Filling material based on multi-element solid waste as well as preparation method and application of filling material

Abstract

The invention discloses a filling material based on multi-element solid waste as well as a preparation method and application of the filling material. The filling material based on the multi-element solid waste is prepared from the following solid components in percentage by mass: 10-20% of artificial granite slag, 0-20% of fly ash, 10-20% of ardealite and the balance of calcined kaolin and carbide slag, and the mass ratio of the calcined kaolin to the carbide slag is 1.6: 1. According to the invention, the utilization rate of bulk industrial solid wastes such as ardealite, carbide slag, fly ash and the like is increased, so that the problems of land occupation, environmental pollution and the like caused by bulk stockpiling of the materials are relieved. The prepared filling material based on the multi-element solid waste can still keep good compressive strength under the condition of high solid waste adding amount, and is suitable for various specific application scenes such as mine pit backfilling and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of industrial solid waste resource utilization, and in particular relates to a filling material based on multi-solid waste and a preparation method and application thereof. Background Art

[0002] In recent years, with the development of green mines and the focus on reducing carbon emissions, people have paid more and more attention to the resource utilization technology of bulk industrial solid waste. At present, cement is still one of the main cementitious materials for mine filling materials. 2 Emissions have reached about 20% of industrial production. The traditional silicate cement burning process is complex and energy-intensive. At the same time, the waste generated during mining has a serious impact on the environment. Therefore, the use of industrial solid waste to coordinate (replace) cement to prepare cementitious materials has become an important measure to reduce cement production capacity and promote the resource utilization of solid waste, achieving waste treatment with waste, achieving multiple goals at one stroke, and having significant economic and environmental benefits. However, there are still some solid wastes with low activity, large stocks and complex components that are difficult to be effectively used.

[0003] Phosphogypsum is the main type of gypsum discharged during the production of wet phosphoric acid. 4 ·2H 2 O), with an annual emission of more than 50 million tons and a cumulative stockpile of more than 800 million tons. The comprehensive utilization rate is less than half, and there is a large room for utilization. The storage of phosphogypsum not only occupies a large amount of land, but also causes serious pollution to the surrounding environment. It is urgent to increase its resource utilization to alleviate environmental pressure. However, the existing phosphogypsum-based cementitious system is still imperfect, facing problems such as high raw material cost, low compressive strength of finished products, and low proportion of phosphogypsum in the system. Therefore, it is particularly urgent to develop phosphogypsum-based cementitious materials and technologies with ideal synergistic effects of multiple solid wastes.

[0004] Calcium carbide slag is a solid waste produced in the process of producing acetylene, PVC, etc. by the calcium carbide method. The annual production volume reaches tens of millions of tons. It has high alkalinity, high humidity and low utilization rate. Long-term storage not only wastes land resources, but also pollutes the environment. The main component of calcium carbide slag is calcium hydroxide, which is a high-quality calcium-based material with low cost and high calcium content, and has the potential to replace limestone.

[0005] Fly ash is fine ash collected from the flue gas of coal-fired power plants and is one of the main solid wastes discharged by these power plants. If left untreated, large amounts of fly ash may generate dust and pollute the air; if discharged into water bodies, it may cause river siltation, and the toxic chemicals it contains may also cause harm to human health and the ecological environment. Fly ash is rich in silicon and aluminum components and has the potential to replace part of kaolin.

[0006] In summary, proposing a solution that can effectively solve the resource utilization of bulk industrial solid wastes such as phosphogypsum, carbide slag and fly ash will not only help reduce the negative impact of these materials on the environment, but also promote the sustainable development of related industries, which is of far-reaching significance. Summary of the invention

[0007] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a filling material based on multi-solid waste and its preparation method and application, aiming to improve the utilization rate of bulk industrial solid wastes such as phosphogypsum, carbide slag and fly ash, thereby alleviating the problems of land occupation and environmental pollution caused by the large-scale storage of these materials.

[0008] The purpose of the present invention is achieved through the following technical solutions: A filling material based on multiple solid wastes is prepared from solid components including the following mass percentages: 10-20% artificial granite slag, 0-20% fly ash, 10-20% phosphogypsum, and the remainder is calcined kaolin and carbide slag, wherein the mass ratio of calcined kaolin to carbide slag is 1.6:1.

[0009] Preferably, it is prepared from solid components including the following mass percentages: 10% artificial kaolin slag, 0-10% fly ash, 10-20% phosphogypsum, and the remainder is calcined kaolin and carbide slag, wherein the mass ratio of calcined kaolin to carbide slag is 1.6:1.

[0010] Preferably, it is prepared from solid components comprising the following mass percentages: 10% artificial kaolin slag, 20% phosphogypsum, and the remainder being calcined kaolin and carbide slag, wherein the mass ratio of calcined kaolin to carbide slag is 1.6:1.

[0011] Preferably, the calcined kaolin is obtained by calcining kaolin at 700° C. for 2 h.

[0012] The preparation method of the above-mentioned filling material based on multiple solid wastes includes the following steps: according to the component ratio, artificial granite slag, fly ash, phosphogypsum, calcined kaolin and carbide slag are mixed and ball-milled until they are uniform to obtain a mixed powder; water is added to the mixed powder so that the water-binder ratio is 0.3-0.6, and the slurry is obtained after sufficient stirring. The slurry is the filling material based on multiple solid wastes.

[0013] Preferably, the parameters of the ball milling process include: the medium is zirconium dioxide balls, the ball-to-material ratio is 8-10:1, the rotation speed is 300-500 rpm, and the ball milling time is 5-20 min.

[0014] Preferably, the ball-to-material ratio is 10:1.

[0015] Preferably, the rotation speed is 400 rpm.

[0016] Preferably, the ball milling time is 10 min.

[0017] The above-mentioned filling materials based on multiple solid wastes are used in road base and surface layers as well as mine backfilling.

[0018] The mechanisms involved in the present invention include: The present invention successfully prepared a filling material by introducing phosphogypsum into a multi-solid waste system. Specifically, the introduction of carbide slag significantly increased the Mc (monocarbon aluminate) content in the product, thereby enhancing the compressive strength of the material. The introduction of phosphogypsum promoted the formation of calcium sulfonate, further improving the mechanical properties and overall strength of the test block. The introduction of fly ash provides siliceous and aluminum raw materials, which can replace calcined kaolin to a certain extent, not only reducing the overall cost, but also optimizing the physical properties of the material.

[0019] Compared with the prior art, the beneficial effects of the present invention include: (1) The present invention uses mechanical ball milling to activate the gelling material. During the ball milling process, energy is continuously input so that the gelling properties are fully activated, the chemical reaction activity between the materials is enhanced, and a new high value-added application path is provided for industrial solid wastes such as phosphogypsum.

[0020] (2) The phosphogypsum, artificial granite slag, carbide slag and fly ash used in the present invention are widely available, which greatly reduces the cost compared with the traditional method, is conducive to the recycling and reuse of resources, and has significant economic benefits.

[0021] (3) The preparation process of the filling material of the present invention is carried out at room temperature, without the need for harsh environmental conditions. The preparation process is simple, time-saving, and easy to achieve large-scale production.

[0022] (4) The multi-solid waste filling material prepared based on phosphogypsum in the present invention still maintains good compressive strength under the condition of high solid waste addition, and is suitable for various specific application scenarios such as mine backfilling. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 XRD spectra of the filling materials prepared in Comparative Example 1, Comparative Example 2 and Example 2 during the 3d curing period.

[0024] Figure 2 XRD spectra of the filling materials prepared in Comparative Example 1, Comparative Example 2 and Example 2 after a curing period of 7 days.

[0025] Figure 3 XRD spectra of the filling materials prepared in Comparative Example 1, Comparative Example 2 and Example 2 after a curing period of 28 days.

[0026] Figure 4FTIR graphs of the filling materials prepared in Comparative Example 1, Comparative Example 2 and Example 2 after a curing period of 28 days. DETAILED DESCRIPTION

[0027] 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 the 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.

[0028] The parameters of the ball milling treatment described in the following examples and comparative examples are: the medium is zirconium dioxide balls, the ball diameter is 15 mm, the ball-to-material ratio is 10:1, the rotation speed is 400 rpm, and the ball milling time is 10 min.

[0029] Example 1 A filling material based on multiple solid wastes is prepared from the following solid components in percentage by mass: 10% artificial granite slag, 20% fly ash, 10% phosphogypsum, and the remainder is calcined kaolin and carbide slag, wherein the mass ratio of calcined kaolin to carbide slag is 1.6:1.

[0030] The specific steps of the preparation method of the above-mentioned filling material based on multiple solid wastes are as follows: according to the component ratio, artificial granite slag, fly ash, phosphogypsum, calcined kaolin and carbide slag are mixed and ball-milled to obtain a mixed powder; water is added to the mixed powder so that the water-to-binder ratio is 0.5, and the slurry is obtained after sufficient stirring. The slurry is the filling material based on multiple solid wastes.

[0031] Example 2 A filling material based on multiple solid wastes is prepared from solid components in the following mass percentages: 10% artificial granite slag, 20% fly ash, 20% phosphogypsum, and the remainder is calcined kaolin and carbide slag, wherein the mass ratio of calcined kaolin to carbide slag is 1.6:1.

[0032] The specific steps of the preparation method of the above-mentioned filling material based on multiple solid wastes are as follows: according to the component ratio, artificial granite slag, fly ash, phosphogypsum, calcined kaolin and carbide slag are mixed and ball-milled to obtain a mixed powder; water is added to the mixed powder so that the water-to-binder ratio is 0.5, and the slurry is obtained after sufficient stirring. The slurry is the filling material based on multiple solid wastes.

[0033] Example 3 A filling material is prepared from the following solid components in mass percentage: 10% artificial kaolin slag, 10% phosphogypsum, and the remainder calcined kaolin and carbide slag, wherein the mass ratio of calcined kaolin to carbide slag is 1.6:1.

[0034] The specific steps of the preparation method of the above-mentioned filling material based on multiple solid wastes are as follows: according to the component ratio, artificial granite slag, phosphogypsum, calcined kaolin and carbide slag are mixed and ball-milled to obtain a mixed powder; water is added to the mixed powder so that the water-to-binder ratio is 0.5, and the slurry is obtained after sufficient stirring. The slurry is the filling material based on multiple solid wastes.

[0035] Example 4 A filling material based on multiple solid wastes is prepared from solid components in the following mass percentages: 10% artificial granite slag, 20% phosphogypsum, and the remainder calcined kaolin and carbide slag, wherein the mass ratio of calcined kaolin to carbide slag is 1.6:1.

[0036] The specific steps of the preparation method of the above-mentioned filling material based on multiple solid wastes are as follows: according to the component ratio, artificial granite slag, phosphogypsum, calcined kaolin and carbide slag are mixed and ball-milled to obtain a mixed powder; water is added to the mixed powder so that the water-to-binder ratio is 0.5, and the slurry is obtained after sufficient stirring. The slurry is the filling material based on multiple solid wastes.

[0037] Example 5 A filling material based on multiple solid wastes is prepared from the following solid components in percentage by mass: 10% artificial granite slag, 10% fly ash, 20% phosphogypsum, and the remainder is calcined kaolin and carbide slag, wherein the mass ratio of calcined kaolin to carbide slag is 1.6:1.

[0038] The specific steps of the preparation method of the above-mentioned filling material based on multiple solid wastes are as follows: according to the component ratio, artificial granite slag, fly ash, phosphogypsum, calcined kaolin and carbide slag are mixed and ball-milled to obtain a mixed powder; water is added to the mixed powder so that the water-to-binder ratio is 0.5, and the slurry is obtained after sufficient stirring. The slurry is the filling material based on multiple solid wastes.

[0039] Comparative Example 1 A filling material is prepared from calcined kaolin and carbide slag in a mass ratio of 1.6:1.

[0040] The preparation method of the above-mentioned filling material has the following specific steps: calcined kaolin and carbide slag are mixed in a mass ratio of 1.6:1 and ball-milled to obtain a mixed powder; water is added to the mixed powder so that the water-to-binder ratio is 0.5, and the slurry is obtained after being fully stirred. The slurry is the filling material.

[0041] Comparative Example 2 A filling material is prepared from the following solid components in percentage by mass: 10% of artificial kaolin slag, and the remainder of calcined kaolin and carbide slag, wherein the mass ratio of calcined kaolin to carbide slag is 1.6:1.

[0042] The specific steps of the preparation method of the above-mentioned filling material based on multiple solid wastes are as follows: according to the component ratio, artificial granite slag, calcined kaolin and carbide slag are mixed and ball-milled to obtain a mixed powder; water is added to the mixed powder so that the water-to-binder ratio is 0.5, and the slurry is obtained after sufficient stirring. The slurry is the filling material based on multiple solid wastes.

[0043] Comparative Example 3 A filling material is prepared from the following solid components in mass percentage: 20% artificial kaolin slag, and the remainder calcined kaolin and carbide slag, wherein the mass ratio of calcined kaolin to carbide slag is 1.6:1.

[0044] The specific steps of the preparation method of the above-mentioned filling material based on multi-solid waste are as follows: according to the component ratio, artificial granite slag, calcined kaolin and carbide slag are mixed and ball-milled to obtain a mixed powder; water is added to the mixed powder so that the water-to-binder ratio is 0.5, and the slurry is obtained after sufficient stirring, and the slurry is the filling material.

[0045] Comparative Example 4 A filling material is prepared from the following solid components in percentage by mass: 30% of artificial kaolin slag, and the remainder of calcined kaolin and carbide slag, wherein the mass ratio of calcined kaolin to carbide slag is 1.6:1.

[0046] The specific steps of the preparation method of the above-mentioned filling material based on multi-solid waste are as follows: according to the component ratio, artificial granite slag, calcined kaolin and carbide slag are mixed and ball-milled to obtain a mixed powder; water is added to the mixed powder so that the water-to-binder ratio is 0.5, and the slurry is obtained after sufficient stirring, and the slurry is the filling material.

[0047] Comparative Example 5 A filling material is prepared from the following solid components in mass percentage: 40% artificial kaolin slag, and the remainder calcined kaolin and carbide slag, wherein the mass ratio of calcined kaolin to carbide slag is 1.6:1.

[0048] The specific steps of the preparation method of the above-mentioned filling material based on multi-solid waste are as follows: according to the component ratio, artificial granite slag, calcined kaolin and carbide slag are mixed and ball-milled to obtain a mixed powder; water is added to the mixed powder so that the water-to-binder ratio is 0.5, and the slurry is obtained after sufficient stirring, and the slurry is the filling material.

[0049] Comparative Example 6 A filling material is prepared from the following solid components in mass percentage: 10% artificial kaolin slag, 30% phosphogypsum, and the remainder calcined kaolin and carbide slag, wherein the mass ratio of calcined kaolin to carbide slag is 1.6:1.

[0050] The specific steps of the preparation method of the above-mentioned filling material based on multi-solid waste are as follows: according to the component ratio, artificial granite slag, phosphogypsum, calcined kaolin and carbide slag are mixed and ball-milled to obtain a mixed powder; water is added to the mixed powder so that the water-to-binder ratio is 0.5, and the slurry is obtained after sufficient stirring, and the slurry is the filling material.

[0051] Comparative Example 7 A filling material is prepared from the following solid components in mass percentage: 10% artificial kaolin slag, 40% phosphogypsum, and the remainder calcined kaolin and carbide slag, wherein the mass ratio of calcined kaolin to carbide slag is 1.6:1.

[0052] The specific steps of the preparation method of the above-mentioned filling material based on multi-solid waste are as follows: according to the component ratio, artificial granite slag, phosphogypsum, calcined kaolin and carbide slag are mixed and ball-milled to obtain a mixed powder; water is added to the mixed powder so that the water-to-binder ratio is 0.5, and the slurry is obtained after sufficient stirring, and the slurry is the filling material.

[0053] Comparative Example 8 A filling material is prepared from the following solid components in mass percentage: 10% artificial kaolin slag, 50% phosphogypsum, and the remainder calcined kaolin and carbide slag, wherein the mass ratio of calcined kaolin to carbide slag is 1.6:1.

[0054] The specific steps of the preparation method of the above-mentioned filling material based on multi-solid waste are as follows: according to the component ratio, artificial granite slag, phosphogypsum, calcined kaolin and carbide slag are mixed and ball-milled to obtain a mixed powder; water is added to the mixed powder so that the water-to-binder ratio is 0.5, and the slurry is obtained after sufficient stirring, and the slurry is the filling material.

[0055] Comparative Example 9 Comparative Example 9 provides a filling material prepared from the following solid components in the following mass percentages: 10% artificial granite slag, 30% fly ash, 20% phosphogypsum, and the remainder being calcined kaolin and carbide slag, wherein the mass ratio of calcined kaolin to carbide slag is 1.6:1.

[0056] The specific steps of the preparation method of the above-mentioned filling material based on multi-solid waste are as follows: according to the component ratio, artificial granite slag, fly ash, phosphogypsum, calcined kaolin and carbide slag are mixed and ball-milled to obtain a mixed powder; water is added to the mixed powder so that the water-to-binder ratio is 0.5, and the slurry is obtained after sufficient stirring, and the slurry is the filling material.

[0057] The filling materials prepared in Examples 1 to 5 and Comparative Examples 1 to 9 were poured on 20 mm 3 The molds were then wrapped with plastic wrap and placed in a curing box for standard curing; the curing conditions were 90% relative humidity and 20°C. One day later, the molds were demoulded and the test blocks were placed under the same curing conditions for standard curing. Subsequently, the compressive strength of the test blocks was tested on the 3rd, 7th and 28th days of curing. The test method for compressive strength refers to GB / T17671-2021 Cement Mortar Strength Test Method (ISO Method). The test results are shown in Table 1.

[0058] Table 1 Compressive strength of test blocks of examples and comparative examples at different ages

[0059] As can be seen from Table 1, the embodiments of the present invention adopt a quaternary system of carbide slag-calcined kaolin-artificial kaolin slag-phosphogypsum, and a quinary system formed by adding fly ash on this basis. After preparing test blocks by adjusting the proportion of raw materials in each system, the compressive strength of these test blocks at different ages is higher than that of the comparative example.

[0060] It is worth noting that in the quaternary system, comparing the data of Examples 3 to 4 with those of Comparative Examples 6 to 8, when the mass ratio of calcined kaolin and carbide slag was fixed at 1.6:1, the content of artificial kaolin slag was 10%, and the content of phosphogypsum was 20%, the maximum 28-day compressive strength was obtained.

[0061] In the five-element system, by comparing Example 2, Example 5 and Comparative Example 9, we found that when the mass ratio of calcined kaolin and carbide slag is fixed at 1.6:1, the artificial kaolin slag is 10%, the phosphogypsum is 20%, and the fly ash content is 20%, the amount of kaolin can be minimized without changing the compressive strength.

[0062] In summary, the filling material based on multi-solid waste prepared by the present invention exhibits high compressive strength at different ages. Therefore, the material is very suitable for mine filling.

[0063] Figure 1XRD spectra of the filling materials prepared in Comparative Example 1, Comparative Example 2 and Example 2 during the 3d curing period, wherein CS-MK corresponds to Comparative Example 1, CS-MK-AMWs corresponds to Comparative Example 2, and CS-MK-AMWs-PG-FA corresponds to Example 2; 0-Ms: Monosulfoaluminate, 1-Portlandite: calcium hydroxide, 6-CSH: hydrated calcium silicate gel, and 8-Mc: Monocarboaluminate. Figure 1 It can be seen that after 3 days of curing, in the binary system, the products in the hydration system are 4, 5, and 6. In the ternary system with artificial granite slag, Mc in the product increases. Since the compressive strength of the system increases with the addition of artificial granite slag, Mc can increase the mechanical strength of the test block. In the quinary system with the addition of phosphogypsum, the phase of ettringite (9) is generated, and the generation of ettringite greatly improves the compressive strength of the system.

[0064] Figure 2 The XRD spectra of the filling materials prepared in Comparative Example 1, Comparative Example 2 and Example 2 after 7 days of curing are shown in FIG. Figure 2 It can be seen that after 7 days of curing, the Mc content in the ternary system and the ettringite content in the pentad system continued to increase, and the compressive strength of the system was further improved.

[0065] Figure 3 The XRD spectra of the filling materials prepared in Comparative Example 1, Comparative Example 2 and Example 2 after 28 days of curing. Figure 3 It can be seen that after 28 days of curing, Mc in the ternary system continues to accumulate, and the stability of the system is further consolidated through crystal phase optimization; in the quinary system, calcium aluminate fills the pores through crystal phase interlacing, agglomerating particles, and densifying the system on a microscopic scale. The synergy of the two enables the pore structure of the system to be regulated, the stress distribution to be more uniform and reasonable, and the compressive strength to show a more significant jump compared to 7 days, laying a solid foundation for the long-term service of the material.

[0066] Figure 4 FTIR images of the filling materials prepared in Comparative Example 1, Comparative Example 2 and Example 2 during the 28-day curing period. Figure 4It can be seen that the FTIR spectrum of the ball-milled binary system (kaolin and carbide slag) shows their typical functional group vibration peaks. When it comes to the ternary system, the addition of artificial granite slag brings about siliceous mineral peaks. Ball milling promotes particle refinement and mixing, destroys the crystal structure, makes the components contact more closely, is conducive to the formation of an interwoven structure, and enhances the compressive strength. In the quinary system, calcium sulfate of phosphogypsum contributes characteristic peaks, which participate in the reaction to fill the pores and further strengthen the system. At the same time, although the Si-O-Al peak brought in by fly ash enriches the composition of the system, after replacing part of the kaolin, on the one hand, the kaolin that plays a key role in bonding in the system is reduced, weakening the originally stable particle connection; on the other hand, the fly ash glass phase has low reaction activity and cannot fully participate in the reaction to generate high-strength hydration products like kaolin, resulting in a decrease in compressive strength.

[0067] The specific implementation of the present invention described above does not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A filling material based on multi-solid waste, characterized in that: The invention is prepared from solid components in the following mass percentages: 10-20% artificial ash slag, 0-20% fly ash, 10-20% phosphogypsum, and the remainder calcined kaolin and carbide slag, wherein the mass ratio of calcined kaolin to carbide slag is 1.6:

1.

2. The filling material based on multi-solid waste according to claim 1, characterized in that: The invention is prepared from solid components in the following mass percentages: 10% artificial kaolin slag, 0-10% fly ash, 10-20% phosphogypsum, and the remainder calcined kaolin and carbide slag, wherein the mass ratio of calcined kaolin to carbide slag is 1.6:

1.

3. The filling material based on multiple solid wastes according to claim 2, characterized in that: The invention is prepared from solid components in the following mass percentages: 10% artificial kaolin slag, 20% phosphogypsum, and the remainder calcined kaolin and carbide slag, wherein the mass ratio of calcined kaolin to carbide slag is 1.6:

1.

4. The filling material based on multiple solid wastes according to claim 1, characterized in that: The calcined kaolin is obtained by calcining kaolin at 700° C. for 2 hours.

5. The method for preparing a filling material based on multi-solid waste according to any one of claims 1 to 4, characterized in that: The method comprises the following steps: mixing artificial granite slag, fly ash, phosphogypsum, calcined kaolin and carbide slag according to the component ratio and subjecting them to ball milling treatment until they are uniform to obtain mixed powder; adding water to the mixed powder so that the water-binder ratio is 0.5, and stirring the mixed powder to obtain slurry, which is the filling material based on multi-solid waste.

6. The method for preparing a filling material based on multi-solid waste according to claim 5, characterized in that: The parameters of the ball milling process include: the medium is zirconium dioxide balls, the ball-to-material ratio is 8-10:1, the rotation speed is 300-500 rpm, and the ball milling time is 5-20 min.

7. The method for preparing a filling material based on multi-solid waste according to claim 6, characterized in that: The ball-to-material ratio is 10:

1.

8. The method for preparing a filling material based on multi-solid waste according to claim 5, characterized in that: The rotation speed is 400 rpm.

9. The method for preparing a filling material based on multi-solid waste according to claim 5, characterized in that: The ball milling time is 10 min.

10. Use of the filling material based on multi-solid waste according to any one of claims 1 to 4 in road base and surface layers and mine backfill.

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