Ternary solid waste gel mine cemented filling material, preparation method and application

Abstract

The invention discloses a ternary solid waste gelling system mine cemented filling material, a preparation method and application, phosphogypsum and water-quenched slag powder are used as main gelling components, carbide slag is used as an exciting agent, and phosphate tailings and phosphorus tail mud are used as filling body aggregate to form the high-content phosphogypsum ternary solid waste gelling system mine cemented filling material. Wherein the ternary solid waste gel system comprises the following components in percentage by weight: 10-18% of carbide slag, 36-54% of ardealite and 36-54% of water-quenched slag powder, and the ratio of ardealite / (ardealite + water-quenched slag powder) is 0.4-0.6. The mine cemented filling material disclosed by the invention is prepared by taking solid wastes of industrial byproducts of a phosphorite mountain and the periphery of the phosphorite mountain as main raw materials, and the mechanical property of the prepared filling slurry after solidification needs to meet an engineering filling strength index, so that efficient resource utilization of a large amount of industrial solid wastes for phosphorite resource development can be realized; good mechanical properties and remarkable economic and environmental benefits are achieved.

Description

Technical Field

[0001] This invention relates to a ternary solid waste cementitious mine cemented backfill material, its preparation method, and its application, belonging to the technical field of mine backfill materials. Background Technology

[0002] Cemented backfilling is a method for controlling ground pressure in mines by mixing solid waste (such as tailings and waste rock) with water to form a slurry, which is then transported to underground goaf areas for backfilling. However, traditional cemented backfills heavily rely on silicate cement as a cementing material. Chinese patent application CN116924750A discloses a high-content solid waste-based mine backfill material, the composition of which includes aluminate cement, high-calcium minerals, aggregates, and retarder. However, it fails to utilize all industrial solid waste, which not only leads to high costs for mine backfilling but also results in significant energy consumption and high carbon emissions.

[0003] At the same time, existing mine backfilling applications have seen trials of using various industrial solid wastes as mine backfilling materials. Among them, the application of phosphogypsum in mine backfilling materials is particularly common. Phosphogypsum is a by-product produced when phosphate rock reacts with sulfuric acid to produce phosphoric acid. For every ton of phosphoric acid produced (calculated as P2O5), about 5 tons of phosphogypsum are generated. Since there are no economically viable applications for the phosphogypsum, it is mostly directly stockpiled, resulting in a significant waste of resources.

[0004] Chinese patent application CN117658568A discloses a phosphogypsum-based solid waste backfill material, which is a mixture of baked phosphogypsum powder, fly ash powder, blast furnace slag powder and steel slag powder in a certain proportion. This method involves high-temperature baking of the phosphogypsum powder, which changes the physical properties of phosphogypsum to hemihydrate calcium sulfate, thus limiting its practical application scenarios.

[0005] Phosphogypsum's main component is calcium sulfate dihydrate, but it contains impurities from phosphate rock, such as fluorides, phosphates, heavy metals, and naturally occurring radioactive nuclides. Therefore, direct stockpiling of large quantities of phosphogypsum poses serious environmental risks. Currently, the global cumulative stockpile of phosphogypsum exceeds 6 billion tons, with an annual increase of over 300 million tons. The harmless treatment of phosphogypsum has become a global issue. Summary of the Invention

[0006] The technical problem solved by this invention is to address the limitations of using phosphogypsum, a byproduct of phosphoric acid production, in mine backfill materials, and to provide a ternary solid waste cementitious mine backfill material, its preparation method, and its application.

[0007] This invention is achieved using the following technical solution: This invention first discloses a ternary solid waste cementitious system for mine cemented backfill material. The backfill material includes cementitious material and aggregate. The cementitious material is a ternary solid waste cementitious system material composed of phosphogypsum, water-quenched slag powder and carbide slag. The mass percentage of each component of the cementitious material is: carbide slag 10-18%, phosphogypsum 36-54%, water-quenched slag powder 36-54%. The aggregate is composed of phosphate tailings and phosphate tailings mud.

[0008] In a ternary solid waste cementitious mine cemented backfill material of the present invention, the mass ratio of phosphogypsum to water-quenched slag powder satisfies: phosphogypsum / (phosphogypsum + water-quenched slag powder) = (0.4-0.6).

[0009] In a ternary solid waste cementitious mine cemented backfill material of the present invention, the mass ratio of phosphorus tailings to phosphorus tailings mud in the aggregate is further 3:1.

[0010] In a ternary solid waste cementitious mine cemented backfill material of the present invention, the phosphogypsum is further described as dihydrate phosphogypsum.

[0011] In a ternary solid waste cementitious mine cemented filling material of the present invention, the water-quenched slag powder is further described as water-quenched granulated blast furnace slag after grinding.

[0012] In a ternary solid waste cementitious mine cemented backfill material of the present invention, the calcium carbide slag is a by-product of acetylene production by the calcium carbide method, which is used after drying and grinding.

[0013] In a ternary solid waste cementitious mine cemented backfill material of the present invention, the mass ratio of the cementitious material to the aggregate is further 1:4.

[0014] This invention also discloses a method for preparing the filling slurry of the above-mentioned ternary solid waste cementitious mine cemented backfill material, comprising the following steps: S1. Dry the phosphogypsum, water-quenched slag and carbide slag, and grind them to a particle size of no more than 0.5 mm. S2. Dewater or dry the phosphorus tailings and phosphorus tailings mud. Screen the phosphorus tailings to a particle size of 0.5mm. Mix the screened coarse particles with fine particles at a mass ratio of 1:1, and then mix them with phosphorus tailings mud at a mass ratio of 3:1 to form a homogeneous composite aggregate. S3. Mix 10-18% carbide slag, 36-54% phosphogypsum and 36-54% water-quenched slag powder evenly according to the mass percentage of each component of the cementitious material to obtain a ternary solid waste cementitious material powder with high phosphogypsum content. S4. The homogeneous composite aggregate formed by mixing phosphorus tailings and phosphorus tailings mud is mixed with ternary solid waste cementitious material powder at a mass ratio of 4:1. Water is added and stirred evenly to obtain filling slurry.

[0015] In the preparation method of the ternary solid waste cementitious mine cemented backfill material of the present invention, the drying temperature of the phosphogypsum does not exceed 50°C.

[0016] The ternary solid waste cementitious mine cemented filling material of the present invention is used for filling the goaf of a mine. The filling slurry prepared by the above method is poured into the goaf mold and shaken to eliminate air bubbles. After standing at room temperature for 24 hours, it is demolded. Then, the filled mine goaf is cured to the required age under the conditions of temperature 20±2℃ and relative humidity not less than 95%.

[0017] The present invention, by adopting the above technical solution, has the following beneficial effects: This invention provides a high-content phosphogypsum ternary solid waste cementing backfill material for mines. It uses industrial solid wastes such as phosphogypsum, carbide slag, water-quenched slag, phosphate tailings, and phosphate tailings mud as all raw materials. The raw materials are mainly solid wastes produced by phosphate mines and surrounding industrial by-products. This invention achieves the complete solid waste treatment and low cost at the source of the backfill material. At the same time, it solves the environmental problems caused by the comprehensive utilization of phosphogypsum and its surface storage, and realizes the efficient resource utilization of large quantities of industrial solid waste from phosphate mine development.

[0018] The cemented backfill material provided by this invention employs a ternary solid waste cementing system with a high content of phosphogypsum. From a cementing perspective, since the main component of phosphogypsum is sulfate, it can release a large amount of sulfate ions in an alkaline environment, which combine with aluminosilicates to form ettringite (AFt), thus playing a cementing role. Its core utilizes the strongly alkaline environment (OH-) provided by calcium carbide slag, which is mainly composed of calcium hydroxide. - ) and calcium ions (Ca 2+ The synergistic activation of the potential cementitious activity of water-quenched slag, under alkaline activation, dissolves the active aluminosilicates in the water-quenched slag, and reacts with the sulfate ions (SO4) provided by phosphogypsum. 2- The system involves the reaction of calcium ions, resulting in the early formation of numerous needle-like ettringite (AFt) crystals that interlock and form the main structural framework of the cemented filling material. Simultaneously, hydrated calcium silicate (CSH) gel continuously forms, filling pores and enhancing density. The synergistic hydration process of the high-dosage phosphogypsum ternary solid waste cementing system is the fundamental reason for the strength achieved by the cemented filling material in this invention.

[0019] This invention also optimizes the amount of calcium carbide slag and the ratio of phosphogypsum / water-quenched slag. When the cementitious material is mixed with phosphate tailings and phosphate tailings mud as aggregate and the filling slurry is prepared with a high slurry concentration, it can obtain unconfined compressive strength that meets the requirements of downhole cemented filling, enabling the cemented filling material to exhibit excellent early and late strength. Experiments show that its unconfined compressive strength can reach 3.47 MPa at 7 days and 5.47 MPa at 28 days, fully meeting the strength requirements of downhole cemented filling.

[0020] In summary, the ternary solid waste cementitious backfill material provided by this invention completely eliminates the need for cement. It uses phosphogypsum and water-quenched slag powder as the main cementing components and carbide slag as the activator to form a high-content phosphogypsum multi-element solid waste ternary cementitious system. It also uses phosphate tailings and phosphate tailings mud as aggregates, which can realize the efficient resource utilization of bulk industrial solid waste. It solves the problems of existing backfill materials such as strong dependence on cement, high cost, and the need for complex pretreatment processes. Furthermore, it helps to solve the environmental problems caused by the surface accumulation of phosphogypsum. As a result, the backfill structure of the mine goaf has good mechanical properties and significant economic and environmental benefits. Detailed Implementation

[0021] The present invention will be further described below with reference to specific embodiments.

[0022] To make the technical solution and beneficial effects of the present invention clearer, the implementation methods of the present invention will be described in detail below with reference to specific embodiments and comparative examples. It should be understood that the embodiments described herein are only for explaining the present invention and are not intended to limit the present invention.

[0023] The preparation of the ternary solid waste cementitious mine cemented backfill material of the present invention includes cementitious material and aggregate, with a mass ratio of cementitious material to aggregate of 1:4. The cementitious material is a ternary solid waste cementitious system composed of phosphogypsum, water-quenched slag powder, and carbide slag, and the aggregate is composed of phosphate tailings and phosphate tailings mud.

[0024] In the cementitious material, taking the total mass of phosphogypsum, water-quenched slag powder and carbide slag as 100%, the mass percentage of each component of the cementitious material is as follows: carbide slag 10-18%, phosphogypsum 36-54%, water-quenched slag powder 36-54%, and the mass ratio of phosphogypsum to water-quenched slag powder must also meet the following condition: phosphogypsum / (phosphogypsum + water-quenched slag powder) = (0.4-0.6).

[0025] The phosphogypsum is dihydrate phosphogypsum produced during the wet-process phosphoric acid production process. Its main component is calcium sulfate dihydrate (CaSO4·2H2O). It is dehydrated by low-temperature drying, but not by calcination or baking at temperatures exceeding 50°C. The water-quenched slag powder is water-quenched granulated blast furnace slag produced by steel enterprises after grinding. The calcium carbide slag is a byproduct of the calcium carbide-based acetylene production process, which is used after drying and grinding.

[0026] The aggregate consists of phosphorus tailings and phosphorus tailings mud, both of which are used as backfill aggregates in phosphorus mine production, with a mass ratio of 3:1. The phosphorus tailings are screened through a 0.5mm sieve, and the coarse particles on the sieve and the fine particles on the under-sieve are mixed at a mass ratio of 1:1 before being mixed with the phosphorus tailings mud to form a homogeneous composite aggregate.

[0027] The phosphogypsum, carbide slag, water-quenched slag, phosphate tailings, and phosphate tailings mud used in the cemented filling materials prepared in the following examples were all obtained from a phosphate mine and related enterprises in Yichang, Hubei Province. The phosphogypsum is a by-product of wet-process phosphoric acid production, with calcium sulfate dihydrate as its main component, and also contains a certain amount of typical impurities such as free calcium oxide, phosphate, and fluoride. The water-quenched slag powder was obtained by drying and grinding. The carbide slag is a by-product of acetylene production, with calcium hydroxide as its main component. Its chemical composition and physical properties are consistent with those described in the background and content of this invention. The test water was ordinary tap water.

[0028] The preparation method of filling slurry using cemented filling materials is as follows: S1. Dry and dehydrate phosphogypsum, water-quenched slag and carbide slag at a maximum temperature of 50°C, and grind them to a particle size of no more than 0.5 mm.

[0029] S2. Dewater or dry the phosphorus tailings and phosphorus tailings mud. Screen the phosphorus tailings to a particle size of 0.5mm. Mix the screened coarse and fine particles at a mass ratio of 1:1, and then mix them with the phosphorus tailings mud at a mass ratio of 3:1 to form a homogeneous composite aggregate.

[0030] S3. Mix 10-18% carbide slag, 36-54% phosphogypsum and 36-54% water-quenched slag powder evenly according to the mass percentage of each component of the cementitious material to obtain a ternary solid waste cementitious material powder with high phosphogypsum content.

[0031] S4. Mix the homogeneous composite aggregate of phosphorus tailings and phosphorus tailings mud with ternary solid waste cementitious material powder at a mass ratio of 4:1. Add tap water at a slurry mass concentration of 74±2% and stir for 120 seconds to obtain a uniform slurry.

[0032] The slurry was poured into a cylindrical plastic mold with a diameter of 50mm × 100mm, and gently shaken to remove bubbles, thus preparing cemented filling material specimens for each embodiment. Strength tests were then conducted. Before the strength test, the specimens were allowed to stand at room temperature (20℃) for 24 hours before demolding, and then immediately transferred to a standard curing chamber (temperature 20±2℃, relative humidity ≥95%) for curing to the specified age (7 days, 28 days). The specimens were then subjected to unconfined compressive strength testing using a universal testing machine at a loading rate of 0.5mm / min, and the result was taken as the average of three specimens. Example 1

[0033] Based on the total mass of phosphogypsum, water-quenched slag powder, and carbide slag as 100%, the formula of the filling material cementing system in this embodiment is: carbide slag 10%, phosphogypsum 54%, water-quenched slag powder 36%, and the corresponding mass ratio of phosphogypsum / (phosphogypsum + water-quenched slag powder) is 0.40.

[0034] After curing to the specified age, the unconfined compressive strength was tested using a universal testing machine at a loading rate of 0.5 mm / min. The result was the average of three specimens. The unconfined compressive strength of the cemented filling material specimen in this embodiment was 1.210 MPa after 7 days of curing and 2.629 MPa after 28 days. Example 2

[0035] Based on the total mass of phosphogypsum, water-quenched slag powder, and carbide slag as 100%, the formula of the filling material cementing system in this embodiment is: carbide slag 10%, phosphogypsum 36%, water-quenched slag powder 54%, and the corresponding mass ratio of phosphogypsum / (phosphogypsum + water-quenched slag powder) is 0.60.

[0036] After curing to the specified age, the unconfined compressive strength was tested using a universal testing machine at a loading rate of 0.5 mm / min. The result was the average of three specimens. The unconfined compressive strength of the cemented filling material specimen in this embodiment was 1.475 MPa after 7 days of curing and 3.207 MPa after 28 days. Example 3

[0037] Based on the total mass of phosphogypsum, water-quenched slag powder, and carbide slag as 100%, the formula of the filling material cementing system in this embodiment is: carbide slag 12%, phosphogypsum 35.2%, water-quenched slag powder 52.8%, and the corresponding mass ratio of phosphogypsum / (phosphogypsum + water-quenched slag powder) is 0.40.

[0038] After curing to the specified age, the unconfined compressive strength was tested using a universal testing machine at a loading rate of 0.5 mm / min. The result was the average of three specimens. The unconfined compressive strength of the cemented filling material specimen in this embodiment was 2.112 MPa after 7 days of curing and 5.107 MPa after 28 days. Example 4

[0039] Based on the total mass of phosphogypsum, water-quenched slag powder, and carbide slag as 100%, the formula of the filling material cementing system in this embodiment is: carbide slag 15%, phosphogypsum 34.0%, water-quenched slag powder 51.0%, and the corresponding mass ratio of phosphogypsum / (phosphogypsum + water-quenched slag powder) is 0.40.

[0040] After curing to the specified age, the unconfined compressive strength was tested using a universal testing machine at a loading rate of 0.5 mm / min. The result was the average of three specimens. The unconfined compressive strength of the cemented filling material specimen in this embodiment was 3.470 MPa after 7 days of curing and 5.466 MPa after 28 days. Example 5

[0041] Based on the total mass of phosphogypsum, water-quenched slag powder, and carbide slag as 100%, the formula of the filling material cementing system in this embodiment is: carbide slag 15%, phosphogypsum 51.0%, water-quenched slag powder 34.0%, and the corresponding mass ratio of phosphogypsum / (phosphogypsum + water-quenched slag powder) is 0.60.

[0042] After curing to the specified age, the unconfined compressive strength was tested using a universal testing machine at a loading rate of 0.5 mm / min. The result was the average of three specimens. The lateral confined compressive strength of the cemented filling material specimen in this embodiment was 2.285 MPa after 7 days of curing and 3.653 MPa after 28 days. Example 6

[0043] Based on the total mass of phosphogypsum, water-quenched slag powder, and carbide slag as 100%, the formula of the filling material cementing system in this embodiment is: carbide slag 18%, phosphogypsum 45.6%, water-quenched slag powder 36.4%, and the corresponding mass ratio of phosphogypsum / (phosphogypsum + water-quenched slag powder) is 0.55.

[0044] After curing to the specified age, the unconfined compressive strength was tested using a universal testing machine at a loading rate of 0.5 mm / min. The result was the average of three specimens. The unconfined compressive strength of the cemented filling material specimen in this embodiment was 2.42 MPa after 7 days of curing and 3.897 MPa after 28 days.

[0045] The following comparative examples were prepared using the same preparation method.

[0046] Comparative Example 1 In this comparative example, the filling material was not activated by carbide slag, but instead used steel slag powder instead of carbide slag in this invention. The steel slag powder is waste slag material from a steel company, which is dried and ground before use.

[0047] Based on the total mass of phosphogypsum, water-quenched slag powder and steel slag powder as 100%, the formula of the filling material cementing system in this comparative example is: 25% steel slag powder, 40% phosphogypsum, and 35% water-quenched slag powder, with a corresponding mass ratio of phosphogypsum / (phosphogypsum + water-quenched slag powder) of 0.53.

[0048] The remaining raw materials and preparation methods are the same as in the examples.

[0049] After curing to the specified age, the unconfined compressive strength was tested using a universal testing machine at a loading rate of 0.5 mm / min. The result was the average of three specimens. The unconfined compressive strength of the cemented filling material specimen in this comparative example was 0.695 MPa after 7 days of curing and 1.62 MPa after 28 days.

[0050] Comparative Example 2 The filling material in this comparative example was not activated by carbide slag, but instead used steel slag powder instead of carbide slag in this invention. With the total mass of phosphogypsum, water-quenched slag powder and steel slag powder as 100%, the formula of the cementitious system of the filling material in this comparative example is: 40% steel slag powder, 40% phosphogypsum, and 20% water-quenched slag powder, and the corresponding mass ratio of phosphogypsum / (phosphogypsum + water-quenched slag powder) is 0.66.

[0051] The remaining raw materials and preparation methods are the same as in the examples.

[0052] After curing to the specified age, the unconfined compressive strength was tested using a universal testing machine at a loading rate of 0.5 mm / min. The result was the average of three specimens. The unconfined compressive strength of the cemented filling material specimen in this comparative example was 0.640 MPa after 7 days of curing and 1.165 MPa after 28 days.

[0053] Comparative Example 3 The amount of carbide slag used in the filling material in this comparative example is less than that in the example. Based on the total mass of phosphogypsum, water-quenched slag powder and carbide slag as 100%, the formula of the cementitious system of the filling material in this comparative example is: 5% carbide slag, 57% phosphogypsum, and 38% water-quenched slag powder. The corresponding mass ratio of phosphogypsum / (phosphogypsum + water-quenched slag powder) is 0.60.

[0054] After curing to the specified age, the unconfined compressive strength was tested using a universal testing machine at a loading rate of 0.5 mm / min. The result was the average of three specimens. The unconfined compressive strength of the cemented filling material specimen in this comparative example was 0.698 MPa after 7 days of curing and 1.661 MPa after 28 days.

[0055] Comparative Example 4 The amount of carbide slag used in the filling material in this comparative example is less than that in the example. Based on the total mass of phosphogypsum, water-quenched slag powder and carbide slag as 100%, the formula of the cementitious system of the filling material in this comparative example is: 5% carbide slag, 47.5% phosphogypsum, and 47.5% water-quenched slag powder, with a corresponding mass ratio of phosphogypsum / (phosphogypsum + water-quenched slag powder) of 0.5.

[0056] After curing to the specified age, the unconfined compressive strength was tested using a universal testing machine at a loading rate of 0.5 mm / min. The result was the average of three specimens. The unconfined compressive strength of the cemented filling material specimen in this comparative example was 0.822 MPa after 7 days of curing and 1.811 MPa after 28 days.

[0057] The proportions and unconfined compressive strengths of the above embodiments and comparative examples are summarized in the table below.

[0058] formula Calcium carbide slag (%) phosphogypsum (%) Water-quenched slag (%) Steel slag (%) Phosphogypsum / (Phosphogypsum + water-quenched slag) 7-day compressive strength (MPa) 28-day compressive strength (MPa) Example 1 10 54.0 36.0 0 0.40 1.210 2.629 Example 2 10 36.0 54.0 0 0.60 1.475 3.154 Example 3 12 35.2 52.8 0 0.40 2.112 5.107 Example 4 15 34.0 51.0 0 0.40 3.470 5.466 Example 5 15 51.0 34.0 0 0.60 2.285 3.653 Example 6 18 45.6 36.4 0 0.55 2.42 3.897 Comparative Example 1 0 40 35 25 0.53 0.695 1.620 Comparative Example 2 0 40 20 40 0.66 0.640 1.165 Comparative Example 3 5 57 38 0 0.60 0.698 1.661 Comparative Example 4 5 47.5 47.5 0 0.50 0.822 1.811 In summary, this high-dosage phosphogypsum ternary solid waste cementitious material for mine cemented backfill exhibits significant environmental and economic advantages. It utilizes industrial solid wastes such as phosphogypsum, water-quenched slag, carbide slag, phosphate tailings, and phosphate tailings sludge as raw materials, achieving complete solid waste utilization of the backfill material. This not only effectively addresses the environmental pressure caused by large-scale phosphogypsum stockpiling but also significantly reduces reliance on traditional cement, saving costs and reducing carbon emissions. The material uses uncalcined phosphogypsum directly, resulting in a simple process and low energy consumption. By optimizing the carbide slag content and the ratio of phosphogypsum to water-quenched slag in the high-dosage phosphogypsum ternary solid waste cementitious system, the system exhibits excellent early strength and high later-stage strength. For example, the 7-day strength in Example 4 reaches 3.47 MPa, and the 28-day strength reaches 5.47 MPa, fully meeting the engineering requirements for mine cemented backfill. It is a green backfill material that combines solid waste resource utilization, low cost, and high performance.

[0059] Based on the strength of the cemented filling material specimens prepared in the above embodiments, the cemented filling material prepared in the above embodiments can meet the strength requirements for filling goaf areas in mines, and is particularly suitable for cemented filling of goaf areas in phosphate mines or other metal mines.

[0060] The above description is merely a specific embodiment of the present invention, and not all possible implementations. Those skilled in the art can make various adjustments and improvements without departing from the inventive concept, and these should all fall within the scope of protection of the present invention. The scope of protection of the present invention is determined by the contents of the claims, and the specific embodiments in the specification can be used to interpret the claims.

Claims

1. A ternary solid waste cementitious mine cemented backfill material, the backfill material comprising cementitious materials and aggregates, characterized in that: The cementing material is a ternary solid waste cementing system composed of phosphogypsum, water-quenched slag powder, and carbide slag. The mass percentage of each component in the cementing material is as follows: carbide slag 10-18%, phosphogypsum 36-54%, and water-quenched slag powder 36-54%. The aggregate consists of phosphorus tailings and phosphorus tailings mud.

2. The ternary solid waste cementitious mine cemented backfill material according to claim 1, characterized in that: The mass ratio of phosphogypsum to water-quenched slag powder satisfies: phosphogypsum / (phosphogypsum + water-quenched slag powder) = (0.4-0.6).

3. The ternary solid waste cementitious mine cemented backfill material according to claim 1, characterized in that: The mass ratio of phosphorus tailings to phosphorus tailings mud in the aggregate is 3:

1.

4. The ternary solid waste cementitious mine cemented backfill material according to claim 1, characterized in that: The phosphogypsum is dihydrate phosphogypsum.

5. The ternary solid waste cementitious mine cemented backfill material according to claim 1, characterized in that: The water-quenched slag powder is water-quenched granulated blast furnace slag after grinding.

6. The ternary solid waste cementitious mine cemented backfill material according to claim 1, characterized in that: The calcium carbide slag is a byproduct of acetylene production via the calcium carbide process, and is used after drying and grinding.

7. The ternary solid waste cementitious mine cemented backfill material according to claim 1, characterized in that: The mass ratio of the cementitious material to the aggregate is 1:

4.

8. A method for preparing a filling slurry of a ternary solid waste cementitious mine cemented backfill material according to any one of claims 1-7, characterized in that: Includes the following steps: S1. Dry the phosphogypsum, water-quenched slag and carbide slag, and grind them to a particle size of no more than 0.5 mm. S2. Dewater or dry the phosphorus tailings and phosphorus tailings mud. Screen the phosphorus tailings to a particle size of 0.5mm. Mix the screened coarse particles with fine particles at a mass ratio of 1:1, and then mix them with phosphorus tailings mud at a mass ratio of 3:1 to form a homogeneous composite aggregate. S3. Mix 10-18% carbide slag, 36-54% phosphogypsum and 36-54% water-quenched slag powder evenly according to the mass percentage of each component of the cementitious material to obtain a ternary solid waste cementitious material powder with high phosphogypsum content. S4. The homogeneous composite aggregate formed by mixing phosphorus tailings and phosphorus tailings mud is mixed with ternary solid waste cementitious material powder at a mass ratio of 4:

1. Water is added and stirred evenly to obtain filling slurry.

9. The preparation method of the ternary solid waste cementitious mine cemented backfill material according to claim 8, characterized in that: The drying temperature of the phosphogypsum shall not exceed 50°C.

10. The ternary solid waste cementitious mine cemented backfill material of claims 1-7 is used for backfilling of mine goaf areas, characterized in that: The filling slurry prepared according to claim 8 or 9 is poured into the mold of the goaf area of ​​the mine and shaken to eliminate air bubbles. After standing at room temperature for 24 hours, it is demolded and then cured to the required age under the conditions of temperature 20±2℃ and relative humidity not less than 95%.