Multi-solid-waste cementing material as well as preparation and application methods thereof

Abstract

The invention provides a multi-solid-waste cementing material as well as a preparation method and an application method thereof. The multi-solid-waste cementing material comprises a multi-solid-waste cementing material and engineering residue soil, wherein the multi-solid-waste cementing material comprises 25%-35% (by mass) of superfine slag powder, 25%-35% (by mass) of fly ash, 7%-15% (by mass) of coal gangue, 8%-15% (by mass) of carbide slag, 5%-12% (by mass) of superfine steel slag powder and 8%-14% (by mass) of an alkali activator; the mass ratio of the multi-solid waste cementing material to the engineering residue soil is 1: (6-8). The cementing material is prepared from a plurality of industrial solid wastes, and has the characteristics of high backfill strength, good fluidity, difficulty in shrinkage, low carbon and environmental protection.

Description

Technical Field

[0001] The invention relates to a cementing material mainly used for foundation backfilling, mine backfilling, mine filling and tailings solidification treatment, and in particular to a multi-solid waste cementing material and a preparation and application method thereof. Background Art

[0002] The filling materials used in foundations, mines, and mine backfill are composed of cementitious materials, aggregates, admixtures, and additives. During the hydration process of the filling materials, the physical and chemical properties change, and then the hydration products with adhesive properties are generated. The material that can bond the aggregates into a whole with a certain strength is called cementitious material.

[0003] Cementitious materials are the core of cementitious filling material preparation. They are not only the key factor in determining the strength of the cemented body, but also the most important factor affecting the cost. For example, the filling mining method currently used in underground mining has a filling cost of about 50% of the total cost, of which cementitious materials account for a relatively high proportion of the cost, and some cementitious materials account for as much as 60%. On the basis of ensuring various indicators, the research and development of cementitious materials with low cost, small dosage and excellent performance is a current technical problem.

[0004] At present, the main goal of reducing the cost of cementitious filling projects is to use cheap materials that can partially or completely replace cement. Using different types of industrial solid waste to develop cementitious filling materials can effectively reduce the cost of projects on the basis of meeting various indicators, while greatly reducing carbon emissions in material production, which has good economic value and environmental benefits. Summary of the invention

[0005] In order to solve the deficiencies of the prior art, the present invention provides a multi-solid waste cementing material, which is prepared from different types of industrial solid wastes and has the characteristics of high backfill strength, good fluidity, not easy to shrink, low carbon and environmental protection. Another object of the present invention is to provide a method for preparing the multi-solid waste cementing material as described above. Another object of the present invention is to provide an application of the multi-solid waste cementing material as described above in foundation backfill, mine backfill, mine filling and tailings solidification treatment.

[0006] The present invention is achieved through the following technical solutions:

[0007] On the one hand, the present invention provides a multi-solid waste binder material, including a multi-solid waste cementitious material and construction slag; wherein the multi-solid waste cementitious material includes the following components: the multi-solid waste binder material includes 25% to 35% by mass of slag powder, 25% to 35% by mass of fly ash, 7% to 15% by mass of coal gangue, 8% to 15% by mass of carbide slag, 5% to 12% by mass of steel slag powder and 8% to 14% by mass of alkali activator; the mass ratio of the multi-solid waste cementitious material to the construction slag is 1:6 to 8.

[0008] According to the multi-solid waste cementing material of the present invention, preferably, the alkali activator is sodium hydroxide and sodium silicate.

[0009] According to the multi-solid waste cementing material of the present invention, preferably, the alkaline activator consists of sodium hydroxide and sodium silicate; wherein the mass ratio of sodium hydroxide to sodium silicate is 1:1.

[0010] According to the multi-solid waste cementing material of the present invention, preferably, the specific surface area of ​​the slag powder is 400-450m 2 / kg; the specific surface area of ​​fly ash is 400~450m 2 / kg; the specific surface area of ​​coal gangue is 500~550m 2 / kg; the specific surface area of ​​carbide slag is 450~500m 2 / kg; the specific surface area of ​​steel slag powder is 350~500m 2 / kg.

[0011] According to the multi-solid waste cementing material of the present invention, preferably, the particle size of the engineering waste soil is ≤4.75 mm.

[0012] According to the multi-solid waste cementitious material of the present invention, preferably, the mass ratio of the multi-solid waste cementitious material to the construction waste is 1:6-8.

[0013] In another aspect, the present invention provides a method for preparing the above-mentioned multi-solid waste cementitious material, comprising the following steps:

[0014] (1) Slag powder, fly ash, coal gangue, carbide slag, steel slag powder and alkali activator are uniformly mixed to obtain a multi-solid waste cementitious material;

[0015] (2) Weighing the construction waste according to the mass ratio of the multi-solid waste cementitious material to the construction waste, and evenly mixing the multi-solid waste cementitious material and the construction waste, and then adding water to obtain a slurry, and then stirring the slurry to obtain the multi-solid waste cementitious material.

[0016] Furthermore, the water is preferably untreated tap water; the mass concentration of the slurry may be 60-85%, preferably 68-83%, and more preferably 75-80%.

[0017] On the other hand, the present invention provides a use of the multi-solid waste binder material as described above in foundation backfill, mine backfill, mine filling and tailings solidification treatment.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] (1) The present invention completely adopts different types of solid waste as the main raw materials of the cementing material, combines the use of alkali activators, and uses engineering slag as aggregate. The resulting filling material can fully meet the performance requirements of foundation backfill, mine backfill, mine filling and tailings solidification treatment.

[0020] (2) The present invention does not use cement, thus avoiding the high energy consumption and high pollution in cement production, and effectively improving the problems of poor strength and easy shrinkage caused by using cement as a filling binder material.

[0021] (3) The resource utilization rate of large-scale industrial solid waste has been improved, and construction waste has been used as aggregate, solving the problem of handling large-scale construction waste. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is further described below in conjunction with specific embodiments.

[0023] 1. The composition ratio of multi-solid waste cementing materials is as follows:

[0024] The multi-solid waste cementing material of the present invention is prepared from multi-solid waste cementing materials and aggregates, wherein the multi-solid waste cementing materials include slag powder, fly ash, coal gangue, carbide slag, steel slag powder and alkali activator; and the aggregates are engineering slag.

[0025] In the present invention, the slag powder can be selected from the slag powder in GB / T18046-2017, preferably slag powder of grade S95 or above; the specific surface area of ​​the slag powder can be 400 to 450 m 2 / kg, the mass proportion of slag powder can be 25% to 35% (mass).

[0026] In the present invention, the fly ash can be selected from the fly ash in GB / T1596-2017, preferably Class F fly ash; the specific surface area of ​​the fly ash can be 400 to 450 m 2 / kg, the mass proportion of fly ash can be 25% to 35% (mass).

[0027] In the present invention, the coal gangue may be selected from the coal gangue in GB / T 29163-2012, and the specific surface area of ​​the coal gangue may be 500 to 550 m 2 / kg, the mass proportion of coal gangue can be 7% to 15% (mass).

[0028] In the present invention, the carbide slag can be selected from the carbide slag in T / NMSNXH 001-2023, preferably dry-discharged carbide slag; the specific surface area of ​​the carbide slag can be 450-500m 2 / kg, the mass proportion of carbide slag can be 8% to 15% (mass).

[0029] In the present invention, the steel slag powder can be selected from the steel slag powder in GB / T20491-2017, preferably the first-grade steel slag powder. The specific surface area of ​​the steel slag powder can be 350 to 500 m 2 / kg, the mass proportion of steel slag powder can be 5% to 12% (mass).

[0030] In the present invention, the alkaline activator can be sodium hydroxide and sodium silicate, and the mass ratio of sodium hydroxide to sodium silicate is 1:1.

[0031] In the present invention, the particle size of the construction waste soil may be less than 4.75 mm, and the mass ratio of the multi-solid waste cementitious material to the construction waste soil may be 1:6-8.

[0032] 2. The preparation method of the multi-solid waste cementing material is as follows:

[0033] Step 1, slag powder, fly ash, coal gangue, carbide slag, steel slag powder and alkali activator are mixed evenly to obtain a multi-solid waste cementitious material.

[0034] Step 2, weighing the engineering waste according to the mass ratio of the multi-solid waste cementitious material to the engineering waste, and evenly mixing the multi-solid waste cementitious material and the engineering waste, and then adding water to obtain a slurry, and stirring the slurry evenly to obtain the multi-solid waste cementitious material.

[0035] Furthermore, the water is preferably untreated tap water; the mass concentration of the slurry may be 60-85%, preferably 68-83%, and more preferably 75-80%.

[0036] Furthermore, there is no special regulation on the mixing method, and the commonly used methods in the art can be used, such as mechanical stirring.

[0037] 3. The application of multi-solid waste cementing materials is as follows:

[0038] The multi-solid waste cementing material of the present invention can be used in foundation backfill, mine backfill, mine filling and tailings solidification treatment; preferably used in mine backfill.

[0039] Example 1

[0040] 25% (mass) slag powder, 25% (mass) fly ash, 15% (mass) coal gangue, 8% (mass) carbide slag, 15% (mass) steel slag powder, and 12% (mass) alkali activator are mixed evenly to obtain a cementitious material. The specific surface area of ​​the slag powder is 450m 2 / kg, the specific surface area of ​​fly ash is 450m 2 / kg, the specific surface area of ​​coal gangue is 550m 2 / kg, the specific surface area of ​​carbide slag is 500m 2 / kg, the specific surface area of ​​steel slag powder is 500m 2 / kg.

[0041] Weigh the construction waste soil according to the mass ratio of multi-solid waste cementitious material to construction waste soil (as aggregate) of 1:8; mix the multi-solid waste cementitious material and construction waste soil weighed above, add water to obtain a slurry with a concentration of 75%, and stir evenly in a mixer to obtain a multi-solid waste cementitious material.

[0042] Example 2

[0043] 25% by mass of slag powder, 25% by mass of fly ash, 15% by mass of coal gangue, 8% by mass of carbide slag, 15% by mass of steel slag powder and 12% by mass of alkali activator are uniformly mixed to obtain a cementitious material.

[0044] Weigh the construction waste soil according to the mass ratio of multi-solid waste cementitious material to construction waste soil (as aggregate) of 1:8; mix the multi-solid waste cementitious material and construction waste soil weighed above, add water to obtain a slurry with a concentration of 85%, and stir evenly in a mixer to obtain a multi-solid waste cementitious material.

[0045] Example 3

[0046] 25% by mass of slag powder, 25% by mass of fly ash, 12% by mass of coal gangue, 8% by mass of carbide slag, 22% by mass of steel slag powder and 8% by mass of alkali activator are uniformly mixed to obtain a cementitious material.

[0047] Weigh the construction waste soil according to the mass ratio of multi-solid waste cementitious material to construction waste soil (as aggregate) of 1:8; mix the multi-solid waste cementitious material and construction waste soil weighed above, add water to obtain a slurry with a concentration of 75%, and stir evenly in a mixer to obtain a multi-solid waste cementitious material.

[0048] Example 4

[0049] 35% by mass of slag powder, 35% by mass of fly ash, 7% by mass of coal gangue, 8% by mass of carbide slag, 5% by mass of steel slag powder and 10% by mass of alkali activator are uniformly mixed to obtain a cementitious material.

[0050] Weigh the construction waste soil according to the mass ratio of multi-solid waste cementitious material to construction waste soil (as aggregate) of 1:8; mix the multi-solid waste cementitious material and construction waste soil weighed above, add water to obtain a slurry with a concentration of 75%, and stir evenly in a mixer to obtain a multi-solid waste cementitious material.

[0051] Example 5

[0052] 25% by mass of slag powder, 25% by mass of fly ash, 15% by mass of coal gangue, 15% by mass of carbide slag, 8% by mass of steel slag powder and 12% by mass of alkali activator are uniformly mixed to obtain a cementitious material.

[0053] Weigh the construction waste soil according to the mass ratio of the multi-solid waste cementitious material to the construction waste soil (as aggregate) of 1:6; mix the multi-solid waste cementitious material and the construction waste soil, add water to obtain a slurry with a concentration of 75%, and stir evenly in a mixer to obtain the multi-solid waste cementitious material.

[0054] The slurries of Examples 1 to 5 were cast and cured to different ages for compressive strength tests, and the test method was based on the method in JC / T2468-2018 "Cement-based backfill materials". The test results are shown in Table 1.

[0055] Table 1 Compressive strength test results of different embodiments

[0056]

[0057] From the results in Table 1, it can be seen that the multi-solid waste cementing material provided by the present invention has good compressive strength, the compressive strength after curing for 28 days is greater than 2.5MPa, the fluidity is greater than 200mm, and the 28d shrinkage rate is less than 0.1%, which meets the requirements of mine filling. At the same time, the small shrinkage rate makes the volume change of the backfill material smaller, which can effectively reduce the deformation and cracking problems after backfilling, thereby improving the stability and integrity of the backfill structure. Without using cement as a cementitious material, a multi-solid waste cementing material with both strength and fluidity can be prepared by using a large number of different types of industrial solid waste raw materials and alkali activators.

[0058] The present invention is described above by way of example. It should be noted that, without departing from the core of the present invention, any simple deformation, modification or other equivalent replacement that can be made by those skilled in the art without inventive effort falls within the protection scope of the present invention.

Claims

1. A multi-solid waste cementing material, characterized by: It includes multi-solid waste cementitious materials and construction slag; wherein, the multi-solid waste cementitious materials include the following components: the multi-solid waste cementitious materials include 25% to 35% by weight of slag powder, 25% to 35% by weight of fly ash, 7% to 15% by weight of coal gangue, 8% to 15% by weight of carbide slag, 5% to 12% by weight of steel slag powder and 8% to 14% by weight of alkali activator; the mass ratio of the multi-solid waste cementitious materials to the construction slag is 1:6 to 8.

2. The multi-solid waste cementing material according to claim 1, characterized in that: The alkaline activator is sodium hydroxide and sodium silicate.

3. The multi-solid waste cementing material according to claim 1, characterized in that: The alkaline activator consists of sodium hydroxide and sodium silicate; wherein the mass ratio of sodium hydroxide to sodium silicate is 1:

1.

4. The multi-solid waste cementing material according to claim 1, characterized in that: The specific surface area of ​​the slag powder is 400-450m 2 / kg; the specific surface area of ​​fly ash is 400~450m 2 / kg; the specific surface area of ​​coal gangue is 500~550m 2 / kg; the specific surface area of ​​carbide slag is 450~500m 2 / kg; the specific surface area of ​​steel slag powder is 350~500m 2 / kg.

5. The multi-solid waste cementing material according to claim 1, characterized in that: The particle size of the engineering slag is ≤4.75mm.

6. The multi-solid waste cementing material according to claim 1, characterized in that: The mass ratio of the multi-solid waste cementitious material to the engineering slag is 1:6-8.

7. A method for preparing a multi-solid waste cementitious material according to any one of claims 1 to 6, characterized in that: The steps include: Step 1, slag powder, fly ash, coal gangue, carbide slag, steel slag powder and alkali activator are mixed evenly to obtain a multi-solid waste gelling material; Step 2, weighing the engineering waste according to the mass ratio of the multi-solid waste cementitious material to the engineering waste, and evenly mixing the multi-solid waste cementitious material and the engineering waste, and then adding water to obtain a slurry, and stirring the slurry evenly to obtain the multi-solid waste cementitious material.

8. The preparation method according to claim 7, characterized in that: The mass concentration of the slurry is 75-80%.

9. Use of the multi-solid waste binder material as claimed in any one of claims 1 to 6 or the multi-solid waste binder material obtained by the preparation method of claim 7 in foundation backfill, mine backfill, mine filling and tailings solidification treatment.

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