All-solid-waste high-flow-state mine filling material, slurry containing all-solid-waste high-flow-state mine filling material and preparation method

Abstract

The invention relates to the technical field of filling materials, in particular to a full-solid-waste high-flow-state mine filling material, slurry containing the full-solid-waste high-flow-state mine filling material and a preparation method. The invention provides an all-solid-waste high-flow-state mine filling material which comprises the following components in parts by mass: 130-160 parts of a cementing material, 20-50 parts of an admixture, 300-400 parts of aggregate and 1-12 parts of an additive, the additive is prepared from the following components in parts by weight: 1 to 10 parts of exciting agent, 0.05 to 0.1 part of water-retaining thickening agent, 0.1 to 0.5 part of water reducing agent and 0.01 to 0.5 part of coagulation accelerator. According to the filling material, various solid wastes are used as main raw materials and matched with specific additives, so that synergistic utilization of different solid wastes is realized, and the green filling material with low carbon emission, low energy consumption and low cost is obtained. Slurry of the filling material has the high flow state maintaining characteristic of 3-4 h, the purpose of being capable of being pumped for a long time is achieved, and the slurry can be gradually coagulated within 6-8 h and reach the demolding self-standing standard.

Description

Technical Field

[0001] The present invention relates to the technical field of filling materials, and in particular to a full-solid waste high-fluidity mine filling material, a slurry containing the same, and a preparation method thereof. Background Art

[0002] Mine backfilling is a widely used mining method in the world, and mine backfilling materials are one of the most important technologies. my country has been exploring and developing mine backfilling materials since the 1950s, and has experienced the iterative development of dry backfilling, water-sand + cementing two-phase pipeline backfilling, full water solidification backfilling, paste-like backfilling and paste backfilling. At present, paste pumping backfilling has become the main backfilling technology at this stage. However, the current paste backfilling materials mainly use silicate cement as the main cementing component, which leads to high overall carbon emissions and production costs of backfilling materials, so its environmental sustainability and economic benefits need to be further optimized.

[0003] The rapid resource utilization of bulk solid waste and the research and development and use of low-carbon cementitious materials have become long-term development goals in the future. However, due to the large number of solid waste types in my country and the large differences between solid wastes, it is difficult to achieve large-scale synergistic and comprehensive utilization of various types of solid wastes, and the composition and function of various types of solid wastes have not been fully utilized and exerted. In order to achieve full utilization of solid waste, patent CN114133199A discloses a semi-hydrated phosphogypsum-based polymer-cemented phosphate tailings filling material and a preparation method thereof, which uses semi-hydrated phosphogypsum, a by-product of the phosphorus chemical industry, as the main raw material and mixed with auxiliary materials as a cementing material, and uses phosphorus tailings and mine waste rock as aggregates to prepare a mixed filling material with high early strength, good water permeability, good fluidity and good water resistance. However, this filling material can only consume by-products of the phosphorus chemical industry and mine waste rock, and has not achieved comprehensive and synergistic utilization of other types of solid wastes such as fly ash, slag, copper / iron tailings and coal gangue. Patent CN 113443884A discloses a paste filling material, slurry and filling body for goaf, wherein the filling material includes the following raw materials: 100-140 parts of coal gangue, 60-120 parts of fly ash, 10-32 parts of cement, 20-50 parts of desulfurized gypsum and 10-50 parts of stone powder. Although solid wastes such as coal gangue, fly ash, gypsum and stone powder are used in its raw materials, there are still many solid wastes that have not been comprehensively utilized; moreover, the water seepage rate of the obtained slurry is not less than 5%, which may cause the slurry to lose fluidity during the working process, thereby seriously affecting the workability and reliability of the slurry, causing segregation or pump blockage, and causing adverse consequences for the quality of the project.

[0004] Therefore, it is necessary to develop a filling material that can not only absorb and utilize a variety of solid waste raw materials, but also maintain a long flow and pumpable state and have a short setting and hardening time, so as to help achieve rapid filling and mining of mine goafs. Summary of the invention

[0005] In view of this, the present invention provides a fully solid waste high-fluidity mine filling material, which uses various types of solid waste as the main raw materials and is used in combination with specific admixtures to achieve the coordinated resource utilization of different types of solid wastes, thereby obtaining a green mine filling material with low carbon emissions, low energy consumption and low cost.

[0006] In order to solve the above technical problems, the present invention provides a full-solid waste high-fluidity mine filling material, which includes, in terms of mass percentage, 130-160 parts of cementitious material, 20-50 parts of admixture, 300-400 parts of aggregate, and 1-12 parts of admixture; wherein the admixture includes 1-10 parts of activator, 0.05-0.1 parts of water-retaining thickener, 0.1-0.5 parts of water reducer, and 0.01-0.5 parts of coagulant.

[0007] The all-solid waste high-fluidity mine filling material provided by the present invention, the cementitious materials, admixtures and aggregates used are all solid wastes, and the weight proportion is as high as more than 95%. Among them, the cementitious materials can cement various components and improve the strength of the filling materials, the admixtures can improve the fluidity of the slurry and reduce the material cost, and the aggregates mainly play the role of reducing the material cost. The present invention combines the above multiple different types of solid waste with a small amount of admixtures to successfully obtain a full-solid waste high-fluidity mine filling material in which the slurry can maintain high fluidity pumpability for 3 to 4 hours, and can gradually solidify in 6 to 8 hours and reach the standard of demolding and self-reliance.

[0008] In combination with the first aspect, the cementitious material includes 100 parts of a main cementitious material and 30-60 parts of an auxiliary cementitious material: the main cementitious material includes 60-70 parts of fly ash and 30-40 parts of slag or steel slag; the auxiliary cementitious material includes 20-40 parts of power plant slag, kaolin and / or cement, and 10-20 parts of desulfurized gypsum, phosphogypsum and / or titanium gypsum.

[0009] Preferably, the fly ash is secondary fly ash, the slag is S95 grade slag, the particle size of the steel slag is 20-40 μm; and the particle size of the auxiliary cementitious material is 20-40 μm.

[0010] In combination with the first aspect, the admixture is selected from one or more of copper tailings, iron tailings, quartz tailings and gold tailings, and the aggregate is selected from one or more of coal gangue, construction solid waste machine-made sand and waste incineration slag.

[0011] In combination with the first aspect, the particle size of the aggregate is 0.3-10 mm, wherein, by weight percentage, the aggregate with a particle size of 0.3-1 mm accounts for less than 20%, and the aggregate with a particle size of 5-10 mm accounts for less than 20%.

[0012] In combination with the first aspect, the activator includes 5-10 parts of water glass or quick-dissolving sodium silicate, or 1-5 parts of sodium hydroxide, calcium hydroxide or red mud.

[0013] The present invention can stimulate the potential activity of various solid wastes by using the above composite activator, promote the generation of gel phase, and thus improve the strength performance of the filling material.

[0014] In combination with the first aspect, the water-retaining thickener is sodium polyacrylate, hydroxymethyl propyl cellulose or calcium stearate. The addition of the water-retaining thickener can increase the viscosity and water retention of the filling slurry, reduce the water bleeding rate, and reduce the segregation of the slurry.

[0015] In combination with the first aspect, the water reducer is a polycarboxylate water reducer, a naphthalene water reducer or sodium lignin sulfonate. The addition of the water reducer can reduce the amount of water used and increase the viscosity of the filling material slurry.

[0016] In combination with the first aspect, the coagulant includes 0.1-0.5 parts of sodium chloride or 0.01-0.1 parts of catechol. The use of the coagulant can promote the coagulation of the filling material and improve the early strength.

[0017] The second aspect of the present invention provides a fully solid waste high-fluidity mine filling slurry, comprising: 130-160 parts of cementitious materials, 20-50 parts of admixtures, 300-400 parts of aggregates, 1-12 parts of admixtures, and 150-180 parts of water; wherein the admixtures include 1-10 parts of activators, 0.05-0.1 parts of water-retaining thickeners, 0.1-0.5 parts of water-reducing agents, and 0.01-0.5 parts of coagulants.

[0018] Preferably, the amount of water added is 150-160 parts.

[0019] The all-solid waste high-fluidity mine filling slurry provided by the present invention has high fluidity characteristics and fluidity retention characteristics. It can maintain high fluidity pumpability for 3 to 4 hours and maintain a long-term pipeline pumping state. At the same time, it can gradually coagulate in 6 to 8 hours and reach the standard of demoulding self-reliance.

[0020] The initial slump of the filling slurry is >260mm, and the fluidity is >500mm; the slump loss in 3h is <10%, and the fluidity loss is <10%; the slump loss in 4h is <15%, and the fluidity loss is <15%; at the same time, the filling slurry has a shorter setting and hardening time, the initial setting time is <6h, and it can reach the standard of demoulding and self-supporting in 6-8h, and the final setting time can be controlled at 10-12h; the water bleeding rate is <5%; the compressive strength 3d after demoulding is >2Mpa, the compressive strength 7d after demoulding is >4MPa, and the compressive strength 28d after demoulding is >5MPa.

[0021] The third aspect of the present invention provides a method for preparing a fully solid waste high-fluidity mine filling slurry, the specific steps of which are: uniformly mixing the cementitious material, admixture, aggregate and additive, adding water and stirring sufficiently to obtain the fully solid waste high-fluidity mine filling slurry.

[0022] To ensure the stirring effect, the cementitious material, admixture and aggregate should be mixed evenly first, then the admixture should be added and mixed, and then water should be added and stirred.

[0023] The characteristics and innovations of the present invention are: using various types of solid waste as the main raw materials, by using a specific type of admixture, using alkali excitation technology to make different solid wastes give full play to their role, realizing the coordinated resource utilization of different solid wastes, and successfully obtaining a low-carbon emission, low-energy consumption, low-cost green mine filling material. The slurry of the filling material (i.e., the filling slurry) has a high fluidity retention characteristic of up to 3 to 4 hours, which can achieve the purpose of being pumpable for a long time. Specifically: within 3 to 4 hours, the fluidity / slump of the filling material slurry not only has a small loss, but also can maintain a flowing and pumpable state. At the same time, the slurry of the filling material has a short coagulation time, and can be coagulated and hardened in 6 to 8 hours to achieve self-demolding, and completely coagulate in 10 to 12 hours, so as to achieve rapid demolding, thereby not affecting mining efficiency. The all-solid waste high-fluidity mine filling material provided by the present invention is conducive to the rapid and large-scale disposal of bulk solid waste, and provides assistance for the rapid filling and mining of mine goafs. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A preparation process roadmap of the filling material provided by the present invention;

[0025] Figure 2 This is a photograph of the fluidity test of the filling slurry obtained in Example 1 of the present invention for 4 hours. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0027] In view of the low utilization rate of solid waste in current mine filling materials, and the poor pumpability of the corresponding slurry during pipeline transportation, which is prone to pipe blockage, the present invention provides a full solid waste high-flow mine filling material with a solid waste ratio of more than 95% and a corresponding filling slurry, which can not only maintain high flow pumpability for 3 to 4 hours, but also gradually solidify and reach the standard of demolding and self-supporting in 6 to 8 hours. Compared with the existing mainstream cement-based system, the material system of the filling material has obvious material component differences and outstanding economic benefits. However, since the main components of the filling material come from different types of solid waste materials, the filling material system provided by the present invention has greater difficulty and challenges in the time controllability of various indicators compared with the existing mainstream cement-based system.

[0028] The raw materials and reagents used in the following examples and comparative examples are all commercially available industrial products, and the instruments used for preparation or testing are also commonly used instruments in the industry. Among them, the particle size of the aggregate used is 0.3-10 mm, the aggregate with a particle size of 0.3-1 mm accounts for less than 20wt%, and the aggregate with a particle size of 5-10 mm accounts for less than 20wt%.

[0029] Example 1

[0030] This embodiment provides a fully solid waste high-fluidity mine filling material and a fully solid waste high-fluidity mine filling slurry, the specific raw material composition and proportion of which are shown in Table 1:

[0031] Table 1

[0032]

[0033] Among them, the preparation method of the all-solid waste high-fluidity mine filling slurry is: according to the composition ratio of the filling material in Table 1, the raw materials are mixed evenly, and the formulated amount of water is added and stirred sufficiently to obtain the filling slurry.

[0034] Example 2

[0035] This embodiment provides a fully solid waste high-fluidity mine filling material and a fully solid waste high-fluidity mine filling slurry, the specific raw material composition and proportion of which are shown in Table 2:

[0036] Table 2

[0037]

[0038] Among them, the preparation method of the all-solid waste high-fluidity mine filling slurry is: according to the composition ratio of the filling material in Table 2, the raw materials are mixed evenly, and the formulated amount of water is added and stirred sufficiently to obtain the filling slurry.

[0039] Example 3

[0040] This embodiment provides a fully solid waste high-fluidity mine filling material and a fully solid waste high-fluidity mine filling slurry, the specific raw material composition and proportion of which are shown in Table 3:

[0041] Table 3

[0042]

[0043] Among them, the preparation method of the all-solid waste high-fluidity mine filling slurry is: according to the composition ratio of the filling material in Table 3, the raw materials are mixed evenly, and the formulated amount of water is added and stirred sufficiently to obtain the filling slurry.

[0044] Example 4

[0045] This embodiment provides a fully solid waste high-fluidity mine filling material and a fully solid waste high-fluidity mine filling slurry, the specific raw material composition and proportion of which are shown in Table 4:

[0046] Table 4

[0047]

[0048] Among them, the preparation method of the all-solid waste high-fluidity mine filling slurry is: according to the composition ratio of the filling material in Table 4, the raw materials are mixed evenly, and the formulated amount of water is added and stirred sufficiently to obtain the filling slurry.

[0049] Comparative Example 1

[0050] This comparative example provides a fully solid waste high-fluidity mine filling material and a fully solid waste high-fluidity mine filling slurry, the specific raw material composition and proportion are basically the same as the proportion in Example 1, the only difference is that the admixture used does not include a coagulant, and the remaining composition and dosage are the same as in Example 1, and the preparation method of the slurry is also the same as in Example 1.

[0051] Comparative Example 2

[0052] This comparative example provides a fully solid waste high-fluidity mine filling material and a fully solid waste high-fluidity mine filling slurry, the specific raw material composition and proportion are basically the same as the proportion in Example 1, the only difference is that the admixture used does not include an activator, and the remaining composition and dosage are the same as in Example 1, and the preparation method of the slurry is also the same as in Example 1.

[0053] Comparative Example 3

[0054] This comparative example provides an all-solid waste high-fluidity mine filling material and an all-solid waste high-fluidity mine filling slurry, the specific raw material composition and proportion are basically the same as the proportion in Example 1, the only difference is that the admixture used does not include a water-retaining thickener, and the other compositions and amounts are the same as in Example 1, and the preparation method of the slurry is also the same as in Example 1.

[0055] Comparative Example 4

[0056] This comparative example provides a fully solid waste high-fluidity mine filling material and a fully solid waste high-fluidity mine filling slurry, the specific raw material composition and proportion are basically the same as the proportion in Example 1, the only difference is that the admixture used does not include a water reducer, and the other compositions and amounts are the same as in Example 1, and the preparation method of the slurry is also the same as in Example 1.

[0057] Comparative Example 5

[0058] This comparative example provides an all-solid waste high-fluidity mine filling material and an all-solid waste high-fluidity mine filling slurry, the specific raw material composition and proportion are basically the same as the proportion in Example 1, the only difference is that the coagulant is replaced by calcium acrylate, and the other compositions and amounts are the same as in Example 1, and the preparation method of the slurry is also the same as in Example 1.

[0059] Comparative Example 6

[0060] This comparative example provides an all-solid waste high-fluidity mine filling material and an all-solid waste high-fluidity mine filling slurry, the specific raw material composition and proportion are basically the same as the proportion in Example 1, the only difference is that the coagulant is replaced by sodium fluoride and calcium silicate mixed in an equal mass ratio, and the other compositions and amounts are the same as in Example 1, and the preparation method of the slurry is also the same as in Example 1.

[0061] Test example

[0062] The performance tests were carried out on the all-solid waste high-fluidity mine filling slurry obtained in Examples 1 to 4 and Comparative Examples 1 to 6, respectively, and the slump and fluidity at initial, 1h, 2h, 3h and 4h were tested according to the standard "Standard for Performance Test Methods of Ordinary Concrete Mixtures" (GB / T 50080-2016). At the same time, during the slump test, the water seepage rate of the slurry is tested at the same time, according to the concrete water seepage rate test method (Standard for Performance Test Methods of Ordinary Concrete Mixtures (GB / T 50080-2016). After the 4h slump test is completed, the slurry is poured into the concrete test mold, and the setting time is tested every half an hour after 6h (the setting time in Tables 5 to 14 refers to the time when the slurry can be demolded and self-supporting) until the slurry is finally set. The strength test of the material after final setting is carried out according to the concrete strength test standard (Standard for Inspection and Evaluation of Concrete Strength (GB / T 50107-2010), and the compressive strength of the material is tested at 3d, 7d and 28d after final setting. The test results of Examples 1 to 4 and Comparative Examples 1 to 6 are shown in Tables 5 to 15.

[0063] Table 5

[0064]

[0065] Table 6

[0066]

[0067] Table 7

[0068]

[0069]

[0070] Table 8

[0071]

[0072] Table 9

[0073]

[0074] Table 10

[0075]

[0076]

[0077] Table 11

[0078]

[0079] Table 12

[0080]

[0081] Table 13

[0082]

[0083] Table 14

[0084]

[0085] Comparing the data in Tables 9 to 12 with those in Table 5, it can be seen that when one of the admixtures used in the present invention is deleted, the slump, fluidity, water seepage rate and setting time of the obtained filling slurry will change, and the compressive strength of the final solidified material will decrease to varying degrees compared with Example 1. Comparing Comparative Example 1 with Example 1, it can be seen that the use of a coagulant can promote the coagulation of the filling slurry, shortening the setting time from 10h in Comparative Example 1 to 7.5h, and at the same time improving the early strength of the solidified material. From the 3d, 7d, and 28d compressive strengths of Comparative Example 2, it can be seen that the activator can stimulate the potential activity of various types of solid wastes, the alkalinity of the slurry will increase, and the formation of the gel phase will be promoted, thereby significantly improving the strength performance of the filling material. In Comparative Example 3, no water-retaining thickener was added, which resulted in an increase in the water seepage rate of the slurry from 3.8% to 7.6% in 4 hours, indicating that the water-retaining thickener can improve the viscosity and water retention of the filling slurry, and the water seepage rate in 4 hours was reduced from 7.7% to 3.8%, significantly reducing the water seepage rate of the slurry, thereby reducing the segregation of the slurry; in Comparative Example 4, no water-reducing agent was added, resulting in a significant decrease in slump and fluidity, and the compressive strength was ultimately reduced, indicating that the water-reducing agent can reduce the water consumption while improving the viscosity and strength of the filling slurry.

[0086] By comparing the data in Tables 13 to 14 with those in Table 5, it can be seen that when the coagulant used in the present invention is replaced with other types of coagulants, the setting time of the resulting filling slurry is longer than the 7.5 hours in Example 1, and the compressive strength of the final solidified material is lower than that in Example 1, indicating that the coagulant used in the present invention has good adaptability to the full solid waste system, can give full play to its coagulant effect, further improve the compressive strength of the solidified material, and control the demolding and self-supporting time to 6 to 8 hours.

[0087] What is described above is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A fully solid waste high-fluidity mine filling material, characterized in that: In terms of mass proportions, it includes: 130-160 parts of cementitious materials, 20-50 parts of admixtures, 300-400 parts of aggregates, and 1-12 parts of admixtures; wherein the admixtures include 1-10 parts of activators, 0.05-0.1 parts of water-retaining thickeners, 0.1-0.5 parts of water-reducing agents, and 0.01-0.5 parts of accelerators.

2. The all-solid waste high-fluidity mine filling material according to claim 1, characterized in that: The cementitious material includes 100 parts of a main cementitious material and 30-60 parts of an auxiliary cementitious material: the main cementitious material includes 60-70 parts of fly ash and 30-40 parts of slag or steel slag; the auxiliary cementitious material includes 20-40 parts of power plant slag, metakaolin and / or cement, and 10-20 parts of desulfurized gypsum, phosphogypsum and / or titanium gypsum.

3. The all-solid waste high-fluidity mine filling material according to claim 1, characterized in that: The admixture is selected from one or more of copper tailings, iron tailings, quartz tailings and gold tailings, and the aggregate is selected from one or more of coal gangue, construction solid waste machine-made sand and garbage incineration slag.

4. The all-solid waste high-fluidity mine filling material according to claim 3, characterized in that: The particle size of the aggregate is 0.3-10 mm, wherein, by weight percentage, the aggregate with a particle size of 0.3-1 mm accounts for less than 20%, and the aggregate with a particle size of 5-10 mm accounts for less than 20%.

5. The all-solid waste high-fluidity mine filling material according to any one of claims 1 to 4, characterized in that: The activator is 5-10 parts of water glass or quick-dissolving sodium silicate, or 1-5 parts of sodium hydroxide, calcium hydroxide or red mud.

6. The all-solid waste high-fluidity mine filling material according to any one of claims 1 to 4, characterized in that: The water-retaining thickener is sodium polyacrylate, hydroxymethylpropyl cellulose or calcium stearate.

7. The all-solid waste high-fluidity mine filling material according to any one of claims 1 to 4, characterized in that: The water reducer is a polycarboxylate water reducer, a naphthalene water reducer or sodium lignin sulfonate.

8. The all-solid waste high-fluidity mine filling material according to any one of claims 1 to 4, characterized in that: The coagulant is 0.1-0.5 parts of sodium chloride or 0.01-0.1 parts of catechol.

9. A fully solid waste high-fluidity mine filling slurry, characterized in that: include: 130-160 parts of cementitious materials, 20-50 parts of admixtures, 300-400 parts of aggregates, 1-12 parts of admixtures, and 150-180 parts of water; wherein the admixtures include 1-10 parts of activators, 0.05-0.1 parts of water-retaining thickeners, 0.1-0.5 parts of water-reducing agents, and 0.01-0.5 parts of accelerators.

10. The method for preparing the all-solid waste high-fluidity mine filling slurry according to claim 9, characterized in that: The cementitious material, admixture, aggregate and additive are uniformly mixed, water is added and stirred sufficiently to obtain the all-solid waste high-fluidity mine filling slurry.

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