CN112011697A

CN112011697A - Method for electrically exploiting rare earth ore and leaching agent for electrically exploiting rare earth ore

Info

Publication number: CN112011697A
Application number: CN202011019740.1A
Authority: CN
Inventors: 何宏平; 朱建喜; 王高锋; 冉凌瑜; 王园园; 陈情泽; 马灵涯; 魏景明; 朱润良
Original assignee: Guangzhou Institute of Geochemistry of CAS
Current assignee: Guangzhou Institute of Geochemistry of CAS
Priority date: 2020-09-24
Filing date: 2020-09-24
Publication date: 2020-12-01
Anticipated expiration: 2040-09-24
Also published as: CN112011697B

Abstract

The application relates to the field of rare earth mining, in particular to a method for mining rare earth ore by electrifying and a leaching agent for mining rare earth ore by electrifying. The method for electrically exploiting the rare earth ore comprises the following steps: arranging an anode in at least one liquid injection well, arranging at least one cathode on the mine, and arranging the anode and the cathode at intervals; adding leaching agent into the well injection liquid, and applying voltage to the anode and the cathode; wherein the leaching agent comprises a carbonate. Carbonate and H generated by the electrifying process near the anode⁺A dissolution reaction takes place with a neutralizing anode region H⁺When H is present⁺The soil pH remains unchanged when the neutralization results in a decrease in concentration insufficient to dissolve the carbonate. Therefore, the carbonate in the leaching agent can adjust and stabilize the pH value of the anode area, maintain electroosmotic flow and ensure continuous electric mining. Carbonate reacts with H under the acidic condition of the anode area⁺After reaction, metal cations are released to replace rare earth oreThe ionic rare earth in the mineral is beneficial to improving the rare earth mining efficiency.

Description

Method for electrically exploiting rare earth ore and leaching agent for electrically exploiting rare earth ore

Technical Field

The application relates to the field of rare earth mining, in particular to a method for mining rare earth ore by electrifying and a leaching agent for mining rare earth ore by electrifying.

Background

The ion adsorption type rare earth ore is a source of more than 90% of heavy rare earth in the world and is an extremely important strategic resource. The rare earth in the ion adsorption type rare earth ore exists mainly in the forms of hydration or hydroxyl water and cations, so the rare earth can be leached by adopting an electrolyte solution and the rare earth to carry out ion replacement. The currently predominant mining method is the in-situ leaching process.

The in-situ leaching process includes injecting leaching agent into the pre-dug liquid injection well network, replacing the leaching agent with RE ion in ore body during gradual permeation to obtain RE leached mother liquid, adding oxalic acid to precipitate, washing and burning to obtain mixed RE oxide.

However, in the in-situ leaching process, the seepage speed of the leaching solution and the mother solution is very slow, and a method for electrically exploiting the rare earth ore is provided in CN 201811574520.8; mainly comprises an anode liquid injection pipe with higher potential is added near a liquid injection well, and a cathode liquid collection pipe with lower potential is added near a liquid collection groove; to improve the leaching rate and shorten the mother liquor collection time.

But as time increases, electroosmotic flow decreases affect efficiency, and existing solutions primarily maintain electroosmotic flow strength by increasing voltage, which increases production costs.

Disclosure of Invention

An object of the embodiments of the present application is to provide a method for electrically exploiting a rare earth ore and a leaching agent for electrically exploiting a rare earth ore, which aim to solve the problem of a decrease in electroosmotic flow over time in the conventional method for electrically exploiting a rare earth ore.

In a first aspect, the present application provides a method for electrically mining rare earth ore, comprising:

arranging an anode in at least one liquid injection well, arranging at least one cathode on a mine, and arranging the anode and the cathode at intervals;

adding a leaching agent into the well injection liquid, and applying voltage to the anode and the cathode;

wherein the leaching agent comprises a carbonate.

Applying a voltage to the anode and the cathode; under the action of electric field force, the rare earth ions replaced by the leaching agent can flow to the cathode rapidly, so that the leaching progress of the rare earth ions is accelerated, and the leaching time is saved.

The leaching agent comprises carbonate, the carbonate and H generated by anode electrolysis⁺A dissolution reaction occurs; having a neutralizing anode region H⁺When H is present⁺The soil pH remains unchanged when the neutralization results in a decrease in concentration insufficient to dissolve carbonate minerals. Therefore, the carbonate in the leaching agent can adjust and stabilize the pH value of the anode area, maintain the electroosmotic flow velocity and ensure the continuous operation of the electrified exploitation. Carbonate and H⁺And cations are released after the reaction to replace the ionic rare earth in the rare earth ore, so that the rare earth mining efficiency is improved.

In some embodiments of the first aspect of the present application, the carbonate is selected from at least one of calcium carbonate, sodium carbonate, potassium carbonate, iron carbonate, and magnesium carbonate;

optionally, the carbonate is calcium carbonate.

In some embodiments of the first aspect of the present application, the carbonate is a water insoluble carbonate;

optionally, the leaching agent comprises a carbonate-containing mineral or a carbonate-containing rock;

optionally, the mineral comprises at least one of aragonite, calcite, dolomite, magnesite, siderite; the rock comprises at least one of limestone, marble rock, dolomitic marble rock and marl rock;

optionally, the mineral has a particle size of less than 75 μm; the rock has a particle size of less than 75 μm.

In some embodiments of the first aspect of the present application, the carbonate is used in an amount of 0.5 to 5 times the total mass of the rare earth sample;

optionally, the carbonate is used in an amount of 1-2 times the total mass of the rare earth sample.

In some embodiments of the first aspect of the present application, a voltage is applied between the anode and the cathode such that the voltage gradient in the ore body is between 0.01 and 0.2V/cm.

In some embodiments of the first aspect of the present application, the leaching agent further comprises an ammonium or magnesium salt.

In some embodiments of the first aspect of the present application, the ammonium salt is selected from at least one of ammonium sulfate, ammonium chloride, ammonium acetate, and ammonium citrate.

In a second aspect, the present application provides a leaching agent for the powered mining of rare earth ores, the leaching agent for the powered mining of rare earth ores comprising an ammonium salt and a carbonate;

alternatively, the leaching agent for electrowinning of rare earth ore comprises magnesium salt and carbonate.

In some embodiments of the second aspect of the present application, the carbonate is selected from at least one of calcium carbonate, sodium carbonate, potassium carbonate, iron carbonate, and magnesium carbonate;

optionally, the carbonate is calcium carbonate. In some embodiments of the second aspect of the present application, the leaching agent comprises a carbonate-containing mineral or a carbonate-containing rock;

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained from the drawings without inventive effort.

FIG. 1 shows the volume of leachate versus time for example 1 and comparative example 1;

FIG. 2 is a graph showing the rare earth leaching amounts of example 1 and comparative example 1 as a function of time.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the embodiments of the present application will be clearly and completely described below. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

The method for electrically mining rare earth ore and the leaching agent for electrically mining rare earth ore according to the embodiment of the present application will be specifically described below.

A method of electrowinning rare earth ore comprising:

and arranging an anode in at least one liquid injection well, and arranging at least one cathode on the mine, wherein the anode and the cathode are arranged at intervals.

Injecting a leaching agent into the well injection liquid, and applying a voltage to the anode and the cathode;

wherein the leaching agent comprises a carbonate.

At least one cathode is arranged on the mine, the arrangement position of the cathode can be the position of an ore body, a liquid collecting ditch and the like, the number of the anodes can be one, two, three or more, and the number of the cathodes can be one, two, three or more; the number of anodes and the number of cathodes are not limited in this application. Correspondingly, the cathode is arranged at a position different from the anode; the anode and the cathode can be arranged in a mutually crossed mode; or the anode is arranged at a high point, and the cathode is arranged at a position lower than the anode, and the relative positions of the anode and the cathode are not limited in the application.

In the process of electrically exploiting the rare earth ore, corresponding facilities such as a liquid injection well, a liquid collection ditch and the like need to be arranged. In the method for electrically exploiting the rare earth ore, an anode is arranged in a liquid injection well, and a cathode is arranged on a mine; injecting leaching agent into the well injection liquid, and applying voltage to the anode and the cathode; voltage is arranged between the liquid injection well and the liquid collection ditch, and current is formed under the action of the leaching liquid; under the action of current, the rare earth ions replaced by the leaching agent can flow to the cathode rapidly, so that the leaching progress of the rare earth ions is accelerated, and the leaching time is saved.

Electroosmotic flow is weakened after a period of time of applying voltage to the anode and the cathode; the inventor researches and discovers that the reason of the reduction of the electroosmotic flow is that H is continuously generated near the anode under the action of electrolysis due to the electrolytic water reaction near the anode⁺The pH of this region is lowered, thereby forming an acidic band. The acid band migrates to the cathode under the action of the electric field. In the migration process, the pH value of the soil is reduced, when the pH value of the soil is lower than the zero-electricity point of the soil, the Zeta potential of the soil is reduced, the electroosmotic flow is weakened, the effect of the current on the rapid movement of the rare earth ions is weakened, and the mining efficiency is reduced.

The reactions at the anode and cathode are as follows:

2H₂-4e→O₂↑+4H⁺E₀= 1.229(V) (anode)

4H₂O+4e→2H₂↑+4OH-E₀= 0.828(V) (cathode)

If the electroosmotic flow intensity is maintained by adopting the increased voltage, on one hand, the energy consumption and the cost are increased, on the other hand, the current density is increased, and H is generated at the anode⁺The speed is accelerated, so that an acid zone is formed again, electroosmotic flow is weakened, and vicious circle is caused.

In embodiments of the present application, anodes may be disposed within one or more injection wells; or an anode may be provided within each injection well.

The liquid injection well in which the anode needs to be arranged can be determined according to the distance between the liquid injection well and the liquid collection groove, the distance between the adjacent liquid injection wells, the voltage between the anode and the cathode and the like.

The main function of the leaching agent is to provide an electrolyte solution to carry out ion exchange with the rare earth so as to leach the rare earth.

In an embodiment of the present application, the leaching agent comprises a carbonate.

The leaching agent comprises carbonate, the carbonate and H generated by anode electrolysis⁺A dissolution reaction occurs; with neutralisation of electrolytically generated H at the anode⁺When H is present⁺The soil pH remains unchanged when the neutralization results in a decrease in concentration insufficient to dissolve carbonate minerals. Therefore, the carbonate in the leaching agent can adjust and stabilize the pH value of the anode area, maintain the electroosmotic flow velocity and ensure the continuous operation of the electrified exploitation. Carbonate and H⁺And cations are released after the reaction to replace the ionic rare earth in the rare earth ore, so that the rare earth mining efficiency is improved.

In addition, carbonates with H⁺Carbon dioxide is generated after the reaction, and acts on the ore body to enable the ore body to have small gaps, so that the ore body is prevented from blocking the flow of the leaching solution, the flow of rare earth ions and the leaching solution can be further accelerated, and the mining efficiency is improved.

The carbonate contained in the lixiviant can increase the flow rate of the lixiviant by 20-200%.

It should be noted that in the embodiments of the present application, the leaching agent includes carbonate, which means that the leaching agent may include only carbonate as an electrolyte, or may include other electrolytes besides carbonate.

As an example, the carbonate may be selected from at least one of calcium carbonate, sodium carbonate, potassium carbonate, iron carbonate, and magnesium carbonate.

Further, in the examples of the present application, the carbonate is a water-insoluble carbonate; for example, calcium carbonate, magnesium carbonate, and the like.

For the embodiment where the carbonate is water-soluble, the lower concentration of hydrogen ions in the solution will react with the carbonate, causing the system pH of the leachate to approach neutral.

For the embodiment that the carbonate is water-insoluble carbonate, hydrogen ions in the solution must be accumulated to a certain concentration before the carbonate can be dissolved and reacted; the pH value of the leaching solution system can be inhibited in a weak acidic range, and a proper acidic environment is favorable for dissolving rare earth ions and increasing the leaching efficiency.

In an embodiment of the application, the leaching agent comprises a carbonate-containing mineral or a carbonate-containing rock.

In other words, the leaching agent includes at least one of a mineral and a rock, and the mineral or rock includes carbonate. The mineral or rock is crushed and mixed with water to prepare suspension which is injected into the well injection liquid.

Illustratively, the minerals include at least one of aragonite, calcite, dolomite, magnesite, siderite; the rock comprises at least one of limestone, marble rock, dolomitic marble rock and marl rock;

in some embodiments, the mineral has a particle size of less than 75 μm; the rock has a particle size of less than 75 μm.

Illustratively, the minerals include at least one of aragonite, calcite, dolomite, limestone, and magnesite.

The mineral is cheap, the cost can be reduced, and the leaching of the rare earth ions cannot be influenced by the components in the mineral except calcium carbonate.

In the examples of the application, the mineral powder has a particle size of less than 75 μm, for example, the mineral is crushed through a 200 mesh screen, and the mineral powder having a particle size of less than 75 μm is able to move in the ore body.

It should be noted that in other embodiments of the present application, the leaching agent may also include commercially pure carbonates, etc. Alternatively, the leaching agent may be a water soluble carbonate solution, such as potassium carbonate, sodium carbonate, and the like.

In the examples of the present application, the mass of the carbonate is 0.5 to 5 times the total mass of the rare earth ore sample.

The dosage of the carbonate is 0.5 to 5 times of the total mass of the rare earth sample; for example, the amount may be 0.6 times, 1 time, 1.3 times, 1.8 times, 2.1 times, 2.5 times, 2.7 times, 3.3 times, 4.1 times, 4.4 times, or 5 times.

Illustratively, in some embodiments, the concentration of carbonate in the injection fluid may be in the range of 0.01 to 1mol/L, or in other embodiments of the present application, the concentration of carbonate in the injection fluid may be other than the above-mentioned values.

As mentioned above, in some embodiments of the present application, the leaching agent contains the remaining electrolyte in addition to carbonate.

Such as ammonium or magnesium salts.

Illustratively, the ammonium salt is selected from at least one of ammonium sulfate, ammonium chloride, ammonium acetate, and ammonium citrate.

As mentioned above, during the process of mining rare earth ore, a voltage is applied between the anode and the cathode, and in the embodiment of the application, the voltage gradient in the ore body is 0.01-0.2V/cm. When the voltage gradient in the ore body is 0.01-0.2V/cm, the rare earth ions can flow to the cathode. As a series of rows, the voltage gradient in the ore body may be 0.01V/cm, 0.02V/cm, 0.05V/cm, 0.1V/cm, 0.14V/cm, 0.18V/cm, or 0.2V/cm, and so forth.

It will be appreciated that in other embodiments of the present application, a voltage may be applied between the anode and cathode as is practical, with the voltage gradient in the ore body being in other ranges.

The application also provides a leaching agent for the electrified exploitation of the rare earth ore, wherein the leaching agent for the electrified exploitation of the rare earth ore comprises ammonium salt and carbonate;

Magnesium salts may include magnesium chloride, magnesium nitrate, magnesium carbonate, and the like.

In summary, the leaching agent for the electrified exploitation of the rare earth ore is suitable for the method for the electrified exploitation of the rare earth ore.

Under the action of electric current, water is electrolyzed to generate a large amount of H⁺Carbonates and H⁺The reaction reduces the acidity of the system and, in addition, carbonates with H⁺The reaction generates carbon dioxide which can improve the flow rate of the leaching solution for in-situ leaching and improve the leaching rate.

Illustratively, the carbonate is selected from at least one of calcium carbonate, sodium carbonate, potassium carbonate, iron carbonate, and magnesium carbonate.

In some embodiments of the present application, the carbonate is a water insoluble carbonate. The non-water soluble carbonate salt can make H in the leaching solution to be higher than water soluble carbonate salt⁺The concentration is higher, which is beneficial to the replacement of rare earth ions.

Further, in some embodiments of the present application, the leaching agent includes at least one of a mineral, a rock. Wherein the mineral or rock contains carbonate.

The leaching agent comprises mineral powder, the raw materials are easy to obtain, the cost of the leaching agent can be reduced, and the leaching of rare earth ions is hardly influenced by the rest components in the minerals.

The features and properties of the present application are described in further detail below with reference to examples.

Example 1

The embodiment provides a method for mining rare earth ore by simulating electrification in a laboratory, which comprises the following steps:

the method adopts a column device with the diameter and height of 6cm and 12cm to simulate the electric mining of the ion adsorption type rare earth ore. Firstly, 0.1kg of semi-weathered layer, 0.2kg of total weathered layer and 0.1kg of surface soil layer sample simulation weathered shell sample are sequentially added into a cylindrical pipe from bottom to top and are respectively compressed to 3cm, 6cm and 3 cm. Adding 80mL of calcium carbonate suspension with the molar concentration of 0.1mol/L and 80mL of ammonium sulfate solution with the molar concentration of 0.1mol/L into the simulated weathered shell sample, and continuously dropwise adding 0.4mL/min of deionized water after complete wetting. Graphite electrode plates are respectively applied to the upper part and the lower part of the cylindrical device, a 24V direct current power supply is introduced, the voltage gradient of the system is maintained at 2V/cm, the leaching solution is continuously received at the cathode, the volume of the collected liquid is recorded, and the concentration of rare earth in the collected liquid is measured.

The electroosmotic flow rate of the added calcium carbonate suspension is 1.1mL/min, the leaching amount of the rare earth is 200mg/kg in 3h, and the pH of the soil in the rare earth ore after electric mining is 6.37.

Comparative example 1

This comparative example 1 provides a method for mining rare earth ore by laboratory simulation of electrification, which is different from example 1 in that: 160mL of ammonium sulfate solution with a molar concentration of 0.1mol/L is added into the simulated weathering crust sample.

The electroosmosis flow rate is 0.44mL/min, the leaching amount of the rare earth in 8h is 120mg/kg, and the pH value of the soil in the rare earth ore after electric mining is 2.31.

From example 1 and comparative example 1, compared with the ammonium sulfate solution as the leaching agent in comparative example 1, the calcium carbonate suspension as the leaching agent in example 1 has the advantages that under the conditions of the same voltage gradient, injection rate, concentration and the like, the electroosmotic flow speed is increased by 150%, the rare earth collection amount is increased by 66%, and the soil pH after electric mining is close to neutral.

FIG. 1 shows the relationship between the volume of leachate and time in example 1 and comparative example 1, FIG. 2 shows the relationship between the leaching amount of Rare Earth and time in example 1 and comparative example 1, and in FIG. 2, REE is English letter (Rare Earth Element) of Rare Earth Element. As can be seen from fig. 1 and 2, the electroosmotic flow velocity of example 1 is significantly higher than that of comparative example 1; the leaching solution volume and the rare earth leaching amount of the comparative example 1 are also obviously higher than those of the comparative example 1.

Example 2

The embodiment provides a method for mining rare earth ore by electrifying, which is used for carrying out experiments in a Ministry district of Meizhou city, Guangdong province; the method for electrically exploiting the rare earth ore comprises the following steps:

(1) mine arrangement: drilling twenty liquid injection wells on a rare earth mine body, and arranging anodes in the liquid injection wells; two liquid collecting holes are formed under the mountain legs, and cathodes are arranged in the liquid collecting holes; and filter cloth can be attached to the periphery of the cathode liquid collecting pipe, a liquid collecting ditch is dug below the cathode liquid collecting hole, liquid collecting pools are arranged at two ends of the liquid collecting ditch, the positions of the liquid collecting pools are 3 meters below the liquid collecting ditch, the cathode liquid collecting hole is arranged above the liquid collecting ditch, and the liquid outlet end of the cathode liquid collecting pipe is communicated with the liquid collecting ditch.

(2) In-situ leaching: and (3) injecting the anode into a liquid injection pipe according to the mass ratio of liquid to solid of 1: 3, injecting calcite and ammonium sulfate mixed suspension with the molar concentration of 0.05 mol/L.

(3) Collecting mother liquor: and (3) taking the anode liquid injection pipe and the cathode liquid collection pipe as the anode and cathode, applying a 0.05V/cm potential difference, and electrifying direct current to accelerate the liquid to flow to the cathode liquid collection pipe, collecting water in the liquid collection ditch firstly, then collecting low-concentration mother liquor, finally collecting the mother liquor reaching the industrial standard, draining the water collected in the liquid collection ditch firstly, and then introducing the mother liquor into the liquid collection pool.

8.5 tons of mother liquor are collected in 15 days, and the leaching rate of the rare earth is 82.6 percent.

Comparative example 2

The comparative example provides a method for mining rare earth ore by electrifying, and experiments are carried out in the Ministry of Meizhou, Guangdong province; the process differs from example 2 in step (2); in this comparative example: (2) in-situ leaching: and (3) injecting the anode into a liquid injection pipe according to the mass ratio of liquid to solid of 1: 3, injecting ammonium sulfate solution with the molar concentration of 0.05 mol/L.

The yield of the mother liquor of the comparative example is 6.5 tons, and the leaching rate of the rare earth is 66.7 percent.

As can be seen from comparative example 2 and example 2, the method provided in example 2 improves the collection amount by 30.7% in the same time as that of comparative example 2, namely the electroosmotic flow rate is improved by 30.7%, and the leaching rate is improved by 15.9%.

Example 3

The embodiment provides a method for mining rare earth ore by electrifying, which is used for carrying out experiments in a Ministry district of Meizhou city, Guangdong province; the process differs from example 2 in steps (2) and (3); in this embodiment:

(2) in-situ leaching: and (3) injecting the anode into a liquid injection pipe according to the mass ratio of liquid to solid of 1: 3, injecting ammonium sulfate and sodium carbonate suspension with the molar concentration of 0.05 mol/L.

6.2 tons of mother liquor are collected in 15 days, and the rare earth leaching rate is 61.1 percent by using the method.

As can be seen from example 2 and example 3, the method provided in example 3 reduced the amount of collection by 4.61% over the same time period as in example 2, i.e. the electroosmotic flow rate was reduced by 4.61% and the leaching rate was reduced by 5.6%, indicating that the soluble carbonate was slightly less efficient than the insoluble carbonate.

Example 4

(2) in-situ leaching: and (3) injecting the anode into a liquid injection pipe according to the mass ratio of liquid to solid of 1: 2, magnesium sulfate and dolomite suspension with the molar concentration of 0.1mol/L is injected.

(3) Collecting mother liquor: and (3) taking the anode liquid injection pipe and the cathode liquid collection pipe as the anode and cathode, applying a 0.1V/cm potential difference, and electrifying direct current to accelerate the liquid to flow to the cathode liquid collection pipe, collecting water in the liquid collection ditch firstly, then collecting low-concentration mother liquor, finally collecting the mother liquor reaching the industrial standard, draining the water collected in the liquid collection ditch firstly, and then introducing the mother liquor into the liquid collection pool.

In the embodiment, 10.6 tons of mother liquor are collected in 15 days, and the leaching rate is 92.6 percent.

Comparative example 3

The comparative example provides a method for mining rare earth ore by electrifying, and experiments are carried out in the Ministry of Meizhou, Guangdong province; the process differs from example 4 in step (2); in this comparative example: (2) in-situ leaching: and (3) injecting the anode into a liquid injection pipe according to the mass ratio of liquid to solid of 1: 2, magnesium sulfate solution with the molar concentration of 0.1mol/L is injected.

The collection amount of the mother liquor is 7.2 tons, and the leaching rate of the rare earth is 71.2 percent.

As can be seen from comparative example 3 and example 4, the method provided in example 4 improves the collection amount by 47.2%, i.e., the electroosmotic flow rate by 47.2% and the leaching rate by 21.4% in the same time as that of comparative example 3.

Example 5

(2) in-situ leaching: and (3) injecting the anode into a liquid injection pipe according to the mass ratio of liquid to solid of 1: 1 injecting ammonium citrate and magnesite suspension with the molar concentration of 0.15 mol/L.

(3) Collecting mother liquor: and (3) taking the anode liquid injection pipe and the cathode liquid collection pipe as the anode and cathode, applying a 0.15V/cm potential difference, and electrifying direct current to accelerate the liquid to flow to the cathode liquid collection pipe, collecting water in the liquid collection ditch firstly, then collecting low-concentration mother liquor, finally collecting the mother liquor reaching the industrial standard, draining the water collected in the liquid collection ditch firstly, and then introducing the mother liquor into the liquid collection pool.

15.9 tons of mother liquor are collected in 15 days, and the rare earth leaching rate is 98.6 percent by using the method.

Comparative example 4

The comparative example provides a method for mining rare earth ore by electrifying, and experiments are carried out in the Ministry of Meizhou, Guangdong province; the process differs from example 5 in step (2); in this comparative example: (2) in-situ leaching: and (3) injecting the anode into a liquid injection pipe according to the mass ratio of liquid to solid of 1: 1, injecting ammonium citrate solution with the molar concentration of 0.15 mol/L.

The collection amount of the mother liquor is 8.4 tons, and the leaching rate of the rare earth is 77.8 percent.

As can be seen from comparative example 4 and example 5, the method provided in example 5 improves the collection amount by 89.3%, i.e., the electroosmotic flow rate by 89.3% and the leaching rate by 20.8% in the same time as that of comparative example 4.

In conclusion, in the method provided by the embodiment of the application, the leaching agent comprises sodium carbonate, so that the electroosmosis flow speed, the leaching liquid volume and the rare earth leaching amount can be obviously improved; the leaching efficiency can be improved.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method of electrically mining rare earth ore, comprising:

adding a leaching agent into the well injection liquid, and applying a voltage to the anode and the cathode;

wherein the leaching agent comprises a carbonate.

2. The method of electrowinning a rare earth ore according to claim 1 wherein the carbonate is selected from at least one of calcium carbonate, sodium carbonate, potassium carbonate, iron carbonate and magnesium carbonate;

optionally, the carbonate is calcium carbonate.

3. The method of electrowinning of rare earth ore according to claim 1,

the carbonate is water-insoluble carbonate;

4. A method for electrowinning of rare earth ore according to any of claims 1 to 3, characterised in that the mass of the carbonate is 0.5 to 5 times the total mass of the rare earth ore sample;

optionally, the mass of the carbonate is 1-2 times the total mass of the rare earth sample.

5. A method of electrowinning rare earth ores as claimed in any one of claims 1 to 3, wherein a voltage is applied across the anode and the cathode such that the voltage gradient in the ore body is in the range of 0.01 to 0.2V/cm.

6. The method for electrowinning of rare earth ore according to any one of claims 1 to 3, wherein the leaching agent further comprises an ammonium or magnesium salt.

7. The method of electrowinning of rare earth ore according to claim 6,

the ammonium salt is selected from at least one of ammonium sulfate, ammonium chloride, ammonium acetate, and ammonium citrate.

8. The leaching agent for the electrified exploitation of the rare earth ore is characterized by comprising ammonium salt and carbonate;

9. The leaching agent for electrowinning of rare earth ores as claimed in claim 8, wherein the carbonate is selected from at least one of calcium carbonate, sodium carbonate, potassium carbonate, iron carbonate and magnesium carbonate;

optionally, the carbonate is calcium carbonate.

10. The leaching agent for electrowinning of rare earth ores as claimed in claim 8, wherein the leaching agent comprises a carbonate-containing mineral or a carbonate-containing rock;