Method for efficiently removing thallium from thallium sulfate-containing acid solution

Abstract

The invention belongs to the technical field of sewage and waste treatment, and discloses a method for efficiently removing thallium from an acid solution containing thallium sulfate. The method comprises the following steps: adding a coordination agent and a complex salt into water to prepare a precursor solution, adding the precursor solution into an acidic solution containing thallium sulfate, stirring, and then adding metal reducing powder to react for a period of time to obtain precipitate particles, namely thallium alloy; the complex salt is any one or more than two of complexes containing lead, bismuth and tin. According to the method, introduced lead, bismuth and tin metal ions are subjected to coordination transformation, so that sulfate precipitates are not immediately generated after the metal ions enter a solution containing sulfate radicals, and slow-release dissociation reaction and reduction eutectoid reaction are generated, so that the effective utilization rate of the introduced ions is increased, and the reagent consumption is greatly reduced. And through cooperation of the precursor solution and the metal reduction powder, the precipitation effect of thallium in the acid waste liquid is enhanced, deep thallium removal is achieved, and the thallium removal rate is greatly increased.

Description

Technical Field

[0001] The invention belongs to the technical field of waste treatment, relates to the extraction of nonferrous metals, and specifically relates to a method for efficiently removing thallium from an acidic solution containing thallium sulfate. Background Art

[0002] Thallium is a highly toxic element, which is more toxic than cadmium, mercury, lead and other highly toxic heavy metals. It also has strong bioaccumulation, posing a great threat to the human body and the ecological environment. Thallium is present in very low concentrations in the natural environment and is a rare dispersed element. A certain amount of thallium is often associated with zinc, iron, copper and lithium concentrates, and it is difficult to remove during the smelting process. It eventually enters wastewater or waste residues for terminal treatment.

[0003] At present, the main methods for removing thallium from acidic wastewater are precipitation, adsorption and replacement. The precipitation method can be divided into oxidation precipitation and sulfidation precipitation. The principle is to use the extremely low solubility product of Tl(OH)3 and Tl2S, add an oxidant or a sulfiding agent to the solution, and remove thallium by precipitation. The adsorption method uses the porous and high specific surface characteristics of the adsorbent to adsorb thallium into the adsorbent, thereby removing thallium. The precipitation method and the adsorption method are widely used in the removal of thallium from wastewater, and the thallium removal effect is good, but due to the limitations of the precipitation process, the precipitation method and the adsorption method are difficult to carry out in acidic solutions. The replacement method uses active metals such as zinc to replace thallium and remove thallium from the solution, and it will not affect the solution. However, due to the high overpotential of thallium precipitation, the thallium removal effect of single zinc powder is poor and the dosage is large. Therefore, some researchers add auxiliary thallium removal agents to zinc powder to improve the thallium removal effect of zinc powder, and lead salt is a good auxiliary agent.

[0004] Patent CN109957668A discloses a process for purifying a hydrometallurgical zinc solution and removing thallium, preparing a lead acetate solution with a concentration of 200-800g / L; adding the lead acetate solution prepared in step A to a solution purification tank to remove thallium; performing liquid-solid separation after the thallium removal reaction, and thallium enters the slag. In the prior art, lead acetate is directly added to the purification tank, and auxiliary zinc powder is added to remove thallium. Due to the presence of a large amount of sulfate in the solution, the lead acetate is quickly converted into lead sulfate precipitation after dissolution and lost, which reduces the utilization rate of the raw materials and increases the cost. Summary of the invention

[0005] In view of the defects and shortcomings of the prior art, the present invention provides a method for efficiently removing thallium from an acidic solution containing thallium sulfate.

[0006] A method for efficiently removing thallium from an acidic solution containing thallium sulfate, characterized in that it comprises the following steps: Step 1, adding a complexing agent and a complexing salt into water to prepare a precursor solution; Step 2, adding the precursor solution to the acidic solution containing thallium sulfate and stirring, and then adding the metal reduction powder to react for a period of time to obtain thallium alloy precipitation particles; The complex salt is any one or more of a complex containing lead, bismuth and tin.

[0007] Preferably, the complex salt is any one or more of lead nitrate, lead acetate, lead chloride, lead oxide, bismuth nitrate, bismuth acetate, bismuth chloride, bismuth oxide, tin nitrate, tin acetate, tin chloride, and tin oxide.

[0008] Preferably, the complexing agent is any one or two of acetic acid-sodium acetate and hydrochloric acid-sodium chloride.

[0009] Preferably, the metal reducing powder is any one or more of zinc powder, aluminum powder and iron powder.

[0010] Preferably, the particle size of the metal reduction powder is 38-150 μm.

[0011] Preferably, the total concentration of lead, bismuth and tin metal ions in the precursor solution is 1-100 g / L; the concentration of the complexing agent in the precursor solution is 5-120 g / L.

[0012] Preferably, in step 1, the preparation temperature of the precursor solution is 50-80° C.; the complexing agent and the complexing salt are mixed and reacted for 1-2 hours.

[0013] Preferably, in step 2, the molar ratio of the thallium ions in the acidic solution to the metal ions in the precursor solution added to the acidic solution is 1:0.2-3.

[0014] Preferably, in step 2, the mass ratio of the metal reducing powder added to the acidic solution to the thallium in the acidic solution is 1:300-600.

[0015] Preferably, in step 2, the reaction temperature is 30-80° C. and the reaction time is 0.5-2 h.

[0016] Compared with the prior art, the present invention has the following obvious beneficial effects: The thallium removal method provided by the present invention is applicable to sulfate systems. By performing complex chemical transformation on the introduced lead, bismuth and tin metal ions, sulfate precipitation will not be generated immediately after they enter the solution containing sulfate ions, but a slow-release dissociation reaction and reduction eutectic reaction will occur, thereby improving the effective utilization rate of the introduced ions and greatly reducing the reagent consumption. In addition, by combining the precursor solution and the metal reduction powder, the precipitation effect of thallium in the acidic waste liquid is enhanced, deep thallium removal is achieved, and the thallium removal rate is greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1A process flow chart of a method for efficiently removing thallium from an acidic solution containing thallium sulfate provided by the present invention; Figure 2 (a) is a SEM image of the thallium alloy prepared in Example 1; (b) is a SEM scan of the Zn element in the thallium alloy prepared in Example 1; (c) is a SEM scan of the Pb element in the thallium alloy prepared in Example 1; (d) is a SEM scan of the TI element in the thallium alloy prepared in Example 1; Figure 3 (a) is a SEM image of the thallium alloy prepared in Example 3; wherein, (b) is a SEM scan of the Al element in the thallium alloy prepared in Example 3; (c) is a SEM scan of the Bi element in the thallium alloy prepared in Example 3; (d) is a SEM scan of the TI element in the thallium alloy prepared in Example 3; Figure 4 (a) is a SEM image of the thallium alloy prepared in Example 4; wherein, (b) is a SEM scan of the Fe element in the thallium alloy prepared in Example 4; (c) is a SEM scan of the Sn element in the thallium alloy prepared in Example 4; (d) is a SEM scan of the TI element in the thallium alloy prepared in Example 4. DETAILED DESCRIPTION

[0018] The present invention provides the following specific technical solutions.

[0019] Aiming at the problem of large loss of lead salt in the process of assisting zinc powder in removing thallium, the present invention proposes a method for efficiently removing thallium from an acidic solution containing thallium sulfate, the principle of which is: metal reducing powder and complex ions jointly precipitate thallium under the coordination action of a complexing agent, and thallium is removed from the acidic solution containing thallium sulfate. The method has the advantages of low equipment investment, simple operation, good thallium removal effect and low cost.

[0020] A method for efficiently removing thallium from an acidic solution containing thallium sulfate comprises the following steps: Step 1, adding a complexing agent and a complexing salt into water to prepare a precursor solution; Step 2, adding the precursor solution to the acidic solution containing thallium sulfate and stirring, and then adding the metal reduction powder to react for a period of time to obtain thallium alloy precipitation particles; The complex salt is any one or more of a complex containing lead, bismuth and tin.

[0021] The specific operation is: first, the salt and the complexing agent are dissolved with pure water in a slurry mixing tank, and a precursor solution is prepared after the reaction; then, the precursor solution is added to an acidic solution containing thallium sulfate, and after stirring evenly, metal reducing powder is added, and thallium and the complexing ions accept the electrons of the metal reducing powder to produce a co-precipitation reaction, and thallium is removed from the solution in the form of a thallium alloy.

[0022] Aiming at the problem of large loss of lead salt in the process of assisting zinc powder to remove thallium, the present invention proposes to transform the reagent pair by adding acetic acid-sodium acetate or hydrochloric acid-sodium chloride to the complex of lead, tin and bismuth, so that lead, tin and bismuth are transformed from free single ions into free complex ions, improve the stability of the three elements of lead, tin and bismuth in solution, reduce the thermodynamic driving force for combining with other ions, and avoid the problem of generating sulfate precipitation in the sulfuric acid system of the precursor solution. The complex ions in the precursor solution continuously undergo dissociation reaction, and there is a large thermodynamic window for slow-release eutectoid reaction with thallium. The process of continuous dissociation can increase the reaction time, thereby increasing the binding rate with thallium, and achieving the purpose of efficient thallium removal. The method is simple to operate, has low equipment investment, and has good thallium removal effect. The single ion complex transformation and slow-release eutectoid reaction are utilized to improve the thallium removal rate, reduce the requirements for the solution environment, and expand the scope of application.

[0023] Preferably, the complex salt is any one or more of lead nitrate, lead acetate, lead chloride, lead oxide, bismuth nitrate, bismuth acetate, bismuth chloride, bismuth oxide, tin nitrate, tin acetate, tin chloride, and tin oxide.

[0024] Preferably, the complexing agent is any one or two of acetic acid-sodium acetate and hydrochloric acid-sodium chloride.

[0025] Wherein, acetic acid-sodium acetate is a mixture or mixed solution of acetic acid and sodium acetate, and hydrochloric acid-sodium chloride is a mixture or mixed solution of hydrochloric acid and sodium chloride.

[0026] Preferably, the metal reducing powder is any one or more of zinc powder, aluminum powder and iron powder.

[0027] Preferably, the particle size of the metal reduction powder is 38-150 μm.

[0028] The metal reduction powder is an electron donor, which causes the complex ions to undergo a reduction eutectic reaction with the thallium ions. The particle size of the metal reduction powder has a direct impact on the reaction rate. The finer the particle size, the larger the reaction surface and the faster the reaction rate. However, too fine a particle size is not conducive to the subsequent filter press process and is likely to cause the metal reduction powder in the acid solution to be consumed too quickly. Too coarse a particle size will cause the reaction rate to be too low, and the powder is easy to deposit, resulting in a reduced thallium removal effect. Therefore, the inventors propose that the preferred range is 38-150μm; more preferably 74-100μm.

[0029] Preferably, the total concentration of lead, bismuth and tin metal ions in the precursor solution is 1-100 g / L; and the concentration of the complexing agent in the precursor solution is 5-120 g / L.

[0030] Preferably, in step 1, the preparation temperature of the precursor solution is 50-80° C.; the complexing agent and the complexing salt are mixed and reacted for 1-2 hours.

[0031] Preferably, in step 2, the molar ratio of the thallium ions in the acidic solution to the total amount of the lead, bismuth and tin metal ions added to the acidic solution is 1:0.2-3.

[0032] Preferably, in step 2, the mass ratio of the metal reducing powder added to the acidic solution to the thallium in the acidic solution is 1:300-600.

[0033] Preferably, in step 2, the reaction temperature is 30-80° C. and the reaction time is 0.5-2 h.

[0034] The slurry mixing process in the technical solution of the present invention is carried out in a slurry mixing tank, and the solvent used for the coordination salt and the coordination agent is pure water. The following reactions mainly occur during the process: Me x (SO4) y / Me x (NO3) y / MeCl x / MeAc x / Me x O y +Cl - →MeCl z n- +SO4 2- / NO3 - / Cl - / Ac - Me x (SO4) y / Me x (NO3) y / MeCl x / MeAc x / Me x O y +Ac - →MeAc z n- +SO4 2- / NO3 - / Cl - / Ac - In a high concentration of the complexing agent solution, the target metal ions are converted into complex ion forms. When a small amount of the complex ion solution is added to the acidic solution containing thallium sulfate, the following gradual dissociation and eutectoid reduction reactions will occur: MeAc z n- →MeAc z-1 n-1 →MeAc z-2 n-2 →MeAc z-3 n-3 →… MeCl z n- →MeCl z-1 n-1 →MeCl z-2 n-2 →MeCl z-3 n-3 →… The dissociation of the complex ions is not instantaneous, but a continuous slow-release process, thus avoiding the direct addition of lead, bismuth and tin metal ions to directly react with SO4 in the solution. 2- The formation of a precipitate allows the eutectoid reaction to continue.

[0035] MeAc z n- +Tl + +Metal reduction powder→MeTl+Ac - MeAc z-1 n-1 +Tl + +Metal reduction powder→MeTl+Ac - MeAc z-2 n-2 +Tl + +Metal reduction powder→MeTl+Ac - MeCl z n- +Tl + +Metal reduction powder→MeTl+Cl - MeCl z-1 n-1 +Tl + +Metal reduction powder→MeTl+Cl - MeCl z-2 n-2 +Tl + +Metal reduction powder→MeTl+Cl - .

[0036] In order to make the technical problems, technical solutions and technical advantages to be solved by the present invention more clear, they will be described in detail below with reference to specific examples, but the protection scope of the present invention is not limited to the following specific embodiments.

[0037] Unless otherwise defined, all professional terms used below have the same meanings as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0038] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0039] The components of the acidic waste liquid used in the specific embodiment of the present invention are: Tl is 3.20 mg / L, and the pH of the acidic waste liquid is 5.5. The lead salt, bismuth salt, tin salt, acetic acid, sodium acetate, hydrochloric acid, and sodium chloride used are all chemically pure, and the solvent is water.

[0040] Embodiment 1: A method for efficiently removing thallium from an acidic solution containing thallium sulfate comprises the following steps: Step 1, preparation of precursor solution: weigh 1g of lead nitrate and add it into a beaker, add 40g of acetic acid and 20g of sodium acetate, pour in 1L of water, heat to 60°C, react for 1h, and then filter to obtain a lead-containing precursor solution.

[0041] Step 2: Measure 1L of acidic waste liquid with a measuring cylinder, add 4.16mL of lead-containing precursor solution, that is, the molar ratio of thallium in the acidic waste liquid to lead in the precursor solution is 1: 1. Weigh 0.5g of zinc powder with an average particle size of 79μm and add it to the solution, and stir and react at a temperature of 50℃ for 0.5h.

[0042] Step 3, after the reaction is completed, the solution is subjected to solid-liquid separation, and the obtained solid particles are thallium alloy.

[0043] The liquid obtained by solid-liquid separation in step 3 was analyzed for thallium content, and the thallium content was measured to be 0.19 mg / L, and the thallium removal rate was calculated to be 94.06%.

[0044] Figure 2 (a) is a SEM image of the thallium alloy obtained in Example 1. Figure 2 It can be seen that the surface of the thallium alloy is finely fuzzy, which indirectly proves that the thallium element and other elements are successfully alloyed.

[0045] Figure 2 In the figure, (b) is the SEM scan of the Zn element in the thallium alloy prepared in Example 1, (c) is the SEM scan of the Pb element in the thallium alloy prepared in Example 1; (d) is the SEM scan of the TI element in the thallium alloy prepared in Example 1. Combining (c) and (d), it can be seen that there are a large number of lead and thallium aggregation areas in the particles, and the distribution behavior of lead and thallium is consistent, which proves that thallium and lead are successfully alloyed. It can be reasonably inferred that the thallium removal method provided by the present invention can reduce the loss of reagents.

[0046] Embodiment 2: A method for efficiently removing thallium from an acidic solution containing thallium sulfate comprises the following steps: Step 1, preparation of precursor solution: weigh 1g of lead chloride and add it into a beaker, add 60g of hydrochloric acid and 60g of sodium chloride, pour in 1L of water, heat to 80°C, react for 1h, and then filter to obtain a lead-containing precursor solution.

[0047] Step 2: Measure 1L of acidic waste liquid with a measuring cylinder, add 7.48mL of lead-containing precursor solution, that is, the molar ratio of thallium in the acidic waste liquid to lead ions in the precursor solution is 1:2. Weigh 1g of zinc powder with an average particle size of 126μm and add it to the solution, and stir and react at a temperature of 70℃ for 2h.

[0048] Step 3, after the reaction is completed, the solution is subjected to solid-liquid separation, and the obtained solid particles are thallium alloy.

[0049] The liquid obtained by solid-liquid separation in step 3 was analyzed for thallium content, and the thallium content was measured to be 0.25 mg / L. The calculated thallium removal rate was 92.19%.

[0050] Embodiment 3: A method for efficiently removing thallium from an acidic solution containing thallium sulfate comprises the following steps: Step 1, preparation of precursor solution: weigh 1g of bismuth oxide and add it into a beaker, add 100g of acetic acid and 40g of sodium acetate, pour in 1L of water, heat to 70°C, react for 1h, and then filter to obtain a bismuth-containing precursor solution.

[0051] Step 2: Measure 1L of acidic waste liquid with a measuring cylinder, add 7.48mL of bismuth-containing precursor solution, that is, the molar ratio of thallium in the acidic waste liquid to bismuth in the precursor solution is 1:2. Weigh 1.5g of aluminum powder with an average particle size of 87μm and add it to the solution, and stir and react at a temperature of 80°C for 1h.

[0052] Step 3, after the reaction is completed, the solution is subjected to solid-liquid separation, and the obtained solid particles are thallium alloy.

[0053] The liquid obtained by solid-liquid separation in step 3 was analyzed for thallium content, and the thallium content was measured to be 0.13 mg / L, and the thallium removal rate was calculated to be 95.94%.

[0054] Figure 3 (a) is a SEM image of the thallium alloy obtained in Example 3. Figure 3 It can be seen that the surface of the thallium alloy is finely fuzzy, which indirectly proves that the thallium element and other elements are successfully alloyed.

[0055] Figure 3In the figure, (b) is the SEM scan of the Al element in the thallium alloy prepared in Example 3, (c) is the SEM scan of the Bi element in the thallium alloy prepared in Example 3; (d) is the SEM scan of the TI element in the thallium alloy prepared in Example 3. Combining (c) and (d), it can be seen that there are a large number of bismuth and thallium aggregation areas in the particles, and the distribution behavior of bismuth and thallium is consistent, which further proves that thallium and bismuth are successfully alloyed.

[0056] Embodiment 4: A method for efficiently removing thallium from an acidic solution containing thallium sulfate comprises the following steps: Step 1, preparation of precursor solution: weigh 1g of tin nitrate and add it into a beaker, add 70g of hydrochloric acid and 50g of sodium chloride, pour in 1L of water, heat to 60°C, react for 2h, and then filter to obtain a tin-containing precursor solution.

[0057] Step 2: Measure 1L of acidic waste liquid with a measuring cylinder, add 14.60mL of tin-containing precursor solution, that is, the molar ratio of thallium in the acidic waste liquid to tin in the precursor solution is 1:3. Weigh 2g of iron powder with an average particle size of 73μm and add it to the solution, and stir and react at 35℃ for 2h.

[0058] Step 3, after the reaction is completed, the solution is subjected to solid-liquid separation, and the obtained solid particles are thallium alloy.

[0059] The liquid obtained by solid-liquid separation in step 3 was analyzed for thallium content, and the thallium content was measured to be 0.20 mg / L, and the thallium removal rate was calculated to be 93.75%.

[0060] Figure 4 (a) is a SEM image of the thallium alloy obtained in Example 4. Figure 4 It can be seen that the thallium alloy is composed of stacked flaky fine particles, which indirectly proves that thallium and other elements are successfully alloyed.

[0061] Figure 4 In the figure, (b) is the SEM scan of the Fe element in the thallium alloy prepared in Example 4, (c) is the SEM scan of the Sn element in the thallium alloy prepared in Example 4; (d) is the SEM scan of the TI element in the thallium alloy prepared in Example 4. Combining (c) and (d), it can be seen that there are a large number of tin and thallium aggregation areas in the particles, and the distribution behavior of tin and thallium is consistent, which further proves that thallium and tin are successfully alloyed.

[0062] Embodiment 5: A method for efficiently removing thallium from an acidic solution containing thallium sulfate comprises the following steps: Step 1, preparation of precursor solution, weigh 1g of bismuth acetate and add it into a beaker, add 110g of hydrochloric acid and 100g of sodium chloride, pour in 1L of water, heat to 50°C and react for 2h, then filter to obtain a bismuth-containing precursor solution.

[0063] Step 2: Measure 1L of acidic waste liquid with a measuring cylinder, add 0.96mL of bismuth-containing precursor solution, that is, the molar ratio of thallium in the acidic waste liquid to bismuth in the precursor solution is 1:0.3. Weigh 0.8g of zinc powder with an average particle size of 42μm and add it to the solution, and stir and react at a temperature of 45°C for 1h.

[0064] Step 3, after the reaction is completed, the solution is subjected to solid-liquid separation, and the obtained solid particles are thallium alloy.

[0065] The liquid obtained by solid-liquid separation in step 3 was analyzed for thallium content, and the thallium content was measured to be 0.26 mg / L, and the thallium removal rate was calculated to be 91.88%.

[0066] Embodiment 6: A method for efficiently removing thallium from an acidic solution containing thallium sulfate comprises the following steps: Step 1, preparation of precursor solution: weigh 1g of tin oxide and add it into a beaker, add 30g of acetic acid and 50g of sodium acetate, pour in 1L of water, heat to 70°C, react for 1h, and then filter to obtain a bismuth-containing precursor solution.

[0067] Step 2: Measure 1L of acidic waste liquid with a measuring cylinder, add 8.08mL of bismuth-containing precursor solution, that is, the molar ratio of thallium in the acidic waste liquid to bismuth in the precursor solution is 1:2. Weigh 1.3g of aluminum powder with an average particle size of 42μm and add it to the solution, and stir and react at a temperature of 75°C for 1.5h.

[0068] Step 3, after the reaction is completed, the solution is subjected to solid-liquid separation, and the obtained solid particles are thallium alloy.

[0069] The liquid obtained by solid-liquid separation in step 3 was analyzed for thallium content, and the thallium content was measured to be 0.11 mg / L. The calculated thallium removal rate was 96.56%.

[0070] Comparative Example 1: A method for removing thallium comprises the following steps: Step 1: Use a measuring cylinder to measure 1L of acidic waste liquid, add 1.3g of aluminum powder with an average particle size of 42μm into the solution, and stir the reaction at a temperature of 75°C for 1.5h.

[0071] Step 2, after the reaction is completed, the solution is subjected to solid-liquid separation, and the obtained solid particles are thallium alloy.

[0072] The liquid obtained by solid-liquid separation in step 2 was analyzed for thallium content, and the thallium content was measured to be 2.15 mg / L, and the thallium removal rate was calculated to be 32.81%.

[0073] By comparing the thallium removal rates of Example 6 and Comparative Example 1, it can be seen that the method provided by the present invention has a better thallium removal effect.

[0074] The embodiments described above are only preferred specific implementation modes of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and concepts of the present invention within the technical scope of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for efficiently removing thallium from an acidic solution containing thallium sulfate, characterized in that: The following steps are involved: Step 1, adding a complexing agent and a complexing salt into water to prepare a precursor solution; Step 2, adding the precursor solution to the acidic solution containing thallium sulfate and stirring, and then adding the metal reduction powder to react for a period of time to obtain thallium alloy precipitation particles; The complex salt is any one or more of a complex containing lead, bismuth and tin.

2. The method for efficiently removing thallium in an acidic solution containing thallium sulfate as claimed in claim 1, characterized in that: The complex salt is any one or more of lead nitrate, lead acetate, lead chloride, lead oxide, bismuth nitrate, bismuth acetate, bismuth chloride, bismuth oxide, tin nitrate, tin acetate, tin chloride, and tin oxide.

3. A method for efficiently removing thallium in an acidic solution containing thallium sulfate as claimed in claim 1 or 2, characterized in that: The complexing agent is any one or two of acetic acid-sodium acetate and hydrochloric acid-sodium chloride.

4. The method for efficiently removing thallium in an acidic solution containing thallium sulfate as claimed in claim 1, characterized in that: The metal reduction powder is any one or more of zinc powder, aluminum powder and iron powder.

5. A method for efficiently removing thallium in an acidic solution containing thallium sulfate as claimed in claim 1 or 4, characterized in that: The particle size of the metal reduction powder is 38-150 μm.

6. A method for efficiently removing thallium from an acidic solution containing thallium sulfate as claimed in claim 1 or 2, characterized in that: The total concentration of lead, bismuth and tin metal ions in the precursor solution is 1-100 g / L; the concentration of the complexing agent in the precursor solution is 5-120 g / L.

7. A method for efficiently removing thallium from an acidic solution containing thallium sulfate as claimed in claim 1, characterized in that: In step 1, the preparation temperature of the precursor solution is 50-80° C.; the complexing agent and the complexing salt are mixed and reacted for 1-2 hours.

8. A method for efficiently removing thallium from an acidic solution containing thallium sulfate as claimed in claim 1 or 7, characterized in that: In step 2, the molar ratio of the thallium ions in the acidic solution to the metal ions in the precursor solution added to the acidic solution is 1:0.2-3.

9. A method for efficiently removing thallium from an acidic solution containing thallium sulfate as claimed in claim 1, characterized in that: In step 2, the mass ratio of the metal reducing powder added to the acidic solution to the thallium in the acidic solution is 1:300-600.

10. A method for efficiently removing thallium from an acidic solution containing thallium sulfate as claimed in claim 1 or 9, characterized in that: In step 2, the reaction temperature is 30-80°C and the reaction time is 0.5-2h.

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