Red mud-based filling paste and preparation method thereof

Abstract

The invention relates to the technical field of comprehensive recycling of solid wastes, in particular to filling paste based on red mud and a preparation method of the filling paste. The preparation method comprises the following steps: grinding and mixing industrial solid wastes, an adsorbent and red mud to obtain ground powder; carrying out dry activation on the ground powder under the condition of a preset temperature, so as to obtain gelling powder; the method comprises the following steps: mixing Bayer process red mud, aggregate and a cementing material to obtain a pre-filling dry material with a mixed red mud component; mixing an acid activator, a water reducing agent, water and the pre-filling dry material to obtain filling paste; wherein the preset temperature is less than or equal to 350 DEG C. According to the preparation method, the compressive strength of the filling paste can be improved, and in addition, large-scale consumption of the red mud can be realized.

Description

Technical Field

[0001] The present application relates to the technical field of comprehensive recycling of solid waste, and in particular to a filling paste based on red mud and a preparation method thereof. Background Art

[0002] At present, domestic mines have formed a large number of underground voids due to mining activities. If these underground voids are not filled, they will cause huge hidden dangers to the engineering activities above the voids and the safety of surface buildings. At present, underground voids in mines are generally mined with cementitious materials as the base material, and the most representative cementitious material is cement. However, the use of cement will increase the filling cost of underground voids, which will undoubtedly restrict the sustainable development of mining companies using cementitious filling mining methods. Red mud is the largest solid waste produced by the aluminum industry, and it has potential cementitious activity, but the current comprehensive utilization rate of red mud is less than 10%. If red mud can be modified and regulated and prepared into a cement substitute, this will undoubtedly reduce the filling cost of mining companies using the cementitious filling mining method, improve economic benefits, and at the same time help to achieve large-scale consumption of red mud and promote the green and sustainable development of the aluminum industry.

[0003] Due to the low strength of red mud, the current technology for preparing filling materials based on red mud needs to reduce the amount of red mud doping for compressive strength considerations. In addition, most filling materials also require the use of red mud in combination with higher-cost materials such as cement and solid alkali agents to meet the use requirements of filling materials, which undoubtedly further increases the cost of red mud as a filling material.

[0004] At present, the technologies for preparing filling materials based on red mud include: (1) A Bayer process red mud-based filling material, its preparation method and its application. This technology uses red mud, fly ash and cement to form the basic filling material, and uses inorganic salts, organic acids and neutral mineral admixtures to form the solid alkali material, and these two are used to prepare the filling material. (2) A method for preparing a filling paste for the residual mining area of ​​a coal mine using red mud. This technology first crushes and screens the coal gangue to prepare coarse aggregate and fine aggregate respectively, and at the same time, the fine aggregate is combined with a water reducer, an early strength agent, an expansion agent and a retarder to obtain the filling material. (3) A filling material mixed with red mud, desulfurized gypsum and slag and its preparation method. This technology uses fixed red mud, slag and desulfurized gypsum as raw materials to prepare a cementitious material, and then uses coal gangue as aggregate to mix and obtain the filling material. Summary of the invention

[0005] The present application provides a filling paste based on red mud and a preparation method thereof to solve the following technical problem: how to improve the compressive strength of the filling material prepared based on red mud.

[0006] In a first aspect, the present application provides a method for preparing a filling paste based on red mud, wherein the red mud includes Bayer process red mud and / or sintering process red mud, and the preparation method includes:

[0007] Grinding and mixing industrial solid waste, an adsorbent and the red mud to obtain a ground powder;

[0008] Dry activating the ground powder at a preset temperature to activate the gelling components of the red mud in the ground powder and the adsorption performance of the adsorbent to obtain a gelling powder;

[0009] Mixing the Bayer red mud, aggregate and the gelled powder material to obtain a pre-filled dry material having a mixed red mud component; and

[0010] Mixing an acidic activator, a water reducing agent, water and the pre-filled dry material, so that the acidic activator activates the gelling effect of the gelling material in the pre-filled dry material to obtain a filling paste;

[0011] Wherein, the preset temperature is ≤350°C.

[0012] Optionally, the preset temperature is 120° C. to 350° C., and the dry activation time is 10 min to 60 min.

[0013] Optionally, the components of the ground powder meet the following requirements in parts by weight:

[0014] Red mud: 10 to 50 parts, industrial solid waste: 40 to 80 parts and adsorbent: 1 to 10 parts.

[0015] Optionally, the industrial solid waste includes at least two of the following:

[0016] Fly ash, slag powder, slag, carbide slag and desulfurized gypsum; and / or

[0017] The adsorbent comprises at least one of the following:

[0018] Montmorillonite, sepiolite and diatomaceous earth.

[0019] Optionally, the particle size of the ground powder is less than 178 μm.

[0020] Optionally, the components of the pre-filled dry material include, by weight:

[0021] Cementitious powder material: 10 to 30 parts, Bayer red mud: 20 to 60 parts and aggregate: 0 to 80 parts.

[0022] Optionally, the aggregate includes at least one of the following:

[0023] Gravel, tailings and slag.

[0024] Optionally, the weight m1 of the acidic activator and the weight m2 of the pre-filled dry material satisfy the relationship: m1:m2=(0.2-2.0):100, and the weight m3 of the water reducer and the weight m2 of the pre-filled dry material satisfy the relationship: m3:m2=(0.2-1.0):100;

[0025] The weight m4 of the water and the total weight m5 of the pre-filled dry material, the acidic activator and the water reducer satisfy the relationship: m4:m5=(0.5-1.0):1.

[0026] Optionally, the acidic stimulant includes at least one of the following:

[0027] Acetic acid, phosphoric acid and aluminum dihydrogen phosphate; and / or

[0028] The water reducing agent comprises at least one of the following:

[0029] Lignin sulfonate, naphthalene-based high-efficiency water reducer, polycarboxylate-based water reducer and aminosulfonate water reducer.

[0030] In a second aspect, the present application provides a filling paste based on red mud, wherein the filling paste is obtained by the preparation method described in the first aspect.

[0031] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:

[0032] A method for preparing a filling paste based on red mud is provided in an embodiment of the present application. The method performs dry activation under a preset temperature of ≤350°C. The gelling component of the red mud in the ground powder and the adsorption performance of the adsorbent can be activated based on medium-low temperature dry activation. The activated adsorbent adsorbs the red mud and industrial solid waste together through adsorption, and then the red mud and the industrial solid waste are gelled and combined through the gelling effect of the red mud activated by the gelling component to obtain a gelled powder material. The activated adsorbent can also inhibit the migration of heavy metal ions in the industrial solid waste and the red mud, so as to avoid the migration of these heavy metal ions damaging the gelling effect of the red mud after the activation of the gelling component, so as to obtain a gelled powder material with good gelling performance. Then, the pre-filling dry material obtained by mixing the gelled powder material, Bayer process red mud and aggregate, firstly uses the gelled powder material with good gelling performance to preliminarily gel the Bayer process red mud and the aggregate together, and then the high strength characteristics of the aggregate can be used to improve the strength of the filling paste. In order to improve the strength of the high filling paste, the pre-filling dry material, the acid activator, the water reducer and the water are finally mixed, and the pre-filling dry material and the acid activator are dispersed by the dispersing effect of water, so as to facilitate the uniform mixing of the pre-filling dry material and the acid activator. The acid activator can activate the gelling effect of the gelling powder material in the pre-filling dry material through the excitation effect, so as to further gel the Bayer red mud and the aggregate in the pre-filling dry material completely, so as to facilitate the improvement of the compressive strength of the filling paste through the high strength characteristics of the aggregate; in addition, the acid activator will also react with the alkaline components in the mixed red mud components composed of red mud and Bayer red mud to produce acid-base neutralization reaction, which can improve the compressive strength of the filling paste while reducing the amount of solid alkali agent used; in addition, the addition of the water reducer reduces the water content of the filling paste on the one hand, promotes the complete forming of the filling paste, and on the other hand, the water reducer forms a colloidal component in the water, and the formation of the colloidal material can improve the gelling effect strength of the gelling powder material, thereby improving the compressive strength of the filling paste. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0034] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0035] Figure 1 A schematic flow chart of a method for preparing a red mud-based filling paste provided in an embodiment of the present application. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0037] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity and should not be understood as a rigid limitation on the scope of the present application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within the range; for example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which applies regardless of the range; in addition, whenever a numerical range is indicated in this document, it is meant to include any cited numbers (fractions or integers) within the indicated range.

[0038] In this article, the terms including "including" and the like mean "including but not limited to". "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone; wherein A and B can be singular or plural. "At least one" means one or more, and "plurality" means two or more; "at least one", "at least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items; for example, "at least one of a, b, or c", or "at least one of a, b, and c", can all represent: a, b, c, ab (i.e., a and b), ac, bc, or abc, wherein a, b, c can be single or multiple, respectively. Unless otherwise specified, the various raw materials, reagents, instruments and equipment used in this application can be purchased on the market or prepared by existing methods.

[0039] It should be noted that, with respect to the prior art (1) recorded in the background technology, the inventors found that: the technology has the problem of small amount of red mud used (the weight of red mud is 30% to 60% of the total weight of the basic filling material), and the technology also requires the additional use of a large amount of cement and solid alkali materials; with respect to the prior art (2) recorded in the background technology, the inventors found that: the amount of red mud doped in the technology is small, and the cost of preparing the filling material is relatively high; with respect to the prior art (2) recorded in the background technology, the inventors found that: the technology has the problem of small amount of red mud doped.

[0040] Therefore, the common problems commonly existing in these existing technologies are that the amount of red mud doped is relatively small, and it needs to be used in combination with relatively high-cost materials such as cement and solid alkali agent, which undoubtedly increases the cost of the filling material.

[0041] Figure 1 The schematic diagram of the process of preparing a filling paste based on red mud provided in an embodiment of the present application is exemplarily shown;

[0042] like Figure 1 As shown, the embodiment of the present application provides a method for preparing a filling paste based on red mud, and the preparation method comprises:

[0043] S1. mixing red mud, industrial solid waste and an adsorbent, and grinding them to obtain a ground powder;

[0044] S2. The ground powder is dry activated at a preset temperature to obtain a gelled powder material having a red mud component;

[0045] S3. The gelled powder material having a red mud component, the Bayer red mud and the aggregate are mixed to obtain a pre-filled dry material having a red mud component; and

[0046] S4. The pre-filled dry material having a red mud component, an acidic activator, a water reducer and water are mixed to obtain a filling paste having a red mud component;

[0047] Wherein, the preset temperature is ≤350°C.

[0048] It should be noted that the red mud can be Bayer process red mud or sintering process red mud.

[0049] It should be noted that the heat required for the dry activation can be the waste heat of the flue gas of the alumina roaster, the waste heat of the roaster, or the waste heat of the flue gas of the rotary kiln. The heat generated in the aluminum electrolysis production process can be recycled.

[0050] In some optional embodiments, the preset temperature is 120° C. to 350° C., and the dry activation time is 10 min to 60 min;

[0051] In these embodiments, the preset temperature can be 120°C to 350°C, and the dry activation time can be 10min to 60min. The gelling component of the red mud in the ground powder and the adsorption performance of the adsorbent can be activated based on medium and low temperature dry activation. The activated adsorbent adsorbs the red mud and industrial solid waste together through adsorption, and then the red mud and industrial solid waste are gelled and combined through the gelling effect of the red mud activated by the gelling component to obtain a gelled powder material. The activated adsorbent can also inhibit the migration of heavy metal ions in industrial solid waste and red mud, thereby preventing the migration of these heavy metal ions from damaging the gelling effect of the red mud after the activation of the gelling component, so as to obtain a gelled powder material with good gelling properties.

[0052] The preset temperature may be 120°C, 130°C, 140°C, 150°C, 200°C, 250°C, 300°C or 350°C.

[0053] The dry activation time can be 10 min, 20 min, 30 min, 40 min, 50 min or 60 min.

[0054] In some optional embodiments, the components of the ground powder meet the following requirements in parts by weight:

[0055] Red mud: 10-50 parts, industrial solid waste: 40-80 parts and adsorbent: 1-10 parts;

[0056] In these embodiments, the components of the ground powder can meet the following requirements: red mud: 10 to 50 parts, industrial solid waste: 40 to 80 parts and adsorbent: 1 to 10 parts, so that the ground powder has sufficient red mud, industrial solid waste and adsorbent. The sufficient red mud, industrial solid waste and adsorbent can activate the gelling component of the red mud in the ground powder and the adsorption performance of the adsorbent after dry activation treatment. The activated adsorbent adsorbs the red mud and the industrial solid waste together through adsorption, and then the red mud and the industrial solid waste are gelled and combined through the gelling effect of the red mud activated by the gelling component to obtain a gelled powder. The activated adsorbent can also inhibit the migration of heavy metal ions in the industrial solid waste and red mud, and avoid the migration of these heavy metal ions damaging the gelling effect of the red mud after the gelling component is activated, so as to obtain a gelled powder with good gelling properties.

[0057] The weight proportions of the red mud may be 10 parts, 20 parts, 30 parts, 40 parts or 50 parts.

[0058] The weight proportions of the industrial solid waste may be 40, 50, 60, 70 or 80 parts.

[0059] The weight proportions of the adsorbent can be 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts or 10 parts.

[0060] In some optional embodiments, the industrial solid waste includes at least two of the following:

[0061] Fly ash, slag powder, slag, carbide slag and desulfurized gypsum; and / or

[0062] The adsorbent comprises at least one of the following:

[0063] montmorillonite, sepiolite, and diatomaceous earth;

[0064] In these embodiments, industrial solid waste may include: at least two of fly ash, slag powder, slag, carbide slag and desulfurized gypsum, and the adsorbent may include: at least one of montmorillonite, sepiolite and diatomaceous earth, which can cover most of the industrial solid waste and adsorbent, and facilitate the activation of the adsorption performance of the adsorbent in the ground powder by dry activation. The activated adsorbent adsorbs red mud and industrial solid waste together through adsorption, and the activated adsorbent can also inhibit the migration of heavy metal ions in industrial solid waste and red mud, avoiding the migration of these heavy metal ions to damage the gelling effect of the red mud after the activation of the gelling component, so as to obtain a gelling powder material with good gelling properties.

[0065] In some optional embodiments, the particle size of the ground powder is less than 178 μm;

[0066] In these embodiments, the particle size of the ground powder can be less than 178 μm, which can make the ground powder have a sufficiently fine particle size. The ground powder with a sufficiently fine particle size can facilitate the dry activation on the one hand, and on the other hand, it can also facilitate the sufficient mixing of the ground powder, Bayer red mud and aggregate. The high strength characteristics of the aggregate can be used subsequently to improve the strength of the filling paste, thereby obtaining a pre-filled dry material.

[0067] In some optional embodiments, the components of the pre-filled dry material include, by weight:

[0068] Cementitious powder material: 10 to 30 parts, Bayer red mud: 20 to 60 parts and aggregate: 0 to 80 parts;

[0069] In these embodiments, the components of the pre-filling dry material may include: 10 to 30 parts of cementitious powder, 20 to 60 parts of Bayer red mud and 0 to 80 parts of aggregate, which can ensure that the pre-filling dry material has sufficient cementitious powder, Bayer red mud and aggregate, so that the Bayer red mud and aggregate can be further gelled together by the cementitious powder, so as to improve the compressive strength of the filling paste by the high strength of the aggregate and facilitate the subsequent molding of the filling paste.

[0070] The weight proportion of the gelled powder material can be 10 parts, 15 parts, 20 parts, 25 parts or 30 parts.

[0071] The weight proportions of the Bayer process red mud can be 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 55 parts or 60 parts.

[0072] The weight proportions of the aggregate can be 0, 10, 20, 30, 40, 50, 60, 70 or 80 parts.

[0073] In some optional embodiments, the aggregate includes at least one of the following:

[0074] crushed stone, tailings and slag;

[0075] In these embodiments, the aggregate may include at least one of crushed stone, tailings and slag, and the high strength of the aggregate may be used to increase the compressive strength of the filling paste to increase the doping amount of the red mud.

[0076] It should be noted that the particle size of the aggregate can be 0.15 mm to 5 mm, which has a positive effect of improving the volume stability, workability and strength of the filling paste.

[0077] In some optional embodiments, the weight m1 of the acidic activator and the weight m2 of the pre-filled dry material satisfy the relationship: m1:m2=(0.2-2.0):100, and the weight m3 of the water reducer and the weight m2 of the pre-filled dry material satisfy the relationship: m3:m2=(0.2-1.0):100;

[0078] The weight m4 of the water and the total weight m5 of the pre-filled dry material, the acidic activator and the water reducing agent satisfy the relationship: m4:m5=(0.5-1.0):1;

[0079] In these embodiments, the weight m1 of the acidic stimulant and the weight m2 of the pre-filled dry material can satisfy the relationship: m1:m2=(0.2-2.0):100, which can promote the pre-filled dry material to have a sufficient amount of acidic stimulant, and the sufficient amount of acidic stimulant can activate the gelling effect of the gelling powder in the pre-filled dry material, so as to further gel the Bayer red mud and the aggregate in the pre-filled dry material, and facilitate the improvement of the compressive strength of the filling paste through the high strength characteristics of the aggregate; in addition, the weight m3 of the water reducer and the weight m2 of the pre-filled dry material can satisfy the relationship: m3:m2=(0.2-1.0):100, so that the pre-filled dry material has a sufficient amount of water reducer, and the sufficient amount of water reducer can form a colloidal material in water, and the formation of the colloidal material can improve the gelling strength of the gelling powder, thereby To improve the compressive strength of the filling paste; in addition, the weight of water m4 and the total weight of pre-filling dry material, acid activator, and water reducer m5 can satisfy the relationship: m4:m5=(0.5~1.0):1, the pre-filling dry material and the acid activator can be effectively dispersed by the dispersing effect of water, so that the pre-filling dry material, the acid activator and the water reducer are mixed evenly, and the evenly mixed three can activate the gelling effect of the gelling powder in the pre-filling dry material, so as to completely gel the Bayer red mud and the aggregate in the pre-filling dry material, so as to improve the compressive strength of the filling paste through the high strength characteristics of the aggregate. In addition, the combination of water and water reducer can also increase the gelling effect strength of the gelling powder through the water reducer while reducing the water content of the filling paste, so as to improve the compressive strength of the filling paste.

[0080] The weight m1 of the acidic activator and the weight m2 of the pre-filled dry material can satisfy the relationship: m1:m2=0.2:100, 0.3:100, 0.4:100, 0.5:100, 0.6:100, 0.7:100, 0.8:100, 0.9:100, 1.0:100, 1.1:100, 1.2:100, 1.3:100, 1.4:100, 1.5:100, 1.6:100, 1.7:100, 1.8:100, 1.9:100 or 2.0:100.

[0081] The weight m3 of the water reducing agent and the weight m2 of the pre-filled dry material can satisfy the relationship: m3:m2=0.2:100, 0.3:100, 0.4:100, 0.5:100, 0.6:100, 0.7:100, 0.8:100, 0.9:100 or 1.0:100.

[0082] The weight m4 of the water and the total weight m5 of the pre-filled dry material, the acid activator and the water reducer can satisfy the relationship: m4:m5=0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1 or 1.0:1.

[0083] In some optional embodiments, the acidic stimulant includes at least one of the following:

[0084] Acetic acid, phosphoric acid and aluminum dihydrogen phosphate; and / or

[0085] The water reducing agent comprises at least one of the following:

[0086] Lignin sulfonate, naphthalene-based high-efficiency water reducer, polycarboxylate-based water reducer and aminosulfonate water reducer;

[0087] In these embodiments, the acidic stimulant may include: at least one of acetic acid, phosphoric acid and aluminum dihydrogen phosphate, and the gelling effect of the gelling powder material in the pre-filling dry material can be activated by the stimulating effect of the acidic stimulant. The gelling powder material with gelling effect can completely gel the Bayer red mud and the aggregate in the pre-filling dry material, so as to improve the strength of the filling paste through the high strength characteristics of the aggregate; in addition, the water reducer may include: at least one of lignin sulfonate, naphthalene-based high-efficiency water reducer, polycarboxylate-based water reducer and aminosulfonate water reducer. By matching water and the water reducer, the gelling effect strength of the gelling powder material can be increased by the water reducer while reducing the water content of the filling paste, so as to improve the compressive strength of the filling paste.

[0088] Based on a general inventive concept, an embodiment of the present application provides a filling paste based on red mud, and the filling paste is obtained by the preparation method.

[0089] The filling paste is realized based on the above-mentioned preparation method. The specific steps of the preparation method can refer to the above-mentioned embodiment. Since the filling paste adopts part or all of the technical solutions of the above-mentioned embodiment, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiment, which will not be described one by one here.

[0090] It should be noted that, since the filling paste has a high compressive strength, when the filling paste meets the performance requirements of the filling material, it can accommodate more red mud raw materials to increase the doping amount of the red mud.

[0091] The present application is further described below in conjunction with specific examples. The experimental methods in the following examples that do not specify specific conditions are usually measured according to industry standards; if there are no corresponding industry standards, they are carried out according to common international standards, conventional conditions, or conditions recommended by the manufacturer.

[0092] Example 1

[0093] like Figure 1 As shown, a method for preparing a filling paste based on red mud comprises:

[0094] S1. Grinding and mixing industrial solid waste, adsorbent and Bayer red mud to obtain a ground powder;

[0095] S2. Dry-activating the ground powder under a preset temperature to activate the gelling component of the red mud in the ground powder and the adsorption properties of the adsorbent to obtain a gelled powder material;

[0096] S3. The gelled powder material, Bayer red mud, aggregate and gelled powder material are mixed to obtain a pre-filled dry material having a mixed red mud component; and

[0097] S4. The acidic activator, the water reducing agent, the water and the pre-filled dry material of the mixed red mud component are mixed to stimulate the gelation of the mixed red mud component in the pre-filled dry material by the acidic activator to obtain a filling paste having a red mud component;

[0098] Among them, the preset temperature is 350°C and the dry activation time is 60 minutes.

[0099] The components of the ground powder shall satisfy the following requirements in parts by weight:

[0100] Bayer process red mud: 10 parts, industrial solid waste: 80 parts and adsorbent: 10 parts.

[0101] In terms of weight, the industrial solid waste includes: fly ash: 30 parts, slag powder: 30 parts and desulfurized gypsum: 20 parts;

[0102] The adsorbent is montmorillonite.

[0103] The particle size of the ground powder is less than 178 μm.

[0104] The components of the pre-filled dry material include, by weight:

[0105] Cementitious powder material: 30 parts, Bayer red mud: 20 parts and aggregate: 50 parts.

[0106] The aggregate is tailings.

[0107] The weight m1 of the acidic activator and the weight m2 of the pre-filled dry material satisfy the relationship: m1:m2=2.0:100, and the weight m3 of the water reducing agent and the weight m2 of the pre-filled dry material satisfy the relationship: m3:m2=1.0:100;

[0108] The weight of water m4 and the total weight of pre-filled dry materials, acid activator and water reducer m5 satisfy the relationship: m4:m5=0.5:1.

[0109] The acidic activator is acetic acid;

[0110] The water reducer is a naphthalene-based high-efficiency water reducer.

[0111] Example 2

[0112] Based on the contents disclosed in Example 1, the following modifications are further made:

[0113] The preset temperature is 120°C and the dry activation time is 10 minutes.

[0114] The components of the ground powder shall satisfy the following requirements in parts by weight:

[0115] Red mud: 50 parts, industrial solid waste: 40 parts and adsorbent: 10 parts.

[0116] In terms of weight, the industrial solid waste includes: fly ash: 20 parts, carbide slag: 10 parts and desulfurized gypsum: 10 parts;

[0117] The adsorbent is sepiolite.

[0118] The components of the pre-filled dry material include, by weight:

[0119] Cementitious powder material: 10 parts, Bayer red mud: 60 parts and aggregate: 30 parts.

[0120] The aggregate is tailings.

[0121] The weight m1 of the acidic activator and the weight m2 of the pre-filled dry material satisfy the relationship: m1:m2=0.2:100, and the weight m3 of the water reducing agent and the weight m2 of the pre-filled dry material satisfy the relationship: m3:m2=0.2:100;

[0122] The weight of water m4 and the total weight of pre-filled dry materials, acid activator and water reducer m5 satisfy the relationship: m4:m5=0.8:1.

[0123] The acidic activator is phosphoric acid;

[0124] The water reducer is a naphthalene-based high-efficiency water reducer.

[0125] Example 3

[0126] Based on the contents disclosed in Example 1, the following modifications are further made:

[0127] The preset temperature is 150°C and the dry activation time is 20 minutes.

[0128] The components of the ground powder shall satisfy the following requirements in parts by weight:

[0129] Red mud: 20 parts, industrial solid waste: 79 parts and adsorbent: 1 part.

[0130] In terms of weight, the industrial solid waste includes: fly ash: 39 parts, slag: 20 parts and desulfurized gypsum: 20 parts;

[0131] The adsorbent is sepiolite.

[0132] The components of the pre-filled dry material include, by weight:

[0133] Cementitious powder material: 25 parts, Bayer red mud: 50 parts and aggregate: 25 parts.

[0134] The aggregate is crushed stone.

[0135] The weight m1 of the acidic activator and the weight m2 of the pre-filled dry material satisfy the relationship: m1:m2=1.5:100, and the weight m3 of the water reducing agent and the weight m2 of the pre-filled dry material satisfy the relationship: m3:m2=1.0:100;

[0136] The weight of water m4 and the total weight of pre-filled dry materials, acid activator, and water reducer m5 satisfy the relationship:

[0137] m4:m5=0.65:1.

[0138] The acidic activator is acetic acid;

[0139] The water reducer is a naphthalene-based high-efficiency water reducer.

[0140] Example 4

[0141] Based on the contents disclosed in Example 1, the following modifications are further made:

[0142] The preset temperature is 200°C and the dry activation time is 30 minutes.

[0143] The components of the ground powder shall satisfy the following requirements in parts by weight:

[0144] Red mud: 25 parts, industrial solid waste: 60 parts and adsorbent: 8 parts.

[0145] In terms of weight, the industrial solid waste includes: fly ash: 25 parts, slag powder: 25 parts and desulfurized gypsum: 10 parts;

[0146] The adsorbent is diatomaceous earth.

[0147] The components of the pre-filled dry material include, by weight:

[0148] Cementitious powder material: 25 parts, Bayer red mud: 40 parts and aggregate: 35 parts.

[0149] The aggregate is slag.

[0150] The weight m1 of the acidic activator and the weight m2 of the pre-filled dry material satisfy the relationship: m1:m2=1.2:100, and the weight m3 of the water reducing agent and the weight m2 of the pre-filled dry material satisfy the relationship: m3:m2=0.5:100;

[0151] The weight of water m4 and the total weight of pre-filled dry materials, acid activator and water reducer m5 satisfy the relationship: m4:m5=0.75:1.

[0152] The acidic activator is aluminum dihydrogen phosphate;

[0153] The water reducer is aminosulfonate water reducer.

[0154] Example 5

[0155] Based on the contents disclosed in Example 1, the following modifications are further made:

[0156] The preset temperature is 250°C and the dry activation time is 40 minutes.

[0157] The components of the ground powder shall satisfy the following requirements in parts by weight:

[0158] Red mud: 15 parts, industrial solid waste: 80 parts and adsorbent: 5 parts.

[0159] In terms of weight, the industrial solid waste includes: fly ash: 25 parts, slag powder: 30 parts and desulfurized gypsum: 25 parts;

[0160] The adsorbent is diatomaceous earth.

[0161] The components of the pre-filled dry material include, by weight:

[0162] Cementitious powder material: 25 parts, Bayer red mud: 50 parts and aggregate: 25 parts.

[0163] The aggregate is crushed stone.

[0164] The weight m1 of the acidic activator and the weight m2 of the pre-filled dry material satisfy the relationship: m1:m2=0.3:100, and the weight m3 of the water reducing agent and the weight m2 of the pre-filled dry material satisfy the relationship: m3:m2=0.5:100;

[0165] The weight of water m4 and the total weight of pre-filled dry materials, acid activator and water reducer m5 satisfy the relationship: m4:m5=0.75:1.

[0166] The acidic activator is acetic acid;

[0167] The water reducing agent is a polycarboxylate water reducing agent.

[0168] Example 6

[0169] Based on the contents disclosed in Example 1, the following modifications are further made:

[0170] The preset temperature is 250°C and the dry activation time is 40 minutes.

[0171] The components of the ground powder shall satisfy the following requirements in parts by weight:

[0172] Red mud: 19 parts, industrial solid waste: 80 parts and adsorbent: 1 part.

[0173] In terms of weight, the industrial solid waste includes: fly ash: 25 parts, slag powder: 30 parts and desulfurized gypsum: 25 parts;

[0174] The adsorbent is sepiolite.

[0175] The components of the pre-filled dry material include, by weight:

[0176] Cementitious powder material: 25 parts, Bayer red mud: 50 parts and aggregate: 25 parts.

[0177] The aggregate is crushed stone.

[0178] The weight m1 of the acidic activator and the weight m2 of the pre-filled dry material satisfy the relationship: m1:m2=0.3:100, and the weight m3 of the water reducing agent and the weight m2 of the pre-filled dry material satisfy the relationship: m3:m2=0.5:100;

[0179] The weight of water m4 and the total weight of pre-filled dry materials, acid activator and water reducer m5 satisfy the relationship: m4:m5=0.75:1.

[0180] The acidic activator is acetic acid;

[0181] The water reducing agent is a polycarboxylate water reducing agent.

[0182] Example 7

[0183] Based on the contents disclosed in Example 1, the following modifications are further made:

[0184] The preset temperature is 300°C and the dry activation time is 45 minutes.

[0185] The components of the ground powder shall satisfy the following requirements in parts by weight:

[0186] Sintering red mud: 19 parts, industrial solid waste: 80 parts and adsorbent: 1 part.

[0187] In terms of weight, the industrial solid waste includes: fly ash: 25 parts, slag powder: 30 parts and desulfurized gypsum: 25 parts;

[0188] The adsorbent is montmorillonite.

[0189] The components of the pre-filled dry material include, by weight:

[0190] Cementitious powder material: 10 parts, Bayer red mud: 60 parts and aggregate: 30 parts.

[0191] The aggregate is slag.

[0192] The weight m1 of the acidic activator and the weight m2 of the pre-filled dry material satisfy the relationship: m1:m2=0.2:100, and the weight m3 of the water reducing agent and the weight m2 of the pre-filled dry material satisfy the relationship: m3:m2=0.5:100;

[0193] The weight of water m4 and the total weight of pre-filled dry materials, acid activator and water reducer m5 satisfy the relationship: m4:m5=0.85:1.

[0194] The acidic activator is aluminum dihydrogen phosphate;

[0195] The water reducing agent is lignin sulfonate.

[0196] Example 8

[0197] Based on the contents disclosed in Example 1, the following modifications are further made:

[0198] The preset temperature is 300°C and the dry activation time is 45 minutes.

[0199] The components of the ground powder shall satisfy the following requirements in parts by weight:

[0200] Bayer process red mud: 19 parts, industrial solid waste: 80 parts and adsorbent: 1 part.

[0201] In terms of weight, the industrial solid waste includes: fly ash: 25 parts, slag powder: 30 parts and desulfurized gypsum: 25 parts;

[0202] The adsorbent is montmorillonite.

[0203] The components of the pre-filled dry material include, by weight:

[0204] Cementitious powder material: 10 parts, Bayer red mud: 60 parts and aggregate: 30 parts.

[0205] The aggregate is slag.

[0206] The weight m1 of the acidic activator and the weight m2 of the pre-filled dry material satisfy the relationship: m1:m2=1.8:100, and the weight m3 of the water reducing agent and the weight m2 of the pre-filled dry material satisfy the relationship: m3:m2=0.5:100;

[0207] The weight of water m4 and the total weight of pre-filled dry materials, acid activator and water reducer m5 satisfy the relationship: m4:m5=0.85:1.

[0208] The acidic activator is acetic acid;

[0209] The water reducing agent is lignin sulfonate.

[0210] Comparative Example 1

[0211] Based on the basic content disclosed in Example 1, the following modifications are further made:

[0212] No dry activation was used.

[0213] Comparative Example 2

[0214] Based on the basic content disclosed in Example 1, the following modifications are further made:

[0215] The preset temperature is 100°C and the dry activation time is 5 minutes.

[0216] Comparative Example 3

[0217] Based on the basic content disclosed in Example 1, the following modifications are further made:

[0218] The preset temperature is 400°C and the dry activation time is 80 minutes.

[0219] Comparative Example 4

[0220] Based on the basic content disclosed in Example 1, the following modifications are further made:

[0221] No adsorbent is added. In parts by weight, the components of the ground powder satisfy:

[0222] Bayer process red mud: 20 parts and industrial solid waste: 80 parts.

[0223] Comparative Example 5

[0224] The components of the ground powder shall satisfy the following requirements in parts by weight:

[0225] The weight proportion of the adsorbent is 20 parts.

[0226] Comparative Example 6

[0227] The components of the pre-filled dry material include, by weight:

[0228] The weight proportion of the gelled powder material is 5 parts.

[0229] Comparative Example 7

[0230] The components of the pre-filled dry material include, by weight:

[0231] The weight proportion of the gelled powder material is 40 parts.

[0232] Comparative Example 8

[0233] The components of the pre-filled dry material include, by weight:

[0234] Do not use acidic activators.

[0235] Comparative Example 9

[0236] The components of the pre-filled dry material include, by weight:

[0237] The weight m1 of the acidic activator and the weight m2 of the pre-filled dry material satisfy the relationship: m1:m2=5.0:100.

[0238] Related experiments and effect data:

[0239] The compressive strength test was performed on the filling pastes obtained in each embodiment and the comparative example, and the pH of the leachate of the filling pastes was tested, and the results are shown in Table 1; in addition, the leachate of the filling paste was tested for harmful factors according to the Class III water index of the groundwater quality standard (GB14848-2017), and the results are shown in Table 2.

[0240] Table 1 Compressive strength test results of filling pastes and pH test results of leaching solution of various embodiments and comparative examples

[0241]

[0242] Table 2 Detection results of harmful factors of filling pastes of various embodiments and comparative examples

[0243]

[0244]

[0245] It can be seen from Tables 1 and 2 that the preparation method of a red mud-based filling paste provided in the embodiment of the present application, the filling paste obtained by the preparation method has a compressive strength of more than 2.0 MPa at the 3rd and 7th days, which can fully meet the strength requirements of the filling materials in the mine goaf, and the pH of the leachate of the filling paste is less than 9. In addition, the content of harmful factors in the leachate of the filling paste meets the Class III water index of the groundwater quality standard (GB14848-2017), and meets the environmental protection indicators for filling in mine goafs.

[0246] In addition, compared with the data of each embodiment, comparative example 3 increases the preset temperature of dry activation to above 350°C, and the obtained product performance is close to that of the embodiment, but its dry activation is not in a medium-low temperature state, which will increase the energy consumption of the production equipment; and comparative example 5 adds an excessive amount of adsorbent, although it can give full play to the role of the adsorbent, but it obviously increases the raw material consumption of the preparation method of a filling paste based on red mud provided in the embodiment of the present application, and also increases the production cost of the preparation method; in addition, comparative example 7 adds an excessive amount of gelling powder, although it can give full play to the gelling effect of the gelling powder, but it will increase the raw material consumption of the preparation method, and also increase the production cost of the preparation method; in addition, comparative example 9 adds an excessive amount of acidic stimulant, although it can give full play to the stimulating effect of the acidic stimulant, it will increase the raw material consumption of the preparation method, and also increase the production cost of the preparation method. In addition, compared with the content disclosed in comparative example 4, although no adsorbent is added, and the compressive strength of the obtained filling paste is similar, the content of harmful factors in the obtained filling paste is large, and it is difficult to be continuously applied.

[0247] In addition, an embodiment of the present application provides a method for preparing a filling paste based on red mud. When the filling paste obtained by the preparation method meets the material performance requirements for filling mine goafs, the total doping amount of red mud in the preparation method can be as high as 75%, which can realize large-scale disposal of red mud. On the premise of solving the environmental risks of red mud storage, the filling cost of cemented filling mining method can be reduced, which contributes to the sustainable development of the enterprise.

[0248] In summary, the method for preparing a filling paste based on red mud provided in the embodiments of the present application can avoid the addition of cement while increasing the conversion rate of Bayer process red mud into the filling paste, thereby reducing the cost of red mud as a filling material.

[0249] The above is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. It will be apparent to those skilled in the art that various modifications to these embodiments are possible, and the general principles defined in the present application can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown in the present application, but will conform to the widest scope consistent with the principles and novel features applied for by the present application.

Claims

1. A method for preparing a filling paste based on red mud, characterized in that: The red mud includes Bayer red mud and / or sintered red mud, and the preparation method includes: Grinding and mixing industrial solid waste, an adsorbent and the red mud to obtain a ground powder; Dry-activating the ground powder under a preset temperature to activate the gelling components of the red mud in the ground powder and the adsorption performance of the adsorbent to obtain a gelling powder; Mixing the Bayer red mud, aggregate and the gelled powder material to obtain a pre-filled dry material having a mixed red mud component; and Mixing an acidic activator, a water reducing agent, water and the pre-filled dry material having a mixed red mud component, so as to activate the gelling effect of the mixed red mud component in the pre-filled dry material through the acidic activator to obtain a filling paste; Wherein, the preset temperature is ≤350°C.

2. The preparation method according to claim 1, characterized in that: The preset temperature is 120° C. to 350° C., and the dry activation time is 10 min to 60 min.

3. The preparation method according to claim 1, characterized in that: The components of the ground powder meet the following requirements in parts by weight: Red mud: 10 to 50 parts, industrial solid waste: 40 to 80 parts and adsorbent: 1 to 10 parts.

4. The preparation method according to claim 1 or 3, characterized in that: The industrial solid waste includes at least two of the following: Fly ash, slag powder, slag, carbide slag and desulfurized gypsum; and / or The adsorbent comprises at least one of the following: Montmorillonite, sepiolite and diatomaceous earth.

5. The preparation method according to claim 1, characterized in that: The particle size of the ground powder is less than 178 μm.

6. The preparation method according to claim 1, characterized in that: The components of the pre-filled dry material include, by weight: Cementitious powder material: 10 to 30 parts, Bayer red mud: 20 to 60 parts and aggregate: 0 to 80 parts.

7. The preparation method according to claim 1 or 6, characterized in that: The aggregate comprises at least one of the following: Gravel, tailings and slag.

8. The preparation method according to claim 1, characterized in that: The weight m1 of the acidic activator and the weight m2 of the pre-filled dry material satisfy the relationship: m1:m2=(0.2-2.0):100, and the weight m3 of the water reducer and the weight m2 of the pre-filled dry material satisfy the relationship: m3:m2=(0.2-1.0):100; The weight m4 of the water and the total weight m5 of the pre-filled dry material, the acidic activator and the water reducer satisfy the relationship: m4:m5=(0.5-1.0):

1.

9. The preparation method according to claim 1, characterized in that: The acidic stimulant comprises at least one of the following: Acetic acid, phosphoric acid and aluminum dihydrogen phosphate; and / or The water reducing agent comprises at least one of the following: Lignin sulfonate, naphthalene-based high-efficiency water reducer, polycarboxylate-based water reducer and aminosulfonate water reducer.

10. A filling paste based on red mud, characterized in that: The filling paste is obtained by the preparation method according to any one of claims 1 to 9.

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