Backfill material made of gold mine tailings sand, preparation method and application

Abstract

The application provides a backfill material made of gold mine tailings, a preparation method and application, and belongs to the field of gold mine tailings recycling. The backfill material made of gold mine tailings comprises the following components: a mine backfill special curing agent and gold mine tailings; the mine backfill special curing agent comprises the following components: cement clinker, slag, sodium chloride, sodium sulfate, aluminum sulfate and polyacrylamide; the specific surface area of the mine backfill special curing agent is greater than or equal to 450 m 2 / Kg. The backfill material made of gold mine tailings can effectively recycle gold mine tailings, effectively solves the problems of few utilization ways, low consumption and inability to effectively recycle in the recycling of existing gold mine tailings, and the problems of environmental pollution, serious dust and management difficulties caused by gold mine tailings.

Description

Technical Field

[0001] This invention relates to the field of gold mine tailings sand recycling, and in particular to a backfill material made from gold mine tailings sand, its preparation method, and its application. Background Technology

[0002] In recent years, with the continuous development of mineral resources, the current accumulated tailings and waste rock are nearly 60 billion tons. Of this, 43.8 billion tons are waste rock, 75% of which is coal gangue and waste rock from iron and copper mining; and 14.6 billion tons are tailings, 83% of which are tailings from iron, copper, and gold mining. While these tailings have good secondary utilization potential and high comprehensive utilization value, the current comprehensive utilization rate is only 18.9%, and they are mainly used for backfilling and building materials. Although the growth rate of tailings utilization is significantly higher than the growth rate of emissions, the amount utilized still cannot keep up with the increase in tailings. The large accumulation of tailings has become a major environmental problem affecting the region.

[0003] In existing technologies, using gold mine tailings as backfill material is one of the important ways to reuse gold mine tailings. However, current technologies for preparing backfill material from gold mine tailings cannot effectively utilize all of the gold mine tailings. Only about 40 wt% of the gold mine tailings produced during mining can be reused as qualified backfill aggregate. Furthermore, the space created during mining cannot accommodate all the tailings. Currently, gold mine tailings produced have a particle size of less than 40 mesh, and can be divided into coarse and fine gold mine tailings, with a weight ratio of approximately 50:50, using 270 mesh as the dividing line. However, due to the excessively small particle size of fine gold mine tailings, it cannot meet the performance requirements of backfill material. Moreover, due to the constraints of mining backfill space, generally only coarse gold mine tailings (particle size greater than 270 mesh) can be used as backfill aggregate. Therefore, the remaining fine gold mine tailings (particle size less than 270 mesh) constitute the majority and cannot be effectively processed. Meanwhile, due to limitations such as particle size, the remaining fine gold ore tailings sand has few utilization pathways and low consumption, making it impossible to effectively reuse it. Summary of the Invention

[0004] To address the technical problems existing in the prior art, this invention provides a backfill material made from gold mine tailings sand, its preparation method, and its application. This material can effectively reuse gold mine tailings sand (especially fine gold mine tailings sand), effectively solving the problems of limited utilization pathways, low consumption, and ineffective reuse of fine gold mine tailings sand in existing gold mine tailings sand reuse methods, as well as the environmental pollution, severe dust, and management difficulties caused by gold mine tailings sand.

[0005] To solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0006] A backfill material made from gold mine tailings sand includes the following components: a special solidifying agent for mine backfilling and gold mine tailings sand;

[0007] The special solidifying agent for mine backfilling includes the following components: cement clinker, slag, sodium chloride, sodium sulfate, aluminum sulfate, and polyacrylamide;

[0008] The specific surface area of ​​the special solidifying agent for mine backfilling is ≥450m². 2 / Kg.

[0009] Preferably, the backfill material comprises, by weight, the following components: 3-12 parts of a special curing agent for mine backfilling and 48-67 parts of gold mine tailings sand.

[0010] Furthermore, the gold mine tailings sand is at least one of the following: coarse gold mine tailings sand, fine gold mine tailings sand.

[0011] Furthermore, the coarse gold ore tailings sand has a particle size of less than 40 mesh and greater than 270 mesh; the fine gold ore tailings sand has a particle size of less than 270 mesh.

[0012] Preferably, the special curing agent for mine backfilling comprises, by weight, the following components: 20-40 parts cement clinker, 55-78 parts slag, 0.5-1.5 parts sodium chloride, 2-3.5 parts sodium sulfate, 0.2-0.7 parts aluminum sulfate, and 0.1-0.2 parts polyacrylamide.

[0013] Preferably, the specific surface area of ​​the mine backfill-specific curing agent is 450-500 m². 2 / Kg.

[0014] Furthermore, in the aforementioned mine backfill-specific curing agent, the cement clinker is silicate cement clinker with a particle size of <10mm;

[0015] The slag is water-quenched granulated blast furnace slag with a moisture content of ≤1.0wt%.

[0016] A method for preparing the aforementioned backfill material made from gold mine tailings sand includes the following steps: preparing a special solidifying agent for mine backfilling, and mixing the materials;

[0017] The method for preparing the special solidifying agent for mine backfilling is as follows: cement clinker, slag, sodium chloride, sodium sulfate, aluminum sulfate, and polyacrylamide are fed into a ball mill and ground until the specific surface area is ≥450 m². 2 / Kg, to obtain a special solidifying agent for mine backfilling;

[0018] The mixing method involves uniformly mixing a special solidifying agent for mine backfilling with gold mine tailings sand to obtain backfill material made from gold mine tailings sand.

[0019] Furthermore, the preparation method further includes the following step: material preparation;

[0020] The method for preparing the materials is as follows: the cement clinker is crushed to a particle size of <10mm and set aside; the slag is dried to a moisture content of ≤1.0wt% and set aside; the cement clinker, slag, sodium chloride, sodium sulfate, aluminum sulfate, and polyacrylamide are weighed according to their weight parts to complete the material preparation.

[0021] An application of the aforementioned backfill material made from gold mine tailings sand involves mixing the backfill material made from gold mine tailings sand with water to obtain a backfill slurry; and using the backfill slurry for mine backfilling.

[0022] Preferably, the weight ratio of water to gold mine tailings sand in the backfill material is 30-40:48-67.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] 1. The backfill material made from gold mine tailings sand of the present invention can effectively reuse gold mine tailings sand (especially fine gold mine tailings sand), effectively solving the problems of limited utilization channels, low consumption, and ineffective reuse of fine gold mine tailings sand in the existing gold mine tailings sand reuse, as well as the environmental pollution, serious dust, and management difficulties caused by gold mine tailings sand.

[0025] 2. The backfill material made from gold mine tailings sand of the present invention is designed with specific raw material composition and specifications (specific surface area) of a curing agent that is tailings sand with particular characteristics of gold mine tailings sand, especially fine gold mine tailings sand. This effectively improves the coating of cementitious materials onto aggregates (especially fine gold mine tailings sand), and, in conjunction with flocculation components, accelerates the dewatering rate of the backfill material. It also incorporates early strength components to stimulate the early strength of the backfill material, thereby achieving effective backfilling of mines and meeting mining progress requirements.

[0026] 3. In the backfill material made from gold mine tailings sand of the present invention, the special curing agent for mine backfilling has a good curing effect on fine gold mine tailings sand, coarse gold mine tailings sand, or a combination of both. It has strong adaptability to gold mine tailings sand of different particle sizes, and can enable the backfill material made from fine gold mine tailings sand to obtain ideal strength performance, thereby realizing the full and effective recycling of gold mine tailings sand.

[0027] 4. Through testing, the backfill material made from gold mine tailings sand of the present invention, when mixed with a predetermined amount of water to obtain backfill slurry, can be directly used for mine backfilling operations; using fine gold mine tailings sand as aggregate, the 2-day strength can reach 1.29 MPa and the 3-day strength can reach 2.31 MPa; using both fine and coarse gold mine tailings sand as aggregate, the 2-day strength can reach 1.25 MPa and the 3-day strength can reach 2.24 MPa; using coarse gold mine tailings sand as aggregate, the 2-day strength can reach 1.27 MPa and the 3-day strength can reach 2.22 MPa. Detailed Implementation

[0028] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention are now described.

[0029] Example 1

[0030] This embodiment provides a backfill material made from gold mine tailings sand, which, by weight, consists of the following components: 8.5 parts of a special solidifying agent for mine backfilling and 51.5 parts of fine gold mine tailings sand (ocean-dry weight).

[0031] Among them, the particle size of the fine gold ore tailings sand is less than 270 mesh.

[0032] The special hardener for mine backfilling, by weight, consists of the following components: 21 parts cement clinker, 75 parts slag, 0.7 parts sodium chloride, 2.9 parts sodium sulfate, 0.3 parts aluminum sulfate, and 0.1 parts polyacrylamide; the specific surface area of ​​the special hardener for mine backfilling is 465 m². 2 / Kg.

[0033] The cement clinker is silicate cement clinker with a particle size of <10mm.

[0034] The slag is water-quenched granulated blast furnace slag, with a silica content of 35wt%, aluminum oxide of 16wt%, calcium oxide of 38wt%, magnesium oxide of 10wt%, and a moisture content of ≤1.0wt%.

[0035] This embodiment also provides a method for preparing the aforementioned backfill material made from gold mine tailings sand, specifically:

[0036] Step 1) Material preparation

[0037] Cement clinker is crushed to a particle size of <10mm and set aside; slag is dried to a moisture content of ≤1.0wt% and set aside; by weight, 21 parts of cement clinker, 75 parts of slag, 0.7 parts of sodium chloride, 2.9 parts of sodium sulfate, 0.3 parts of aluminum sulfate, and 0.1 parts of polyacrylamide are weighed to complete the material preparation.

[0038] Step 2) Preparation of a special curing agent for mine backfilling

[0039] The prepared cement clinker, slag, sodium chloride, sodium sulfate, aluminum sulfate, and polyacrylamide are fed into a ball mill and ground until the specific surface area is 465 m². 2 / Kg, to obtain a special solidifying agent for mine backfilling.

[0040] Step 3) Mixing

[0041] Weigh out 8.5 parts of mine backfill solidifying agent and 51.5 parts of fine gold mine tailings sand (dry weight) by weight, mix them evenly, and obtain backfill material made of gold mine tailings sand.

[0042] This embodiment also provides the application of the aforementioned backfill material made from gold mine tailings sand, specifically:

[0043] The backfill material made from gold mine tailings sand is mixed with water and stirred evenly (stirring time 5 minutes) to obtain backfill slurry, and then the mine backfilling operation is carried out.

[0044] The weight ratio of water to fine gold ore tailings sand (dry weight) in the backfill material is 40:51.5.

[0045] According to the test, the backfill material made from gold mine tailings sand in this embodiment has a 2-day compressive strength of 1.29 MPa and a 3-day compressive strength of 2.31 MPa.

[0046] Example 2

[0047] This embodiment provides a backfill material made from gold mine tailings sand, which, by weight, consists of the following components: 7.2 parts of a special solidifying agent for mine backfilling, 28.9 parts of fine gold mine tailings sand (ocean dry weight), and 28.9 parts of coarse gold mine tailings sand (ocean dry weight).

[0048] Among them, the particle size of the fine gold ore tailings sand is less than 270 mesh.

[0049] The particle size of the tailings sand from coarse gold ore is less than 40 mesh and greater than 270 mesh.

[0050] The special hardener for mine backfilling, by weight, consists of the following components: 32 parts cement clinker, 64 parts slag, 1.2 parts sodium chloride, 2.2 parts sodium sulfate, 0.5 parts aluminum sulfate, and 0.1 parts polyacrylamide; the specific surface area of ​​the special hardener for mine backfilling is 472 m². 2 / Kg.

[0051] The cement clinker is silicate cement clinker with a particle size of <10mm.

[0052] The slag is water-quenched granulated blast furnace slag, with a silica content of 35wt%, aluminum oxide of 16wt%, calcium oxide of 38wt%, magnesium oxide of 10wt%, and a moisture content of ≤1.0wt%.

[0053] This embodiment also provides a method for preparing the aforementioned backfill material made from gold mine tailings sand, specifically:

[0054] Step 1) Material preparation

[0055] Cement clinker is crushed to a particle size of <10mm and set aside; slag is dried to a moisture content of ≤1.0wt% and set aside; by weight, 32 parts of cement clinker, 64 parts of slag, 1.2 parts of sodium chloride, 2.2 parts of sodium sulfate, 0.5 parts of aluminum sulfate, and 0.1 parts of polyacrylamide are weighed to complete the material preparation.

[0056] Step 2) Preparation of a special curing agent for mine backfilling

[0057] The prepared cement clinker, slag, sodium chloride, sodium sulfate, aluminum sulfate, and polyacrylamide are fed into a ball mill and ground until the specific surface area is 472 m². 2 / Kg, to obtain a special solidifying agent for mine backfilling.

[0058] Step 3) Mixing

[0059] Weigh out 7.2 parts of mine backfill solidifying agent, 28.9 parts of fine gold ore tailings sand (dry weight), and 28.9 parts of coarse gold ore tailings sand (dry weight) by weight, mix them evenly, and obtain backfill material made of gold ore tailings sand.

[0060] This embodiment also provides the application of the aforementioned backfill material made from gold mine tailings sand, specifically:

[0061] The backfill material made from gold mine tailings sand is mixed with water and stirred evenly (stirring time 8 minutes) to obtain backfill slurry, and then the mine backfilling operation is carried out.

[0062] The weight ratio of water to fine gold ore tailings sand (dry weight) in the backfill material is 35:28.9.

[0063] According to the test, the backfill material made from gold mine tailings sand in this embodiment has a 2-day compressive strength of 1.25 MPa and a 3-day compressive strength of 2.24 MPa.

[0064] Example 3

[0065] This embodiment provides a backfill material made from gold mine tailings sand, which, by weight, consists of the following components: 5.4 parts of a special solidifying agent for mine backfilling and 64.6 parts of coarse gold mine tailings sand (ocean-dry weight).

[0066] Among them, the particle size of the crude gold ore tailings sand is less than 40 mesh and greater than 270 mesh.

[0067] The special hardener for mine backfilling, by weight, consists of the following components: 40 parts cement clinker, 55.2 parts slag, 1.5 parts sodium chloride, 2.0 parts sodium sulfate, 0.7 parts aluminum sulfate, and 0.2 parts polyacrylamide; the specific surface area of ​​the special hardener for mine backfilling is 460 m². 2 / Kg.

[0068] The cement clinker is silicate cement clinker with a particle size of <10mm.

[0069] The slag is water-quenched granulated blast furnace slag, with a silica content of 35wt%, aluminum oxide of 16wt%, calcium oxide of 38wt%, magnesium oxide of 10wt%, and a moisture content of ≤1.0wt%.

[0070] This embodiment also provides a method for preparing the aforementioned backfill material made from gold mine tailings sand, specifically:

[0071] Step 1) Material preparation

[0072] Cement clinker is crushed to a particle size of <10mm and set aside; slag is dried to a moisture content of ≤1.0wt% and set aside; by weight, 40 parts of cement clinker, 55.2 parts of slag, 1.5 parts of sodium chloride, 2.0 parts of sodium sulfate, 0.7 parts of aluminum sulfate, and 0.2 parts of polyacrylamide are weighed to complete the material preparation.

[0073] Step 2) Preparation of a special curing agent for mine backfilling

[0074] The prepared cement clinker, slag, sodium chloride, sodium sulfate, aluminum sulfate, and polyacrylamide are fed into a ball mill and ground until the specific surface area is 460 m². 2 / Kg, to obtain a special solidifying agent for mine backfilling.

[0075] Step 3) Mixing

[0076] Weigh out 5.4 parts by weight of a special solidifying agent for mine backfilling and 64.6 parts by weight of crude gold ore tailings sand (dry weight), mix them evenly, and obtain backfill material made from gold ore tailings sand.

[0077] This embodiment also provides the application of the aforementioned backfill material made from gold mine tailings sand, specifically:

[0078] The backfill material made from gold mine tailings sand is mixed with water and stirred evenly (stirring time 10 minutes) to obtain backfill slurry, and then the mine backfilling operation is carried out.

[0079] The weight ratio of water to crude gold ore tailings sand (dry weight) in the backfill material is 30:64.6.

[0080] According to the test, the backfill material made from gold mine tailings sand in this embodiment has a 2-day compressive strength of 1.27 MPa and a 3-day compressive strength of 2.22 MPa.

[0081] As can be seen from Examples 1-3, the backfill material made from gold mine tailings sand of the present invention exhibits good curing effect on fine gold mine tailings sand, coarse gold mine tailings sand, or a combination of both, and is highly adaptable to gold mine tailings sand of different particle sizes. Compared with Example 3, which uses coarse gold mine tailings sand, Example 1, which uses fine gold mine tailings sand, has comparable 2d and 3d compressive strengths, both achieving ideal backfill performance. This enables effective reuse of gold mine tailings sand (especially fine gold mine tailings sand), solving the problems of limited utilization pathways, low consumption, and ineffective reuse of fine gold mine tailings sand, as well as the environmental pollution, severe dust, and management difficulties caused by gold mine tailings sand. Furthermore, the backfill material made from gold mine tailings sand of the present invention exhibits good early strength during application, enabling effective backfilling of mines and meeting mining progress requirements.

[0082] Example 4

[0083] This embodiment provides a backfill material made from gold mine tailings sand, which, by weight, consists of the following components: 8.5 parts of a special solidifying agent for mine backfilling, 51.5 parts of fine gold mine tailings sand (ocean dry weight), and 2.5 parts of a reinforcing agent.

[0084] Among them, the particle size of the fine gold ore tailings sand is less than 270 mesh.

[0085] The special hardener for mine backfilling, by weight, consists of the following components: 21 parts cement clinker, 75 parts slag, 0.7 parts sodium chloride, 2.9 parts sodium sulfate, 0.3 parts aluminum sulfate, and 0.1 parts polyacrylamide; the specific surface area of ​​the special hardener for mine backfilling is 465 m². 2 / Kg.

[0086] The cement clinker is silicate cement clinker with a particle size of <10mm.

[0087] The slag is water-quenched granulated blast furnace slag, with a silica content of 35wt%, aluminum oxide of 16wt%, calcium oxide of 38wt%, magnesium oxide of 10wt%, and a moisture content of ≤1.0wt%.

[0088] The preparation method of the reinforcing agent is as follows:

[0089] A. Pretreatment

[0090] Silicon carbide particles were placed in a plasma device, and hydrogen and nitrogen in a volume ratio of 0.15:1 were used as plasma treatment gases. The flow rate of the plasma treatment gases was controlled at 400 sccm, the plasma treatment power was 800 W, and the plasma treatment time was 10 min to obtain the first pretreated material, which was ready for use. Aramid fibers were placed in a plasma device, and nitrogen was used as plasma treatment gas. The flow rate of the plasma treatment gases was controlled at 200 sccm, the plasma treatment power was 1000 W, and the plasma treatment time was 5 min to obtain the second pretreated material, which was ready for use.

[0091] The aramid fiber has a filament length of 10 mm and a filament diameter of 0.08 mm.

[0092] The silicon carbide particles have a particle size of 325 mesh.

[0093] B. Modification

[0094] The first and second pretreated materials were added to a 70% (v / v) ethanol solution and dispersed evenly. The mixture was stirred and heated to 55°C, kept at this temperature, and silane coupling agent KH-570 was added dropwise. After the addition was complete, the mixture was kept at this temperature and stirred for another 8 hours. The solid was then separated. The solid was washed with 5 times its weight of deionized water and dried at 90°C for 6 hours to obtain the dried product. The dried product was then transferred to a ball mill, and a 45% (v / v) polyethyleneimine aqueous solution was added to the ball mill. After ball milling for 30 minutes, the ball-milled product was removed and placed in a vacuum environment of 0.02 MPa. It was then dried at 80°C to constant weight to obtain the reinforcing agent.

[0095] The weight ratio of the first pretreatment material, the second pretreatment material, the ethanol solution, and the silane coupling agent KH-570 is 2.5:6:0.4:60.

[0096] The weight ratio of the dried material to the polyethyleneimine aqueous solution is 10:3.

[0097] This embodiment also provides a method for preparing the aforementioned backfill material made from gold mine tailings sand, specifically:

[0098] Step 1) Material preparation

[0099] Cement clinker is crushed to a particle size of <10mm and set aside; slag is dried to a moisture content of ≤1.0wt% and set aside; by weight, 21 parts of cement clinker, 75 parts of slag, 0.7 parts of sodium chloride, 2.9 parts of sodium sulfate, 0.3 parts of aluminum sulfate, and 0.1 parts of polyacrylamide are weighed to complete the material preparation.

[0100] Step 2) Preparation of a special curing agent for mine backfilling

[0101] The prepared cement clinker, slag, sodium chloride, sodium sulfate, aluminum sulfate, and polyacrylamide are fed into a ball mill and ground until the specific surface area is 465 m². 2 / Kg, to obtain a special solidifying agent for mine backfilling.

[0102] Step 3) Mixing

[0103] Weigh out 8.5 parts of a special solidifying agent for mine backfilling, 51.5 parts of fine gold mine tailings sand (dry weight), and 2.5 parts of a reinforcing agent by weight, mix them evenly, and obtain a backfill material made from gold mine tailings sand.

[0104] This embodiment also provides the application of the aforementioned backfill material made from gold mine tailings sand, specifically:

[0105] The backfill material made from gold mine tailings sand is mixed with water and stirred evenly (stirring time 5 minutes) to obtain backfill slurry, and then the mine backfilling operation is carried out.

[0106] The weight ratio of water to fine gold ore tailings sand (dry weight) in the backfill material is 40:51.5.

[0107] According to the test, the backfill material made from gold mine tailings sand in this embodiment has a 2-day compressive strength of 1.83 MPa, a 3-day compressive strength of 3.09 MPa, a 7-day compressive strength of 22.62 MPa, a 7-day flexural strength of 9.2 MPa, and a permeability grade of P6.

[0108] Comparative Example 1

[0109] Corresponding to Example 3, the backfill material of Comparative Example 1, by weight, consists of the following components: 5.4 parts of commercially available curing agent and 64.6 parts of crude gold ore tailings sand.

[0110] Among them, the particle size of the crude gold ore tailings sand is less than 40 mesh and greater than 270 mesh.

[0111] The backfill material of Comparative Example 1 was mixed with water to obtain backfill slurry. After that, a performance test was conducted. The 2-day compressive strength was 0.69 MPa and the 3-day compressive strength was 1.22 MPa.

[0112] The weight ratio of water to crude gold ore tailings sand (dry weight) in the backfill material is 30:64.6.

[0113] Comparative Example 2

[0114] Corresponding to Example 1, the backfill material of Comparative Example 2, by weight, consists of the following components: 8.5 parts of commercially available curing agent and 51.5 parts of fine gold ore tailings sand.

[0115] Among them, the particle size of the fine gold ore tailings sand is less than 270 mesh.

[0116] The backfill material of Comparative Example 2 was mixed with water to obtain backfill slurry. After that, a performance test was conducted. The 2-day compressive strength was 0.67 MPa and the 3-day compressive strength was 1.09 MPa.

[0117] The weight ratio of water to crude gold ore tailings sand (dry weight) in the backfill material is 40:51.5.

[0118] As can be seen from Comparative Examples 1-2, the curing agents in the existing backfill materials cannot effectively solidify gold mine tailings sand, especially for fine gold mine tailings sand. They have low early strength and cannot effectively backfill the mine, thus failing to meet the mining schedule requirements and causing delays in the mining period.

[0119] Unless otherwise stated, all percentages used in this invention are mass percentages.

[0120] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A backfill material made from gold mine tailings sand, characterized in that, The backfill material, by weight, consists of the following components: 3-12 parts of a special solidifying agent for mine backfilling and 48-67 parts of gold mine tailings sand. The gold mine tailings sand is fine gold mine tailings sand; the particle size of the fine gold mine tailings sand is less than 270 mesh. The special solidifying agent for mine backfilling, by weight, is composed of the following components: 20-40 parts cement clinker, 55-78 parts slag, 0.5-1.5 parts sodium chloride, 2-3.5 parts sodium sulfate, 0.2-0.7 parts aluminum sulfate, and 0.1-0.2 parts polyacrylamide. The specific surface area of ​​the special solidifying agent for mine backfilling is 450-500 m². 2 / Kg; The cement clinker is silicate cement clinker with a particle size of <10mm; The slag is water-quenched granulated blast furnace slag with a moisture content of ≤1.0wt%.

2. A method for preparing backfill material made from gold mine tailings sand as described in claim 1, characterized in that, The preparation method includes the following steps: preparing a special solidifying agent for mine backfilling, and mixing the materials; The method for preparing the special solidifying agent for mine backfilling involves feeding cement clinker, slag, sodium chloride, sodium sulfate, aluminum sulfate, and polyacrylamide into a ball mill and grinding them until the specific surface area is 450-500 m². 2 / Kg, to obtain a special solidifying agent for mine backfilling; The mixing method involves uniformly mixing a special solidifying agent for mine backfilling with gold mine tailings sand to obtain backfill material made from gold mine tailings sand.

3. An application of a backfill material made from gold mine tailings sand as described in claim 1, characterized in that, The backfill material made from gold mine tailings sand is mixed evenly with water to obtain backfill slurry; the backfill slurry is used for mine backfilling.

4. The application of the backfill material made from gold mine tailings sand according to claim 3, characterized in that, The weight ratio of water to gold mine tailings sand in the backfill material is 30-40:48-67.