A method for filling underground mines

Abstract

The embodiments of the present application provide a mine filling method, which relates to the field of mine filling technology. The method includes dewatering the tailings slurry in the mine. During the dewatering process, an underflow pump is used to control the underflow concentration, and a flocculant is used to control the overflow turbidity and mud layer thickness. The method also includes determining the required amount of cement and adding cement according to the required amount. The cement and dewatered tailings are mixed with water to form a filling slurry. The filling slurry is then transported to the underground goaf for filling. This method can effectively ensure filling quality, reduce filling costs, and improve economic benefits.

Description

Technical Field

[0001] The present application relates to the field of mine filling technology, and in particular to an underground mine filling method. Background Art

[0002] Underground mine filling refers to the process of fully mixing tailings slurry, cement and an appropriate amount of water in a high-concentration mixing tank according to the required ratio to produce a filling slurry with uniform mixing and better flow properties, which is then transported to the underground goaf through a pipeline for filling.

[0003] With the development of green mines, more and more underground mines are opting for backfill mining. Backfill mining effectively supports rock formations, controls ground pressure, protects surface features, maximizes resource recovery, and avoids production accidents caused by large goafs. However, the backfill process often presents problems such as unstable fill composition, pipe blockage, and excessive or insufficient cement addition. There is an urgent need to develop a method that precisely controls the fill ratio, stabilizes the fill composition, reduces the amount of flocculants and cement added, and ultimately ensures backfill quality, reduces costs, and improves economic efficiency. Summary of the Invention

[0004] The embodiments of the present application provide an underground mine filling method, which can effectively ensure the filling quality of the underground mine and reduce the filling cost.

[0005] Other features and advantages of the present application will become apparent from the following detailed description, or may be learned in part by practice of the present application.

[0006] According to a first aspect of an embodiment of the present application, a method for filling an underground mine is provided, comprising:

[0007] Dewatering of tailings slurry in mines. During the dewatering process, underflow pumps are used to control underflow concentration, and flocculants are used to control overflow turbidity and mud layer thickness.

[0008] Confirm the demand for cement and add cement according to the demand;

[0009] Cement and dehydrated tailings are mixed with water to form a filling slurry;

[0010] The filling slurry is transported to the underground goaf for filling.

[0011] In some embodiments of the present application, based on the above solution, controlling the underflow concentration by using an underflow pump includes:

[0012] Determine the current underflow pump frequency setting value based on the current concentration feedback value;

[0013] The underflow pump operates according to the underflow pump frequency setting value to control the underflow concentration.

[0014] In some embodiments of the present application, based on the aforementioned solution, determining the current underflow pump frequency setting value based on the current concentration feedback value includes:

[0015] Determine the low flow pump frequency setting value of the thickener at the current moment based on the following rules;

[0016] Rule 1: When When y 1sp (k) = y 1sp (k―1)+ε;

[0017] Rule 2: When When y 1sp (k) = y 1sp (k―1)―Ψ;

[0018] Rule Three: When When y 1sp (k) = y 1sp (k―1)+ΔC;

[0019] in, is the lower control limit of concentration; is the upper limit of concentration control; C(k) is the concentration feedback value at the current moment; y 1sp (k) is the current underflow pump frequency setting value; y 1sp (k-1) is the frequency setting value of the underflow pump at the previous moment; F g is the ore flow rate before the thickener; C g is the feed concentration of the thickener at the moment before; ε, Ψ, δ are correction values ​​obtained by combining experiments.

[0020] In some embodiments of the present application, based on the above solution, the method of controlling overflow turbidity and mud layer thickness by using flocculants includes:

[0021] Determine the current flocculant valve setting value based on the current turbidity and the current mud bed thickness;

[0022] Add flocculant based on the flocculant valve setting to control overflow turbidity and mud layer thickness.

[0023] In some embodiments of the present application, based on the above solution, determining the current flocculant valve setting value based on the current turbidity and the current mud bed thickness includes:

[0024] Determine the flocculant valve setting based on the following rules;

[0025] Rule 1: When T(K)≤T B And H(K)≥H B When y 2sp(k) = y 2sp (k―1);

[0026] Rule 2: When T(K)>T B or H(K) <H B When y 2sp (k) = y 2sp (k―1)+ω;

[0027] Among them, T(K) is the turbidity at the current moment, T B is the circulating water turbidity control standard, H(K) is the mud bed thickness at the current moment, H B To ensure the minimum mud bed thickness for underflow concentration, Y 2sp (k-1) is the flocculant valve setting value at the previous moment, y 2sp (k) is the flocculant valve setting value at the current moment, and ω is the correction value obtained through experiments.

[0028] In some embodiments of the present application, based on the above solution, the step of confirming the demand for cement includes:

[0029] Calculate the dry volume of tailings based on the concentration and flow of tailings slurry after dewatering;

[0030] Calculate the cement demand based on the dry ore content and mix ratio requirements.

[0031] In some embodiments of the present application, based on the above solution, the step of adding cement according to the required amount of cement includes:

[0032] Add cement to the cement silo via a cement tanker, and monitor the silo level in real time during the addition process;

[0033] The cement in the cement silo is transported to the mixing tank for mixing using a variable frequency speed regulating screw feeder, and the transported cement is measured in real time during the transportation process.

[0034] In some embodiments of the present application, based on the above solution, the step of adding water to cement and dehydrated tailings and stirring them to form a filling slurry includes:

[0035] The dewatered tailings and cement are fed into the mixing tank;

[0036] Add water to the stirring tank and perform initial stirring to obtain a primary slurry;

[0037] The primary slurry is transported to a high-efficiency activated mixer for secondary mixing to obtain a filling slurry.

[0038] In some embodiments of the present application, based on the above scheme, the initial stirring after adding water to the stirring tank includes:

[0039] The amount of water to be added is calculated based on the underflow concentration, underflow flow, cement quantity and filling concentration;

[0040] Convert the amount of water added into the opening of the water adding regulating valve;

[0041] Open the water adding regulating valve, add water to the mixing tank for initial stirring, and use the water adding flow meter to correct the opening of the water adding regulating valve in real time.

[0042] In some embodiments of the present application, based on the aforementioned solution, during the initial stirring process, a PI controller is used to adjust the amount of water added to the stirring tank.

[0043] The technical solution of the present application can effectively dehydrate the mine tailings slurry by controlling the underflow concentration, overflow turbidity and mud layer thickness. In the subsequent filling slurry production process, the cement demand and water injection volume are scientifically calculated, and the cement addition process is monitored in real time to ensure the accuracy of the cement addition amount. At the same time, water is reasonably injected according to the ratio to ensure that the obtained filling slurry is qualified and stable, thereby ensuring the quality of subsequent filling.

[0044] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The accompanying drawings are incorporated into and constitute a part of the specification, illustrating embodiments consistent with the present application and, together with the specification, explaining the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can derive other drawings based on these drawings without inventive effort. In the drawings:

[0046] Figure 1 A schematic flow chart of a mine filling method according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0047] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this application will be thorough and complete and will fully convey the concepts of the example embodiments to those skilled in the art.

[0048] Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.In the following description, numerous specific details are provided to give a full understanding of the embodiments of the present application.

[0049] The flowcharts shown in the accompanying drawings are for illustrative purposes only and do not necessarily include all contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps may be decomposed, while others may be combined or partially combined. Therefore, the actual execution order may vary depending on the actual situation.

[0050] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0051] The following will describe some embodiments of the present application in detail with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features therein may be combined with each other.

[0052] See also Figure 1 , showing a schematic flow chart of a mine filling method according to an embodiment of the present application.

[0053] like Figure 1 As shown, this embodiment provides an underground mine filling method, which specifically includes steps S100 to S400.

[0054] Step S100: dewatering the tailings slurry in the mine.

[0055] It should be noted that, in this embodiment, this step mainly involves dehydrating the tailings slurry with a concentration of about 40% through a thickener, and the concentration of the tailings slurry after dehydration is controlled at about 73%.

[0056] The primary dewatering equipment is the thickener, equipped with an automatic dosing device and instrumentation to monitor mud layer thickness, overflow water turbidity, slurry level, underflow concentration, and underflow flow rate in real time. The main parameters that require control during thickener operation include underflow concentration and overflow solids content. These two parameters are primarily adjusted by adjusting underflow concentration and the amount of flocculant added.

[0057] Specifically, in this embodiment, during the dehydration process, an underflow pump is used to control the underflow concentration, and a flocculant is used to control the overflow turbidity and the thickness of the mud layer.

[0058] The underflow pump is located at the bottom of the thickener. By controlling the rotation of the underflow pump, the underflow can be driven to flow, thereby achieving control of the underflow concentration.

[0059] Flocculants primarily bring together positively (negatively) charged groups and negatively (positively) charged particles or granules in water that are difficult to separate, lowering their electrical potential and rendering them unstable. Their aggregation properties then concentrate these particles and allow them to be separated physically or chemically. In this embodiment, the flocculant has two functions: accelerating tailings settling and purifying water. When added to the thickener, the flocculant accelerates settling, clearing the overflow and purifying the water, resulting in water that meets demand.

[0060] In some feasible embodiments, controlling the underflow concentration by using an underflow pump includes:

[0061] Determine the current underflow pump frequency setting value based on the current concentration feedback value;

[0062] The underflow pump operates according to the underflow pump frequency setting value to control the underflow concentration.

[0063] The current concentration feedback value can accurately reflect the current underflow concentration. According to the underflow concentration, the range of underflow concentration that needs to be controlled can be accurately determined, and then the corresponding underflow pump frequency can be set to control the underflow concentration using the underflow pump.

[0064] Specifically, in this embodiment, determining the current underflow pump frequency setting value based on the current concentration feedback value includes:

[0065] Determine the low flow pump frequency setting value of the thickener at the current moment based on the following rules;

[0066] Rule 1: When When y 1sp (k) = y 1sp (k―1)+ε;

[0067] Rule 2: When When y 1sp (k) = y 1sp (k―1)―Ψ;

[0068] Rule Three: When ,y 1sp (k) = y 1sp (k―1)+ΔC;

[0069] in, is the lower control limit of concentration; is the upper limit of concentration control; C(k) is the concentration feedback value at the current moment; y 1sp (k) is the current underflow pump frequency setting value; y 1sp (k-1) is the frequency setting value of the underflow pump at the previous moment; F gis the ore flow rate before the thickener; C g is the feed concentration of the thickener at the moment before; ε, Ψ, δ are correction values ​​obtained by combining experiments.

[0070] In some feasible embodiments, the use of flocculants to control overflow turbidity and mud layer thickness specifically includes:

[0071] Determine the current flocculant valve setting value based on the current turbidity and the current mud bed thickness;

[0072] Add flocculant based on the flocculant valve setting to control overflow turbidity and mud layer thickness.

[0073] The current turbidity and mud bed thickness can truly reflect the turbidity of the current overflow. Therefore, the amount of flocculant to be added can be determined based on these two parameters. After converting the flocculant dose into the flocculant valve setting value, the flocculant valve can be opened to add the corresponding flocculant dose to change the overflow turbidity and mud layer thickness.

[0074] Specifically, in this embodiment, determining the current flocculant valve setting value based on the current turbidity and the current mud bed thickness specifically includes:

[0075] Determine the flocculant valve setting based on the following rules;

[0076] Rule 1: When T(K)≤T B And H(K)≥H B When y 2sp (k) = y 2sp (k―1);

[0077] Rule 2: When T(K)>T B or H(K) <H B When y 2sp (k) = y 2sp (k―1)+ω;

[0078] Among them, T(K) is the turbidity at the current moment, T B is the circulating water turbidity control standard, H(K) is the mud bed thickness at the current moment, H B To ensure the minimum mud bed thickness for underflow concentration, y 2sp (k-1) is the flocculant valve setting value at the previous moment, y 2sp (k) is the flocculant valve setting value at the current moment, and ω is the correction value obtained through experiments.

[0079] Continue to refer to Figure 1 , step S200, confirming the required amount of cement and adding cement according to the required amount of cement.

[0080] In some feasible embodiments, the step of confirming the demand for cement specifically includes steps S210 to S220.

[0081] Step S210, calculating the dry tailings volume based on the tailings slurry concentration and flow rate after dehydration;

[0082] Step S220: Calculate the required amount of cement based on the dry ore quantity and the required mix ratio.

[0083] In some feasible embodiments, the adding of cement according to the required amount of cement specifically includes steps S230 to S240.

[0084] Step S230: Add cement to the cement silo via a cement tanker, and monitor the position of the cement silo in real time during the adding process.

[0085] It should be noted that the cement silo is equipped with an operating box, and the real-time silo position is displayed on the touchscreen of the operating box. The touchscreen also features buttons such as "deliver" and "stop." When the cement tanker is delivering cement to the silo, clicking "deliver" opens the valve to begin delivery, and the system automatically stops when delivery is complete. The operating box also features a metering management system that monitors the silo position in real time. When the silo is nearly full, it prompts a prohibition notice, and when the silo is about to become empty, it issues an empty silo warning.

[0086] Step S240: Use a variable frequency speed regulating screw feeder to transport the cement in the cement silo to the mixing tank for mixing, and measure the transported cement in real time during the transportation process.

[0087] It should be noted that, during the cement conveying process, the cement demand obtained in step S220 can be converted into the frequency of the variable frequency speed regulating screw feeder, so that the cement conveying amount can be controlled by adjusting the frequency of the variable frequency speed regulating screw feeder, thereby achieving precise cement conveying and ensuring that the conveyed cement amount meets the calculated cement demand; and, during the conveying process, the frequency of the variable frequency speed regulating screw feeder can be continuously corrected by an electronic scale to further ensure the accuracy of the cement conveying amount.

[0088] In addition, in order to prevent the cement silo from being blocked, suspended, or having poor material discharge during cement transportation, in this embodiment, an acoustic wave cleaner is provided on the cement silo, which is started at regular intervals to clean the cement silo.

[0089] Continue to refer to Figure 1 In step S300, water is added to cement and dehydrated tailings and the mixture is stirred to form a filling slurry.

[0090] In some feasible embodiments, step S300 specifically includes steps S310 to S330.

[0091] Step S310, the dehydrated tailings and cement are poured into a mixing tank;

[0092] Step S320, adding water to the stirring tank and performing initial stirring to obtain a primary slurry;

[0093] Step S330: transporting the primary slurry to a high-efficiency activation mixer for secondary stirring to obtain a filling slurry.

[0094] In some feasible embodiments, the initial stirring is performed after adding water to the stirring tank, specifically including steps 321 to 323 .

[0095] Step S321, calculating the amount of water to be added based on the underflow concentration, underflow flow rate, cement quantity, and filling concentration;

[0096] Step S322, converting the water addition amount into the opening of the water addition regulating valve;

[0097] Step S323, open the water adding regulating valve, add water to the stirring tank for initial stirring, and use the water adding flow meter to correct the opening of the water adding regulating valve in real time.

[0098] In some feasible embodiments, during the initial stirring, a PI controller is used to control the amount of water added.

[0099] It should be noted that the PI controller is a linear controller that forms a control deviation based on the given value and the actual output value, and forms a control quantity by linearly combining the proportion and integral of the deviation to control the controlled object.

[0100] It is understandable that during the initial stirring process, the proportion of water added has a significant impact on the quality of the filling slurry. Therefore, a PI (proportional, integral) controller is introduced for adjustment. In this embodiment, the proportional constant Kp of the PI controller is 0.4-1, and the integral constant Ki is 0.1-1. The specific data are determined according to actual conditions.

[0101] Continue to refer to Figure 1 , step S400, transporting the filling slurry to the underground goaf for filling.

[0102] It should be noted that the prepared filling slurry can be transported to the underground goaf for filling using the principle of gravity, or can be transported to the underground goaf for filling using a transmission device such as a transmission pump.

[0103] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the embodiments disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present application that follow the general principles of the present application and include common knowledge or customary techniques in the art that are not disclosed in this application. It should be understood that this application is not limited to the steps described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from the scope thereof. The scope of this application is limited only by the appended claims.

Claims

1. A method for filling an underground mine, characterized in that: include: Dewatering of tailings slurry in mines. During the dewatering process, underflow pumps are used to control underflow concentration, and flocculants are used to control overflow turbidity and mud layer thickness. Confirm the demand for cement and add cement according to the demand; Cement and dehydrated tailings are mixed with water to form a filling slurry; Transport the filling slurry to the underground goaf for filling; The method of controlling the underflow concentration by using an underflow pump comprises: Determine the current underflow pump frequency setting value based on the current concentration feedback value; The underflow pump operates according to the underflow pump frequency setting value to control the underflow concentration; The method of determining the underflow pump frequency setting value at the current moment based on the concentration feedback value at the current moment includes: Determine the current thickener underflow pump frequency setting value based on the following rules: Rule 1: When hour, ; Rule 2: When hour, ; Rule Three: When hour, ; in, ; is the lower control limit of concentration; is the upper limit of concentration control; is the concentration feedback value at the current moment; The current underflow pump frequency setting value; The frequency setting value of the underflow pump at the previous moment; is the ore feed flow rate just before the thickener; It is the feed concentration of the ore just before the thickener; 、 、 is the correction value obtained by combining the test; The method of controlling overflow turbidity and mud layer thickness by using flocculants includes: Determine the current flocculant valve setting value based on the current turbidity and the current mud bed thickness; Add flocculants based on the flocculant valve setting to control overflow turbidity and mud layer thickness; The method of determining the flocculant valve setting value at the current moment based on the current turbidity and the current mud bed thickness includes: Determine the flocculant valve setting based on the following rules; Rule 1: When and hour, ; Rule 2: When or hour, ; in, is the turbidity at the current moment, It is the circulating water turbidity control standard. is the thickness of the mud bed at the current moment, To ensure the minimum mud bed thickness for underflow concentration, is the flocculant valve setting value at the previous moment, is the flocculant valve setting value at the current moment, is the correction value obtained through experiments.

2. The method according to claim 1, characterized in that The determination of cement demand includes: Calculate the dry volume of tailings based on the concentration and flow of tailings slurry after dewatering; Calculate the cement demand based on the dry ore content and mix ratio requirements.

3. The method according to claim 1, characterized in that The step of adding cement according to the required amount of cement comprises: Add cement to the cement silo via a cement tanker, and monitor the silo level in real time during the addition process; The cement in the cement silo is transported to the mixing tank for mixing using a variable frequency speed regulating screw feeder, and the transported cement is measured in real time during the transportation process.

4. The method according to claim 1, wherein The cement and the dehydrated tailings are added with water and stirred to prepare a filling slurry, comprising: The dewatered tailings and cement are fed into the mixing tank; Add water to the stirring tank and perform initial stirring to obtain a primary slurry; The primary slurry is transported to a high-efficiency activated mixer for secondary mixing to obtain a filling slurry.

5. The method according to claim 4, characterized in that The initial stirring after adding water to the stirring tank comprises: The amount of water to be added is calculated based on the underflow concentration, underflow flow, cement quantity and filling concentration; Convert the amount of water added into the opening of the water adding regulating valve; Open the water adding regulating valve, add water to the mixing tank for initial stirring, and use the water adding flow meter to correct the opening of the water adding regulating valve in real time.

6. The method according to claim 4, characterized in that During the initial stirring process, the amount of water added to the stirring tank was regulated using a PI controller.

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