A method and system for harmless filling of cyanide-containing tailings

Abstract

The application discloses a cyanide-containing tailings harmless filling method and system, directly carries out pressure filtration dewatering on cyanide-containing tailings slurry, adopts a ceramic pressure filter, utilizes special microporous ceramic filter plates, and realizes rapid and efficient solid-liquid separation under the action of vacuum. Further, the cyanide-containing wastewater is recycled and treated, the recycled water is used for washing and / or slurry preparation, water resource recycling is realized, fresh water consumption is reduced, and production cost is lowered. A belt conveyor with accurate metering function is used to realize accurate control of tailings filter cake addition amount, and ensure that the raw material proportion is consistent with the target value in subsequent stirring. Moreover, through online concentration monitoring and automatic adjustment of the central control system, water can be adjusted in real time, the slurry concentration is ensured to be close to the set value at all times, and therefore the uniformity and quality of the filling material are improved. In the filling process, the application of real-time monitoring and automatic control technology ensures the accuracy and efficiency of the filling operation.

Description

Technical Field

[0001] This invention relates to the field of mine tailings disposal and resource utilization technology, specifically to a method and system for harmless backfilling of cyanide-containing tailings. Background Technology

[0002] In the cyanide-based carbon-in-pulp (CIP) gold extraction process, a large amount of cyanide-containing tailings slurry is typically generated to improve gold ore extraction rates. Because cyanide is highly toxic, direct discharge without effective treatment can cause serious pollution to water bodies, soil, and the ecological environment, and this pollution is characterized by its long-term nature and difficulty in reversing. Therefore, mining companies must adopt appropriate treatment processes to reduce the cyanide content in tailings to meet stringent environmental standards.

[0003] Traditional tailings treatment processes typically involve the following steps: the tailings slurry is first thickened using a thickener, then subjected to cyanide removal and dewatering, and finally the tailings are discharged into a tailings dam or used for backfilling of underground goaf areas. However, this traditional process has the following drawbacks: First, tailings dam storage gradually reduces cyanide concentration through natural degradation, oxidation, and physical sealing, but it requires a large area, has high construction and management costs, poses a risk of leakage during long-term storage, and can easily cause secondary environmental pollution. Furthermore, tailings dams pose safety hazards such as dam failure, making it difficult to fully guarantee mine safety. Second, chemical cyanide removal uses oxidants (such as sodium hypochlorite, chlorine dioxide, ozone, etc.) or catalysts to oxidize and destroy cyanide in the tailings slurry, converting it into harmless or low-toxic substances. While this method has a certain treatment efficiency, it consumes a large amount of chemical reagents, has high operating costs, and may introduce new pollutants. It is also greatly affected by the composition of the tailings slurry and reaction conditions, resulting in poor treatment stability. Third, thickening and dewatering methods typically use deep cone thickeners or... Vertical sand bin thickeners concentrate tailings slurry, which is then dewatered using a filter press or belt filter press to reduce the moisture content of the tailings. However, this process is lengthy, requires significant equipment investment, and incurs high maintenance costs. Flocculants are typically added during thickening, increasing operating costs and potentially negatively impacting the preparation of subsequent backfill slurry. The moisture content of the dewatered tailings remains high (usually 30%-40%), making it difficult to meet the requirements for subsequent backfilling or resource utilization. Fourthly, the backfilling method mixes the dewatered tailings with cement and other cementing materials to form backfill slurry, which is then transported to the underground goaf for backfilling. However, this method requires high levels of dewatering effect, slurry concentration, and fluidity. Traditional processes, due to the high moisture content of the tailings, are prone to uneven backfill slurry and insufficient strength, thus affecting the overall stability and support effect of the backfill.

[0004] In summary, existing technologies for treating cyanide-containing tailings suffer from several drawbacks, including complex processes, high equipment investment, high operating and maintenance costs, low processing efficiency, difficulty in effectively reducing tailings moisture content through thickening and dewatering, impact on subsequent backfilling effectiveness, significant environmental risks, secondary pollution and safety hazards associated with cyanide breaking and tailings dam storage methods, low resource utilization, and insufficient recovery and utilization of tailings resources. Therefore, there is an urgent need for a solution that simplifies the process, reduces processing costs, improves tailings slurry dewatering efficiency, ensures environmental safety of tailings, and promotes resource utilization. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the present invention aims to provide a method and system for harmless backfilling of cyanide-containing tailings.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A method for harmlessly backfilling cyanide-containing tailings includes the following steps:

[0008] Step 1: Filtration and preliminary harmless treatment:

[0009] A corrosion-resistant high-density polyethylene pipeline is used to directly transport cyanide-containing tailings slurry from the cyanide carbon slurry gold extraction workshop to a ceramic filter press. The ceramic filter press is equipped with microporous ceramic filter plates and alkali-resistant nylon filter cloth. The microporous ceramic filter plates are made of alumina ceramic. After the particle size distribution of the cyanide-containing tailings slurry is detected by a particle size analyzer, alumina ceramic filter plates with pore sizes 10%-30% smaller than the maximum particle size in the cyanide-containing tailings slurry are used to ensure a balance between filtration efficiency and tailings filter cake quality.

[0010] Under vacuum assistance, cyanide-containing tailings slurry achieves solid-liquid separation in a ceramic filter press, and the resulting tailings filter cake has a moisture content of 10%-15%; at the same time, the cyanide-containing wastewater generated by the filter press enters the harmless wastewater treatment module.

[0011] The harmless wastewater treatment module uses one or more of the following methods to treat the cyanide-containing wastewater: pre-precipitation, oxidation-reduction reaction and adsorption treatment, so that the residual cyanide content in the wastewater after treatment is reduced to the environmental protection standard requirements. The wastewater after treatment is used as recycled water and enters step 2.

[0012] Step 2: Filter cake rinsing, metering, and slurry preparation:

[0013] After the tailings filter cake obtained in step 1 is evenly distributed in the ceramic filter press, it is rinsed evenly with clean water or the recycled water obtained in step 1 to fully remove the residual cyanide-containing waste liquid on the tailings filter cake, ensure the stability of the chemical composition on the surface of the tailings filter cake, and not damage the structure of the tailings filter cake.

[0014] Then, the tailings filter cake is weighed in real time using a belt conveyor with a built-in weighing unit, and the tailings filter cake with the set weight is transported to the mixing tank, while the remaining tailings filter cake is transported to the tailings pile for later use.

[0015] In the mixing tank, the concentration data of the tailings slurry in the mixing tank is monitored in real time by an online concentration monitor and transmitted to the central control system. The central control system controls the automatic water adding device to add the recycled water obtained in step 2 into the mixing tank according to the set concentration value, and dynamically adjusts the water addition amount. It controls the agitator to mix the tailings filter cake with water to form tailings slurry, and accurately controls the concentration of the tailings slurry to the set value to meet the filling requirements.

[0016] Step 3: Mixing and harmless filling:

[0017] The tailings slurry obtained in step 2 is transported to the mixing chamber under pressure through a pressure-resistant closed pipeline; cementing material is added to the mixing chamber, and the tailings slurry and cementing material are fully mixed by the mixing device to generate a homogeneous filling slurry.

[0018] Then, a high-pressure plunger pump is used to transport the obtained filling slurry through the filling pipeline to the underground goaf for filling.

[0019] Furthermore, in step 2, the spray pressure for washing the tailings filter cake is set at 0.2MPa to 0.5MPa.

[0020] Furthermore, in step 2, the stirring speed of the stirrer is controlled between 200 and 300 rpm.

[0021] Furthermore, in step 2, gravity or a vibration device is used to directly detach the tailings filter cake onto the belt conveyor.

[0022] Furthermore, in step 3, the applied pressure is 0.3 MPa to 0.6 MPa.

[0023] Furthermore, in step 3, the cementitious material is cement, and the mass ratio of cement to filter cake is controlled between 1:6 and 1:10.

[0024] Furthermore, in step 3, the operating pressure of the high-pressure plunger pump is 2MPa to 5MPa.

[0025] Furthermore, the central control system monitors the motor current, voltage, temperature, and vibration parameters of the high-pressure plunger pump, agitator, and mixing device. If any abnormality occurs, the machine will stop immediately and an alarm will be issued. The central control system precisely controls the amount of cementitious material added through the metering and feeding system.

[0026] Furthermore, in step 3, pressure, flow rate and concentration monitoring devices are installed at multiple locations in the filling pipeline and the underground goaf. The pressure, flow rate and concentration monitoring devices transmit the monitored data to the central control system. The central control system monitors the pressure, flow rate and concentration of the filling slurry in the filling pipeline and the underground goaf in real time to ensure the safe conduct of the filling process.

[0027] Secondly, ultrasonic blockage detectors are installed at the easily blocked parts of the filling pipe. The central control system monitors whether there is a blockage in the filling pipe through the ultrasonic blockage detectors, and starts the backwashing program when a blockage is detected.

[0028] The central control system is equipped with an emergency stop button and a backup power system.

[0029] The present invention also provides a system for implementing the above method, including corrosion-resistant HDPE pipeline, ceramic filter press, harmless wastewater treatment module, belt conveyor with built-in weighing and metering unit, mixing tank, central control system, online concentration monitor, automatic water addition device, stirrer, pressure-resistant sealed pipeline, mixing chamber and high-pressure plunger pump.

[0030] The corrosion-resistant HDPE pipelines are connected to the cyanide carbon slurry gold extraction workshop and the ceramic filter press respectively; the ceramic filter press has built-in microporous ceramic filter plates and alkali-resistant nylon filter cloth, which are used to filter cyanide tailings slurry.

[0031] The harmless wastewater treatment module is used to treat cyanide-containing wastewater obtained by pressure filtration by one or more of the following methods: pre-precipitation, oxidation-reduction reaction and adsorption treatment, so that the residual cyanide content in the wastewater after treatment is reduced to the environmental protection standard requirements.

[0032] The belt conveyor with built-in weighing and metering unit is used to detect the weight of the tailings filter cake obtained by pressure filtration in real time, and to transport the tailings filter cake with the set weight to the mixing tank, while the remaining tailings filter cake is transported to the tailings pile for later use.

[0033] The mixing tank is used to mix tailings filter cake with water to form tailings slurry;

[0034] The online concentration monitor is used to monitor the concentration data of the tailings slurry in the mixing tank in real time and transmit it to the central control system. The central control system is used to control the automatic water addition device to dynamically adjust the water addition according to the set concentration value, and to control the agitator to mix the filter cake with water to form tailings slurry.

[0035] The pressure-resistant and sealed pipelines are respectively connected to the mixing tank and the mixing chamber;

[0036] The mixing chamber is used to fully mix the tailings slurry and cementing materials to generate a homogeneous filling slurry.

[0037] The high-pressure plunger pump is used to transport the obtained filling slurry through the filling pipeline to the underground goaf area for filling.

[0038] The beneficial effects of this invention are as follows:

[0039] 1. This invention directly dewaters cyanide-containing tailings slurry by pressure filtration, omitting the traditional thickening process and effectively simplifying the process flow. By employing a ceramic filter press, utilizing its special microporous ceramic filter plates, rapid and efficient solid-liquid separation is achieved under vacuum, significantly improving dewatering efficiency and reducing the moisture content of the tailings.

[0040] 2. Compared with the traditional deep cone thickening process, the direct pressure filter dewatering method of this invention has significant advantages. In terms of equipment investment, it eliminates the need for expensive deep cone thickeners and their supporting equipment, such as thickener drive units and rake lifting devices, greatly reducing equipment procurement costs. Regarding operating costs, the ceramic filter press has relatively low energy consumption; its vacuum system mainly consumes electricity, and its power is relatively small. In contrast, the deep cone thickener requires a large amount of electricity to drive its rotation and agitation, as well as to maintain the flocculant addition system during the thickening process. In terms of dewatering efficiency, the ceramic filter press can reduce the moisture content of tailings to a lower level in a shorter time. The moisture content of tailings after traditional deep cone thickening is generally 30%-40%, while this invention can reduce it to 10%-15%, providing better material conditions for subsequent processes and improving overall process efficiency.

[0041] 3. The present invention recycles and treats cyanide-containing wastewater, using the recycled water for rinsing and / or slurry preparation, thereby realizing the recycling of water resources, reducing the consumption of fresh water, and lowering production costs.

[0042] 4. This invention utilizes a belt conveyor with precise metering function to accurately control the amount of tailings filter cake added, ensuring that the raw material ratio is consistent with the target value during subsequent mixing, and avoiding fluctuations in slurry concentration due to metering errors.

[0043] 5. In this invention, through online concentration monitoring and automatic adjustment by the central control system, water can be replenished and adjusted in real time to ensure that the slurry concentration is always maintained at the set value, thereby improving the uniformity and quality of the filling material.

[0044] 6. This invention directly washes the filter cake under high pressure on the filter plate of the ceramic filter press, and then uses gravity or vibration devices to make the filter cake fall onto the belt conveyor, eliminating the cumbersome manual handling or multi-stage conveying process.

[0045] 7. The present invention can flexibly adjust the concentration of the filling slurry, so that the filling slurry can form a more stable filling body after solidification in the well, effectively supporting the surrounding rock of the goaf and reducing the risk of geological disasters such as ground collapse.

[0046] 8. The application of real-time monitoring and automatic control technology during the filling process ensures the accuracy and efficiency of the filling operation, avoids filling quality problems caused by uneven filling or unstable pressure, improves the filling effect, shortens the construction time, and improves the efficiency of mining operations. Attached Figure Description

[0047] Figure 1 This is a flowchart illustrating the implementation of the method in Embodiment 1 of the present invention;

[0048] Figure 2 This is a schematic diagram of the system structure in Embodiment 2 of the present invention. Detailed Implementation

[0049] The present invention will be further described below with reference to the accompanying drawings. It should be noted that this embodiment is based on the present technical solution and provides detailed implementation methods and specific operation processes, but the protection scope of the present invention is not limited to this embodiment.

[0050] Example 1

[0051] This embodiment provides a method for the harmless backfilling of cyanide-containing tailings, such as... Figure 1 As shown, it includes the following steps:

[0052] Step 1: Direct pressure filtration dewatering:

[0053] (1) Tailings slurry transportation: Corrosion-resistant HDPE pipelines are used to directly transport cyanide-containing tailings slurry from the cyanide carbon slurry gold extraction workshop to the ceramic filter press;

[0054] (2) Filtration and dewatering: The ceramic filter press is equipped with a microporous ceramic filter plate and an alkali-resistant nylon filter cloth. The microporous ceramic filter plate is an alumina ceramic filter plate.

[0055] First, the particle size distribution of the cyanide-containing tailings slurry is detected by a particle size analyzer. Then, an alumina ceramic filter plate with a pore size 10%-30% smaller than the maximum particle size in the cyanide-containing tailings slurry is selected to ensure a balance between filtration efficiency and filter cake quality.

[0056] The vacuum level is set between -0.05MPa and -0.08MPa. The moisture content of the tailings filter cake is monitored in real time. When the data approaches 15%, the filtration time is automatically extended or the vacuum level is adjusted to keep the moisture content of the tailings filter cake stable at 10%.

[0057] (3) Wastewater recycling and harmless treatment: The cyanide-containing wastewater generated by pressure filtration is transferred to the filtrate treatment tank and monitored in real time by the liquid level sensor. Once the liquid level in the filtrate treatment tank reaches the set value, the automatic wastewater recycling system is immediately started to collect the cyanide-containing wastewater and transport it to the harmless wastewater treatment module.

[0058] The harmless wastewater treatment module employs both physical and chemical treatment. First, the cyanide-containing wastewater undergoes pre-precipitation to remove larger suspended particles. Then, cyanide is decomposed through an oxidation-reduction reaction. Next, adsorption treatment is used to further remove residual harmful substances, ensuring that residual cyanide in the wastewater is reduced to environmental standards. The treated wastewater is reused in step 2, effectively reducing the consumption of fresh water and achieving efficient utilization of water resources.

[0059] Step 2, Filter cake conveying and slurry preparation:

[0060] (1) Washing treatment: After the tailings filter cake forms a certain thickness on the filter plate of the filter press, it is washed evenly with spray water (clean water or recycled water obtained in step 1) at a pressure of 0.2MPa to ensure sufficient washing and not damage the structure of the tailings filter cake.

[0061] (2) Filter cake conveying and metering: The washed tailings filter cake is automatically detached from the filter plate by a vibration device and gravity assistance. The tailings filter cake of the set weight is conveyed to the mixing tank by a belt conveyor with a built-in weighing and metering unit. The excess tailings filter cake is transported to the tailings pile for backup.

[0062] (3) Water addition and concentration control: An online concentration monitor is installed in the mixing tank to provide real-time feedback of slurry concentration data to the central control system; at the same time, an automatic water addition valve is installed in the mixing tank. The central control system controls the opening and closing of the automatic water addition valve based on the data fed back by the online concentration monitor, thereby dynamically adjusting the water addition flow rate to ensure that the slurry concentration is stably set at 70% to meet the filling requirements.

[0063] In the mixing tank, a stirrer (200 rpm) is used to ensure uniform mixing of the tailings filter cake and water for 5 minutes. This ensures that all tailings filter cake and water are fully mixed while preventing over-stirring that could degrade the slurry properties. The water used in this embodiment is the recycled water obtained in step 1.

[0064] Step 3, Mixing and Downhole Filling:

[0065] (1) Preparation of filling slurry: The tailings slurry is transported to the mixing chamber at a pressure of 0.3 MPa in a pressure-resistant closed pipeline, and cement is added to the mixing chamber as a cementing material.

[0066] In this embodiment, cement is added from the cement silo to the mixing bin via a metering and feeding system and a screw conveyor at a cement to tailings filter cake weight ratio of 1:6.

[0067] The materials are mixed evenly in the mixing chamber using a twin-shaft mixer to form a filling slurry. The mixing speed is 150 rpm and the mixing time is 5 minutes. The filling slurry is temporarily stored in the hopper.

[0068] (2) Filling Operation: The filling slurry is transported to the goaf in the underground stope through a high-pressure plunger pump (working pressure 5MPa) via the filling pipeline to form a filling body. The filling retaining wall is constructed before the filling operation. Multiple pressure, flow, and concentration monitoring devices are installed in the filling pipeline and the goaf. The pressure, flow, and concentration data monitored by these devices are uploaded to the central control system. When the filling area reaches the designed height, the filling automatically stops, completing one filling cycle.

[0069] In this embodiment, the central control system monitors the motor current, voltage, temperature, and vibration parameters of the high-pressure plunger pump, agitator, and stirring device. If any abnormality is detected, the system immediately shuts down and issues an alarm. Secondly, ultrasonic blockage detectors are installed at easily clogged sections of the filling pipeline. The central control system uses these detectors to monitor for blockages in the filling pipeline and initiates a backflushing procedure when a blockage is detected. Additionally, the central control system is equipped with an emergency stop button and a backup power system.

[0070] Example 2

[0071] This embodiment provides a system for implementing the method described in Embodiment 1, such as... Figure 2 As shown, it includes corrosion-resistant HDPE pipes, a ceramic filter press 1, a harmless wastewater treatment module 4, a belt conveyor 2 with a built-in weighing and metering unit, a mixing tank 3, a central control system, an online concentration monitor, an automatic water addition device, a stirrer, a pressure-resistant sealed pipe, a mixing chamber 5, and a high-pressure plunger pump 6.

[0072] The corrosion-resistant HDPE pipeline is connected to the cyanide carbon slurry gold extraction workshop and the ceramic filter press 1 respectively; the ceramic filter press 1 has a built-in microporous ceramic filter plate and alkali-resistant nylon filter cloth, which is used to filter cyanide tailings slurry.

[0073] The harmless wastewater treatment module 4 is used to treat the cyanide-containing wastewater obtained by pressure filtration using one or more methods, including pre-precipitation, oxidation-reduction reaction, and adsorption treatment, so that the residual cyanide content in the treated wastewater is reduced to the environmental protection standard requirements. In this embodiment, it also includes a filtrate treatment tank 7, in which the cyanide-containing wastewater obtained by pressure filtration is temporarily stored. When the liquid level in the filtrate treatment tank 7 reaches a set value, the automatic wastewater recovery system automatically collects the cyanide-containing wastewater and transmits it to the harmless wastewater treatment module 4 for treatment.

[0074] The belt conveyor 2 with built-in weighing and metering unit is used to detect the weight of the tailings filter cake obtained by pressure filtration in real time, and to transport the tailings filter cake with the set weight to the mixing tank 3, while the remaining tailings filter cake is transported to the tailings pile 8 for later use.

[0075] The mixing tank 3 is used to mix the filter cake with water to form a tailings slurry.

[0076] The online concentration monitor is used to monitor the concentration data of the tailings slurry in the mixing tank 3 in real time and transmit it to the central control system. The central control system is used to control the automatic water addition device to dynamically adjust the water addition according to the set concentration value, and to control the agitator to mix the filter cake with water to form tailings slurry.

[0077] The pressure-resistant and sealed pipeline 9 is connected to the mixing tank 3 and the mixing chamber 5 respectively;

[0078] The mixing chamber 5 is used to thoroughly mix the tailings slurry and cementitious materials to generate a homogeneous filling slurry. In this embodiment, the mixing device of the mixing chamber 5 is a twin-shaft mixer. The cementitious material is fed into the mixing chamber through the cement silo 14, the metering feeder 15, and the screw conveyor 16.

[0079] The high-pressure plunger pump 6 is used to transport the obtained filling slurry through the filling pipeline 10 to the underground goaf 12 of the stope 11, filling the underground goaf 12 to form a filling body 13. In this embodiment, the obtained filling slurry is temporarily stored in the hopper 17 and transported from the hopper 17 to the underground goaf 12. The construction of the filling retaining wall 18 is completed before the filling operation.

[0080] For those skilled in the art, various corresponding changes and modifications can be made based on the above technical solutions and concepts, and all such changes and modifications should be included within the protection scope of the claims of this invention.

Claims

1. A method for harmlessly backfilling cyanide-containing tailings, characterized in that, Includes the following steps: Step 1: Filtration and preliminary harmless treatment: A corrosion-resistant high-density polyethylene pipeline is used to directly transport cyanide-containing tailings slurry from the cyanide carbon slurry gold extraction workshop to a ceramic filter press. The ceramic filter press is equipped with microporous ceramic filter plates and alkali-resistant nylon filter cloth. The microporous ceramic filter plates are made of alumina ceramic. After the particle size distribution of the cyanide-containing tailings slurry is detected by a particle size analyzer, alumina ceramic filter plates with pore sizes 10%-30% smaller than the maximum particle size in the cyanide-containing tailings slurry are used to ensure a balance between filtration efficiency and filter cake quality. Under vacuum assistance, cyanide-containing tailings slurry achieves solid-liquid separation in a ceramic filter press, and the resulting tailings filter cake has a moisture content of 10%-15%; at the same time, the cyanide-containing wastewater generated by the filter press enters the harmless wastewater treatment module. The harmless wastewater treatment module uses one or more of the following methods to treat the cyanide-containing wastewater: pre-precipitation, oxidation-reduction reaction and adsorption treatment, so that the residual cyanide content in the wastewater after treatment is reduced to the environmental protection standard requirements. The wastewater after treatment is used as recycled water and enters step 2. Step 2: Filter cake rinsing, metering, and slurry preparation: After the tailings filter cake obtained in step 1 is evenly distributed in the ceramic filter press, it is rinsed evenly with clean water or the recycled water obtained in step 1 to fully remove the residual cyanide-containing waste liquid on the tailings filter cake, ensure the stability of the chemical composition on the surface of the tailings filter cake, and not damage the structure of the tailings filter cake. Then, the tailings filter cake is weighed in real time using a belt conveyor with a built-in weighing unit, and the tailings filter cake with the set weight is transported to the mixing tank, while the remaining tailings filter cake is transported to the tailings pile for later use. In the mixing tank, the concentration data of the tailings slurry in the mixing tank is monitored in real time by an online concentration monitor and transmitted to the central control system. The central control system controls the automatic water adding device to add the recycled water obtained in step 1 into the mixing tank according to the set concentration value, and dynamically adjusts the water addition amount. It controls the agitator to mix the tailings filter cake with water to form tailings slurry, and accurately controls the concentration of the tailings slurry to the set value to meet the filling requirements. Step 3: Mixing and harmless filling: The tailings slurry obtained in step 2 is transported to the mixing chamber under pressure through a pressure-resistant closed pipeline; cementing material is added to the mixing chamber, and the tailings slurry and cementing material are fully mixed by the mixing device to generate a homogeneous filling slurry. Then, the obtained filling slurry is transported to the underground goaf through the filling pipeline using a high-pressure plunger pump to fill the underground goaf. Ultrasonic blockage detectors are installed at the easily blocked sections of the filling pipe. The central control system monitors whether there is a blockage in the filling pipe through the ultrasonic blockage detectors, and starts the backflushing program when a blockage is detected.

2. The method according to claim 1, characterized in that, In step 2, the spray pressure for washing the tailings filter cake is set at 0.2MPa to 0.5MPa.

3. The method according to claim 1, characterized in that, In step 2, the stirring speed of the stirrer is controlled between 200 and 300 rpm.

4. The method according to claim 1, characterized in that, In step 2, the tailings filter cake is directly detached onto the belt conveyor using gravity or a vibration device.

5. The method according to claim 1, characterized in that, In step 3, the pressure applied is 0.3 MPa to 0.6 MPa.

6. The method according to claim 1, characterized in that, In step 3, the cementitious material is cement, and the mass ratio of cement to filter cake is controlled between 1:6 and 1:

10.

7. The method according to claim 1, characterized in that, In step 3, the operating pressure of the high-pressure plunger pump is 2MPa to 5MPa.

8. The method according to claim 1, characterized in that, The central control system monitors the motor current, voltage, temperature, and vibration parameters of the high-pressure plunger pump, agitator, and mixing device. If any abnormality occurs, the machine will stop immediately and an alarm will be issued. The central control system precisely controls the amount of cementitious material added through the metering and feeding system.

9. The method according to claim 1, characterized in that, In step 3, pressure, flow rate, and concentration monitoring devices are installed at multiple locations in the filling pipeline and the underground goaf. The pressure, flow rate, and concentration monitoring devices transmit the monitored data to the central control system. The central control system monitors the pressure, flow rate, and concentration of the filling slurry in the filling pipeline and the underground goaf in real time to ensure the safe conduct of the filling process. The central control system is equipped with an emergency stop button and a backup power system.

10. A system for implementing the method of any one of claims 1-9, comprising corrosion-resistant HDPE pipeline, ceramic filter press, harmless wastewater treatment module, belt conveyor with built-in weighing unit, mixing tank, central control system, online concentration monitor, automatic water addition device, agitator, pressure-resistant sealed pipeline, mixing chamber and high-pressure plunger pump; The corrosion-resistant HDPE pipelines are connected to the cyanide carbon slurry gold extraction workshop and the ceramic filter press respectively; the ceramic filter press has built-in microporous ceramic filter plates and alkali-resistant nylon filter cloth, which are used to filter cyanide tailings slurry. The harmless wastewater treatment module is used to treat cyanide-containing wastewater obtained by pressure filtration by one or more of the following methods: pre-precipitation, oxidation-reduction reaction and adsorption treatment, so that the residual cyanide content in the wastewater after treatment is reduced to the environmental protection standard requirements. The belt conveyor with built-in weighing and metering unit is used to detect the weight of the tailings filter cake obtained by pressure filtration in real time, and to transport the tailings filter cake with the set weight to the mixing tank, while the remaining tailings filter cake is transported to the tailings pile for later use. The mixing tank is used to mix tailings filter cake with water to form tailings slurry; The online concentration monitor is used to monitor the concentration data of the tailings slurry in the mixing tank in real time and transmit it to the central control system. The central control system is used to control the automatic water addition device to dynamically adjust the water addition according to the set concentration value, and to control the agitator to mix the filter cake with water to form tailings slurry. The pressure-resistant and sealed pipelines are respectively connected to the mixing tank and the mixing chamber; The mixing chamber is used to fully mix the tailings slurry and cementing materials to generate a homogeneous filling slurry. The high-pressure plunger pump is used to transport the obtained filling slurry through the filling pipeline to the underground goaf area for filling.

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