Preparation method of superfine full tailing and machine-made sand composite filling material
By optimizing the particle size distribution and ash-sand ratio of ultrafine tailings and manufactured sand, a theoretical model was established to solve the problem of uneven proportioning of ultrafine tailings and manufactured sand slurry. This achieved a balance between slurry fluidity and strength, reduced backfilling costs, and improved resource utilization.
Patent Information
- Application Number
- CN202511148696.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-15
- Publication Date
- 2025-12-12
AI Technical Summary
Existing technologies lack scientific methods to balance the ratio of ultrafine tailings and manufactured sand in backfill slurry, resulting in poor fluidity, high backfilling costs, and insufficient resource utilization.
By measuring particle size distribution, determining the mass ratio, optimizing particle size distribution, determining the range of mass ratio of backfill aggregate, and establishing a theoretical model to optimize the preparation method of backfill material by adjusting the lime-sand ratio and critical mass concentration, including the combined use of ultrafine tailings sand and manufactured sand.
It achieves a balance between slurry fluidity and strength, reduces the consumption of cementitious materials, saves filling costs, and achieves 100% resource utilization.
Smart Images
Figure CN121107802A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of mine cemented filling, and particularly relates to a preparation method of filling material with composite of ultra-fine full tailings and machine-made sand. BACKGROUND
[0002] With the deepening of the green development concept in mines, the filling mining method is widely used in mine construction, and the demand for filling aggregates mainly composed of tailings and waste rock is increasing. However, the proportion of fine particles in the tailings produced by some precious metal mines is large, and the proportion of -0.075 mm fine particles is more than 90%, especially when the proportion of -0.02 mm size is more than 70%, which leads to unbalanced full tailings gradation. When preparing paste filling slurry with such ultra-fine tailings, the flowability is poor, and the concentration needs to be reduced to meet the overall flowability requirement of the slurry. Due to the low concentration of filling aggregate, more cementitious materials need to be consumed to meet the cementing strength requirement, which significantly increases the filling cost. Although the incorporation of coarse aggregate can optimize the gradation and reduce the consumption of cementitious materials, the natural sand and stone resources are becoming increasingly scarce and the environmental protection pressure is increasing, and machine-made sand has become an ideal substitute due to its advantages such as adjustable gradation, stable production and waste rock resource utilization. However, the existing technology lacks a systematic filling slurry proportioning method based on the mixed aggregate of "ultra-fine tailings + machine-made sand", and it is difficult to scientifically balance the flowability of the slurry, the strength of the filling body and the economy. SUMMARY
[0003] The main technical problem to be solved by the present application is to provide a preparation method of filling material with composite of ultra-fine full tailings and machine-made sand, so as to scientifically balance the working performance, forming strength and construction economy of the filling slurry.
[0004] In order to solve the above technical problems, the present application provides a preparation method of filling material with composite of ultra-fine full tailings and machine-made sand, comprising the following steps:
[0005] Step 1: determining the particle size distribution of ultra-fine full tailings and machine-made sand; based on the proportion range of the preset size, determining the mass ratio range of ultra-fine full tailings and machine-made sand in the filling aggregate;
[0006] Step 2: fixing the cement-sand ratio, and changing the mass ratio of ultra-fine full tailings and machine-made sand in the range determined in step 1 to prepare several groups of filling slurries; the filling slurry comprises filling aggregate, cementitious material and water; determining the critical mass concentration when each group of filling slurry meets the preset slump;
[0007] Step 3: preparing a first filling body according to the critical mass concentration of each group of filling slurry; curing and testing the age strength, and determining the optimal mass ratio according to the maximum value of the age strength;
[0008] Step 4: changing the sand-binder ratio to prepare several groups of second filling bodies according to the optimal quality ratio and the corresponding critical quality concentration; curing and testing the age strength;
[0009] Step 5: establishing a theoretical model of sand-binder ratio-strength according to the age strength; determining the sand-binder ratio meeting the target strength based on the theoretical model.
[0010] In a preferred embodiment: in the step 4, each sand-binder ratio respectively uses mine glue powder and cement to prepare two groups of second filling bodies.
[0011] In a preferred embodiment: in the step 1, the preset particle size is-0.020mm, and the proportion range is 20%-40%.
[0012] In a preferred embodiment: in the step 2, the preset slump is not less than 28.5cm; and the critical quality concentration is the highest quality concentration meeting the preset slump.
[0013] In a preferred embodiment: in the step 2, the mass ratio of superfine whole tailings to machine-made sand in the filling slurry includes 3:7, 4:6 or 5:5.
[0014] In a preferred embodiment: in the step 4, the sand-binder ratio of the filling slurry includes 1 / 4, 1 / 8, 1 / 12 or 1 / 20.
[0015] In a preferred embodiment: the preparation method of the first filling body or the second filling body includes pouring the filling slurry in a cubic test piece for curing.
[0016] In a preferred embodiment: in the step 5, the theoretical model is fitted as a linear function of strength and sand-binder ratio.
[0017] In a preferred embodiment: in the step 2, the sand-binder ratio is fixed as 1 / 12.
[0018] In a preferred embodiment: the age strength is the strength of 28 days of curing.
[0019] Compared with the prior art, the technical scheme of the present application has the following beneficial effects:
[0020] The method provided by the application has the advantages of (1) by mixing machine-made sand into ultra-fine tailings, the proportion of fine particles is controlled at 20-40%, which improves the fluidity of the mixture, so that higher concentration of filling aggregate in the slurry can also meet the fluidity requirement, and higher concentration of filling aggregate contributes to higher cementing strength, so that the consumption of cementing material is reduced, thereby saving the filling cost; (2) the corresponding relationship between the quality ratio and the quality concentration is established by using the slump, so that the feasible concentration is determined under the premise of meeting the fluidity, and a scientific concentration benchmark is provided for the strength test; (3) the mine cementing powder has excellent wrapping property for the ultra-fine tailings, and the strength reaches 2-4 times of that of cement under the same cement-sand ratio, so that the amount of cementing material is greatly reduced, and the filling cost is reduced; (4) the highly fitted theoretical model is established based on the strength test data of the cementing powder, the model can directly reverse the minimum cement-sand ratio according to the target strength, realizes the rapid and scientific decision of the mixing ratio parameters, and avoids the inefficiency of the traditional experience trial and error; (5) the machine-made sand absorbs waste rocks, and the cementing powder utilizes industrial waste slag, so that the tailings, waste rocks and waste slag are 100% recycled. BRIEF DESCRIPTION OF DRAWINGS
[0021] Figure 1 It is a flowchart of the preparation method described in the embodiments of the application.
[0022] Figure 2 It is the second filling body cement-sand ratio-strength curve of the embodiments of the application, in which the mine cementing powder is used as the cementing material. DETAILED DESCRIPTION
[0023] The technical solutions in the embodiments of the application will be clearly and completely described in combination with the drawings of the embodiments of the application; obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application, and all other embodiments obtained by those skilled in the art without creative labor on the basis of the embodiments of the application belong to the protection scope of the application.
[0024] In the description of the application, it should be noted that the terms “upper”, “lower”, “inner”, “outer”, “top / bottom end” and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application. In addition, the terms “first” and “second” are only for the purpose of description, and cannot be understood as indicating or implying relative importance.
[0025] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "provided with", "sleeved / connected", "connected" and the like should be understood broadly, for example, "connected" can be wall-mounted connection, can be detachable connection, or integral connection, can be mechanical connection, can be electrical connection, can be direct connection, can be indirect connection through intermediate medium, can be internal communication of two elements, and those skilled in the art can understand the specific meaning of the above terms in the present application according to the specific circumstances.
[0026] As Figure 1 shown, the embodiment of the present application provides a preparation method of filling material compounded by ultra-fine full tailings and machine-made sand, to determine the components and proportioning parameters of the filling material. The materials used include ultra-fine full tailings, 0-5mm machine-made sand, 42.5 ordinary portland cement or mine glue solid powder. The mine glue solid powder is a mine high-performance cementing material composed of slag and desulfurization gypsum. For the convenience of description, some parameters are defined as follows: let the mass ratio of ultra-fine full tailings / machine-made sand (hereinafter referred to as mass ratio) be A, the sand ratio (i.e. cementing material / filling aggregate) be B, the mass concentration of filling slurry be W, and the filling body strength be C. The cementing material is the 42.5 ordinary portland cement (hereinafter referred to as cement) or mine glue solid powder, and the filling aggregate includes the ultra-fine full tailings and machine-made sand. The method comprises:
[0027] Step 1: determining the range of filling aggregate mass ratio
[0028] Firstly, the particle size distribution of raw materials is determined. The particle size test results of the full tailings of a certain gold mine are shown in Table 1. The proportion of -0.02mm is about 68%, which belongs to very fine tailings.
[0029] Table 1 Particle size distribution of full tailings
[0030]
[0031] The machine-made sand of 0-5mm is used in the mining area, and the particle size distribution test results are shown in Table 2.
[0032] Table 2 Particle size distribution test results of machine-made sand 0-5mm
[0033]
[0034] Then, B=1 / 12 is selected, and the filling material is prepared according to the proportions of A=5 / 5, 4 / 6, 3 / 7 and 2 / 8 respectively, and the mass proportion of -0.02mm particle size in the filling material is calculated, and the calculation results are shown in Table 3.
[0035] Table 3 Calculation list of -0.02mm content (mass proportion) in different proportioning materials
[0036]
[0037] The gradation of the filling aggregate directly affects the stability of the slurry and the efficiency of the cementitious material. In the paste filling material, the proportion of the -0.02 mm particle size exceeding 40% will significantly increase the amount of cementitious material and water, and less than 20% will easily cause aggregate segregation, therefore, the proportion of the -0.02 mm particle size is controlled in the range of 20%-40% in the embodiment. It can be determined from Table 3 that three groups of A=5 / 5, 4 / 6, 3 / 7 are taken for subsequent tests.
[0038] Step 2: Determine the critical mass concentration of each group of filling slurry
[0039] The fixed ash-sand ratio B=1 / 12, the filling slurry is prepared according to the mass ratio A=5 / 5, 4 / 6, 3 / 7, and an additional test group of filling aggregate containing only full tailings (i.e. A=10 / 0) is added. Take a standard slump cone with an internal size of a top diameter of 10 cm, a bottom diameter of 20 cm, and a height of 30 cm, and the filling slurry of each group with different mass ratios is evenly loaded into the slump cone in multiple times with a small shovel, and is gradually diluted from 80% mass concentration to the spreading of the filling slurry, so as to determine the mass concentration of each group of filling slurry when the slump is 28.5 cm. The test results are shown in Table 4.
[0040] Table 4: Slump and strength test results of different mixed aggregates
[0041]
[0042] It can be known from Table 4 that in order to meet the flowability requirement, when the slump is ≥28.5 cm, the mass concentration of A=5 / 5 filling slurry is W≤64%, the mass concentration of A=4 / 6 filling slurry is W≤68%, and so on. The "64%", "68%" or "72%" is the highest mass concentration, i.e. the critical mass concentration, of each group of filling slurry meeting the slump ≥28.5 cm. The purpose of this step is to determine the preparation concentration of each group of filling slurry before comparing the "28-day strength" of the filling body to determine the optimal mass ratio of the filling aggregate. In order to avoid two independent variables in the same process, the embodiment takes the slump, which is a more engineering significant flowability index, as a unified standard to correspond the mass concentration and the mass ratio one by one. That is, under the premise of meeting the flowability requirement, each specific mass ratio of the filling slurry corresponds to a critical mass concentration. In this way, the mass A is ensured as the core variable, and the preparation concentration of each test group is reasonably determined.
[0043] Step 3: Determine the optimal mass ratio according to the strength of the filling body
[0044] The filling material slurries of different mass ratios in each group were poured into cubic specimens with a side length of 70.7 mm according to the critical mass concentration determined in step two to prepare the first filling body. The strength C of the first filling body was tested after 28 days of standard curing. As can be seen from Table 4 above, when the strength C of the first filling body is the largest, the mass ratio of ultra-fine whole tailings / machine-made sand A = 3 / 7, and the corresponding critical mass concentration is 72%.
[0045] Step 4: Test the strength of the second filling body under different cement / sand ratios
[0046] With A = 3 / 7 and W = 72%, a plurality of second filling bodies were prepared with a cement / sand ratio of B = 1 / 4, 1 / 8, 1 / 12, and 1 / 20, respectively. Two groups of second filling bodies were prepared for each cement / sand ratio using cement and mine solidifying powder, respectively. The strength test was performed after 28 days of standard curing. The specific material usage and 28-day strength test results are shown in Table 5.
[0047] Table 5: Strength of cementitious filling body with different cementitious materials
[0048]
[0049] The test shows that: (1) Under the same cement / sand ratio B, the cementing strength of mine solidifying powder is 2.2-3.3 times that of cement. This means that, under the same strength requirement, the cement / sand ratio can be significantly reduced when using mine solidifying powder instead of cement to cement the filling, and the corresponding filling cost is lower. (2) For the same cementitious material, the larger the cement / sand ratio, the greater the cementing strength. Moreover, with the increase of the cement / sand ratio, the development of the cementing strength of mine solidifying powder is more prominent.
[0050] Step 5: Establish a theoretical model and provide recommended proportions
[0051] As shown in Figure 2 , the cement / sand ratio and cementing strength data of mine solidifying powder are used to draw a cement / sand ratio (x)-strength (y) curve as a theoretical model. Preferably, the theoretical model is fitted as a first-order function of strength and cement / sand ratio, and the fitting formula is specifically:
[0052] y = 35.968x - 1.454
[0053] The goodness of fit R 2 = 0.99087.
[0054] When the strength requirement of underground filling is strength y ≥ 1.0 MPa, x ≥ 1 / 14.7 is calculated from the fitting formula. Considering the engineering safety margin, the recommended filling proportion parameters are: using mine solidifying powder as the cementitious material, the cement / sand ratio is not less than 1 / 14, the mass ratio of ultra-fine whole tailings / machine-made sand is 3 / 7, and the mass concentration is 72%.
[0055] The method has the following technical advantages:
[0056] (1) By mixing machine-made sand into ultra-fine tailings, the proportion of fine particles is controlled at 20%-40%, which improves the flowability of the mixture, so that higher concentration of filling aggregate in the slurry can also meet the flowability requirements. Higher concentration of filling aggregate contributes to higher cementing strength, so that the consumption of cementing material is reduced, thereby saving the filling cost.
[0057] (2) The correspondence between the quality ratio and the mass concentration is established by the slump, so that the feasible concentration is determined under the premise of meeting the flowability, and a scientific concentration benchmark is provided for the strength test.
[0058] (3) The mine gel powder has excellent wrapping property for ultra-fine tailings, and the strength is 2-4 times that of cement under the same sand ratio, which greatly reduces the amount of cementing material and the filling cost.
[0059] (4) A highly fitted theoretical model is established based on the strength test data of the gel powder, which can directly deduce the minimum sand ratio according to the target strength, realize the rapid and scientific decision of the mixing ratio parameters, and avoid the inefficiency of traditional trial and error.
[0060] (5) The machine-made sand absorbs waste rock, and the gel powder utilizes industrial waste slag, so that the tailings, waste rock and waste slag are 100% resourceized.
[0061] The above is only the preferred embodiment of the present application, and is not limited to the scope of the patent of the present application. Any equivalent transformation using the content of the present application is within the scope of protection of the present application.
Claims
1. A method for preparing a backfill material composed of ultrafine tailings and manufactured sand, characterized in that, Includes the following steps: Step 1: Determine the particle size distribution of ultrafine tailings and manufactured sand; based on the preset particle size ratio range, determine the mass ratio range of ultrafine tailings and manufactured sand in the backfill aggregate; Step 2: Fix the ash-sand ratio and change the mass ratio of ultrafine tailings sand to manufactured sand within the range determined in Step 1 to prepare several groups of filling slurries; the filling slurries include filling aggregates, cementitious materials and water; determine the critical mass concentration of each group of filling slurries when it meets the preset slump. Step 3: Prepare the first filling body for each group of filling slurry according to their respective critical mass concentration; cure and test the strength at different ages, and determine the optimal mass ratio based on the maximum strength at different ages; Step 4: According to the optimal mass ratio and the corresponding critical mass concentration, change the ash-sand ratio to prepare several groups of second filling bodies; cure and test the strength at different ages; Step 5: Establish a theoretical model of cement-sand ratio-strength based on the strength at different ages; based on the theoretical model, determine the cement-sand ratio that meets the target strength.
2. The method for preparing a composite backfill material of ultrafine tailings and manufactured sand according to claim 1, characterized in that: In step 4, two sets of second filling bodies are prepared using mineral cementitious powder and cement for each lime-sand ratio.
3. The method for preparing a composite backfill material of ultrafine tailings and manufactured sand according to claim 1, characterized in that: In step 1, the preset particle size is -0.020 mm, and the proportion ranges from 20% to 40%.
4. The method for preparing a composite backfill material of ultrafine tailings and manufactured sand according to claim 1, characterized in that: In step 2, the preset slump is not less than 28.5 cm; the critical mass concentration is the highest mass concentration that meets the preset slump.
5. The method for preparing a composite backfill material of ultrafine tailings and manufactured sand according to claim 1, characterized in that: In step 2, the mass ratio of ultrafine tailings sand to manufactured sand in the filling slurry includes 3:7, 4:6, or 5:
5.
6. The method for preparing a backfill material composed of ultrafine tailings and manufactured sand according to claim 1, characterized in that: In step 4, the ash-sand ratio of the filling slurry includes 1 / 4, 1 / 8, 1 / 12, or 1 / 20.
7. The method for preparing a composite backfill material of ultrafine tailings and manufactured sand according to claim 2, characterized in that: In step 4, the strength data used in the theoretical model comes from the second filler, which uses mineral cementitious powder as the cementing material.
8. The method for preparing a backfill material composed of ultrafine tailings and manufactured sand according to claim 1, characterized in that: The preparation method of the first or second filling body includes: casting the filling slurry into a cubic specimen for curing.
9. The method for preparing a composite backfill material of ultrafine tailings and manufactured sand according to claim 1, characterized in that: In step 2, the ash-sand ratio is fixed at 1 / 12.
10. The method for preparing a backfill material composed of ultrafine tailings and manufactured sand according to claim 1, characterized in that: The age-related intensity refers to the intensity after 28 days of standard maintenance.