High-volume waste gypsum body pipe resistance simulation and prediction method

Abstract

The invention provides a high-volume waste gypsum body pipe resistance simulation and prediction method, and relates to the technical field of mining filling. According to the method, a high-content waste gypsum body is regarded as a composite flow and is formed by compounding a tailing cement slurry continuous phase and a barren rock discrete phase, rheological parameters of the tailing cement slurry and basic parameters of barren rock are measured, a viscous flow model is used for simulating the tailing cement slurry, whether fluid is laminar flow or turbulent flow is judged through Reynolds number, and then the corresponding viscous flow model is selected. Then fluid is defined by using a Herschel-Bulkley rheological model in combination with rheological parameters of tailing cement paste, waste rocks are simulated, and finally pipe resistance is predicted through bidirectional coupling simulation. According to the method, the high-mixing-amount waste gypsum body can be simulated, the problems that due to the fact that a traditional rheological test result is not accurate, a method for calculating pipe resistance theoretically is not accurate, and meanwhile a filling ring pipe test method consumes time and labor are solved, an accurate result can be obtained more simply and conveniently, and the method has application and popularization value.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mining filling, in particular to a high-content waste rock paste pipe resistance simulation prediction method. BACKGROUND

[0002] At present, paste filling has become an important way for green mine construction and has been widely used in many mines at home and abroad. The calculation of filling slurry pipe resistance occupies an extremely important position in the engineering of hydraulic transportation of solid materials. In modern deep filling, the paste pipe resistance is one of the key factors affecting the design of the pipeline and the quality of the stope filling. However, when the proportion of high-content waste rock, i.e. the proportion of waste rock and tailings, reaches 40-60%, the traditional rheological test results are inaccurate, which leads to the inaccuracy of the method of using theoretical calculation pipe resistance, and the filling ring pipe test method is time-consuming and laborious.

[0003] Therefore, the present application provides a high-content waste rock paste pipe resistance simulation prediction method, which can realize fast and relatively accurate calculation of high-content waste rock paste pipe resistance, facilitate the selection of the diameter of the channel, the speed of transportation, pressure reduction measures, full-pipe transportation measures, and the selection of wear-resistant pipes, and has great significance and popularization value. SUMMARY

[0004] In order to solve the above technical problems existing in the prior art, the present application provides a high-content waste rock paste pipe resistance simulation prediction method. The technical solution is as follows:

[0005] A high-content waste rock paste pipe resistance simulation prediction method, the method comprising:

[0006] S1, regarding the high-content waste rock paste as a composite flow composed of tailings cement slurry continuous phase and waste rock discrete phase;

[0007] S2, respectively measuring the rheological parameters of the tailings cement slurry and the basic parameters of the waste rock;

[0008] S3, simulating the tailings cement slurry using a viscous flow model;

[0009] S4, simulating the waste rock;

[0010] S5, bidirectional coupling simulation calculation of pipe resistance.

[0011] The mass ratio of waste rock to tailings in the high-content waste rock paste is not less than 40%.

[0012] In the step S2, the rheological parameters of the tailings cement slurry and the basic parameters of the waste rock are measured through experiments,

[0013] The rheological parameters of the tailings cement slurry include yield stress, viscosity, shear rate, and the density, flow rate and concentration of the tailings cement slurry;

[0014] The basic parameters of the waste rock include particle size, particle flow, non-uniformity coefficient, curvature coefficient, density, incident direction and incident velocity.

[0015] In the step S3, first, the Reynolds number is calculated according to the density and flow rate of the tailings cement slurry, and whether the tailings cement slurry is laminar flow is determined, and the calculation formula is:

[0016]

[0017] Wherein, Re is the Reynolds number; p is the density of the tailings cement slurry, kg / m 3 ; u is the flow rate of the tailings cement slurry, m / s; D is the inner diameter of the pipeline, m; k is the viscosity, Pa·s;

[0018] If Re < 2320, the tailings cement slurry is laminar flow, otherwise it is turbulent flow, the laminar flow uses the laminar model in viscous, the turbulent flow uses the k-epsilon model in viscous, simulation is carried out, and the tailings cement slurry is defined as a fluid material, the Herschel-Bulkley rheological model is used, and the rheological parameters of the tailings cement slurry measured are input to define the fluid.

[0019] The Herschel-Bulkley rheological model is:

[0020] τ = τ y + kγ n

[0021] Wherein, τ is the shear stress, Pa; τ y is the yield stress, Pa; γ is the shear rate, s -1 ; n is the power-law index, n = 1, at this time, the Herschel-Bulkley rheological model is the Bingham model, thereby defining the Bingham fluid, and the corresponding boundary conditions are input to simulate the tailings cement slurry.

[0022] The corresponding boundary conditions are the velocity inlet condition of the tailings cement slurry and the pressure outlet condition; wherein the velocity inlet condition is the flow rate of the tailings cement slurry, and the pressure outlet condition is the static pressure of the tailings cement slurry flowing out of the pipeline (since the outlet is connected to the atmosphere, the relative atmospheric pressure is 0, that is, the static pressure is 0).

[0023] In the step S4, the waste rock is regarded as a discrete phase, one of the DEM, DPM, DDPM and MPM discrete models is selected according to the measured basic parameters of the waste rock, and the related incident parameters and particle parameters are set to simulate the waste rock, and the waste rock is simulated into a discrete phase particle; wherein the incident parameters include the incident direction and the incident velocity, and the particle parameters are the particle size.

[0024] The step S5 couples the tailings cement slurry continuous phase and the waste rock discrete phase to simulate a two-way coupled composite flow, by checking the Enable Interaction with Continuous Phase option in the Particle Tracking panel of the MPM model, the particle-fluid two-way coupling calculation can be used, and the monitoring surface is set according to the actual requirement, the pressure values of each monitoring surface are determined through the pressure nephogram of the composite flow, and then the pipe resistance is calculated, and the calculation formula is:

[0025]

[0026] Wherein, i is the pipe resistance, Pa / m; p1 is the pressure close to the monitoring surface at the inlet of the pipeline, Pa; p2 is the pressure away from the monitoring surface at the inlet of the pipeline, Pa; L is the length of the pipeline, m. The positions of p1 and p2 are selected according to the requirement, and p1 is close to the monitoring surface at the inlet of the pipeline, and p2 is away from the monitoring surface at the inlet of the pipeline.

[0027] In the above scheme, the diameters of the pipelines are the same.

[0028] The technical scheme provided by the embodiment of the present application has at least the following beneficial effects:

[0029] In the above scheme, the rheological parameters of the tailings cement slurry and the basic parameters of the waste rock are determined to simulate the high-mixing waste rock paste, and then the pressure at each position is detected to calculate the pipe resistance, so that the pipe resistance calculation is more accurate and more convenient; by using the present application, the simulation and prediction of the pressure and the pipe resistance calculation of the high-mixing waste rock paste pipeline transportation can be realized, which is convenient for the design of pipeline transportation, and can avoid the inaccuracy of the traditional rheological test, the time and labor consumption of the filling ring pipeline test method, and the reduction of the pipeline transportation cost. Based on the present application, the theoretical basis for the pipeline transportation design of the paste filling is provided, the effect of the pipeline transportation is improved, and the filling cost is saved, which has important value. The method of the present application is suitable for metal and non-metal mine enterprises. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical scheme in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creating laborious work.

[0031] Figure 1 It is a high-mixing waste rock paste pipe resistance simulation prediction method flow chart provided by the embodiment of the present application;

[0032] Figure 2 It is a tailings cement slurry flow simulation longitudinal section view in the embodiment of the present application;

[0033] Figure 3 is a simulation horizontal section view of tailings cement slurry flow in the embodiment of the present application;

[0034] Figure 4 is a simulation view of waste rock in the embodiment of the present application;

[0035] Figure 5 is a simulation vertical section view of high-content waste rock gypsum body in the embodiment of the present application;

[0036] Figure 6 is a monitoring surface pressure nephogram at 0.05m in the embodiment of the present application;

[0037] Figure 7 is a monitoring surface pressure nephogram at 0.95m in the embodiment of the present application. DETAILED DESCRIPTION

[0038] The technical solutions in the present application will be described below with reference to the drawings.

[0039] In the embodiments of the present application, the words such as "example", "for example" and the like are used to represent as an example, illustration or description. Any embodiment or design scheme described as "example" in the present application should not be interpreted as more preferred or more advantageous than other embodiments or design schemes. Rather, the word "example" is intended to present the concept in a specific manner. In addition, in the embodiments of the present application, the meaning expressed by "and / or" can be both, or can be one of the two.

[0040] In the embodiments of the present application, sometimes the subscript such as W1 may be written in the form of non-subscript such as W1, and when the difference is not emphasized, the meanings expressed are consistent.

[0041] In order to make the technical problems, technical solutions and advantages to be solved by the present application more clear, the following will be described in detail with reference to the drawings and specific embodiments.

[0042] The embodiments of the present application provide a high-content waste rock gypsum body pipe resistance simulation prediction method. As shown in the flow chart of the high-content waste rock gypsum body pipe resistance simulation prediction method, the method can include the following steps: Figure 1

[0043] S1, considering the high-content waste rock gypsum body as a composite flow composed of tailings cement slurry continuous phase and waste rock discrete phase;

[0044] S2, respectively measuring the rheological parameters of the tailings cement slurry and the basic parameters of the waste rock;

[0045] S3, simulating the tailings cement slurry using a viscous flow model;

[0046] S4, simulating the waste rock;

[0047] ​S5, bidirectional coupling analog computing tube resistance.

[0048] The mass ratio of waste rock to tailings in the high-doped waste gypsum body is not less than 40%.

[0049] The rheological parameters of the tailings cement slurry and the basic parameters of the waste rock in the step S2 are determined by experiments,

[0050] The rheological parameters of the tailings cement slurry include yield stress, viscosity, shear rate, density, flow rate and concentration of the tailings cement slurry.

[0051] The basic parameters of the waste rock include particle size, particle flow, non-uniformity coefficient, curvature coefficient, density, incident direction and incident velocity.

[0052] In the step S3, first, the Reynolds number is calculated according to the density and flow rate of the tailings cement slurry, and whether the tailings cement slurry is laminar flow is determined, and the calculation formula is:

[0053]

[0054] Wherein, Re is the Reynolds number; p is the density of the tailings cement slurry, kg / m 3 ; u is the flow rate of the tailings cement slurry, m / s; D is the inner diameter of the pipeline, m; k is the viscosity, Pa·s;

[0055] If Re < 2320, the tailings cement slurry is laminar flow, otherwise it is turbulent flow, the laminar flow uses the laminar model in viscous, the turbulent flow uses the k-epsilon model in viscous, simulation is carried out, and the tailings cement slurry is defined as a fluid material, the Herschel-Bulkley rheological model is used, and the rheological parameters of the tailings cement slurry determined are input to define the fluid.

[0056] The Herschel-Bulkley rheological model is:

[0057] τ = τ y + kγ n

[0058] Wherein, τ is the shear stress, Pa; τ y is the yield stress, Pa; γ is the shear rate, s -1 ; n is the power-law index, n = 1, at this time, the Herschel-Bulkley rheological model is the Bingham model, thereby defining the Bingham fluid, and the corresponding boundary conditions are input to simulate the tailings cement slurry.

[0059] The corresponding boundary conditions are the velocity inlet condition and the pressure outlet condition of the tailings cement slurry.

[0060] In step S4, the waste rock is regarded as a discrete phase. According to the measured basic parameters of the waste rock, one of the DEM, DPM, DDPM, and MPM discrete models is selected, and the relevant incident parameters and particle parameters are set to simulate the waste rock and simulate it into discrete phase particles.

[0061] In step S5, the tailings cement slurry continuous phase and the waste rock discrete phase are bidirectionally coupled to simulate the composite flow, and monitoring surfaces are set. The pressure value of each monitoring surface is monitored through the pressure cloud map of the composite flow, and then the pipe resistance is calculated. The calculation formula is:

[0062]

[0063] Where i is the pipe resistance, Pa / m; p1 is the pressure of the monitoring surface close to the pipeline inlet, Pa; p2 is the pressure of the monitoring surface far from the pipeline inlet, Pa; L is the pipeline length, m.

[0064] The following describes this with reference to specific embodiments.

[0065] For a copper mine paste filling horizontal pipeline, the yield stress τ of the tailings cement slurry is y The viscosity k is 79.798 Pa, the viscosity k is 1.489 Pa·s, and the density of tailings cement slurry is 1796 kg / m 3 , the horizontal pipe length L is 1m, the pipe inner diameter D is 100mm, the tailings cement slurry flow rate is about 1m / s through flow calculation, according to the Bingham fluid Reynolds number calculation formula:

[0066]

[0067] Substituting the data into the equation, we get Re = 120.618, which is much smaller than 2320, indicating a laminar flow state.

[0068] Therefore, the laminar flow model in viscous flow is selected, and the Bingham fluid is defined in the material options according to the measured rheological parameters of the tailings cement slurry. The boundary conditions are set according to the corresponding parameters of the velocity inlet and pressure outlet. In this example, the velocity inlet parameter is 1m / s. Since it is connected to the atmosphere, the relative pressure is used and the pressure outlet parameter is set to 0. The simulation results are as follows: Figure 2 、 Figure 3 shown.

[0069] The average particle size of waste rock is about 10mm and the density is 2692kg / m 3, randomly distributed in the pipeline, so the MPM model is selected to simulate the waste rock, the particle incidence model selects the volume incidence, and the incidence position (0, 0, 0) is set, the incidence direction is the positive direction of the Y axis, the incidence velocity is 1m / s, it is a cylindrical incidence, the size is the inner diameter of the pipeline 100mm, and the inlet is set as a velocity inlet, the discrete type is an escape condition simulation, and the results are shown in Figure 4 .

[0070] Finally, the two-way coupling simulation of the high-content waste rock gypsum body composite flow is carried out, as shown in Figure 5 , the pressure cloud maps of the monitoring surfaces at two different positions of 0.05m and 0.95m are determined, and the pressure values are shown in Figure 6 , Figure 7 , P1 is 12646.488Pa, P2 is 5688.6558Pa, the distance L of the two monitoring surfaces is 0.9m, and the calculation formula is:

[0071]

[0072] The pipe resistance can be calculated as: 7730.9247Pa / m.

[0073] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited to this, any skilled person in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for simulating and predicting pipe resistance of high-content waste gypsum, characterized in that: The method comprises: S1. The high-content waste gypsum is regarded as a composite flow composed of a continuous phase of tailings cement slurry and a discrete phase of waste rock; S2. Determine the rheological parameters of tailings cement slurry and basic parameters of waste rock respectively; S3, using viscous flow model to simulate tailings cement slurry; S4, simulated waste rock; S5. Calculate the tube resistance by bidirectional coupling simulation.

2. The method for simulating and predicting pipe resistance of high-content waste gypsum according to claim 1, characterized in that: The mass ratio of waste rock to tailings in the high-content waste gypsum is not less than 40%.

3. The method for simulating and predicting pipe resistance of high-content waste gypsum according to claim 1, characterized in that: In step S2, the rheological parameters of the tailings cement slurry and the basic parameters of the waste rock are determined experimentally. The rheological parameters of the tailings cement slurry include: yield stress, viscosity, shear rate, and density, flow rate, and concentration of the tailings cement slurry; The basic parameters of the waste rock include: particle size, particle flow, unevenness coefficient, curvature coefficient, density, incident direction, and incident velocity.

4. The method for simulating and predicting pipe resistance of high-content waste gypsum according to claim 1, characterized in that: In step S3, the Reynolds number is first calculated based on the density and flow velocity of the tailings cement slurry to determine whether the tailings cement slurry is laminar flow. The calculation formula is: Where Re is the Reynolds number; ρ is the density of the tailings cement slurry, kg / m 3 ; u is the flow rate of tailings cement slurry, m / s; D is the inner diameter of the pipe, m; k is the viscosity, Pa·s; If Re is less than 2320, the tailings cement slurry is laminar, otherwise it is turbulent. The laminar model in Viscous is used for laminar flow, and the k-epsilon model in Viscous is used for turbulent flow. The tailings cement slurry is defined as a fluid material and the Herschel-Bulkley rheological model is used. The measured rheological parameters of the tailings cement slurry are input to define the fluid.

5. The method for simulating and predicting pipe resistance of high-content waste gypsum according to claim 4, characterized in that: The Herschel-Bulkley rheological model is: τ=τ y +kγ n Where τ is the shear stress, Pa; τ y is the yield stress, Pa; γ is the shear rate, s -1 ; n is the power law exponent, and n=1. At this time, the Herschel-Bulkley rheological model is the Bingham model. The Bingham fluid is defined based on this, and the corresponding boundary conditions are input to simulate the tailings cement slurry.

6. The method for simulating and predicting pipe resistance of high-content waste gypsum according to claim 5, characterized in that: The corresponding boundary conditions are the velocity inlet condition of the tailings cement slurry, i.e. the flow velocity of the tailings cement slurry, and the pressure outlet condition, i.e. the static pressure of the tailings cement slurry flowing out of the pipeline.

7. The method for simulating and predicting pipe resistance of high-content waste gypsum according to claim 1, characterized in that: In step S4, the waste rock is regarded as a discrete phase. According to the measured basic parameters of the waste rock, one of the DEM, DPM, DDPM, and MPM discrete models is selected, and the relevant incident parameters and particle parameters are set to simulate the waste rock into discrete phase particles. The incident parameters include the incident direction and the incident velocity, and the particle parameter is the particle size.

8. The method for simulating and predicting pipe resistance of high-content waste gypsum according to claim 1, characterized in that: In step S5, the continuous phase of the tailings cement slurry and the discrete phase of the waste rock are bidirectionally coupled to simulate the composite flow, and monitoring surfaces are set according to actual needs. The pressure value of each monitoring surface is determined by the pressure cloud diagram of the composite flow, and then the pipe resistance is calculated. The calculation formula is: Where i is the pipe resistance, Pa / m; p1 is the pressure at the monitoring surface close to the pipeline inlet, Pa; p2 is the pressure at the monitoring surface far from the pipeline inlet, Pa; L is the pipeline length, m.

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