A device and method for real-time monitoring of the concentration of a filling slurry in a stirring process

Abstract

The application provides a device and method for real-time monitoring of filling slurry concentration in a stirring process, and belongs to the technical field of mine filling. The device comprises a micro bypass loop system, a remote control system and a data acquisition visualization system. In the micro bypass loop system, a flow guide pipe is arranged at the bottom of a stirring tank, a pressure pump is connected through a flow guide gate valve, and a series micro loop is connected after the pressure pump. In the data acquisition visualization system, a high-precision pressure sensor is connected to the series micro loop, a flow meter is arranged at the outlet end of the series micro loop, and a gate valve switch and a pressure pump controller are connected to a PLC control cabinet of the remote control system. The device has a simple structure and high automation degree, provides an effective device and method for realizing real-time feedback and intelligent control of filling slurry concentration in a stirring process, and provides a good reference for promoting the development of intelligent and precise filling mining of metal mines.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mine filling, in particular to a device and method for real-time monitoring of filling slurry concentration in the mixing process. BACKGROUND

[0002] Mining is a basic industry supporting the development of national economy and society. More than 90% of energy raw materials, more than 80% of industrial raw materials, and more than 70% of agricultural production materials in China come from mineral resources. The output value of mining and its downstream industries accounts for more than 30% of the total industrial output value in China.

[0003] Mine filling mining is an important way to realize green development of metal mines. It is a process of preparing one or more mine solid wastes and water into high-concentration slurry with certain stability, fluidity and plasticity, and under the action of pump pressure or gravity, the slurry is transported through pipeline and fills the underground goaf. This technology not only makes full use of mine solid waste, but also solves the problems of tailings pond occupation and environmental safety, eliminates the two safety hazards of tailings pond and goaf from the source, and has the remarkable characteristics of "green, safe and efficient".

[0004] Filling slurry has the characteristics of ultra-high solid content and no excess free water excretion, and can maintain good fluidity and stability during pipeline transportation and stope solidification. The slurry concentration is the core element throughout the filling process links of tailings thickening, mixing preparation, pipeline transportation and stope solidification. ① When the slurry concentration decreases, the water excretion of filling slurry increases, the underground filling environment is poor, the strength performance of filling body decreases, and the particles of low-concentration slurry are easy to separate and settle, resulting in large settlement rate of filling body, poor roof contact effect, poor control of surface subsidence effect, and even pipe blockage due to settlement of filling pipe. ② When the concentration increases, the transportation resistance of filling slurry increases, the energy consumption of pumping equipment increases, and pipe blockage accidents are prone to occur. In addition, the ultra-high concentration of slurry requires higher requirements for each filling process link.

[0005] For a long time, the difficulty in measuring the concentration of filling slurry is the bottleneck problem restricting the development of filling technology. The filling slurry belongs to a super-high solid two-phase fluid, and presents complex flow characteristics in the filling process. The online monitoring of the concentration of the filling slurry is difficult, the detection method of the low-concentration slurry cannot be followed, and due to the small particle size spacing of the filling material and the large interference, the received signal of the ultrasonic wave after passing through the slurry is greatly deviated, the concentration measurement precision is low, and the filling slurry concentration measuring device has problems of low precision, large error and easy failure. The most reliable, simple and direct way for detecting the concentration of the filling slurry is the drying method, but the system is closed and runs at high speed during operation, and cannot be frequently sampled, dried and weighed. Therefore, the indirect method is often used for online detection, and the most widely used is the nuclear density meter. However, it has been proved that the composition of the material in the pipeline fluctuates greatly, the gas is mixed, and there are many interference factors, which causes the detection data to fluctuate greatly and is difficult to provide basis for real-time control. At the same time, the nuclear density meter can only detect the volume of the solid component in the pipeline cross section and then calculate the concentration, and cannot feedback the rheological characteristics and other parameters to reflect the homogeneity of the slurry. Only relying on the nuclear density detection cannot provide reliable reference for the regulation and control of the preparation of the filling slurry.

[0006] In summary, due to the problems of insufficient measuring method and instrument, and many interference factors, the accurate measurement of the concentration of the filling slurry is difficult to realize, which becomes the bottleneck problem restricting the development of the filling technology. SUMMARY

[0007] The technical problem to be solved by the present application is to provide a device and method for real-time monitoring of the concentration of filling slurry in the stirring process, to realize real-time feedback of the concentration in the filling process, and to promote the development of intelligent and accurate filling mining of metal mines.

[0008] The device comprises a micro bypass loop system, a remote control system and a data acquisition visualization system. The micro bypass loop system comprises a drainage pipe, a sampling port, a series micro loop, a return pipe and a stirring tank. The remote control system comprises a PLC control cabinet, a drainage gate valve, a pressure pump, a sampling gate valve and a confluence gate valve. The data acquisition visualization system comprises a high-precision pressure sensor, a flow meter and a data integrated computer.

[0009] The drainage pipe is installed at the bottom of the stirring tank and connected with the pressure pump through the drainage gate valve. The filling slurry in the stirring tank is flowed into the series micro loop through the drainage pipe after being pressurized by the pressure pump.

[0010] The sampling gate valve and the sampling port are arranged on the drainage pipe, and the confluence gate valve is arranged on the series micro loop.

[0011] The high-precision pressure sensor is connected with the series micro loop through a flange, and the flow meter is installed at the end outlet of the series micro loop through a flange.

[0012] The outlet of the series micro loop is connected with the stirring tank through the return pipe.

[0013] The pressurizing pump, the drainage gate valve, the sampling gate valve and the confluence gate valve are connected with the PLC control cabinet through a cable.

[0014] The electric signals collected by the high-precision pressure sensor and the flow meter are all sent to the data integration computer.

[0015] Specifically, a sampling port is arranged at the end of the drainage pipe, a sampling gate valve is arranged in front of the sampling port, a series micro loop is connected between the sampling gate valve and the pressurizing pump, and a confluence gate valve is arranged at the inlet of the series micro loop.

[0016] The series micro loop is composed of three measuring pipe sections with the same length of 1 m and different diameters, and the pipe sections with diameters of 30 mm, 40 mm and 50 mm are sequentially connected in series from the inlet.

[0017] The pressurizing pump controls the flow of the filling slurry by changing the pump pressure.

[0018] When the flow meter and the high-precision pressure sensor are connected with the series micro loop through flanges, rubber gaskets are added to reduce dripping.

[0019] During installation, the flow meter should be installed in the correct direction and position to ensure accurate measurement parameters, and the high-precision pressure sensor should be installed to ensure that the display is directly above the pipe.

[0020] There are six high-precision pressure sensors, which are respectively installed at the front end inlets and rear end outlets of the three-diameter measuring pipe sections of the series micro loop, and the interval between adjacent two high-precision pressure sensors is 1 m.

[0021] The PLC control cabinet can realize remote control of the gate valve and the pressurizing pump to adjust the running line of the filling slurry.

[0022] The data integration computer realizes real-time display of the concentration and the rheological parameters after processing the electric signals generated by the high-precision pressure sensor and the flow meter through the self-developed rheological model solver.

[0023] The three-diameter measuring pipes in the series micro loop are connected through variable-diameter joints, and the series micro loop and the pressurizing pump are connected through variable-diameter joints.

[0024] The monitoring method of the monitoring device comprises the following steps:

[0025] S1: Before the concentration monitoring starts, the drainage gate valve is closed through the PLC control cabinet, and the drainage gate valve is opened after the materials in the stirring tank are fully mixed;

[0026] S2: open the confluence gate valve and the pressure pump through the PLC control cabinet, after the filling slurry is pumped by the pressure pump, it flows through the series micro annular pipe, high precision pressure sensor, flow meter and return pipe in turn, and then returns to the stirring tank to form a closed loop circulation;

[0027] S3: the system is started, after the high precision pressure sensor and the flow meter obtain stable flow value Q and pressure value ΔP, the tested filling slurry parameters and the pipeline parameters of the micro annular pipe are placed into the rheological model solver in the data integration computer, and the solver calculation principle is as follows:

[0028]

[0029] In the formula: Q1, Q2, Q3 are the flow values measured every 5 min after the material is stabilized; ΔP1, ΔP2, ΔP3 are the pressure differences measured at both ends of the pipeline; R is the pipeline radius; L is the pipeline length; τ B is the yield stress; K is the consistency coefficient; n is the power index;

[0030] S4: based on the inner diameter, length, pressure drop and filling slurry flow data of the three groups of measuring pipe sections in the series micro annular pipe, the data is brought into the rheological model solver in the data integration computer in S3 to obtain the yield stress of the slurry;

[0031] S5: the pressure pump is adjusted through the PLC control cabinet to realize the periodic gradient regulation and control of the flow, pressure and pressure drop, and the rheological model solver is repeatedly operated to make the measured value of the rheological parameter approach the true value;

[0032] S6: through the data integration computer, the rheological curve of the filling slurry in the series micro annular pipe, the pipeline flow state, the resistance along the pipeline and the pipeline flow are realized in real time, and the yield stress model based on specific gravity, bulk density and concentration is used to inverse the mass concentration of the filling slurry, so as to realize the real-time monitoring of the slurry concentration; the slurry concentration is represented as:

[0033]

[0034] In the formula: a, b are constants; ρ s is the specific gravity, ρ is the bulk density, C w is the mass concentration. Among them, the specific gravity of a single material can be obtained by a specific gravity bottle test, and the specific gravity ρ s and the bulk density ρ of the slurry are calculated by the addition amount of the material.

[0035] The above constants a and b are obtained in the laboratory, specifically: at least two groups of slurry with different proportions are prepared by using the aggregate obtained on site. According to the material ratio, the mass concentration C w is calculated, and the specific gravity ρ s , the bulk density ρ and the yield stress τ are tested respectively.B Finally, the constants a and b are obtained by solving the problem.

[0036] The beneficial effects of the above-described technical solution of the present invention are as follows:

[0037] The above scheme utilizes a bypass-type micro-loop pipe system combined with a PLC remote control system and a data acquisition and visualization system to achieve real-time monitoring and concentration inversion of the rheological parameters of the filling slurry during the mixing process. This is an effective device and method for real-time monitoring of the filling slurry concentration during mixing. The device has a simple structure and a high degree of automation, providing an effective method for achieving real-time concentration feedback and intelligent control during the filling process, and offering a valuable reference for promoting the development of intelligent and precise filling mining in metal mines. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the device for real-time monitoring of filler slurry concentration during the stirring process according to the present invention.

[0039] Wherein: 1-Drainage pipe; 2-Drainage gate valve; 3-Pressure pump; 4-Sampling gate valve; 5-Sampling port; 6-Combination gate valve; 7-High-precision pressure sensor; 8-Series miniature ring pipe; 9-Flow meter; 10-Data integration computer; 11-Return pipe; 12-PLC control cabinet; 13-Mixing tank. Detailed Implementation

[0040] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0041] This invention provides a device and method for real-time monitoring of the concentration of filling slurry during stirring.

[0042] like Figure 1 As shown, the device includes a miniature bypass loop system, a remote control system, and a data acquisition and visualization system. The miniature bypass loop system includes a drainage pipe 1, a sampling port 5, a series-connected miniature loop 8, a return pipe 11, and a mixing tank 13. The remote control system includes a PLC control cabinet 12, a drainage gate valve 2, a pressurizing pump 3, a sampling gate valve 4, and a manifold gate valve 6. The data acquisition and visualization system includes a high-precision pressure sensor 7, a flow meter 9, and a data integration computer 10.

[0043] The drainage pipe 1 is installed at the bottom of the mixing tank 13 and is connected to the pressurizing pump 3 through the drainage gate valve 2; the filling slurry in the mixing tank 13 is pressurized by the pressurizing pump 3 and flows into the series micro ring pipe 8 through the drainage pipe 1;

[0044] A sampling gate valve 4 and a material inlet 5 are installed on the drainage pipe 1, and a manifold gate valve 6 is installed on the series-connected micro ring pipe 8;

[0045] The high-precision pressure sensor 7 is connected with the series micro annular pipe 8 through a flange, and the flow meter 9 is installed at the end outlet of the series micro annular pipe 8 through a flange;

[0046] The outlet of the series micro annular pipe 8 is connected with the stirring tank 13 through the back material pipe 11;

[0047] The pressurizing pump 3, the drainage gate valve 2, the sampling gate valve 4 and the confluence gate valve 6 are connected with the PLC control cabinet 12 through a cable.

[0048] The electrical signals collected by the high-precision pressure sensor 7 and the flow meter 9 are all integrated into the data integration computer 10.

[0049] Specifically, the sampling port 5 is arranged at the end of the drainage pipe 1, the sampling gate valve 4 is arranged in front of the sampling port 5, the series micro annular pipe 8 is connected between the sampling gate valve 4 and the pressurizing pump 3, and the confluence gate valve 6 is arranged at the inlet of the series micro annular pipe 8.

[0050] The series micro annular pipe 8 is composed of three measuring pipe sections with different diameters and a length of 1 m. From the inlet, the pipe sections with diameters of 30 mm, 40 mm and 50 mm are sequentially connected in series. When the flow meter 9 and the high-precision pressure sensor 7 are connected with the series micro annular pipe 8 through a flange, a rubber gasket is added to reduce dripping.

[0051] When the high-precision pressure sensor 7 is installed, it is ensured that the display is located directly above the pipe.

[0052] The high-precision pressure sensor 7 has a total of 6, which are respectively installed at the front end inlet and the rear end outlet of the three-diameter measuring pipe sections of the series micro annular pipe, and the adjacent two high-precision pressure sensors 7 are spaced 1 m apart.

[0053] The three-diameter measuring pipes in the series micro annular pipe 8 are connected through a variable-diameter joint, and the series micro annular pipe 8 and the pressurizing pump 3 are connected through a variable-diameter joint.

[0054] In practical application, the monitoring device is used according to the following steps:

[0055] S1: Equipment installation and preliminary preparation. Before the concentration monitoring starts, the pressurizing pump 3, the series micro annular pipe 8, the back material pipe 11 and various sensors and gate valves are installed in sequence below the stirring tank. The drainage gate valve 2 is closed through the PLC control cabinet 12, and then opened after the material in the stirring tank 13 is fully mixed, so as to prevent large particles wrapped by insufficient stirring from flowing into the series micro annular pipe 8 and causing blockage;

[0056] S2: Circulation test. The drainage gate valve 2, the pressurizing pump 3 and the confluence gate valve 6 are opened through the PLC control cabinet 12, the filled slurry is pumped through the pressurizing pump 3, and then flows through the series micro annular pipe 8, the high-precision pressure sensor 7, the flow meter 9 and the back material pipe 11 in sequence before returning to the stirring tank, forming a closed loop.

[0057] S3: Parameter output. The system is started to run, and after the high-precision pressure sensor and flow meter obtain stable flow value Q and pressure value ΔP, the tested filling slurry parameters (flow and pressure) and the pipeline parameters (pipe diameter and length) of the micro annular channel are placed into the data integration computer rheological model solver, and the solver calculates the principle as follows:

[0058]

[0059] In the formula: Q1, Q2, Q3 are the flow values measured every 5 min after the material is stabilized; ΔP1, ΔP2, ΔP3 are the measured pressure differences at both ends of the three pipeline sections; R is the pipeline radius; L is the pipeline length; τ B is the yield stress; K is the consistency coefficient; n is the power index;

[0060] S4: Based on the inner diameter, length, pressure drop and filling slurry flow data of the three groups of measurement pipeline sections in the series micro annular channel 8, the yield stress of the slurry is obtained through the rheological model solver in the data integration computer 10.

[0061] S5: The periodic gradient regulation and control of flow, pressure and pressure drop are realized by adjusting the pressure pump 3 through the PLC control cabinet 12, and repeated operation is performed through the rheological model solver, so that the rheological parameter measured value approaches the true value.

[0062] S6: Concentration inversion. Through the data integration computer 10, the real-time display of the filling slurry rheological curve, pipeline flow state, along-the-way resistance and pipeline flow in the series micro annular channel 8 is realized, and the yield stress model based on specific gravity, bulk density and concentration is used to invert the filling slurry mass concentration, so as to finally realize the real-time monitoring of the slurry concentration; the slurry concentration is represented as:

[0063]

[0064] In the formula: a, b are constants; ρ s is the specific gravity, ρ is the bulk density, and C w is the mass concentration.

[0065] The constants a and b need to be obtained in the laboratory by preparing at least two groups of slurry with different proportions of the on-site obtained aggregates. According to the material proportion, the mass concentration C w is calculated, and the specific gravity ρ s , bulk density ρ and yield stress τ B are tested respectively, and finally the constants a and b are solved.

[0066] For example:

[0067] Take a mine tailings (specific gravity 2794 kg / m 3 ) and waste rock (specific gravity 2806 kg / m3 ), mine fly ash cement (specific gravity of 30-50 kg / m 3 ), and water (specific gravity of 1000 kg / m 3 ) as materials, slurries with mass concentrations of 77% and 79% were prepared, and their specific gravities were 1.979 and 2.029, and their bulk densities were 19394.2 N / m 3 and 19884.2 N / m 3 , respectively. Rheometer was used to measure their yield stresses, which were 227.4 Pa and 273.6 Pa, respectively. The two sets of data were substituted into the formula in S6, and the simultaneous equations were solved by using matlab:

[0068] clear all;

[0069] syms a b;

[0070] [a b] = solve((227.4 / a(1.979*19394.2 / (19394.2-1.979))^b)^(1 / b)-0.77,(273.6 / a(2.209*19884.2 / (19884.2-2.209))^b)^(1 / b)-0.79); thus the values of a and b were 128 and 1.364, respectively.

[0071] The above is the preferred embodiment of the present application, it should be noted that for those skilled in the art, without departing from the principles of the present application, can make a number of improvements and refinements, these improvements and refinements should also be considered within the scope of the present application.

Claims

1. A device for real-time monitoring of the concentration of a filling slurry in a stirring process, characterized by The micro bypass loop system, remote control system and data acquisition visualization system are included, the micro bypass loop system includes a drainage pipe, a sampling port, a series micro loop, a back material pipe and a stirring tank, the remote control system includes a PLC control cabinet, a drainage gate valve, a pressurizing pump, a sampling gate valve and a confluence gate valve, and the data acquisition visualization system includes high-precision pressure sensors, flow meters and a data integrated computer. The drainage pipe is installed at the bottom of the stirring tank and connected with the pressurizing pump through the drainage gate valve. The sampling gate valve and the sampling port are arranged on the drainage pipe, and the confluence gate valve is arranged on the series micro loop. The high-precision pressure sensors are connected with the series micro loop through flanges, and the flow meters are installed at the end of the series micro loop through flanges. The outlet of the series micro loop is connected with the stirring tank through the back material pipe. The pressurizing pump, the drainage gate valve, the sampling gate valve and the confluence gate valve are connected with the PLC control cabinet through cables. The electric signals collected by the high-precision pressure sensors and the flow meters are all sent to the data integrated computer. The series micro loop is composed of three diameter measuring pipe sections, from the inlet, the pipes with diameters of 30 mm, 40 mm and 50 mm are sequentially connected in series, and the length of each diameter pipe is 1 m. The three diameter measuring pipes in the series micro loop are connected through variable diameter joints, and the series micro loop and the pressurizing pump are connected through a variable diameter joint.

2. The apparatus for real time monitoring of fill material concentration in a stirred process according to claim 1, wherein, The sampling port is arranged at the end of the drainage pipe, the sampling gate valve is arranged in front of the sampling port, the series micro loop is connected between the sampling gate valve and the pressurizing pump, and the confluence gate valve is arranged at the inlet of the series micro loop.

3. The apparatus for real time monitoring of fill material concentration in a stirred process according to claim 1, wherein, When the flow meters and the high-precision pressure sensors are connected with the series micro loop through flanges, rubber gaskets are added to reduce dripping.

4. The apparatus for real time monitoring of fill material concentration in a stirred process according to claim 1, wherein, When the high-precision pressure sensors are installed, it is ensured that the display is located directly above the pipe.

5. The apparatus for real time monitoring of fill material concentration in a stirred process according to claim 1, wherein, There are six high-precision pressure sensors, which are respectively installed at the front end inlet and the rear end outlet of the three diameter measuring pipe sections of the series micro loop, and the interval between adjacent two high-precision pressure sensors is 1 m.

6. The monitoring method for the apparatus for monitoring the filling pulp concentration in real time during the agitation process according to claim 1, characterized by, The steps include the following: S1: Before the concentration monitoring starts, the drainage gate valve is closed through the PLC control cabinet, and after the material in the stirring tank is fully mixed, the drainage gate valve is opened; S2: The confluence gate valve and the pressurizing pump are opened through the PLC control cabinet, the backfill slurry is pumped through the pressurizing pump, and then sequentially flows through the series micro loop, the high-precision pressure sensors, the flow meters and the back material pipe, and then returns to the stirring tank to form a closed loop circulation; S3: After the high-precision pressure sensors and the flow meters obtain stable flow value Q and pressure value ΔP, the tested backfill slurry parameters and the pipe parameters of the micro loop are input into the rheological model solver in the data integrated computer, and the calculation principle of the solver is as follows: In the formula: Q1, Q2, Q3 are flow values measured every 5 min after the material is stabilized; ΔP1, ΔP2, ΔP3 are the measured pressure differences at both ends of the pipeline; R is the pipeline radius; L is the pipeline length; τ B is the yield stress; K is the consistency coefficient; n is the power index; S4: Based on the inner diameter, length, pressure drop and backfill slurry flow data of the three groups of measuring pipe sections in the series micro loop, the data is input into the rheological model solver in the data integrated computer in S3, and the yield stress of the slurry is obtained by simultaneous solution. S5: Adjusting the pressurizing pump through the PLC control cabinet to realize the periodic gradient control of flow, pressure and pressure drop, and repeatedly operating through the rheological model solver to make the rheological parameter measured value approach the true value; S6: Realizing the real-time display of the rheological curve of filling slurry, the flow state of pipeline, the resistance along the way and the flow of pipeline in the series micro annular loop through the data integration computer, and inverting the concentration of filling slurry by using the yield stress model based on specific gravity, bulk density and concentration to finally realize the real-time monitoring of the concentration of slurry; the concentration of slurry is expressed as: wherein: a, b are constants; p s is the specific gravity, p is the bulk density, C w is the mass concentration.

7. The monitoring method for the apparatus for monitoring the filling slurry concentration in real time during the agitation process according to claim 6, characterized by, The constants a, b are determined in advance in the laboratory, specifically: at least two groups of different proportions of slurry are prepared with on-site obtained aggregates, the mass concentration C is calculated according to the material proportion w , the specific gravity ρ s , the bulk density ρ and the yield stress τ B are respectively tested, and finally the constants a, b are solved.

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