CN-121980986-A - Method for predicting mud layer height of thickener

Abstract

The invention belongs to the technical field of thickener control, and particularly provides a method for predicting the height of a thickener mud layer, which comprises the following steps of firstly, describing the rheological property of ore pulp through a Herschel-bulk ley model based on a rheological principle, and obtaining a shear rate; step two, a model of the change of the height of the mud layer along with time is built according to rheological property, particle interaction, turbulence disturbance and wall effect of the ore pulp, step three, distribution of the ore pulp concentration C along with time and space is determined, a diffusion-convection equation of the ore pulp concentration is built, step four, the obtained ore pulp concentration C is substituted into the model of the change of the height of the mud layer, and then the equation is numerically solved, so that a dynamic change relation of the height H of the mud layer along with time t is obtained. The invention builds the mathematical model to fully consider a plurality of parameters in the production process, more accurately calculate the dynamic change of the height of the mud layer of the thickener, has higher accuracy and reliability, and simultaneously provides key data support for the automatic control of the thickener.

Inventors

• WEI KEFENG
• CUI BAOYU
• ZHANG YIQIU

Assignees

• 中冶沈勘工程技术有限公司

Dates

Publication Date

20260505

Application Date

20251218

Claims (6)

1. 1. A method for predicting the height of a mud layer of a thickener is characterized by comprising the following specific steps: describing rheological properties of ore pulp through a Herschel-bulk ley model based on a rheological principle, and acquiring a shear rate; step two, establishing a model of the change of the height of the mud layer along with time according to rheological property, particle interaction, turbulence disturbance and wall effect of ore pulp: In the formula, Q is pulp feed flow (m 3 /h); c 0 is the feed slurry concentration (kg/m 3 ); ρ s is the solid particle density (kg/m 3 ); ρ l is the liquid density (kg/m 3 ); a is the cross-sectional area (m 2 ) of the thickener; h is the height (m) of a mud layer of the thickener; d is the average particle size (μm); d f is the fractal dimension of the floc; K is a precipitation coefficient; Mu is the apparent viscosity of ore pulp; Mu 0 is the reference viscosity; t is a time variable; Gamma is the shear rate; f (C) is a particle interaction function; Alpha is a turbulence correction coefficient; Beta is the boundary layer influence coefficient; g (D, D f ) is a modified function of the incoming particle size and the fractal dimension of the flock; Step three, determining the distribution of the ore pulp concentration C along with time and space, and establishing a diffusion-convection equation of the ore pulp concentration: is a pulp flow velocity vector; d is a diffusion coefficient; substituting the solved ore pulp concentration C into a mud layer height change model, and then carrying out numerical solving on the equation to obtain a dynamic change relation of the mud layer height H along with the time t, wherein the dynamic change relation is specifically as follows: In the formula, H 0 is the starting mud level.
2. 2. The method of claim 1, wherein the formula for shear rate in the first step is ; In the formula, Τ y is the shear stress; τ 0 is the yield stress; K HB is the consistency coefficient; n is the rheological index; The parameters are determined by the physicochemical properties of the pulp, are influenced by the particle size and the fractal dimension of the flocs, and are subjected to rheological test by using a rheometer.
3. 3. A method for predicting the height of a slurry layer in a thickener according to claim 1, wherein the precipitation factor K in the second step is related to the properties of the slurry and the characteristics of the thickener equipment and is used for describing the precipitation characteristics of solid particles in the slurry.
4. 4. The method of claim 1, wherein the reference viscosity μ 0 in the second step is the viscosity of the slurry at a concentration of about 25℃at about C 0 .
5. 5. A method for predicting the mud layer height of a thickener according to claim 1, wherein the cross-sectional area A, the solid particle density ρ s , the liquid density ρ l and the sedimentation coefficient K in the second step are determined according to detailed design parameters of the thickener.
6. 6. The method of claim 1, wherein the combined boundary conditions and initial conditions in the third step are numerically solved to obtain the distribution of the slurry concentration C in the thickener along with time and space.

Description

Method for predicting mud layer height of thickener Technical Field The invention belongs to the technical field of thickener control, and particularly provides a method for predicting the height of a mud layer of a thickener. Background In industries such as mines, metallurgy, chemical industry and the like, a thickener is a key device for realizing solid-liquid separation of suspension liquid such as ore pulp and the like. The accurate control of the height of the mud layer of the thickener is a core element for ensuring the efficient and stable operation of the thickener, and is also a key for ensuring the accurate control of the thickener. At present, the prediction precision and the mud layer height control effect of the existing mathematical model are unstable, and the dynamic change of the mud layer height in the thickener is difficult to accurately predict according to real-time operation data, so that the mud layer height in production is difficult to determine, and is more difficult to stabilize in an ideal range, and the production continuity and the product quality are influenced. Therefore, the method for detecting the mud layer height by the first line production end still depends on experience judgment or a manual basic physical detection means. Disclosure of Invention In order to solve the technical problems, the technical scheme adopted by the invention is that the method for predicting the height of the mud layer of the thickener comprises the following specific steps: describing rheological properties of ore pulp through a Herschel-bulk ley model based on a rheological principle, and acquiring a shear rate; step two, establishing a model of the change of the height of the mud layer along with time according to rheological property, particle interaction, turbulence disturbance and wall effect of ore pulp: In the formula, Q is pulp feed flow (m 3/h); c 0 is the feed slurry concentration (kg/m 3); ρ s is the solid particle density (kg/m 3); ρ l is the liquid density (kg/m 3); a is the cross-sectional area (m 2) of the thickener; h is the height (m) of a mud layer of the thickener; d is the average particle size (μm); d f is the fractal dimension of the floc; K is a precipitation coefficient; Mu is the apparent viscosity of ore pulp; Mu 0 is the reference viscosity; t is a time variable; Gamma is the shear rate; f (C) is a particle interaction function; Alpha is a turbulence correction coefficient; Beta is the boundary layer influence coefficient; g (D, D f) is a modified function of the incoming particle size and the fractal dimension of the flock; Step three, determining the distribution of the ore pulp concentration C along with time and space, and establishing a diffusion-convection equation of the ore pulp concentration: is a pulp flow velocity vector; d is a diffusion coefficient; substituting the solved ore pulp concentration C into a mud layer height change model, and then carrying out numerical solving on the equation to obtain a dynamic change relation of the mud layer height H along with the time t, wherein the dynamic change relation is specifically as follows: In the formula, H 0 is the starting mud level. Further, the formula for taking the shear rate in the first step is as follows; In the formula, Τ y is the shear stress; τ 0 is the yield stress; K HB is the consistency coefficient; n is the rheological index; The parameters are determined by the physicochemical properties of the pulp, are influenced by the particle size and the fractal dimension of the flocs, and are subjected to rheological test by using a rheometer. Further, the precipitation factor K in step two is related to the pulp properties and thickener equipment characteristics for describing the precipitation characteristics of the solid particles in the pulp. Further, the reference viscosity mu 0 in the second step is the viscosity of the ore pulp under the condition that the concentration of 25 ℃ is C 0. Further, the cross-sectional area a, the solid particle density ρ s, the liquid density ρ l and the sedimentation coefficient K in the second step are determined according to the detailed design parameters of the thickener. Further, the equation is solved through a numerical method by combining the boundary condition and the initial condition in the third step, and the distribution of the ore pulp concentration C in the thickener along with time and space is obtained. The beneficial effects of using the invention are as follows: According to the invention, a mathematical model is constructed, various complex factors such as slurry rheological property, particle interaction, turbulence disturbance, wall effect, particle size, flocculation fractal dimension and the like in the production process are fully considered, on the basis of a laboratory basic test, the dynamic change of the height of a mud layer of a thickener can be more accurately calculated according to key parameters such as feed flow, slurry concentra