Method for enriching germanium ions from lignite based on plasma modification

Abstract

The invention relates to a method for enriching germanium ions from lignite based on plasma modification, belongs to the technical field of extraction of germanium from lignite, and solves at least one of the following problems in a method for extracting germanium from lignite in the prior art: (1) the process is complicated; (2) the strong acid consumption is large, and the yield of a high-salt waste acid solution is large; and (3) the method is environment-friendly. The method comprises the following steps: carrying out plasma modification treatment on lignite by adopting plasma; the modified lignite is mixed with a weak acid aqueous solution for leaching, and leaching liquid containing germanium ions is obtained; a leaching agent and a surfactant are introduced into a closed inner cavity of a column body from the lower part of the column body, then gas is introduced into the leaching agent in the column body from the lower part of the column body, and the pressure in the column body is adjusted, so that air bubbles are broken and bubbles containing germanium ions float in the floating process of the bubbles formed by the surfactant, and the supernormal foam enrichment of the germanium ions is realized. The method is simple, generation of a large amount of harmful gas, waste liquid and waste residues is avoided, and the germanium ion enrichment ratio is high.

Description

Technical Field

[0001] The invention relates to the technical field of germanium extraction from lignite, and in particular to a method for enriching germanium ions from lignite based on plasma modification. Background Art

[0002] Germanium is an important key metal, known as the "food of the semiconductor industry", and is widely used in infrared optics, nuclear physics detection and other fields.

[0003] At present, the mature technology of extracting germanium from lignite is based on the combustion of lignite, that is, the germanium is transferred to the fly ash through the combustion of coal under specific conditions, and then the fly ash is dissolved with high-concentration hydrochloric acid to obtain a germanium-containing solution, which is further extracted by chlorination distillation. However, the extraction of germanium from lignite based on combustion faces the problems of large CO2 emissions, low thermal efficiency of coal, high co-solubility and poor selectivity of impurity elements in the acid leaching process, and complex elemental composition of the germanium-containing solution; and the distillation extraction consumes a lot of energy, produces a large amount of waste acid, and requires a large amount of lime to neutralize it. The waste liquid is difficult to recover and is accompanied by a large amount of waste residue; and the process of extracting germanium by chlorination distillation includes distillation, rectification, hydrolysis and other steps, and the process is complicated. Summary of the invention

[0004] In view of the above analysis, the embodiments of the present invention are intended to provide a method for enriching germanium ions from lignite based on plasma modification, so as to solve at least one of the following problems existing in the existing lignite germanium extraction method: (1) the process is complicated; (2) the consumption of a large amount of strong acid and the output of high-salt waste acid solution are large; (3) it is not environmentally friendly.

[0005] The present invention provides a method for enriching germanium ions from lignite based on plasma modification, the method comprising:

[0006] Step 1: Plasma modification treatment of lignite by plasma;

[0007] Step 2: mixing the plasma-modified lignite with a weak acid aqueous solution for leaching to obtain a leaching solution containing germanium ions;

[0008] Step 3: The leachate and surfactant are introduced into the closed inner cavity of the column from the lower part of the column, and then gas is introduced into the leachate in the column from the lower part of the column, and the pressure in the column is adjusted so that the air bubbles formed by the surfactant are burst during the floating process, and the bubbles containing germanium ions float up, thereby achieving extraordinary foam enrichment of germanium ions.

[0009] Preferably, the atmosphere of the plasma modification treatment is at least one of N2 and air.

[0010] Preferably, the atmosphere of the plasma modification treatment is N2.

[0011] Preferably, the power of the plasma modification treatment is 50-80W.

[0012] Preferably, the plasma modification treatment time is 1-3 hours.

[0013] Preferably, the gas flow rate of the plasma modification treatment is 0.5-1 L / min.

[0014] Preferably, the plasma modification treatment is performed in a plasma reaction chamber in a vacuum environment.

[0015] Preferably, the weak acid is at least one of acetic acid, tartaric acid, citric acid and salicylic acid.

[0016] Preferably, the liquid-to-solid volume ratio of the weak acid aqueous solution to the lignite is 3-5:1.

[0017] Preferably, the leaching time is 1-2 hours.

[0018] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0019] 1. The present invention adopts a method of plasma modification treatment + ultra-long foam enrichment. Before the lignite is subjected to weak acid water leaching treatment, the lignite is first modified by plasma to allow the lignite to undergo selective depolymerization and grafting reaction. Specifically, the plasma can bombard the double bonds, aromatic carbon-carbon bonds and saturated structures such as phenolic hydroxyl groups on the surface of the lignite to reduce the aromaticity of the lignite, convert the insoluble germanium-containing structures in the lignite into soluble germanium-containing elements, separate the soluble components from the insoluble components, and thus achieve selective depolymerization; in addition, during the plasma treatment process, the gas is ionized to form plasma, and particles such as electrons, ions and neutral atoms in the plasma break the chemical bonds on the surface of the lignite, and induce a plasma grafting reaction, introducing nitrogen-containing groups (such as -NH2, -NHOH, -CONH2, -NH4, etc.) into the lignite to replace the previous germanium-containing sites, and the germanium is deconstructed and separated, thereby improving the germanium ion leaching rate. In addition, the present invention introduces lignite leachate and surfactant into the closed inner cavity of the column. Since the surface tension of air bubbles is greater than that of bubbles containing metal ions, the air bubbles will be selectively broken under the pressure environment to enrich the bubbles containing germanium ions. Therefore, the present invention adjusts the pressure in the column to make the air bubbles break during the floating process of the bubbles, and the bubbles containing germanium ions float up, thereby achieving extraordinary foam enrichment of germanium ions.

[0020] 2. The method of the present invention does not have the steps of combustion and distillation, does not generate a large amount of CO2 harmful gas, and also avoids the generation of a large amount of waste acid, waste liquid, and waste residue; the acid leaching of the present invention adopts weak acid, and the leachate composition is simple (only includes germanium, sulfur, silicon, magnesium, calcium, organic matter, etc.); and the enrichment method of the present invention for germanium ions is simple, the germanium ion enrichment ratio is high, and germanium concentrate can be further obtained after foam enrichment (in the existing chlorination distillation extraction of germanium, the crude product germanium tetrachloride obtained by chlorination distillation).

[0021] 3. In the method of the present invention, the rupture of air bubbles allows the surfactant to return to the feed liquid system for recycling, thereby achieving efficient enrichment at a low dosage of reagents.

[0022] 4. The method of the present invention couples the bubble theory of the flotation process and the distillation principle of the chemical process, which not only achieves the extraordinary enrichment of germanium ions, but also realizes the recycling of surfactants.

[0023] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0025] Figure 1 A flow chart of a method for enriching germanium ions from lignite based on plasma modification;

[0026] Figure 2 This is a schematic diagram of the structure of the extraordinary foam enrichment device used in the method of the present invention.

[0027] Reference numerals:

[0028] 1-column; 2-feed port; 3-air inlet; 4-pressure regulating valve; 5-solution outlet; 6-foam outlet; 7-probe; 8-computer terminal; 9-high-speed camera; 10-agitator; 11-surfactant inlet; 12-pump; 13-housing; 14-piston; 15-first spring; 16-steel ball; 17-upper cover; 18-second spring; 19-fixed block; 20-air release channel. DETAILED DESCRIPTION

[0029] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0030] The present invention provides a method for enriching germanium ions from lignite based on plasma modification, such as Figure 1 As shown, the method includes:

[0031] Step 1: Plasma modification treatment of lignite by plasma;

[0032] Step 2: mixing the plasma-modified lignite with a weak acid aqueous solution for leaching to obtain a leaching solution containing germanium ions;

[0033] Step 3: The leachate and surfactant are introduced into the closed inner cavity of the column from the lower part of the column, and then gas is introduced into the leachate in the column from the lower part of the column, and the pressure in the column is adjusted so that the air bubbles formed by the surfactant are burst during the floating process, and the bubbles containing germanium ions float up, thereby achieving extraordinary foam enrichment of germanium ions.

[0034] Compared with the prior art, the present invention, on the one hand, uses plasma to modify the lignite before leaching the lignite, so that the lignite undergoes selective depolymerization and grafting reaction, thereby improving the leaching rate of germanium ions. On the other hand, the present invention introduces the lignite leaching solution and the surfactant into the closed inner cavity of the column. Since the surface tension of air bubbles is greater than that of bubbles containing metal ions, the air bubbles will be selectively broken under the pressure environment, thereby enriching the bubbles containing germanium ions. Therefore, the present invention adjusts the pressure in the column to break the air bubbles during the floating process of the bubbles, so that the bubbles containing germanium ions float up, thereby achieving extraordinary foam enrichment of germanium ions.

[0035] Exemplarily, the atmosphere of the plasma modification treatment is at least one of N2 and air.

[0036] Further preferably, the atmosphere of the plasma modification treatment is N2. N2 is more conducive to introducing nitrogen-containing groups into the lignite, deconstructing germanium, and thus improving the leaching rate of germanium.

[0037] Exemplarily, the power of the plasma modification treatment is 50-80W.

[0038] Exemplarily, the plasma modification treatment time is 1-3 hours.

[0039] Exemplarily, the gas flow rate of the plasma modification treatment is 0.5-1 L / min.

[0040] Exemplarily, the plasma modification process is performed in a plasma reaction chamber in a vacuum environment.

[0041] Exemplarily, the weak acid is at least one of acetic acid, tartaric acid, citric acid and salicylic acid.

[0042] Illustratively, in the weak acid aqueous solution, the volume ratio of weak acid to water is 1:9-12.

[0043] Exemplarily, the liquid-to-solid volume ratio of the weak acid aqueous solution to the lignite is 3-5:1.

[0044] Exemplarily, the leaching time is 1-2h.

[0045] It should be noted that the plasma modification treatment is performed in a plasma reaction chamber in a vacuum environment.

[0046] Exemplarily, the height of the leachate in the column does not exceed 2 / 3 of the height of the column.

[0047] Exemplarily, the method further includes: observing the size, morphology and number of bubbles by an online image and particle size analysis device.

[0048] Exemplarily, the viscosity of the leachate is 0.9-1.2 cSt.

[0049] Exemplarily, the surfactant is pyrogallol.

[0050] Exemplarily, in the mixture of the leachate and the surfactant, the mass concentration of the surfactant is 0.02-0.04%. If the mass concentration of the surfactant is too high, the surfactant will capture other impurity ions and rise with the bubbles, thereby reducing the selectivity of the foam product. If the mass concentration of the surfactant is too low, the capture of germanium ions will be incomplete, thereby reducing the recovery rate and the enrichment ratio.

[0051] Exemplarily, the flow rate of the mixture of the leachate and the surfactant is 80-100 mL / min. Too high a flow rate may damage the motor, and too low a flow rate may cause unnecessary waste of time.

[0052] Illustratively, during the enrichment process, the solution in the column is stirred.

[0053] Exemplarily, the stirring rate is 140-170 rpm. A stirring rate that is too high will cause turbulence and instability of the liquid in the reaction chamber, and may also shear the bubbles, causing them to burst. A stirring rate that is too low will cause uneven liquid and incomplete reaction of the surfactant and germanium ions.

[0054] For example, the gas flow rate of the gas introduced from the lower part of the column into the metal ion solution in the column is 0.3-0.4m 3 / h, too large aeration flow rate will result in large and unstable bubbles, while too small aeration flow rate will result in too few bubbles, low efficiency in capturing germanium ions, and low recovery rate of foam products.

[0055] Exemplarily, the gas introduced from the lower part of the column into the metal ion solution in the column is air.

[0056] Exemplarily, the pressure in the column is adjusted to 0.2-0.3 MPa. If the pressure is too low, it is difficult to rupture air bubbles and the surfactant cannot be recycled. If the pressure is too high, the bubbles in the column will rupture indiscriminately, making it difficult to enrich the foam product at the top of the column, and the product recovery rate and enrichment ratio will be reduced.

[0057] Exemplarily, the method for enriching germanium ions from lignite leachate of the present invention uses an extraordinary foam enrichment device, such as Figure 2 As shown, the extraordinary foam enrichment device comprises a column 1 with a sealed inner cavity, a feed inlet 2 and an air inlet 3 arranged at the lower part of the column 1, and a pressure regulating valve 4 arranged at the upper part of the column 2;

[0058] A solution outlet 5 is disposed at the lower portion of the column, and a foam outlet 6 is disposed at the upper portion of the column.

[0059] During implementation, the leachate and surfactant are introduced into the column 1 through the feed port 2; gas is introduced into the liquid in the column through the gas inlet 3 to generate bubbles in the liquid; the pressure in the column 1 is adjusted by the pressure regulating valve 4 so that during the floating process of the bubbles, the air bubbles (bubbles not containing the target metal) burst and the bubbles containing the target metal float up, thereby achieving extraordinary foam enrichment of germanium ions.

[0060] Compared with the prior art, the column of the device of the present invention is closed, and a pressure regulating valve is arranged on the upper part of the column. Since the surface tension of air bubbles is greater than that of bubbles containing metal ions, air bubbles will be selectively broken under pressure environment to enrich germanium ion bubbles. Therefore, by adjusting the pressure in the column through the pressure regulating valve, the air bubbles can be broken during the floating process of the bubbles, and the bubbles containing germanium ions can float up, thereby achieving extraordinary foam enrichment of germanium ions and improving the enrichment ratio of germanium ions.

[0061] Exemplarily, a surfactant inlet 11 is provided on the feed port 2 for introducing a surfactant. The surfactant can selectively capture germanium ions to form bubbles that rise together.

[0062] Exemplarily, the feed inlet 2 is located above the air inlet 3, which is conducive to the formation of bubbles in the feed liquid.

[0063] Exemplarily, the feed port 2 is located at 1 / 4-1 / 5 of the column height above the column bottom.

[0064] Exemplarily, the air inlet 3 is located at 1 / 6-1 / 7 of the column height above the column bottom and is on the same vertical line as the feed inlet 2 .

[0065] Exemplarily, the feed port 2 and the air inlet 3 are respectively connected to a pump 12 for providing power for the feed and the air.

[0066] Exemplarily, a solution outlet 5 is provided at the lower portion of the column 1 for discharging the solution after froth flotation.

[0067] Specifically, the solution outlet 5 is located above the column bottom at 1 / 8-1 / 9 of the column height, and is arranged on the column wall opposite to the feed port 2 .

[0068] Exemplarily, a foam outlet 6 is provided at the upper portion of the column 1. Bubbles containing germanium ions float to the bubble layer and are discharged from the foam outlet 6.

[0069] Exemplarily, the height of the leachate in the column 1 is 5-10 cm below the discharge port 6 .

[0070] Specifically, the foam outlet 6 is located below the top of the column at 1 / 3-1 / 4 of the column height and on the same vertical line as the solution outlet 5 .

[0071] Exemplarily, the pressure regulating valve 4 is located at 1 / 5-1 / 6 of the column height below the column top. If the position is too low, the slurry may gush out during the pressure regulation process.

[0072] Exemplarily, the pressure regulating valve 4 is located higher than the foam outlet 6 to prevent the slurry from gushing out.

[0073] Exemplarily, the height difference between the pressure regulating valve 4 and the foam outlet 6 is 20-30 cm. This is because during the pressure relief process, rising bubbles in the liquid will cause the liquid level to rise briefly. The height difference is set to 20-30 cm to prevent the liquid from gushing out.

[0074] Exemplarily, the extraordinary foam enrichment device further includes an online image and particle size analysis device, which includes a probe 7 and a computer terminal 8, wherein the probe 7 is connected to the computer terminal 8, and the probe 7 extends from the foam outlet 6 into the foam layer in the column 1. The online image and particle size analysis device is used to observe the size, morphology and number of bubbles in the liquid system to adjust the optimal inflation flow rate of the air pump and the optimal stirring rate of the stirrer.

[0075] Exemplarily, the column 1 is made of transparent material.

[0076] Exemplarily, the column 1 is made of transparent glass.

[0077] Exemplarily, scale lines are provided on the column 1, and the volume of the feed liquid can be known through the scale lines.

[0078] Exemplarily, the extraordinary foam enrichment device further includes a high-speed camera 9, which is arranged outside the column 1. The high-speed camera 9 can quickly capture the moment of bubble bursting. Due to the different surface tensions of air bubbles and metal-containing bubbles, there are differences in bubble bursting under high-pressure environment. The high-speed camera 9 is used to record "bubbles carrying target metal ions continue to rise and enrich to the foam layer, and bubbles without target metal ions burst".

[0079] In order to avoid system failure caused by excessive pressure in the column, a safety valve assembly is provided at the upper end of the column 1. The safety valve assembly can relieve pressure when the pressure in the chamber of the column 1 is abnormal, thereby fine-tuning the pressure in the column cavity and reducing system failure. Under normal circumstances, the safety valve assembly does not work.

[0080] Specifically, the safety valve assembly includes a housing 13, an upper cover 17 and a piston 14. The housing 13 is connected to the cylinder 1 through a lower opening. The upper cover 17 is located at the upper end opening of the housing 13. The piston 14 is located in a cavity formed by the upper cover 17 and the housing 13. The piston 14 extends in the cavity in an up-down direction. The lower end of the piston 14 abuts against the lower opening of the housing 13. A first spring 15 is arranged on the periphery of the piston 14. The upper end of the first spring 15 is connected to the upper cover 17. The lower end of the first spring 15 is connected to the lower part of the piston 14.

[0081] The housing 13 is provided with a transverse channel, in which a steel ball 16, a second spring 18 and a fixing block 19 are sequentially arranged in a direction away from the piston, one end of the second spring 18 is connected to the steel ball 16, and the other end is connected to the fixing block 19;

[0082] The housing 13 is also provided with an air leakage channel 20 , one end of which is connected to the transverse channel, and the other end of which is connected to the outside of the housing 13 . The connection point between the air leakage channel 20 and the transverse channel is located between the steel ball 16 and the fixing block 19 .

[0083] When the pressure in the column 1 exceeds the safety range, the piston is pushed upward, and the gas enters the cavity formed by the shell 13 and the upper cover 17, further pushing the steel ball 16 to compress the second spring 18. As the steel ball 16 compresses the second spring 18, the air leakage channel 20 is exposed, and the gas is discharged along the air leakage channel 20, completing the pressure relief in sequence. Under normal working conditions, the steel ball 16 blocks the cavity in the valve, stabilizes the pressure, and realizes dust and water resistance.

[0084] Exemplarily, the upper cover 17 is threadedly connected to the housing 13. By rotating the upper cover 17, the pressure of the piston 14 on the lower opening of the housing 13 can be increased or decreased, thereby adjusting the threshold of the safety pressure.

[0085] Exemplarily, a stirrer 10 is disposed at the bottom of the inner cavity of the column 1. The stirrer 10 is conducive to the mixing of metal ions and bubbles in the feed liquid, so that the bubbles can more easily capture the target metal ions.

[0086] The following is a further explanation of the method for enriching germanium ions from lignite based on plasma modification by using a specific embodiment. The methods of the following embodiments all use an extraordinary foam enrichment device, which includes a column 1 with a closed inner cavity, a feed port 2 and an air inlet 3 arranged at the lower part of the column 1, and a pressure regulating valve 4 arranged at the upper part of the column 2. A surfactant inlet 11 is arranged on the feed port 2, and the feed port 2 is located above the air inlet 3, and the position of the feed port 2 is located at 1 / 4 of the column height above the column bottom. The position of the air inlet 3 is located at 1 / 6 of the column height above the column bottom, and is in the same vertical line as the feed port. A pump 12 is connected to the feed port 2 and the air inlet 3, respectively. A solution outlet 5 is arranged at the lower part of the column 1, and the position of the solution outlet 5 is located at 1 / 8 of the column height above the column bottom, opposite to the feed port. A foam outlet 6 is arranged at the upper part of the column 1. The foam outlet 6 is located at 1 / 3 of the column height below the column top, and is in the same vertical line as the solution outlet. The position of the pressure regulating valve 4 is higher than the foam outlet 6, and the height difference between the pressure regulating valve 4 and the foam outlet 6 is 25 cm. The extraordinary foam enrichment device also includes an online image and particle size analysis device, which includes a probe 7 and a computer terminal 8. The probe 7 is connected to the computer terminal 8, and the probe 7 extends from the foam outlet 6 into the foam layer in the column 1. The column 1 is made of transparent glass. The extraordinary foam enrichment device also includes a high-speed camera 9, which is arranged outside the column 1. A safety valve assembly is provided at the upper end of the column 1, and the safety valve assembly includes a shell 13, an upper cover 17 and a piston 14. The shell 13 is connected to the column 1 through a lower opening, the upper cover 17 is located at the upper end opening of the shell 13, and the piston 14 is located in a cavity formed by the upper cover 17 and the shell 13. The piston 14 extends in the cavity along the up-down direction, and the lower end of the piston 14 abuts against the lower opening of the shell 13. A first spring 15 is provided on the periphery of the piston 14, and the upper end of the first spring 15 is connected to the upper cover 17. The first spring The lower end of 15 is connected to the lower part of the piston 14; the shell 13 is provided with a transverse channel, and the steel ball 16, the second spring 18 and the fixed block 19 are arranged in sequence in the transverse channel in the direction away from the piston, one end of the second spring 18 is connected to the steel ball 16, and the other end is connected to the fixed block 19; the shell 13 is also provided with a degassing channel 20, one end of the degassing channel 20 is connected to the transverse channel, and the other end is connected to the outside of the shell 13, and the connection point of the degassing channel 20 and the transverse channel is located between the steel ball 16 and the fixed block 19. When the pressure in the column 1 exceeds the safety range, the piston is pushed upward, and the gas enters the cavity formed by the shell 13 and the upper cover 17, further pushing the steel ball 16 to compress the second spring 18. As the steel ball 16 compresses the second spring 18, the degassing channel 20 is exposed, and the gas is discharged along the degassing channel 20, completing the pressure relief in sequence. Under normal working conditions, the steel ball 16 blocks the cavity in the valve, stabilizes the pressure and realizes dust and water resistance.The upper cover 17 is threadedly connected to the outer shell 13. By rotating the upper cover 17, the pressure of the piston 14 on the lower opening of the outer shell 13 can be increased or decreased, thereby adjusting the threshold of the safety pressure. A stirrer 10 is arranged at the bottom of the inner cavity of the column 1.

[0087] Example 1

[0088] This embodiment provides a method for enriching germanium ions from lignite based on plasma modification, comprising:

[0089] Step 1: Place the lignite in a plasma reaction chamber, generate plasma in a vacuum environment to modify the lignite surface, and the reaction parameters are: treatment atmosphere N2, treatment power 60W, treatment time 2h, gas flow rate 0.8L / min;

[0090] Step 2: The modified lignite was mixed with an acetic acid aqueous solution (the volume ratio of acetic acid to water was 1:10), and the lignite was leached for 1 hour at 25°C and a liquid-solid ratio of 3:1 to obtain a modified residual coal and a leachate containing germanium ions, which contained germanium ions (0.266 g / L), sulfur (13.52 g / L), silicon, magnesium, calcium, organic matter, etc. The leaching rate of germanium was 83.81%.

[0091] Step 3: introducing a mixture of the extract and a surfactant at a flow rate of 90 mL / min into the column through the feed port, wherein the concentration of the surfactant in the mixture is 0.03 wt.%, the surfactant is pyrogallol, and the stirring rate of the stirrer is 150 rpm;

[0092] Air is introduced into the liquid in the column through the air inlet to generate bubbles in the liquid. The air flow rate is 0.4m 3 / h;

[0093] The pressure in the column is adjusted by a pressure regulating valve, and the chamber pressure is 0.2MPa. During the process of bubble floating, the air bubbles burst, and the bubbles containing germanium ions float up. The bursting of the air bubbles allows the surfactant to return to the liquid system for recycling, thereby achieving extraordinary foam enrichment of germanium ions. The bubble size under the inflation flow rate is recorded using an online image and particle size analysis device, and the equilibrium state of bubble floating and bursting is observed by a high-speed camera. After the process is stable, the concentrations of germanium ion solution and germanium ion foam at the bottom and top outlets are measured, and the average value is taken after multiple records. The germanium ion enrichment ratio is calculated to be 241. The leaching rate of germanium in the lignite leaching process is 84%.

[0094] Example 2

[0095] This embodiment provides a method for enriching germanium ions from lignite based on plasma modification similar to that of Embodiment 1, except that the atmosphere during the plasma modification process is air.

[0096] The leaching rate of germanium in lignite is 76%.

[0097] Example 3

[0098] This embodiment provides a method for enriching germanium ions from lignite based on plasma modification similar to that of Embodiment 1, except that the power of the plasma modification treatment is 45W.

[0099] The leaching rate of germanium in lignite is 72%.

[0100] Example 4

[0101] This embodiment provides a method for enriching germanium ions from lignite based on plasma modification similar to that of Embodiment 1, except that the gas flow rate of the plasma modification treatment is 0.4 L / min.

[0102] The leaching rate of germanium in lignite is 73%.

[0103] Example 5

[0104] This example provides a method for enriching germanium ions from lignite based on plasma modification similar to Example 1, except that the flow rate of the mixture of the leachate and the surfactant is 60 mL / min.

[0105] The germanium ion enrichment ratio is 198.

[0106] Example 6

[0107] This example provides a method for enriching germanium ions from lignite based on plasma modification similar to that of Example 1, except that the stirring speed of the stirrer is 100 rpm.

[0108] The germanium ion enrichment ratio is 201.

[0109] Example 7

[0110] This embodiment provides a method for enriching germanium ions from lignite based on plasma modification similar to that of Embodiment 1, except that the gas flow rate is 0.2 m 3 / h.

[0111] The germanium ion enrichment ratio is 194.

[0112] Example 8

[0113] This embodiment provides a method for enriching germanium ions from lignite based on plasma modification similar to that of Embodiment 1, except that the pressure in the column is 0.1 MPa.

[0114] The germanium ion enrichment ratio is 182.

[0115] Example 9

[0116] This example provides a method for enriching germanium ions from lignite based on plasma modification similar to Example 1, except that the concentration of the surfactant in the mixture is 0.01 wt.%.

[0117] The germanium ion enrichment ratio is 186.

[0118] Comparative Example 1

[0119] This comparative example provides a method for enriching germanium ions from lignite similar to Example 1, except that the lignite is not subjected to plasma modification, but is directly subjected to weak acid aqueous solution leaching.

[0120] The leaching rate of germanium in lignite is 6%.

[0121] Comparative Example 2

[0122] The existing combustion + high-concentration hydrochloric acid dissolution is used to treat the lignite to obtain a leaching solution.

[0123] The leaching rate of germanium in lignite is 50%.

[0124] Comparative Example 3

[0125] This comparative example uses a conventional foam enrichment method to enrich germanium ions from the leachate of Example 1, that is, the upper end of the column is open, there is no pressure regulating valve and safety valve assembly, and metal ion enrichment is carried out under normal pressure. All rising bubbles enter the bubble layer and are directly discharged from the discharge port. Other conditions are the same as in Example 1.

[0126] The enrichment ratio of Comparative Example 3 is 62.

[0127] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for enriching germanium ions from lignite based on plasma modification, characterized in that: The method comprises: Step 1: Plasma modification treatment of lignite by plasma; Step 2: mixing the plasma-modified lignite with a weak acid aqueous solution for leaching to obtain a leaching solution containing germanium ions; Step 3: The leachate and surfactant are introduced into the closed inner cavity of the column from the lower part of the column, and then gas is introduced into the leachate in the column from the lower part of the column, and the pressure in the column is adjusted so that the air bubbles formed by the surfactant are burst during the floating process, and the bubbles containing germanium ions float up, thereby achieving extraordinary foam enrichment of germanium ions.

2. The method according to claim 1, characterized in that The atmosphere of the plasma modification treatment is at least one of N2 and air.

3. The method according to claim 2, characterized in that The atmosphere of the plasma modification treatment is N2.

4. The method according to claim 1, characterized in that: The power of the plasma modification treatment is 50-80W.

5. The method according to claim 1, characterized in that The plasma modification treatment time is 1-3 hours.

6. The method according to claim 1, characterized in that The gas flow rate of the plasma modification treatment is 0.5-1 L / min.

7. The method according to claim 1, characterized in that The plasma modification process is performed in a plasma reaction chamber in a vacuum environment.

8. The method according to claim 1, characterized in that The weak acid is at least one of acetic acid, tartaric acid, citric acid and salicylic acid.

9. The method according to claim 1, characterized in that: The liquid-to-solid volume ratio of the weak acid aqueous solution to the lignite is 3-5:

1.

10. The method according to claim 1, characterized in that The leaching time is 1-2h.

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