Experimental device for simulating co-migration transformation and monitoring of tailings heavy metals and organic agents

Abstract

The invention discloses an experimental device for simulating and monitoring co-migration and transformation of tailings heavy metals and organic agents, and belongs to a mine environment protection simulation research technology. The experimental device comprises a leaching column, a gas conveying assembly, a leaching solution storage assembly, an in-column environment monitoring assembly and a forest solution collecting assembly. According to the device, the beneficiation reagent is added and effluent is collected under the protection of nitrogen, so that the influence of air on xanthate in a sample is avoided, and the problem that the purity of the organic beneficiation reagent entering a leaching column cannot be ensured in an experimental system in the prior art is solved; sulfurized metal tailing weathering environment factors can be simulated by adjusting gas components and liquid types in the leaching column, so that interaction of an organic beneficiation reagent and tailing minerals under different weathering conditions and exploration and research on a heavy metal dissolution and migration mechanism are realized.

Description

Technical Field

[0001] The present application relates to a mining environmental protection simulation research technology, and in particular to an experimental device for simulating the co-migration, transformation and monitoring of heavy metals and organic agents in tailings. Background Art

[0002] Xanthate is a commonly used collector and hydrometallurgical precipitant in froth flotation of sulfide and oxide ores. The application of xanthate and its derivatives has greatly promoted the advancement of mineral processing technology, and the amount used in flotation operations has gradually increased. With the discharge of tailings and mine wastewater, xanthate and its decomposition products are directly exposed to the environment, threatening the health of the surrounding ecological environment such as soil, water, and organisms around the mine, and are listed as emerging pollutants.

[0003] On the one hand, the geochemical properties of sulfide-rich metal mine tailings become extremely unstable after being exposed to the atmospheric environment. Sulfide metal minerals and other silicate / carbonate minerals react with atmospheric O2, microorganisms, and water to undergo oxidation, dissolution, precipitation, and other reactions. At the same time, a large amount of heavy metals (such as As, Cd, Cu, Hg, Ni, Pb, Sb, Se, and Zn) are released into the environment. Studies have shown that plant colonization and organic remediation promote mineral weathering and heavy metal dissolution in sulfide metal mine tailings. However, field surveys have found that heavy metals in surface samples of naturally abandoned sulfide metal mine tailings exist in relatively less toxic valence states and are fixed in iron oxides formed by long-term weathering. In addition, it has been found that there are hard layers rich in heavy metals, Fe, and Si in the profile of the sulfide metal tailings accumulation site, and that under irrigation conditions, regardless of whether there is organic remediation on the surface, heavy metal pollution has a tendency to migrate downward. This shows that sulfide metal tailings generate heavy metal pollution risks during the natural weathering process. At the same time, the iron oxides and precipitation produced by weathering may fix heavy metals and migrate downward with the water flow. The indoor leaching column experiment simulates the weathering process of the mineral phase change and heavy metal dissolution and migration process in sulfide metal tailings, which can provide technical support for the scientific prevention and effective management of metal mine tailings ponds.

[0004] On the other hand, tailings often coexist with mineral processing agents. The xanthate present in the tailings may affect the dissolution and migration of heavy metals in the tailings through the coordination of surface functional groups such as thiol, carboxyl, and quinone groups with heavy metal ions. In addition, xanthate is a weak acid salt, which is easily hydrolyzed in water to produce some xanthogenic acid, decomposes to produce alcohols, CS2, etc. under acidic conditions, and produces sulfides, thiocarbonates, etc. under alkaline conditions. During the natural weathering process, sulfide metal tailings gradually change from alkaline to acidic as the mineral phase changes. It is necessary to understand the interaction between minerals and organic mineral processing agents in sulfide metal tailings with different weathering degrees, and how organic mineral processing agents affect the dissolution and migration of heavy metals.

[0005] However, the chemical properties of the organic mineral processing agent, xanthate, are extremely unstable and can undergo oxidation reactions in the air. Therefore, adding xanthate solution under conditions of exposure to air will result in an unknown composition of xanthate entering the leaching column, which in turn affects the analysis of the interaction between xanthate and minerals, as well as the analysis of the mechanism of influence on the dissolution and migration of heavy metals. Summary of the invention

[0006] Based on the above requirements, the present invention provides a new device for exploring the effect of organic mineral processing reagents on the dissolution and migration of heavy metals in sulfide metal tailings: the specific technical scheme is as follows;

[0007] 1. An experimental device for simulating the co-migration, transformation and monitoring of heavy metals and organic agents in tailings, comprising: a leaching column, a gas delivery component, a leaching solution storage component, an in-column environment monitoring component, and a leaching solution collection component;

[0008] The leaching column comprises a hollow cylindrical tube body, a top cover and a bottom cover; the top cover comprises a funnel-shaped bottom and a top cover plate with a larger cross-section than the upper cross-section of the cylindrical tube body, and the funnel-shaped bottom is extended into the cylindrical tube body through the top cover plate being sealed and connected to the top end of the cylindrical tube body; a liquid inlet, an air inlet and a monitoring port are arranged at a position close to the center of the top cover plate, so that liquid and gas can be mixed in the funnel-shaped cavity of the top cover before flowing into the cylindrical tube body; and through; the bottom cover comprises a funnel-shaped bottom and a bottom cover plate with a larger cross-section than the upper cross-section of the cylindrical tube body, and multiple holes are arranged on the area corresponding to the inner cavity of the hollow cylindrical tube body of the bottom cover plate, and the bottom cover plate is sealed and connected to the bottom end of the cylindrical tube body, so that the liquid of the leaching column can flow into the funnel-shaped cavity of the bottom cover through the evenly arranged multiple holes and be collected and flow out from the funnel mouth;

[0009] The gas delivery assembly comprises a gas cylinder and a gas flow rate supply pump, wherein the gas flow rate supply pump supplies gas to the cylindrical tube body through the gas inlet in the top cover plate and controls the gas flow rate;

[0010] The leaching solution storage component includes a peristaltic pump and at least one leaching solution storage tank (different leaching solutions, such as simulated acid rain solution and mineral processing reagent, can be set as needed). The peristaltic pump accurately injects the leaching solution into the cylindrical tube body through the liquid inlet on the top cover plate.

[0011] The column environment monitoring assembly includes at least one environment monitoring electrode and at least one pore water sampling device. The environment monitoring electrode extends into the cylindrical tube through the monitoring port to dynamically monitor the pH, EC, Eh and soluble heavy metal content in the leaching column. One end of the pore water sampling device is a sampling end extending into the cylindrical tube through the monitoring port, and the other end is a collector (such as a vacuum syringe).

[0012] Leachate collection assembly: includes a gas washing bottle with a double-hole plug, one of the holes is equipped with a catheter, which is connected to the funnel under the bottom cover of the leaching column through the catheter to collect the leachate, and the other hole is an exhaust hole.

[0013] 2. The experimental device described in claim 2 is characterized in that the top and bottom edges of the cylindrical tube body extend outwards to form a top ring plate and a bottom ring plate in an integral manner; the top end of the cylindrical tube body is sealedly connected to the top cover plate through the top ring plate, and the lower end of the cylindrical tube body is sealedly connected to the bottom cover plate of the bottom cover through the bottom ring plate. The sealed connection can be achieved by arranging a sealing kit between the connectors, which is a conventional technical means in the art.

[0014] 3. The experimental device is characterized in that a water-absorbing cotton rope is provided at each liquid inlet of the top cover, and the other ends of all the water-absorbing cotton ropes are gathered into a cluster to facilitate mixing of different leaching solutions before entering the leaching column.

[0015] 4. The experimental device is characterized in that the leaching column, the top cover and the bottom cover are all made of transparent materials, such as polymethyl methacrylate, to ensure visibility during the experiment.

[0016] 5. The experimental device is characterized in that the leaching solution storage tank, the environmental monitoring electrode pore water sampling device, and the gas washing bottle are made of acid and alkali corrosion-resistant materials.

[0017] 6. The experimental device is characterized in that the environmental monitoring electrode integrates one or more of a pH electrode, a conductivity electrode, a dissolved oxygen electrode, a redox potential electrode, and a heavy metal electrode.

[0018] 7. Any of the above experimental devices, characterized in that the environmental monitoring electrodes are multiple and arranged at different heights in the cylindrical tube to monitor changes in different layers, for example, particularly suitable for monitoring changes in the pore conditions of porous media during the reaction process.

[0019] 8. The experimental device is further provided with an in-situ sampling piston having an inner diameter smaller than that of the cylindrical tube.

[0020] 9. Another aspect of the present invention provides a method for simulating and monitoring the co-migration and transformation of heavy metals and organic agents in tailings, characterized in that any of the experimental devices described above is used and the following operations are performed:

[0021] Step 1: The mineral processing reagent to be tested is placed in a glove box under nitrogen protection;

[0022] Step 2: Prepare the experimental device: lay a layer of gauze on the porous position of the bottom cover of the experimental device, and then combine the bottom ring plate of the leaching column with the bottom cover to tighten and seal;

[0023] Combine the top cover plate and the upper end of the leaching column and seal them; connect the leaching solution storage component and the gas delivery component, and perform air tightness test on the entire device; then pass nitrogen, and after the exhaust hole of the gas washing bottle detects nitrogen, pass the organic agent, collect the outflowing organic agent, and compare the molecular composition with the inflowing organic agent to confirm that the organic agent has not been decomposed under the nitrogen protection condition;

[0024] Step 3: Weigh the tailings and fill the leaching column layer by layer, and place the pore water sampler and environmental monitoring electrode into the leaching column through the monitoring port. Lay a layer of gauze on the top of the tailings, and lay 1 cm thick quartz sand on the gauze to allow the leaching solution to flow evenly into the tailings in the leaching column;

[0025] Step 4: Use saturated CaCO3 solution to pre-saturate the tailings column at a predetermined flow rate; after the tailings in the leaching column are saturated, replace the leaching solution with simulated acid rain; adjust the peristaltic pump to set the simulated acid rain and xanthate to enter at a predetermined speed; turn on the gas flow rate air pump, and after the washing bottle is filled with nitrogen, turn on the peristaltic pump, and leaching simulated acid rain and organic agents under nitrogen protection conditions;

[0026] Step 5: Collect the leachate and pore water regularly, monitor the pH, EC, Eh, and the content changes of dissolved heavy metals such as Pb and Zn in the leaching column; use a syringe to absorb the liquid in the washing bottle, part of which is used to determine the ferrous ion content, and part of the sample is used to determine the cation and anion content;

[0027] Step 6: After the leaching experiment is completed, the leaching solution storage component, gas delivery component, and leaching solution collection component are separated from the leaching column, and then the solid samples in the leaching column are separated, and 2 cm thick matrices from the upper, middle, and bottom layers of the leaching column are taken in situ for subsequent analysis.

[0028] The method described in 10 is characterized in that the mineral processing agent is xanthate.

[0029] The principle and beneficial effects of the experimental device provided by the present invention are as follows:

[0030] The configuration of the device allows the addition of mineral processing agents (xanthate solution) and the collection of effluent under nitrogen protection, avoiding the influence of air on the xanthate in the sample, and solving the problem that the purity of the organic mineral processing agents entering the leaching column cannot be ensured in the experimental system of the prior art. Secondly, the weathering environmental factors of metal sulfide tailings can be simulated by adjusting the gas composition and liquid type in the leaching column, so as to realize the interaction between organic mineral processing agents and tailings minerals under different weathering conditions and explore the dissolution and migration mechanism of heavy metals. For example, it can be used for indoor simulation of exposure to air, rainfall, acid rain, oxidants, etc., heavy metal dissolution experiments and heavy metal migration column experiments generated during the dissolution and phase change of metal sulfide tailings minerals, as well as heavy metal dissolution experiments and heavy metal migration column experiments in the presence of different organic mineral processing agents; at the same time, it can also be used to simulate the co-migration column experiments of other organic pollutants and characteristic minerals under different redox conditions; finally, the monitoring system and sampling device of the device can also be used for field site environmental monitoring and pore water sampling, which can be widely used in mine environmental monitoring to provide technical support for ecological restoration and management of mining areas. This device can also be used in related research systems that need to use and collect similar unstable and easily oxidizable solutions in column simulation experiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 . A schematic diagram of the structure of the experimental device for simulating the co-migration, transformation and monitoring of heavy metals and organic agents in tailings according to the present invention;

[0032] Figure 2 . Schematic diagram of the top cover structure in the experimental device of the present invention;

[0033] Figure 3 . A schematic diagram of the bottom cover and a schematic diagram of the washing bottle for receiving the elution liquid in the experimental device of the present invention;

[0034] Among them, 1-elution column, 2-gas delivery component, 3-elution solution storage component, 4-column internal environment monitoring component, 5-elution solution collection component; 6-in-situ sampling piston;

[0035] 11-top cover, 111-funnel-shaped bottom of the top cover, 112-top cover plate, 113-liquid inlet, 114-air inlet, 115-monitoring port, 116-water-absorbing cotton rope;

[0036] 12-bottom cover, 121-funnel-shaped bottom, 122-bottom cover plate, 123-hole;

[0037] 21-gas cylinder, 22-gas flow rate supply pump;

[0038] 31-peristaltic pump, 32-leaching solution storage tank;

[0039] 41-environmental monitoring electrode, 42-pore water sampling device; 421-sampling end, 422-collector

[0040] 51: gas washing bottle, 52: double hole plug, 53: exhaust hole. DETAILED DESCRIPTION

[0041] The present invention is exemplarily described below with reference to the accompanying drawings.

[0042] The experimental device for simulating the co-migration, transformation and monitoring of heavy metals and organic agents in tailings provided in all embodiments of the present invention is as follows: Figures 1 to 3 As shown, it includes: a leaching column 1, a gas transmission component 2, a leaching solution storage component 3, a column environment monitoring component 4, and a leaching solution collection component 5; wherein the leaching column 1 has a hollow cylindrical tube body, a top cover 11 and a bottom cover 12; the top cover has a funnel-shaped bottom 111 and a top cover plate 112 with a larger cross-section than the cylindrical tube body, and the funnel-shaped bottom 111 is extended into the cylindrical tube body through the top cover plate 112 being sealed and connected to the top end of the cylindrical tube body; a liquid inlet 113 and an inlet port 114 are provided near the center of the top cover plate 112. The gas port 114 and the monitoring port 115 enable the liquid and gas to mix in the funnel-shaped cavity of the top cover before flowing into the cylindrical tube body; and through; the bottom cover 12 has a funnel-shaped bottom 121 and a bottom cover plate 122 with a larger cross-section than the upper cross-section of the cylindrical tube body, and a plurality of holes 123 are arranged on the area corresponding to the inner cavity of the hollow cylindrical tube body of the bottom cover plate, and the bottom cover plate 122 is sealed and connected to the bottom end of the cylindrical tube body, so that the liquid of the leaching column can flow into the funnel-shaped cavity of the bottom cover 12 through the evenly arranged plurality of holes 123, and be gathered and flow out from the funnel mouth;

[0043] The gas delivery component 2 includes a gas cylinder 21 and a gas flow rate air supply pump 22, and the gas flow rate air supply pump supplies gas to the cylindrical tube body through the air inlet of the top cover and controls the gas flow rate; that is, it is connected to the gas cylinder through the air inlet above the top cover to control the type of gas entering the leaching column, and also realize the change of redox potential in the leaching column, revealing the chemical reactions in the leaching column under anaerobic and aerobic conditions, and controlling the gas flow rate through the air supply pump.

[0044] The leaching solution storage component 3 includes a peristaltic pump 31 and at least one leaching solution storage tank 32 (different leaching solutions, such as simulated acid rain solution and mineral processing reagent, can be set as needed). The peristaltic pump accurately injects the leaching solution into the cylindrical tube body through the liquid inlet 113 on the top cover plate.

[0045] The column environment monitoring component 4 includes at least one environment monitoring electrode 41 and at least one pore water sampling device 42. The environment monitoring electrode extends into the cylindrical tube body through the monitoring port to dynamically monitor the pH, EC, Eh and soluble heavy metal content in the leaching column; one end of the pore water sampling device is a sampling end 421 extending into the cylindrical tube body through the monitoring port, and the other end is a collector 422 (such as a vacuum syringe);

[0046] The leachate collection assembly 5 comprises a washing bottle 51 with a double-hole plug 52 , one of the holes of which is provided with a catheter, which is connected to the funnel opening under the bottom cover of the leaching column through the catheter to collect the leachate, and the other hole is an exhaust hole 53 .

[0047] In summary, when the experimental device of the present invention is used, the porous medium of the tailings to be tested is filled in the leaching column, and the instantly prepared solution and the organic mineral processing agent (xanthate) are mixed after entering the anaerobic environment through the top cover with a funnel-shaped bottom. The mixture then enters the porous medium of the tailings to simulate the effect of xanthate on the dissolution and migration of heavy metals in the tailings under different solution pH conditions.

[0048] The gas delivery component is used to realize the interaction and co-migration between organic agents and heavy metals in tailings under anaerobic and aerobic environments, and the built-in environmental monitoring electrode reflects the redox potential in the leaching column. It can also be used to simulate the dissolution, migration and interaction research system of heavy metals in sulfide tailings with organic agents during the dynamic changes of redox reactions.

[0049] As the minerals in the tailings dissolve and migrate with the water flow, the mineral composition and porosity of the leaching column change accordingly. The pore water sampling device inserted through the top cover and the porous bottom cover are used to collect the solution flowing through the upper and lower porous media of the tailings, reflecting the interaction between minerals and xanthate during the weathering process of the tailings.

[0050] By inserting environmental monitoring electrodes in the middle and bottom of the column, heavy metal dissolution, migration, solution pH and EC monitoring can be achieved during the weathering of sulfide metal tailings under different redox conditions.

[0051] After the dynamic monitoring is completed, the upper and lower connecting pipes of the column can be closed, and then the column can be moved into the glove box as a whole. A separate or complete set of in-situ sampling pistons can be used to collect the original samples of the leaching column and analyze the pores, geochemistry, minerals, and organic agents of the porous media of different layers of tailings.

[0052] In some embodiments, the experimental device of the present invention has the top and bottom edges of the cylindrical tube extending outward, forming a top ring plate and a bottom ring plate in one piece; the top of the cylindrical tube is sealed and connected to the top cover plate through the top ring plate, and the lower end of the cylindrical tube is sealed and connected to the bottom cover plate of the bottom cover through the bottom ring plate. The sealed connection can be achieved by arranging a sealing kit between the connectors, which is a conventional technical means in the art.

[0053] In some embodiments, the experimental device described in the present invention is characterized in that a water-absorbing cotton rope is provided at each liquid inlet of the top cover, and the other ends of all the water-absorbing cotton ropes are gathered into a cluster to facilitate mixing of different leaching solutions before entering the leaching column.

[0054] In some embodiments, the leaching column, top cover, and bottom cover in the experimental device of the present invention are all made of transparent materials, such as polymethyl methacrylate, to ensure visibility during the experiment.

[0055] In most embodiments, it is characterized in that the leaching solution storage tank, the environmental monitoring electrode pore water sampling device, and the washing bottle are made of acid and alkali corrosion resistant materials.

[0056] In most embodiments, it is characterized in that the environmental monitoring electrode integrates one or more of a pH electrode, a conductivity electrode, a dissolved oxygen electrode, a redox potential electrode, and a heavy metal electrode, for example, all of them.

[0057] In a preferred embodiment, the environmental monitoring electrodes are multiple and arranged at different heights in the cylindrical tube to monitor changes in different layers, for example, they are particularly suitable for monitoring changes in the pore conditions of porous media during reactions.

[0058] In most embodiments, an in-situ sampling piston 6 having an inner diameter smaller than that of the cylindrical tube is also provided.

[0059] Application Examples

[0060] Step 1: The mineral processing reagent to be tested is placed in a glove box under nitrogen protection;

[0061] Step 2: Prepare the experimental device: lay a layer of gauze at the position with multiple holes 123 on the bottom cover plate 12 of the experimental device provided by the present invention, and then combine the bottom end ring plate of the leaching column with the bottom cover plate 12 and tighten and seal;

[0062] Combine the top cover plate 11 and the upper end of the leaching column and seal them; connect the leaching solution storage component and the gas delivery component, and perform air tightness test on the entire device; then pass nitrogen, and after the exhaust hole of the washing bottle detects nitrogen, pass the organic agent, collect the outflowing organic agent, and compare the molecular composition with the inflowing organic agent to determine that the organic agent has not been decomposed under the nitrogen protection condition;

[0063] Step 3: Weigh 180g of tailings and fill the leaching column layer by layer, and place the pore water sampler and environmental monitoring electrode into the leaching column through the monitoring port. Lay a layer of gauze on the top of the tailings, and lay 1cm thick quartz sand on the gauze to allow the leaching solution to flow evenly into the tailings in the leaching column;

[0064] Step 4: Use saturated CaCO3 solution to pre-saturate the leaching tailings column at a flow rate of 0.15ml / min; after the tailings in the leaching column are saturated, replace the leaching solution with simulated acid rain; adjust the peristaltic pump and set the simulated acid rain and yellow medicine to enter the predetermined speed; turn on the gas flow rate air pump, and after the washing bottle is filled with nitrogen, turn on the peristaltic pump, and leaching simulated acid rain and organic agents under nitrogen protection conditions;

[0065] Step 5: Collect the leachate and pore water regularly, monitor the pH, EC, Eh, and the content changes of dissolved heavy metals such as Pb and Zn in the leaching column; use a syringe to absorb the liquid in the washing bottle, part of which is used to determine the ferrous ion content, and part of the sample is used to determine the cation and anion content;

[0066] Step 6: After the leaching experiment is completed, the leaching solution storage component, gas delivery component, and leaching solution collection component are separated from the leaching column, and then the solid samples in the leaching column are separated, and 2 cm thick matrices from the upper, middle, and bottom layers of the leaching column are taken in situ for subsequent analysis.

Claims

1. An experimental device for simulating the co-migration, transformation and monitoring of heavy metals and organic agents in tailings, comprising: Leaching column, gas transmission component, leachate storage component, column environment monitoring component, leachate collection component; The leaching column comprises a hollow cylindrical tube body, a top cover and a bottom cover; the top cover comprises a funnel-shaped bottom and a top cover plate with a larger cross-section than the upper cross-section of the cylindrical tube body, and the funnel-shaped bottom is extended into the cylindrical tube body through the top cover plate being sealed and connected to the top end of the cylindrical tube body; a liquid inlet, an air inlet and a monitoring port are arranged at a position close to the center of the top cover plate, so that liquid and gas can be mixed in the funnel-shaped cavity of the top cover before flowing into the cylindrical tube body; and through; the bottom cover comprises a funnel-shaped bottom and a bottom cover plate with a larger cross-section than the upper cross-section of the cylindrical tube body, and multiple holes are arranged on the area corresponding to the inner cavity of the hollow cylindrical tube body of the bottom cover plate, and the bottom cover plate is sealed and connected to the bottom end of the cylindrical tube body, so that the liquid of the leaching column can flow into the funnel-shaped cavity of the bottom cover through the evenly arranged multiple holes and be collected and flow out from the funnel mouth; The gas delivery assembly comprises a gas cylinder and a gas flow rate supply pump, wherein the gas flow rate supply pump supplies gas to the cylindrical tube body through the gas inlet in the top cover plate and controls the gas flow rate; The shower solution storage component comprises a peristaltic pump and at least one shower solution storage tank, and the peristaltic pump accurately injects the shower solution into the cylindrical tube body through the liquid inlet on the top cover plate; The column environment monitoring component includes at least one environment monitoring electrode and at least one pore water sampling device. The environment monitoring electrode extends into the cylindrical tube body through the monitoring port to dynamically monitor the pH, EC, Eh and soluble heavy metal content in the leaching column. One end of the pore water sampling device is a sampling end extending into the cylindrical tube body through the monitoring port, and the other end is a collector. Leachate collection assembly: includes a gas washing bottle with a double-hole plug, one of the holes is equipped with a catheter, which is connected to the funnel under the bottom cover of the leaching column through the catheter to collect the leachate, and the other hole is an exhaust hole.

2. The experimental device according to claim 1, characterized in that: The top and bottom edges of the cylindrical tube body extend outward, forming a top ring plate and a bottom ring plate in an integral manner; the top end of the cylindrical tube body is sealedly connected to the top cover plate through the top ring plate, and the lower end of the cylindrical tube body is sealedly connected to the bottom cover plate of the bottom cover through the bottom ring plate.

3. The experimental device according to claim 1, characterized in that: A water-absorbing cotton rope is arranged at each liquid inlet of the top cover, and the other ends of all the water-absorbing cotton ropes are gathered into a cluster to facilitate mixing of different leaching solutions before entering the leaching column.

4. The experimental device according to claim 1, characterized in that: The leaching column, top cover and bottom cover are all made of transparent materials, such as polymethyl methacrylate, to ensure visibility during the experiment.

5. The experimental device according to claim 1, characterized in that: The leaching solution storage tank, environmental monitoring electrode pore water sampling device, and gas washing bottle are made of acid and alkali corrosion resistant materials.

6. The experimental device according to claim 1, characterized in that: The environmental monitoring electrode integrates one or more of a pH electrode, a conductivity electrode, a dissolved oxygen electrode, a redox potential electrode, and a heavy metal electrode.

7. The experimental device according to any one of claims 1 to 6, characterized in that: The environmental monitoring electrodes are multiple and are arranged at different heights in the cylindrical tube to monitor changes in different layers. For example, they are particularly suitable for monitoring changes in the pore conditions of porous media during the reaction process.

8. The experimental device according to claim 7 is further provided with an in-situ sampling piston with an inner diameter smaller than that of the cylindrical tube.

9. A method for simulating and monitoring the co-migration and transformation of heavy metals and organic agents in tailings, characterized in that: Use the experimental device described in any one of claims 1 to 8, and perform the following operations: Step 1: The mineral processing reagent to be tested is placed in a glove box under nitrogen protection; Step 2: Prepare the experimental device: lay a layer of gauze on the porous position of the bottom cover of the experimental device, and then combine the bottom ring plate of the leaching column with the bottom cover to tighten and seal; Combine the top cover plate and the upper end of the leaching column and seal them; connect the leaching solution storage component and the gas delivery component, and perform air tightness test on the entire device; then pass nitrogen, and after the exhaust hole of the gas washing bottle detects nitrogen, pass the organic agent, collect the outflowing organic agent, and compare the molecular composition with the inflowing organic agent to confirm that the organic agent has not been decomposed under the nitrogen protection condition; Step 3: Weigh the tailings and fill the leaching column layer by layer, and place the pore water sampler and environmental monitoring electrode into the leaching column through the monitoring port. Lay a layer of gauze on the top of the tailings, and lay 1 cm thick quartz sand on the gauze to allow the leaching solution to flow evenly into the tailings in the leaching column; Step 4: Use saturated CaCO3 solution to pre-saturate the tailings column at a predetermined flow rate; after the tailings in the leaching column are saturated, replace the leaching solution with simulated acid rain; Regulate the peristaltic pump and set the preset speed for the simulated acid rain and xanthate to enter; turn on the gas flow rate supply pump, and after the washing bottle is filled with nitrogen, turn on the peristaltic pump and pour in the simulated acid rain and organic agent under the protection of nitrogen; Step 5: Collect the leachate and pore water regularly to monitor the pH, EC, Eh and the content changes of dissolved heavy metals in the leaching column; absorb the liquid in the washing bottle, part of which is used to determine the ferrous ion content, and part of the sample is used to determine the cation and anion content; Step 6: After the leaching experiment is completed, the leaching solution storage component, gas delivery component, and leaching solution collection component are separated from the leaching column, and then the solid samples in the leaching column are separated, and 2 cm thick matrices from the upper, middle, and bottom layers of the leaching column are taken in situ for subsequent analysis.

10. The method according to claim 9, characterized in that the mineral processing agent is xanthate.

Images