Method for preparing mine filling material by using calcium-based deacidified ash and mine filling material

Abstract

The invention provides a method for preparing a mine filling material from calcium-based deacidified ash and the mine filling material, and belongs to the technical field of mine filling materials.The method comprises the steps that calcium-based dry-process deacidified ash serves as a carrier, polyhydric alcohol, sodium lignin sulfonate and catechol are added, and an exciting agent is obtained; taking slag powder, steel slag powder, wet flue gas desulfurization gypsum and the exciting agent as raw materials, grinding and mixing to obtain a semi-finished product; and screening the semi-finished product to obtain the mine filling materials with different granularities. Compared with the prior art, the mine filling material has the advantages that the alkali excitation characteristic of the calcium-based deacidified ash is utilized, the alkali release speed of the calcium-based deacidified ash and the semi-hydrated gypsum is high in the filling process, and calcium ions can perform hydration reaction on aluminum oxide and silicon oxide in the prepared mine filling material, promote the hardening process and promote solidification of a filling body; and meanwhile, the calcium-based deacidified ash can also improve the conglutination powder and enhance the strength of the filling body.

Description

Technical Field

[0001] The invention relates to the technical field of mine filling material manufacturing, in particular to a method for preparing mine filling material by utilizing calcium-based deacidified ash. Background Art

[0002] With the continuous development of society, mining industry, including metal mines and coal mines, has been developing continuously. Mines contain a large amount of energy materials, especially coal and metals, and my country's future development still relies heavily on them. While mining brings mineral resources, it is also a direct factor that induces geological disasters and pollutes the environment. The most prominent of these is surface subsidence. The ground pressure problem in mines at home and abroad is becoming more and more serious. Backfilling is one of the most effective means to deal with goafs and control ground pressure. Among them, full tailings cementing backfilling has been widely used in mines at home and abroad. It can effectively control ground pressure and reduce the pollution caused by tailings discharge to the environment. However, in practical applications, full tailings cementing backfilling still has certain problems, especially for backfilling mining method, the strength requirements of the backfilling body are relatively high, and the excessive content of certain chemical components in the tailings has an important influence on the cementing effect of the backfilling body, which has a certain restriction on the backfilling of many mines.

[0003] Mine filling is an effective means of controlling mining subsidence. Domestic and foreign scholars have conducted extensive research on it and proposed many effective methods. Since the 1950s, the development of mine filling technology in my country has roughly gone through four stages: the 1950s was the heyday of waste rock dry filling; the 1960s developed and applied graded tailings hydraulic filling, crushed stone hydraulic filling and concrete cement filling; the 1970s and 1980s widely used fine sand cement filling technology with graded tailings and natural sand as filling materials; in the 1990s, new technologies such as full tailings cement filling, block stone mortar cement filling, crushed stone cement slurry cement filling and paste pump pressure conveying cement filling were fully developed, which promoted the progress of mining technology and the development of mining industry in my country. Entering the 21st century, mining will turn to deep ore bodies, "three-down ore bodies" and other complex and difficult-to-mine ore bodies. The problem of ground pressure control will become increasingly prominent and become the main obstacle to efficient and safe operations in deep areas. Cemented filling is one of the effective ways to control ground pressure in deep and complex stress environments. Therefore, filling mining methods and filling process technologies are increasingly valued by people, and innovation and progress have been made in the process of continuous transformation and development of filling mining methods. Through the understanding of the physical and mechanical properties of filling materials and filling bodies, it is imperative to research and develop new filling materials with a wide range of sources, low cost, easy pulping and transportation, and high filling body strength.

[0004] Filling goaf is also an important way to dispose of tailings in large quantities, reduce tailings discharge and effectively utilize other solid wastes. This technology mixes concentrated tailings and cementitious materials into a filling mortar of a certain concentration and fills it into the goaf to form a filling body with a certain strength. Portland cement is a typical building material that has strict technical requirements for the water-cement ratio. The water-cement ratio affects the cement slurry cohesion structure and its density after hardening. Too large or too small a water-cement ratio will affect the strength and other properties. The all-solid waste-based cementitious material is a new type of solid waste-based cementitious material prepared by applying multi-solid waste synergistic excitation technology, using alkali, salt or composite admixtures as exciters to stimulate a series of potential volcanic ash materials such as mineral powder, steel slag powder, fly ash, bauxite, red mud, etc. to produce hydration reactions. The main problems existing in the current filling mining technology in cementitious powder are:

[0005] 1. The mining technology level is not high. The tailings are poor when screening tailings. Some tailings, such as iron ore tailings, have too high mud content and low sand content, which leads to the failure of the cement powder to play a good role, resulting in the filling body strength shrinkage after 28 days;

[0006] 2. During partial underwater filling, the cement powder failed to bind the tailings and fly ash, resulting in insufficient strength of the filling body and inability to play a supporting role. Summary of the invention

[0007] The present invention aims to provide a method for preparing mine filling material by using calcium-based deacidified lime, in order to at least partially solve at least one of the above-mentioned technical problems.

[0008] In order to solve the above technical problems, the present invention provides a method for preparing mine filling materials by using calcium-based deacidified ash, comprising:

[0009] Using calcium-based dry deacidified ash as a carrier, adding polyol, sodium lignin sulfonate and catechol, an activator is obtained;

[0010] Slag powder, steel slag powder, wet desulfurization gypsum and the activator are used as raw materials, ground and mixed to obtain a semi-finished product;

[0011] The semi-finished product is screened to obtain mine filling materials with different particle sizes.

[0012] According to a preferred embodiment of the present invention, the polyol is selected from at least one of ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, glycerol and pentaerythritol.

[0013] According to a preferred embodiment of the present invention, the proportions of the components in the activator are: 0.5%-1.5% of polyol, 0.5%-1% of sodium lignin sulfonate, 0.5%-1.5% of catechol, and the rest is calcium-based dry deacidified ash.

[0014] According to a preferred embodiment of the present invention, the raw materials further include: at least one of calcium-based dry deacidified ash, ferroalumina slag powder, and fly ash.

[0015] According to a preferred embodiment of the present invention, the mass percentages of the raw materials are: slag powder: 50%-70%, steel slag powder: 10%-20%, wet desulfurization gypsum: 7%-15%, calcium-based dry deacidification ash: 2%-10%, ferroalumina slag powder: 0.5%-3%, fly ash: 5%-15%, and the rest are activators.

[0016] According to a preferred embodiment of the present invention, the raw material further includes: slag.

[0017] According to a preferred embodiment of the present invention, the specific surface area of ​​the slag powder is ≥450m2 / kg, the specific surface area of ​​the steel slag powder is ≥450m2 / kg, and the moisture content of the wet desulfurization gypsum is ≤10%.

[0018] In order to solve the above technical problems, the second aspect of the present invention provides a mine filling material prepared by any of the methods described above.

[0019] According to a preferred embodiment of the present invention, the mass percentage of each component is: slag powder: 50%-70%, steel slag powder: 10%-20%, wet desulfurization gypsum: 7%-15%, calcium-based dry deacidification ash: 2%-10%, ferroalumina slag powder: 0.5%-3%, fly ash: 5%-15%, and the rest are activators.

[0020] In summary, the present invention utilizes the alkali-stimulating properties of calcium-based deacidified lime and contains hemihydrated gypsum in the filling process, and the alkalinity is released quickly, wherein the calcium ions can hydrate the aluminum oxide and silicon oxide in the prepared mine filling material, promote the hardening process, and promote the solidification of the filling body; at the same time, the calcium-based deacidified lime can also improve the cement powder and enhance the strength of the filling body. Compared with the prior art, the present invention has at least the following beneficial effects:

[0021] 1. The present invention adopts a variety of solid wastes to carry out composite proportioning and then mix and grind, which can process a large amount of industrial solid waste and realize the transformation of solid waste into treasure.

[0022] 2. The present invention uses multi-solid waste synergistic excitation technology, using alkali, salt or composite admixture as an exciter to excite a series of potential volcanic ash materials such as mineral powder, steel slag powder, bauxite, red mud, etc. to produce hydration reactions, thereby preparing a new type of solid waste-based cementitious material.

[0023] 3. The mine filling material prepared by the present invention can change the setting time by adjusting the ratio of calcium-based dry deacidified ash and ferroalumina slag powder in mine filling, and its flow properties can be adjusted by adjusting the ratio of each component in the homemade activator.

[0024] 4. The mine filling material prepared by the present invention can settle by itself in some permeable mines to form tailings, and its strength can reach the strength of general mine filling bodies, and the strength will basically not shrink after 28 days.

[0025] 5. The mine filling material prepared by the present invention can harden in 10-24 hours by fine-tuning the proportion of each component, and the permeability and service life meet the requirements of the mine. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic flow chart of a method for preparing mine filling material by using calcium-based deacidified lime provided by an embodiment of the present invention;

[0027] Figure 2 It is a schematic diagram of the process of grinding and mixing according to an embodiment of the present invention. DETAILED DESCRIPTION

[0028] The features and exemplary embodiments of various aspects of the present invention will be described in detail below. In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and Examples. It should be understood that the specific embodiments described herein are only configured to explain the present invention and are not configured to limit the present invention. For those skilled in the art, the present invention can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present invention by illustrating examples of the present invention.

[0029] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0030] The present invention provides a method for preparing mine filling material by using calcium-based deacidified ash, such as Figure 1 As shown, the method includes:

[0031] S1. Using calcium-based dry deacidified ash as a carrier, adding polyol, sodium lignin sulfonate and catechol to obtain an activator;

[0032] Wherein: the polyol is selected from: one of ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, glycerol, pentaerythritol, or a combination of several thereof.

[0033] Preferably, the proportions of the components in the activator are: 0.5%-1.5% of polyol, 0.5%-1% of sodium lignin sulfonate, 0.5%-1.5% of catechol, and the rest is calcium-based dry deacidified ash.

[0034] S2, grinding and mixing slag powder, steel slag powder, wet desulfurization gypsum and the activator as raw materials to obtain a semi-finished product;

[0035] The specific surface area of ​​the slag powder is ≥450m2 / kg, the specific surface area of ​​the steel slag powder is ≥450m2 / kg, and the moisture content of the wet desulfurization gypsum is ≤10%.

[0036] Among them: slag powder is preferably: S95 grade slag powder, and the content of active calcium, silicon, aluminum and other inorganic substances is greater than 30%. Steel slag powder is composed of various oxides formed by oxidation of impurities such as silicon, manganese, phosphorus, sulfur and other impurities in pig iron during the smelting process, and salts generated by the reaction of these oxides with solvents. The main mineral phases are tricalcium silicate, dicalcium silicate, calcium magnesian olivine, calcium magnesian rhodonite, calcium ferroaluminate and solid solution formed by oxides of silicon, magnesium, iron, manganese and phosphorus, and also contain a small amount of free calcium oxide and metallic iron, fluoroapatite and the like.

[0037] Furthermore, the raw materials also include at least one of calcium-based dry deacidified ash, iron bauxite slag powder, fly ash, and slag. Among them, fly ash can be used as filling aggregate, slag powder S95, steel slag powder are used as main materials, and iron bauxite slag powder can further promote strength increase and rapid setting effect.

[0038] Before grinding and mixing, the raw materials can be quality inspected and proportioned, where the mass percentages of the raw materials are: slag powder: 50%-70%, steel slag powder: 10%-20%, wet desulfurization gypsum: 7%-15%, calcium-based dry deacidification ash: 2%-10%, ferroalumina slag powder: 0.5%-3%, fly ash: 5%-15%, and the rest are activators.

[0039] Specifically, Figure 2 , grinding and mixing may include:

[0040] Feeding: Feed the raw materials into the ball mill through conveying equipment;

[0041] Grinding: Use the ball mill of the cement grinding station to grind and mix the materials into powder.

[0042] S3. Screening the semi-finished product to obtain mine filling materials of different particle sizes.

[0043] Filling materials of different finenesses can be obtained through screening and grading; specifically, a powder classifier can be used to separate materials of different finenesses and collect filling materials of different particle sizes.

[0044] Furthermore, it may also include:

[0045] Packaging: Pack the filling materials into bags or bulk into the transport vehicle for factory inspection and transportation.

[0046] Product: The product has a grey powdery appearance, a specific surface area of ​​≥400m2 / kg, and solidifies when exposed to water.

[0047] Application: It can be used for filling the mine tailings with glue powder and backfilling the coal mine goaf.

[0048] The performance of the mine filling material prepared by the present invention was tested, and the results were as follows:

[0049] 1. The optimal ratio of mine filling glue powder and the compressive strength of the filling hardened body. Under the conditions that the common mortar-sand ratios of mine filling are 1:8 and 1:12 respectively and the slurry concentration is 75%, the ratio and compressive strength of coal mine fly ash are shown in the following table:

[0050]

[0051] 2. The proportion and compressive strength of mine filling prepared with iron ore tailings are shown in the following table:

[0052]

[0053] Based on the above-mentioned method for preparing mine filling materials using calcium-based deacidified ash, the present invention also provides a mine filling material, which is prepared by using any of the above-mentioned methods for preparing mine filling materials using calcium-based deacidified ash, and the mass percentage of each component is: slag powder: 50%-70%, steel slag powder: 10%-20%, wet desulfurization gypsum: 7%-15%, calcium-based dry deacidified ash: 2%-10%, ferroalumina slag powder: 0.5%-3%, fly ash: 5%-15%, and the rest are activators.

[0054] In summary, the present invention utilizes the alkali-stimulating properties of calcium-based deacidified lime and contains hemihydrated gypsum in the filling process, and the alkalinity is released quickly, wherein the calcium ions can hydrate the aluminum oxide and silicon oxide in the prepared mine filling material, promote the hardening process, and promote the solidification of the filling body; at the same time, the calcium-based deacidified lime can also improve the cement powder and enhance the strength of the filling body. Compared with the prior art, the present invention has at least the following beneficial effects:

[0055] 1. The present invention adopts a variety of solid wastes to carry out composite proportioning and then mix and grind, which can process a large amount of industrial solid waste and realize the transformation of solid waste into treasure.

[0056] 2. The present invention uses multi-solid waste synergistic excitation technology, using alkali, salt or composite admixture as an exciter to excite a series of potential volcanic ash materials such as mineral powder, steel slag powder, bauxite, red mud, etc. to produce hydration reactions, thereby preparing a new type of solid waste-based cementitious material.

[0057] 3. The mine filling material prepared by the present invention can change the setting time by adjusting the ratio of calcium-based dry deacidified ash and ferroalumina slag powder in mine filling, and its flow properties can be adjusted by adjusting the ratio of each component in the homemade activator.

[0058] 4. The mine filling material prepared by the present invention can settle by itself in some permeable mines to form tailings, and its strength can reach the strength of general mine filling bodies, and the strength will basically not shrink after 28 days.

[0059] 5. The mine filling material prepared by the present invention can harden in 10-24 hours by fine-tuning the proportion of each component, and the permeability and service life meet the requirements of the mine.

[0060] It should be clear that the present invention is not limited to the specific structures and processes described above and shown in the figures. For the sake of simplicity, a detailed description of the known methods is omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present invention is not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between the steps after understanding the spirit of the present invention.

[0061] It should also be noted that the exemplary embodiments mentioned in the present invention describe some methods or systems based on a series of steps or devices. However, the present invention is not limited to the order of the above steps, that is, the steps can be performed in the order mentioned in the embodiments, or in a different order from the embodiments, or several steps can be performed simultaneously.

[0062] The above is only a specific implementation of the present invention. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working process of the system, module and unit described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here. It should be understood that the protection scope of the present invention is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be covered within the protection scope of the present invention.

Claims

1. A method for preparing mine filling material using calcium-based deacidified ash, characterized in that: include: Using calcium-based dry deacidified ash as a carrier, adding polyol, sodium lignin sulfonate and catechol, an activator is obtained; Slag powder, steel slag powder, wet desulfurization gypsum and the activator are used as raw materials, ground and mixed to obtain a semi-finished product; The semi-finished product is screened to obtain mine filling materials with different particle sizes.

2. The method for preparing mine filling material by using calcium-based deacidified lime according to claim 1, characterized in that: The polyol is selected from at least one of ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, glycerol and pentaerythritol.

3. The method for preparing mine filling material by using calcium-based deacidified lime according to claim 1, characterized in that: The proportions of the components in the activator are as follows: 0.5%-1.5% of polyol, 0.5%-1% of sodium lignin sulfonate, 0.5%-1.5% of catechol, and the rest is calcium-based dry deacidification.

4. The method for preparing mine filling material by using calcium-based deacidified lime according to claim 1, characterized in that: The raw materials also include: at least one of calcium-based dry deacidified ash, iron-alumina slag powder, and fly ash.

5. The method for preparing mine filling material by using calcium-based deacidified lime according to claim 4, characterized in that: The mass percentages of the raw materials are: slag powder: 50%-70%, steel slag powder: 10%-20%, wet desulfurization gypsum: 7%-15%, calcium-based dry deacidification ash: 2%-10%, ferroalumina slag powder: 0.5%-3%, fly ash: 5%-15%, and the rest are activators.

6. The method for preparing mine filling material by using calcium-based deacidified lime according to claim 1 or 4, characterized in that: The raw materials also include: slag.

7. The method for preparing mine filling material by using calcium-based deacidified lime according to claim 1, characterized in that: The specific surface area of ​​the slag powder is ≥450m2 / kg, the specific surface area of ​​the steel slag powder is ≥450m2 / kg, and the moisture content of the wet desulfurization gypsum is ≤10%.

8. A mine filling material, characterized in that: The method is prepared by any one of claims 1 to 7.

9. The mine filling material according to claim 8, characterized in that: The mass percentage of each component is: slag powder: 50%-70%, steel slag powder: 10%-20%, wet desulfurization gypsum: 7%-15%, calcium-based dry deacidification ash: 2%-10%, ferroalumina slag powder: 0.5%-3%, fly ash: 5%-15%, and the rest is activator.

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