Ca(OH)2→2NaOH+CaCO3 formula II.

[0058] Example 1

[0059] A slag filling material is prepared from the following raw materials: tailings (particle size 0-500 μm), slag (particle size 0-500 μm), water and an alkali activator; the alkali activator is composed of sodium carbonate and calcium hydroxide; the mass ratio of the tailings to the slag is 6:1; the ratio of the total mass of the tailings and the slag to the mass of water is 72:28; the mass ratio of the alkali activator to the slag is 23:100; the mass ratio of the sodium carbonate to the slag in the alkali activator is 14:100; the mass ratio of the calcium hydroxide to the slag in the alkali activator is 9:100;

[0060] The preparation method of the slag filling material is as follows: (1) stirring calcium hydroxide, slag and tailings in a stirrer for 30 seconds to obtain a mixture;

[0061] (2) mixing sodium carbonate and water to obtain a sodium carbonate solution;

[0062] (3) Add the sodium carbonate solution obtained in step (2) to the mixture obtained in step (1) and stir for 2 minutes to obtain a slag filling material, which is recorded as N3.

[0063] Example 2

[0064] The mass ratio of the alkaline activator to the slag in Example 1 is replaced by 46:100; the mass ratio of the sodium carbonate in the alkaline activator to the slag is replaced by 27:100; the mass ratio of the calcium hydroxide in the alkaline activator to the slag is replaced by 19:100, and the other parameters and preparation method are the same as those in Example 1, denoted as N4.

[0065] Example 3

[0066] The calcium hydroxide in the alkaline activator of Example 1 is replaced by carbide slag (particle size 0-500 μm), and other parameters and preparation method are the same as those of Example 1, which is denoted as N5.

[0067] Example 4

[0068] The calcium hydroxide in the alkaline activator of Example 2 is replaced by carbide slag (particle size 0-500 μm), and other parameters and preparation method are the same as those of Example 2, denoted as N6.

[0069] Comparative Example 1

[0070] A slag filling material is prepared from the following raw materials: tailings, slag, water and an alkali activator; the alkali activator is sodium hydroxide; the mass ratio of the tailings to the slag is 6:1; the ratio of the total mass of the tailings and the slag to the mass of water is 72:28; the mass ratio of the alkali activator to the slag is 10:100;

[0071] The preparation method of the slag filling material is as follows: (1) stirring slag and tailings in a stirrer for 30 seconds to obtain a mixture;

[0072] (2) mixing sodium hydroxide and water to obtain a sodium hydroxide solution;

[0073] (3) Add the sodium hydroxide solution obtained in step (2) to the mixture obtained in step (1) and stir for 2 minutes to obtain a slag filling material, which is recorded as N1.

[0074] Comparative Example 2

[0075] The mass ratio of the alkali activator to the slag in Comparative Example 1 was replaced with 20:100, and the other parameters and preparation method were the same as those in Comparative Example 1, which was denoted as N2.

[0076] The XRD patterns of slag and carbide slag in the embodiment are as follows: Figure 1 As shown. Figure 1It can be seen that the slag shows a typical "hump" diffraction pattern, indicating that the slag is mainly amorphous. The main mineral component in carbide slag is Ca(OH)2.

[0077] The particle size distribution of slag, tailings and carbide slag in the embodiment is as follows: Figure 2 shown.

[0078] A mold with an upper diameter of 50 mm, a lower diameter of 100 mm, and a height of 150 mm was used to test the slump of the freshly mixed slag filling materials of Examples 1 to 4 and Comparative Examples 1 to 2: After the filling material filled the mold, the cone was suspended for 2 minutes, and two vertical distances were measured and the average value was taken as the diffusion diameter. In order to study the effect of time on the fluidity of the sample, the diffusion diameter of the filling material was tested once every 10 minutes according to the above method, and the test was carried out for a total of 30 minutes. The results are as follows Figure 3 As shown. Figure 3It can be seen that when NaOH is used as the alkaline activator, the fluidity of the filling material does not change significantly at 0 min as the concentration of the alkaline activator increases. This is because NaOH is completely dissolved in water, and the mass concentration of the filling material remains constant. At the same time, the hydration reaction of the slag under the action of the alkaline activator takes time. The fluidity result at 0 min is carried out immediately after the material preparation is completed. Therefore, it is believed that the hydration reaction of the slag will not affect the fluidity of the filling material. However, as the reaction time increases, the fluidity of the filling material decreases significantly. The higher the concentration of the alkaline activator, the faster the fluidity of the material decreases. The fluidity of N1 after 30 min decreased by 8.72% compared with that at 0 min; under the same circumstances, N2 decreased by 11.86%. Because the high concentration of the alkaline activator leads to a higher pH value of the solution, it promotes the dissolution and hydration of the slag, thereby significantly reducing the fluidity of the material. The composite alkaline activator also significantly reduces the fluidity of the filling material, and the higher the concentration of the alkaline activator, the more obvious the decrease in the fluidity of the filling material. At 0min, the fluidity of N3 and N5 decreased by 21.48% and 11.07% compared with N1, respectively; the fluidity of N4 and N6 decreased by 30.51% and 22.71% compared with N2, respectively. The fluidity is very sensitive to the change of mass concentration. The addition of Ca(OH)2 or carbide slag leads to a slight increase in the mass concentration of the filling material, which is one of the reasons for the decrease in the fluidity of the material. In addition, the chain reaction of the composite alkali activator (6NaOH+2H2O+4CaCO3→3Ca(OH)2+Na2Ca(CO3)22H2O+2Na2CO3 Formula I) consumes a large amount of free water, which also causes the fluidity of the filling material to decrease. From the decrease in the fluidity of N3 and N5 and N4 and N6, it can be seen that the fluidity of the filling material is improved after using carbide slag instead of calcium hydroxide. This is because the reaction activity of carbide slag is slightly lower than that of Ca(OH)2, and the free water consumed by the chain reaction is relatively small. It can be seen that the use of a composite alkali activator with a combination of chemical agents will lead to a significant decrease in the fluidity of the filling material, but the use of carbide slag instead of Ca(OH)2 is expected to alleviate this phenomenon.

[0079] The slag filling materials of Examples 1 to 4 and Comparative Examples 1 to 2 were transferred into a cylindrical plastic mold with a diameter of 50 mm and a height of 100 mm. The uniaxial compressive strength was tested after curing for 3 days and 28 days under standard curing conditions. The results are shown in Tables 1 and Figure 4 As shown in Table 1 and Figure 4It can be seen that no matter what kind of alkali activator is used, the strength of the filling body increases with the increase of the alkali activator concentration and curing time. This is because the increase of the alkali activator concentration and curing time is conducive to the hydration of slag and promotes the formation of hydration products, thereby improving the compressive strength of the filling body. Compared with a single alkali activator, the filling body using a composite alkali activator has a higher compressive strength. The 3d strength of N3 and N5 increased by 43.33% and 26% respectively compared with N1, and the 28d strength increased by 108.89% and 86.11% respectively; the 3d strength of N4 and N6 increased by 93.33% and 65.24% respectively compared with N2, and the 28d strength increased by 95.86% and 90.34% respectively. On the one hand, the addition of Ca(OH)2 and carbide slag causes a decrease in mass concentration. At the same time, the continuous reaction of the composite alkali activator consumes free water, which indirectly leads to a decrease in the water-cement ratio of the filling material, resulting in a significant increase in the strength of the cementitious material. On the other hand, the addition of Ca(OH)2 / carbide slag increases the concentration of calcium ions in the reaction system, which means that the Ca / Si ratio of the CSH gel will be increased, which is also beneficial to improve the mechanical properties of the filling body. From the growth rate of filling body strength over time, the filling body strength using the composite alkali activator has greater development potential, which may be the result of the continuous hydration of unreacted Ca(OH)2 or carbide slag and slag in the filling body. After replacing Ca(OH)2 with carbide slag, the strength of the filling body decreased slightly, which also shows that the activity of carbide slag is slightly lower than that of Ca(OH)2 reagent.

[0080] Table 1 Compressive strength of slag filling slurry after molding and curing in Examples 1 to 4 and Comparative Examples 1 to 2

[0081] 3d compressive strength 28d compressive strength Example 1 2.15 3.76 Example 2 4.06 5.68 Example 3 1.89 3.35 Example 4 3.47 5.52 Comparative Example 1 1.5 1.8 Comparative Example 2 2.1 2.9

[0082] The slag filling materials of Example 2, Example 4 and Comparative Example 2 were transferred into a cylindrical plastic mold with a diameter of 50 mm and a height of 100 mm. After curing for 28 days under standard curing conditions, thermogravimetric and differential thermal analysis was performed. The results are as follows: Figure 5 As shown. Figure 5 It can be seen that the mass loss of the filling body mainly occurs at 30-200℃ and 500-650℃; at 30-200℃, the mass loss of the filling body is mainly attributed to the dehydration reaction of hydration products such as CSH and hydrotalcite; the mass loss at 500-650℃ is mainly due to the decomposition of carbonates. Figure 5As shown in the figure, the mass loss of the filling body using the composite alkali activator is significantly greater than that of the single alkali activator, and the mass loss of the filling body is concentrated in 30-200℃ and 500-650℃. The greater the mass loss in the range of 30-200℃, the higher the content of hydration products in the filling body and the better the mechanical properties of the filling body, which is consistent with the compressive strength results. For the filling body with NaOH as the alkali activator, the carbonate therein is mainly formed after the carbonization of CSH gel; while for the composite alkali activator, it is more due to the reaction of Na2CO3 with Ca(OH)2 or carbide slag. Therefore, the content of calcium carbonate in the composite alkali activator system is much higher than that of the single alkali activator. This calcium carbonate formed by chemical reaction has a certain filling effect and nucleation effect, which helps to reduce the porosity of the filling body and promote the formation of CSH gel. This may be one of the reasons why the filling body using the composite alkali activator has higher strength. The mass loss of the filling body was slightly reduced after using carbide slag to replace Ca(OH)2, which also shows that the reactivity of carbide slag is not as good as Ca(OH)2. However, considering factors such as fluidity and feasibility, it is feasible to use carbide slag to replace Ca(OH)2 as a composite alkali activator.

[0083] The slag filling materials of Example 2, Example 4 and Comparative Example 2 were transferred into a cylindrical plastic mold with a diameter of 50 mm and a height of 100 mm. After curing for 28 days under standard curing conditions, the pore distribution of the filling body was measured. The results are as follows: Figure 6 As shown. Figure 6 It can be seen that the pores in the filling body can be divided into three categories according to their pore size, namely micropores (<20nm), mesopores (20-500nm) and macropores (>500nm); the pores of the filling body are mainly mesopores. At the same time, the content of macropores in the filling body using a single alkali activator is higher than that using a composite alkali activator. This is the result of the filling effect and nucleation effect of calcium carbonate (Formula II) formed by the reaction. Due to the poor reactivity of carbide slag, the porosity of the filling body is significantly increased after replacing Ca(OH)2 with carbide slag. According to the mercury injection results, under the same concentration, the composite alkali activator makes the structure of the filling body denser, thereby improving its compressive strength. After replacing Ca(OH)2 with carbide slag, the porosity of the filling body is improved, but it is still lower than the porosity of the filling body prepared with a single alkali activator.

[0084] In summary, the present invention uses sodium carbonate and calcium hydroxide or carbide slag as alkaline activators, and the mechanical properties of the prepared filling material are better than those of a single sodium hydroxide alkaline activator.

[0085] 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 slag filling material, comprising the following raw materials: tailings, slag, water and an alkali activator; the alkali activator comprises sodium carbonate and calcium hydroxide or carbide slag.

2. The slag filling material according to claim 1, It is characterized in that The mass ratio of the tailings to the slag is (5-7):

1.

3. The slag filling material according to claim 2, It is characterized in that The mass ratio of the tailings to the slag is 6:

1.

4. The slag filling material according to claim 1, It is characterized in that The ratio of the total mass of the tailings and slag to the mass of water is (70-75):(25-30).

5. The slag filling material according to claim 1, It is characterized in that The mass ratio of the alkali activator to the slag is (23-46):

100.

6. The slag filling material according to claim 1, It is characterized in that The mass ratio of sodium carbonate to slag in the alkaline activator is (14-27):

100.

7. The slag filling material according to claim 1, It is characterized in that The mass ratio of calcium hydroxide or carbide slag to slag in the alkaline activator is (9-19):

100.

8. The slag filling material according to claim 1, It is characterized in that The particle sizes of the tailings, slag and carbide slag are independently 0 to 500 μm.

9. Use of the slag filling material according to any one of claims 1 to 8 in filling mining.

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