Application of sodium citrate as retardant in seepage leaching of ion adsorption type rare earth ore

Abstract

The invention provides application of sodium citrate as a retardant in ion adsorption type rare earth ore seepage leaching, and relates to the technical field of nonferrous metal mining. The application provided by the invention comprises the following steps: in the in-situ ore leaching process of the ion adsorption type rare earth ore, injecting a sodium citrate solution as a retardant in the downward direction of a diversion hole excavated in the rare earth ore and in other areas needing closure and speed control in advance, so as to reduce the seepage rate of the ore leaching agent in the areas and realize regulation and control of the seepage direction. According to the invention, the leaching liquid can be prevented from seeping downwards through the flow guide holes so as to improve the liquid yield, the seepage extraction of a mineral leaching agent on wider areas such as a semi-weathered layer is enhanced, the mineral leaching blind area is effectively reduced, and the leaching efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of nonferrous metal mining, in particular to application of sodium citrate as a retarder in seepage leaching of ion-adsorption rare earth ores. Background Art

[0002] Rare earth elements in ion-adsorption rare earth ores exist primarily as ions or hydrated hydroxyl ions, which can be exchanged and leached with other electrolytes. For example, ammonium sulfate in-situ leaching is used to extract rare earths. This involves injecting a leachant through a surface injection system. A collection system is then installed at locations outside the quarry where bedrock leaks occur or where the bedrock cover is thin. The leachate then flows by gravity into the collection system. However, due to geological activity and time evolution, ion-adsorption rare earth deposits have uneven formations. During seepage leaching, the leachant preferentially forms pathways along fully weathered layers, leading to over-leaching and waste. Furthermore, the leachate can seep downward through diversion holes, reducing the leachate recovery rate and increasing the risk of environmental pollution. Furthermore, under-weathered deposits have poor permeability, making them difficult for the leachant to fully penetrate, resulting in inadequate rare earth leaching and a high risk of landslides and other disasters. Therefore, a solution is proposed to address these issues. Summary of the Invention

[0003] The present invention aims to provide a method for using sodium citrate as a retarder in the seepage leaching of ion-adsorption rare earth ores, which can prevent the leachate from seeping downward through the diversion holes, thereby improving the liquid recovery rate, strengthening the seepage extraction of the leaching agent to a wider area such as the semi-weathered layer, effectively reducing the leaching blind area and improving the leaching efficiency.

[0004] The present invention provides a method for using sodium citrate as a retarder in the seepage leaching of ion-adsorption rare earth ores. The method comprises: during the in-situ leaching of ion-adsorption rare earth ores, a sodium citrate solution is pre-injected as a retarder downwardly from diversion holes excavated in the rare earth mine and in other areas requiring flow interception and rate control. This reduces the seepage rate of the leachate in these areas, thereby regulating the direction of seepage. This effectively blocks the downward seepage of leachate through the diversion holes, thereby increasing the liquid recovery rate and enhancing the seepage extraction of the leachate to a wider range of areas, such as the semi-weathered layer, effectively reducing blind spots and improving leaching efficiency.

[0005] In fact, when conducting seepage leaching of ion-adsorption rare earth ores, while excavating liquid collection tunnels and diversion holes below the in-situ leaching ore layer, sodium citrate solution is injected towards the bottom surface as a retarder, and a degradable artificial floor is constructed at the bottom of the in-situ leaching ore layer to prevent the leaching solution from seeping downward and causing rare earth loss.

[0006] Optionally, the concentration of sodium citrate in the sodium citrate solution is 0.1%-5%.

[0007] Optionally, the leaching agent includes various inorganic salt solutions, for example, a combination of one or more of sodium sulfate solution, magnesium sulfate solution, and aluminum sulfate solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 A schematic diagram of the injection and collection of liquid for in-situ leaching of an ion adsorption type rare earth ore provided by the present invention;

[0009] Figure 2 Schematic diagram of the high-density electrical method provided by the present invention for monitoring the seepage of ion adsorption rare earth mine injection fluid;

[0010] Figure 3 This is a comparison chart showing changes in the seepage coefficients of pure water and inorganic salt leaching agents of different concentrations over time when the ore sample is less than 20 mesh and the ore loading mass is 200g in some embodiments of the present invention;

[0011] Figure 4 This is a comparison chart of the stable values ​​of the seepage coefficients of pure water and inorganic salt leaching agents of different concentrations and types when the ore sample is below 20 mesh and the ore loading mass is 200g in some embodiments of the present invention;

[0012] Figure 5 This is a comparison chart of the change in seepage coefficient and the stable seepage coefficient when leaching with pure water and sodium citrate of different concentrations in Example 1 of the present invention, when the ore sample is less than 20 mesh and the ore loading mass is 200g;

[0013] Figure 6 This is a comparison chart of the leaching curves and leaching efficiencies of sodium citrate at different concentrations when the ore sample is below 20 mesh and the ore loading mass is 200g in Example 1 of the present invention;

[0014] Figure 7 This is a comparison chart of the change in permeability coefficient and the stable permeability coefficient when leaching with pure water and 1% sodium citrate in Example 2 of the present invention, when the ore sample is less than 20 mesh and the ore loading mass is 190g;

[0015] Figure 8 This is a comparison chart of the change in permeability coefficient and the stable permeability coefficient when leaching with pure water and 1% sodium citrate in Example 2 of the present invention, when the ore sample is less than 20 mesh and the ore loading mass is 200g;

[0016] Figure 9 This is a comparison chart of the change in permeability coefficient and the stable permeability coefficient when leaching with pure water and 1% sodium citrate for an ore sample with a mesh size of less than 20 and an ore loading mass of 210 g in Example 2 of the present invention;

[0017] Figure 10 This is a comparison chart of the change in seepage coefficient and the stable seepage coefficient when leaching with pure water and 1% sodium citrate in Example 3 of the present invention, when the ore sample is less than 10 mesh and the ore loading mass is 210g;

[0018] Figure 11 This is a comparison chart of the change in permeability coefficient and the stable permeability coefficient when leaching with pure water and 1% sodium citrate in Example 3 of the present invention, when the ore sample is less than 10 mesh and the ore loading mass is 220g;

[0019] Figure 12 This is a comparison chart of the change in seepage coefficient and the stable seepage coefficient when leaching with water and 1% sodium citrate for an ore sample with a mesh size of less than 8 and an ore loading mass of 210 g in Example 4 of the present invention;

[0020] Figure 13 This is a comparison chart of the change in seepage coefficient and the stable seepage coefficient when leaching with water and 1% sodium citrate for an ore sample with a mesh size of less than 8 and an ore loading mass of 220 g in Example 4 of the present invention;

[0021] Figure 14 This is a comparison chart of the change in seepage coefficient and the stable seepage coefficient when leaching with water and 1% sodium citrate for an ore sample with a mesh size of less than 8 and an ore loading mass of 225 g in Example 4 of the present invention;

[0022] Figure 15 This is a comparison chart of the change in seepage coefficient after adding 1% sodium citrate after the seepage is stabilized by using inorganic salt leaching when the ore sample is less than 20 mesh and the ore loading mass is 200g in Example 5 of the present invention;

[0023] Figure 16 This is a comparison chart of the stable seepage value after adding 1% sodium citrate after the seepage is stabilized by using inorganic salt leaching in Example 5 of the present invention, when the ore sample is less than 20 mesh and the ore loading mass is 200g;

[0024] Figure 17 This is a comparison chart of the change of the seepage coefficient of the ore body with time when the electric field is not applied and when the electric field is applied, under 20 kg of the original ore in Example 6 of the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the embodiments described are 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 work are within the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein should be the common meanings understood by people with ordinary skills in the field to which the present invention belongs.

[0026] See also Figure 1The present invention provides a method for using sodium citrate as a retarder in the seepage leaching of ion-adsorption rare earth ores. In practice, during seepage leaching of ion-adsorption rare earth ores, multiple injection wells of varying depths are typically excavated at the top of the mine, and a diversion stream is excavated at the bottom. During leaching, the leaching agent is injected into the mine through the injection wells for ion exchange, and the leachate containing rare earth ions is collected from the diversion stream. To prevent the leachate from seeping into the ground and causing waste, the present invention pre-injects a low-concentration sodium citrate solution into the downward-facing bottom area of ​​the diversion stream, forming a degradable artificial floor that prevents the leachate from seeping downward and being lost.

[0027] At the same time, by injecting sodium citrate solution in the later stage of leaching, the seepage velocity of the leaching agent in the whole weathering layer area can be greatly reduced, thereby redirecting the seepage and strengthening its seepage leaching in a wider area such as the semi-weathering layer, which can effectively improve the leaching efficiency and reduce the blind spots of leaching. After the main leaching project is completed, the sodium citrate and other leaching agents and rare earth ions in the tailings can be overflowed through the electric field promoted seepage method, reducing the amount of pollutants remaining in the tailings, thereby achieving the goal of efficient and green leaching. In addition, the entire leaching and seepage control process can be monitored by high-density electrical methods, which is conducive to timely adjustment of leaching process parameters, such as Figure 2 As shown, the surface weathering crust in the rare earth ore presents an uneven morphology, and the seepage direction and flow rate after the addition of the leaching agent can be evaluated through continuous in situ detection, which can be used to guide the seepage control process.

[0028] In reality, after a leaching agent is injected into a rare earth ore body, the seepage direction, or seepage velocity in each direction, is related to the porosity in that direction. The direction with the lowest seepage resistance exhibits the highest velocity. Therefore, to confirm the feasibility of sodium citrate in seepage extraction, it is necessary to establish a reliable seepage velocity range. This feasibility can be verified based on the range of seepage velocity differences across different regions and directions in actual applications.

[0029] To this end, the present invention provides a seepage test method, comprising: using an ion-adsorption rare earth ore sample that has been dried and passed through a 20-mesh (less than 0.9 mm) sieve to reduce experimental errors caused by differences in particle size and fineness of the ore sample; weighing 200 g of the ore sample with a particle size less than 20 mesh and evenly loading it into a plexiglass column with an inner diameter of 4.9 mm, with filter paper padded above and below the column to a height of 10 cm, and evenly loading the ore sample into the column in multiple batches to avoid experimental errors caused by uneven ore sample; leaving an overflow port at a height of 12 cm, pumping a leaching agent into the column at a controlled flow rate using a peristaltic pump, and recovering excess leaching agent from the overflow port, always maintaining a maximum liquid level 2 cm above the column to maintain stability of measurement conditions; a timed liquid receiving device at the bottom of the column, setting a certain time according to the characteristics of the leaching agent, rotating a new liquid collecting pipe at a certain time interval, obtaining leachate during this period, and recording the volume of leachate discharged during each period; and calculating a seepage coefficient value based on the leachate volume in each time period.

[0030] In some embodiments, the seepage test method provided above is used to change the type and concentration of the added leaching agent to obtain the seepage coefficient values ​​under different leaching agent conditions, and the seepage coefficient values ​​under different concentrations of inorganic salt solutions are measured. The change of the seepage coefficient over time is shown in FIG. Figure 3 As shown, the stable value of the seepage coefficient is as follows Figure 4 As shown. Figure 3 and Figure 4 It can be seen that the seepage rates of pure water and inorganic salt solutions of different types and concentrations in the ore layer are different during leaching. For example, there is a large difference in the seepage rate between pure water and calcium chloride, magnesium chloride, ammonium sulfate and aluminum sulfate solutions. The seepage rate of pure water is 0.96 cm / h, while the seepage rates of 0.06N calcium chloride, magnesium chloride, aluminum chloride, aluminum sulfate and sodium sulfate solutions are 0.57 cm / h, 0.55 cm / h, 0.67 cm / h, 0.71 cm / h and 0.64 cm / h respectively. The seepage rates of 0.12N calcium chloride, magnesium chloride, aluminum chloride, aluminum sulfate and ammonium sulfate are 0.64 cm / h, 0.62 cm / h, 0.69 cm / h, 0.68 cm / h and 0.71 cm / h respectively. It can be seen that there are significant differences between different leachants, but the differences do not exceed 0.16 cm / h. Changes in concentration can also change the seepage velocity. For monovalent and divalent cation electrolytes, the general trend is that there is a low-concentration region with the slowest seepage velocity. Then, as the concentration increases, the seepage velocity increases, but the increase does not exceed 0.1 cm / h. For aluminum ion electrolyte solutions, changes in concentration have little effect on the seepage velocity.

[0031] Example 1

[0032] This Example 1 provides a use of sodium citrate as a retarder in simulated seepage extraction of ion-adsorption rare earth ore, comprising: weighing 200 g of rare earth ore passed through a 20-mesh sieve and evenly loading it into a plexiglass column with an inner diameter of 4.9 mm; filter paper is padded at the upper and lower ends of the glass column (during the column loading process, the ore can be evenly loaded in multiple times, and the column height is 10 cm); after loading, an overflow port is provided at a height of 12 cm in the glass column; sodium citrate solutions of different mass concentrations are pumped into the glass column by a peristaltic pump, and excess sodium citrate solution is recovered from the overflow port, with the maximum liquid level always being maintained at 2 cm above the ore column; a timed liquid collection device is used at the bottom of the glass column; and according to the characteristics of the injected leaching agent, a new liquid collecting pipe is rotated at intervals to obtain the leachate within that time period.

[0033] Record the volume of leachate flowing out in each period and calculate the seepage coefficient of sodium citrate solution with different concentrations. Determine the rare earth concentration of each sample, the change of seepage coefficient with time and the stable value of seepage coefficient. Figure 5 As shown, the seepage leaching curve and efficiency are as follows Figure 6 As shown. Figure 5 and Figure 6 As can be seen from the data, sodium citrate solution has a better leaching effect. When the concentration exceeds 2% and the liquid-to-solid ratio is 0.3-0.5, rare earth can be completely leached. However, sodium citrate solution with a lower concentration (less than or equal to 1%) has a long seepage decline phase. The lower the concentration, the longer the seepage stability time and the smaller the stable seepage value. This shows that low-concentration sodium citrate solution has a more significant seepage retardation effect. Compared with the seepage coefficient of pure water, the seepage coefficient of sodium citrate solution with a concentration greater than 2% decreases by about 45%, the seepage coefficient of 1% sodium citrate solution decreases by 63.54%, and the seepage coefficient of 0.5% sodium citrate solution decreases by 70.83%, showing a more significant seepage retardation effect.

[0034] Example 2

[0035] This Example 2 provides a use of sodium citrate as a retarder in simulated seepage extraction of ion-adsorption rare earth ore, comprising: weighing 190 g, 200 g, and 210 g of the rare earth ore, respectively, and passing through a 20-mesh sieve, and evenly loading them into a plexiglass column with an inner diameter of 4.9 mm; filter paper is placed at the upper and lower ends of the glass column (during the column loading process, the ore can be evenly loaded in multiple times, and the column height is 10 cm); after loading, an overflow port is provided at a height of 12 cm in the glass column; pure water and a 1% sodium citrate solution are pumped into the glass column by a peristaltic pump, and excess solution is recovered from the overflow port, so that the maximum liquid level is always maintained at 2 cm above the ore column; a timed liquid collection device is used at the bottom of the glass column; and according to the characteristics of the injected leaching agent, a new liquid collecting pipe is rotated at intervals to obtain the leachate within that time period.

[0036] The volume of leachate flowing out in each period of time was recorded. According to the volume of leachate in each period of time, the seepage coefficient values ​​of sodium citrate with different concentrations were calculated. The change of seepage coefficient with time and the stable value of seepage coefficient were shown as follows: Figure 7 、 Figure 8 and Figure 9 As shown. Figures 7 to 9 As can be seen, the permeability coefficient of pure water decreases significantly with increasing packing density, from 1.01 to 0.79, and then to 0.54, a decrease of 46.5%. The permeability coefficient of 1% sodium citrate stabilizes for a long period of time, with a lower value. Comparing the three ore samples with different packing densities, the permeability coefficient of 1% sodium citrate decreases significantly, from 0.41 to 0.35, and then to 0.26, respectively, a decrease of 36.6%. This demonstrates that the greater the packing density, the lower the overall permeability coefficient of the ore sample. Under these column leaching conditions, the permeability coefficient decreases by 59.43%, 55.55%, and 50.98% after adding 1% sodium citrate compared to pure water, significantly exceeding the effect of packing density on permeability. By adjusting the concentration and leaching reagent, it is possible to control the difference in permeability velocity caused by differences in ore density, thus enabling flow control.

[0037] Example 3

[0038] This Example 3 provides the use of sodium citrate as a retarder in simulated seepage extraction of ion-adsorption rare earth ores, comprising: weighing 210 g and 220 g of rare earth ore, respectively, and passing through a 10-mesh sieve, and evenly loading them into a plexiglass column with an inner diameter of 4.9 mm; filter paper is placed at the upper and lower ends of the glass column (during the column loading process, the ore can be evenly loaded in multiple times, and the column height is 10 cm); after loading, an overflow port is provided at a height of 12 cm in the glass column; pure water and a 1% sodium citrate solution are pumped into the glass column by a peristaltic pump, and excess solution is recovered from the overflow port, so that the maximum liquid level is always maintained at 2 cm above the ore column; a timed liquid collection device is used at the bottom of the glass column; and according to the characteristics of the injected leaching agent, a new liquid collecting pipe is rotated at intervals to obtain the leachate within that time period.

[0039] The volume of leachate flowing out in each period of time was recorded. According to the volume of leachate in each period of time, the seepage coefficient values ​​of sodium citrate with different concentrations were calculated. The change of seepage coefficient with time and the stable value of seepage coefficient were shown as follows: Figure 10 and Figure 11 As shown. Figure 10 and Figure 11As can be seen, the permeability coefficient of pure water decreases significantly with increasing packing density, from 1.22 to 0.93, a decrease of 27.8%. The permeability coefficient of 1% sodium citrate stabilizes for a long period of time, with a lower value. Comparing the two ore samples with different packing densities, the permeability coefficient of 1% sodium citrate decreases significantly, from 0.47 to 0.37, respectively, a decrease of 21.3%. This demonstrates that the greater the packing density, the lower the overall permeability coefficient of the ore sample. Under these column leaching conditions, the permeability coefficient decreases by 61.48% and 60.21% after adding 1% sodium citrate, compared to pure water. This significantly exceeds the effect of packing density on permeability velocity. By adjusting the concentration and leaching reagent, it is possible to control the permeability velocity caused by differences in ore density, thus enabling flow control.

[0040] Example 4

[0041] This Example 4 provides a use of sodium citrate as a retarder in simulated seepage extraction of ion-adsorption rare earth ore, comprising: weighing 210 g, 220 g, and 225 g of rare earth ore, respectively, and passing through an 8-mesh sieve, and evenly loading them into a plexiglass column with an inner diameter of 4.9 mm; filter paper is placed at the upper and lower ends of the glass column (during the column loading process, the ore can be evenly loaded in multiple times, and the column height is 10 cm); after loading, an overflow port is provided at a height of 12 cm in the glass column; pure water and a 1% sodium citrate solution are pumped into the glass column by a peristaltic pump, and excess solution is recovered from the overflow port, so that the maximum liquid level is always maintained at 2 cm above the ore column; a timed liquid collection device is used at the bottom of the glass column; and according to the characteristics of the injected leaching agent, a new liquid collection pipe is rotated at intervals to obtain the leachate within that time period.

[0042] The volume of leachate flowing out in each period of time was recorded. According to the volume of leachate in each period of time, the seepage coefficient values ​​of sodium citrate with different concentrations were calculated. The change of seepage coefficient with time and the stable value of seepage coefficient were shown as follows: Figure 12 、 Figure 13 and 14 As shown. Figures 12 to 14It can be seen that the permeability coefficient of pure water decreases significantly with increasing packing density, from 1.36 to 0.95, and then to 0.83, a decrease of 39%. The permeability coefficient of 1% sodium citrate stabilizes for a long period of time, with a lower value. Comparing the two ore samples with different packing densities, the permeability coefficient of 1% sodium citrate decreases significantly, from 0.46 to 0.42, and then to 0.38, respectively, a decrease of 17.4%. This demonstrates that the greater the packing density, the lower the overall permeability coefficient of the ore sample. Under these column leaching conditions, the permeability coefficient decreased by 66.18%, 55.79%, and 54.21% after adding 1% sodium citrate compared to pure water. This significantly exceeds the effect of packing density on permeability velocity. By adjusting the concentration and leaching reagent, it is possible to control the permeability velocity caused by differences in ore density, thus enabling flow control.

[0043] Example 5

[0044] This Example 5 provides a use of sodium citrate as a retarder in simulated seepage extraction of ion-adsorption rare earth ores, comprising: weighing 200 g of rare earth ore passed through a 20-mesh sieve and evenly loading it into a plexiglass column with an inner diameter of 4.9 mm; filter paper is placed at the upper and lower ends of the glass column (during the column loading process, the ore can be evenly loaded in multiple times, and the column height is 10 cm); after loading, an overflow port is provided at a height of 12 cm in the glass column; different solutions are pumped into the glass column by a peristaltic pump, and excess solution is recovered from the overflow port, with the highest liquid level always maintained at 2 cm above the ore column; in a first stage, different chloride solutions are used for leaching; after the seepage rate stabilizes, a 1% sodium citrate solution is pumped in until the seepage rate stabilizes; a timed liquid collection device is used at the bottom of the glass column; and according to the characteristics of the injected leaching agent, a new liquid collecting pipe is rotated at intervals to obtain the leachate within that time period.

[0045] Record the volume of leachate flowing out in each period of time. According to the volume of leachate in each period of time, calculate the seepage coefficient of pure water. The relationship between the seepage coefficient and time is as follows: Figure 15 As shown in the figure, the seepage stability values ​​of 0.12N calcium chloride, magnesium chloride and aluminum chloride and the seepage stability value after adding 1% sodium citrate are as follows Figure 16 .from Figure 15 and Figure 16As can be seen, the stable seepage values ​​of chlorides decreased by more than 30% compared to pure water, with aluminum chloride showing the smallest decrease. The seepage coefficients of columns containing calcium chloride, magnesium chloride, and aluminum chloride after leaching and adding 1% sodium citrate decreased by 48.43%, 48.38%, and 46.97%, respectively. After adding 1% sodium citrate, the final stable seepage values ​​of calcium chloride, magnesium chloride, and aluminum chloride decreased by 65.63%, 66.67%, and 63.54%, respectively, compared to pure water, with the final seepage coefficients all decreasing by approximately 65%. These experimental results demonstrate that low concentrations of sodium citrate have a significant effect on seepage retardation.

[0046] Example 6

[0047] This Example 6 provides the use of sodium citrate as a retarder in simulated seepage extraction of ion-adsorption rare earth ores, comprising: weighing 20 kg of rare earth ore and evenly loading it into a 30 cm inner diameter organic glass column in multiple times, with the column height controlled to 20 cm; adding electrode plates (the outer side is a positive electrode, the inner side is a negative electrode) to the outside and middle of the column; first adding a 1% sodium citrate solution with a liquid-to-solid ratio of 0.4; after the ore body fully absorbs the sodium citrate solution, connecting a 30 V power supply and evenly adding alcohol water into the glass column, and comparing the results with the same conditions without an electric field; using a timed liquid collection device at the bottom of the glass column, rotating a new liquid collection pipe at intervals according to the characteristics of the injected leaching agent to obtain the leachate within this time period.

[0048] Record the volume of leachate flowing out in each period of time. According to the volume of leachate in each period of time, calculate the seepage coefficient of the ore body under the conditions of electric field and no electric field, such as Figure 17 As shown. Figure 17 As can be seen from the data, within the first 3000 minutes, the presence of sodium citrate in the ore body caused the permeability coefficient to slowly decrease. After 3000 minutes, the addition of pure water to the ore body continuously diluted the sodium citrate concentration, causing the permeability coefficient to rapidly decrease, then slowly decrease, before finally stabilizing. Under the overall seepage test conditions, the permeability of the ore body in the presence of an electric field was higher than that of the ore body without an electric field. This indicates that low concentrations of sodium citrate have a significant seepage retardation effect and can promote the permeability of ore bodies in low-permeability zones after the addition of an electric field.

[0049] While the embodiments of the present invention have been described in detail above, it will be apparent to those skilled in the art that various modifications and variations of these embodiments are possible. However, it should be understood that such modifications and variations are within the scope and spirit of the present invention as set forth in the claims. Furthermore, the invention described herein is susceptible to other embodiments and may be practiced or implemented in a variety of ways.

Claims

1. An application of sodium citrate as a retarder in the seepage leaching of ion adsorption type rare earth ores, characterized in that: include: During the in-situ leaching process of ion adsorption rare earth ores, sodium citrate solution is pre-injected as a retarder in the downward direction of the diversion holes excavated in the rare earth mine and in the areas where flow interception and rate control are required, thereby reducing the seepage rate of the leaching agent in the said areas and realizing the regulation of the seepage direction.

2. The use according to claim 1, characterized in that The concentration of sodium citrate in the sodium citrate solution is 0.1%-5%.

3. The use according to claim 1, characterized in that The leaching agent includes various inorganic salt solutions, and the inorganic salt solution includes one or more of sodium sulfate solution, magnesium sulfate solution, and aluminum sulfate solution.

4. The use according to claim 1, characterized in that After completing the main leaching project, an external electric field is applied to cause the sodium citrate, leaching agent and leached ions in the tailings to overflow, reducing the residual rare earth and electrolyte solution in the tailings and achieving the goal of efficient and green leaching.

5. The use according to claim 4, characterized in that Rely on high-density electrical methods to monitor the seepage process and adjust the seepage control targets in a timely manner.

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