Method for purifying heavy metal ions in high-salinity water by using chlorine efficiently

Abstract

The application discloses a method for efficiently purifying heavy metal ions in high-salt water by chlorine, and a reaction device thereof. The reaction device comprises a Venturi gas-liquid mixer, which is sequentially connected with first-stage, second-stage and third-stage chlorine recycling reaction devices. The first-stage, second-stage and third-stage chlorine recycling reaction devices are of the same structure and are of an external circulation self-suction type, and each comprises a reaction kettle body, wherein a stirring paddle is arranged in the reaction kettle body. The stirring paddle is a large-page porous stirring paddle, and stirring power is provided by a frequency conversion motor arranged at the top of the reaction kettle. After high-salt solution and chlorine are subjected to preliminary gas-liquid mixing reaction by the Venturi gas-liquid mixer, the unreacted chlorine is subjected to deep gas-liquid mixing reaction in the chlorine recycling reaction device, and after passing through the multi-stage chlorine recycling reaction device, the high-salt solution enters a hydrolysis tank for heavy metal hydrolysis and precipitation. The heavy metal ions in the reacted high-salt water solution can be reduced to below 0.0002 g / L, thereby meeting the purification requirement of the high-salt water solution.

Description

Technical Field

[0001] This invention relates to a gas-liquid reaction device for a highly efficient reaction method for purifying and removing metal ions in hydrometallurgy and chemical processes. Specifically, chlorine gas reacts with metal ions in the device to efficiently oxidize, hydrolyze, and precipitate heavy metal ions, thereby removing harmful metal ions from solutions. Background Technology

[0002] Chlorine, as a strong oxidant, can be used to purify heavy metal ions in high-salt solutions in chemical production. A domestic group has applied it to the chlorine oxidation reaction for cobalt removal, simultaneously removing lead ions from high-salt solutions. To ensure the lead ion content in the solution meets relevant production technology requirements, it is often necessary to increase the amount of precipitate residue to entrain trace amounts of lead ions. Therefore, the purification process for cobalt and lead removal faces technical challenges such as large precipitate residue volume, high nickel content in the precipitate residue, low chlorine utilization rate, and complex post-treatment of the precipitate residue. Furthermore, no efficient chemical precipitation method for removing cobalt ions from high-nickel solutions has been reported. Based on the principle of chlorine oxidation and hydrolysis precipitation of heavy metal ions, this invention develops a reaction method for the efficient purification of heavy metal ions using chlorine. Through the implementation of efficient chlorine purification of heavy metal ions, the concentration of harmful heavy metal ions in high-salt solutions can be reduced to below 0.0002 g / L, and the nickel-cobalt ratio of the precipitate residue can be reduced from approximately 3.0 to 0.02. Summary of the Invention

[0003] The purpose of this invention is to provide a method for efficiently purifying heavy metal ions in high-salt solutions with chlorine gas, so as to ensure the smooth progress of the efficient oxidation-hydrolysis precipitation reaction between chlorine gas and heavy metal ions, reduce the emission of chlorine gas tail gas, and maintain the constant composition of high-salt solutions.

[0004] The present invention provides a reaction method for the efficient purification of heavy metal ions using chlorine gas, which is accomplished by the following equipment and process:

[0005] The reaction apparatus includes a Venturi gas-liquid mixer, which is sequentially connected to a primary chlorine recovery reaction unit, a secondary chlorine recovery reaction unit, and a tertiary chlorine recovery reaction unit. The primary, secondary, and tertiary chlorine recovery reaction units have identical structures and employ an external circulation self-priming design. Each unit includes a reaction vessel body containing a stirring impeller. The stirring impeller is a large-blade, porous impeller, composed of a titanium porous impeller and a stirring rod. The impeller is made of a large-blade, porous titanium plate with 4-6 blades and multiple holes on each blade. The agitator is powered by a variable frequency motor located at the top of the reactor. The agitator is sealed to the reactor body using a PTFE mechanical seal. The bottom of the reactor body is equipped with a liquid inlet pipe and a residual gas inlet pipe, with the residual gas inlet pipe nested inside the liquid inlet pipe. A T-junction is installed on the liquid inlet pipe. The upper part of the reactor body is equipped with a liquid outlet, and the top of the reactor body is equipped with a flange cover plate. The flange cover plate is equipped with an exhaust port, which is connected to the residual gas inlet pipe through a gas external circulation pipe. The gas external circulation pipe is equipped with a vent pipe, and the vent pipe is equipped with an exhaust valve to control the circulation of residual gas.

[0006] The first pipe of the three-way connector is connected to the liquid inlet pipe, the second pipe is connected to the gas-liquid outlet of the Venturi gas-liquid mixer, and the third pipe serves as the discharge pipe, which is equipped with a discharge valve.

[0007] The inlet of the Venturi gas-liquid mixer is connected to the chlorine gas pipeline, and the liquid inlet is connected to the high-salt solution pipeline. The gas-liquid outlet of the Venturi gas-liquid mixer is connected to the liquid inlet of the primary chlorine recycling reactor via a T-junction. The liquid outlet of the primary chlorine recycling reactor is connected to the liquid inlet of the secondary chlorine recycling reactor via a pipeline. The liquid outlet of the secondary chlorine recycling reactor is connected to the liquid inlet of the tertiary chlorine recycling reactor via a pipeline. The liquid outlet of the tertiary chlorine recycling reactor is connected to the hydrolysis precipitation tank. A chlorine flow meter is installed on the chlorine gas pipeline, and a magnetic pump is installed on the high-salt solution pipeline.

[0008] Reaction process: The above-mentioned device is used to perform deep removal of lead, cobalt, manganese, and nickel from a high-salt solution with a pH of 4.0-5.0. The chlorine gas flow rate is set to 10-15% of the high-salt solution liquid flow rate, and the high-salt solution liquid flow rate is 35-45 L / h. The reaction temperature in the chlorine recycling reactor is 60-70℃, and the hydrolysis reaction time is 25-35 min. The specific operation procedure is as follows:

[0009] (1) Turn on the chlorine recycling reaction device and set the stirring rate to 1000 r / min; close the exhaust valve and the feed valve to ensure the airtightness of the system;

[0010] (2) Set the chlorine gas flow rate into the Venturi gas-liquid mixer to 66.7-520 ml / min, and stably control the liquid flow rate of the high-salt solution at 35-45 L / h; control the amount of chlorine gas to be 1.5-3.3 times the molar amount of cobalt ions;

[0011] A high-salt solution of nickel chloride and nickel sulfate with a pH of 4.0-5.0, along with chlorine gas, enters a Venturi gas-liquid mixer. After a preliminary gas-liquid mixing reaction, the unreacted chlorine gas and high-salt solution sequentially enter the primary, secondary, and tertiary chlorine recycling reactors through the inlet pipes. Deep gas-liquid mixing occurs in these reactors. To ensure the reuse of residual gas, the unreacted residual gas is circulated from the top to the bottom of the reactor via an external circulation system. The residual gas then re-enters the reactor body through the exhaust port, external gas circulation pipe, and residual gas inlet pipe for reuse. After passing through the multi-stage chlorine recycling reactors, the high-salt solution enters a hydrolysis precipitation tank for heavy metal hydrolysis precipitation.

[0012]

[0013] (3) When the solution overflows from the three-stage chlorine recycling reaction device to the hydrolysis precipitation tank, adjust the alkaline addition rate to maintain the pH of the reaction solution at 4.5~5.5; control the hydrolysis reaction time to 25~35 min; the alkaline solution is sodium hydroxide, sodium carbonate, sodium bicarbonate or ammonium carbonate solution, preferably sodium hydroxide solution;

[0014] (4) Unreacted chlorine tail gas enters the tail gas absorption device, is absorbed by sodium hydroxide solution, and the chlorine content is measured;

[0015] (5) After the hydrolysis precipitation tank reaction is completed, the solution is filtered through slow filter paper, and the lead and cobalt ion content of chlorine gas and the nickel and cobalt content of solid slag are measured. The analysis shows that the cobalt ion content in the solution is less than 0.001 g / L, the lead ion content is less than 0.0002 g / L, and the nickel content in the solid slag is as low as 0.65%, with a nickel-cobalt ratio of 0.02.

[0016] (6) After the operation stops, the liquid in the chlorine recycling reactor is discharged into the reactor through the feed pipe.

[0017] The beneficial effects of this invention are as follows: Through the purification method of this invention, the cobalt ion content in the high-salt solution is less than 0.001 g / L, and the lead ion content is less than 0.0002 g / L, meeting the purification requirements for high-salt aqueous solutions. Furthermore, the nickel content in the solid slag is as low as 0.65%, and the nickel-cobalt ratio of 0.02 is far lower than the actual production requirement of 3.0; simultaneously, the chlorine utilization rate is increased from 80% to over 95%. Attached Figure Description

[0018] Figure 1This is a schematic diagram of the chlorine recycling reaction device of the present invention;

[0019] Figure 2 This is a schematic diagram of the connection of the reaction device of the present invention;

[0020] In the diagram, 1-variable frequency motor, 2-PTFE mechanical seal, 3-flange cover, 4-reactor body, 5-exhaust port, 6-vent, 7-external gas circulation pipe, 8-liquid outlet, 9-stirring paddle, 10-liquid inlet pipe, 11-residual gas inlet pipe, 12-tee pipe, L-1 is a Venturi gas-liquid mixer, L-2 is a primary chlorine recycling reaction device, L-3 is a secondary chlorine recycling reaction device, and L-4 is a tertiary chlorine recycling reaction device. Detailed Implementation

[0021] The following will be combined with the appendix Figure 1 The apparatus and method for removing heavy metal ions using chlorine gas according to the present invention will be further described below.

[0022] Example 1

[0023] The reaction apparatus includes a Venturi gas-liquid mixer L-1, which is sequentially connected to a primary chlorine recycling reactor L-2, a secondary chlorine recycling reactor L-3, and a tertiary chlorine recycling reactor L-4. The primary, secondary, and tertiary chlorine recycling reactors have identical structures and employ an external circulation self-priming design. Each reactor includes a reactor body 4, within which is installed a stirring paddle 9. The stirring paddle 9 is a large-blade, porous stirring paddle composed of a titanium porous paddle and a stirring rod. The stirring paddle 9 has 4-6 blades with multiple holes. The stirring paddle 9 is powered by a variable frequency motor 1 located at the top of the reactor. The stirring paddle 9 is sealed to the reactor body 4 using a PTFE mechanical seal plug 2. The bottom of the reactor body 4 is provided with a liquid inlet pipe 10 and a residual gas inlet pipe 11. The residual gas inlet pipe 11 is nested inside the liquid inlet pipe 10. A three-way pipe 12 is installed on the liquid inlet pipe 10. The upper part of the reactor body 4 is provided with a liquid outlet 8. The top of the reactor body 4 is provided with a flange cover plate 3. The flange cover plate 3 is provided with an exhaust port 5. The exhaust port 5 is connected to the residual gas inlet pipe 11 through a gas external circulation pipe 7. The gas external circulation pipe 7 is provided with an vent pipe 6. The vent pipe 6 is provided with an exhaust valve for controlling the circulation of residual gas.

[0024] For ease of maintenance, the reactor body 4 is connected by flanges. To ensure effective gas-liquid separation, the liquid outlet 8 is located slightly above the center of the reactor body 4. The liquid inlet pipe 10 and the residual gas inlet pipe 11 are located at the center of the bottom of the reactor body 4. To improve the utilization rate of residual gas, the agitator 9 is made of large-page porous titanium plate. To improve the mechanical strength of the agitator 9 and replace the hollow design of the self-priming agitator, the agitator rod is made of solid titanium. To ensure the reuse of residual gas, the residual gas is led from the top of the reactor to the bottom of the reactor through external circulation.

[0025] The first pipe of the three-way pipe 12 is connected to the liquid inlet pipe, the second pipe is connected to the gas-liquid outlet of the Venturi gas-liquid mixer, and the third pipe serves as the discharge pipe, which is equipped with a discharge valve.

[0026] The inlet of the Venturi gas-liquid mixer L-1 is connected to the chlorine gas pipeline, and the liquid inlet is connected to the high-salt solution pipeline. The gas-liquid outlet of the Venturi gas-liquid mixer L-1 is connected to the liquid inlet of the primary chlorine recycling reactor L-2 via a three-way pipe 12. The liquid outlet of the primary chlorine recycling reactor L-2 is connected to the liquid inlet of the secondary chlorine recycling reactor L-3 via a pipeline. The liquid outlet of the secondary chlorine recycling reactor L-3 is connected to the liquid inlet of the tertiary chlorine recycling reactor L-4 via a pipeline. The liquid outlet of the tertiary chlorine recycling reactor L-4 is connected to the hydrolysis precipitation tank. A chlorine flow meter is installed on the chlorine gas pipeline, and a magnetic pump is installed on the high-salt solution pipeline.

[0027] Reaction Process: The above-mentioned equipment was used to conduct intermittent deep lead and cobalt removal experiments on a mixed high-salt solution of nickel chloride and nickel sulfate (pH 4.5), where the lead and cobalt ion concentrations were 0.012 g / L and 0.30 g / L, respectively. The chlorine gas flow rate was set to 15% of the high-salt solution liquid flow rate, the reaction temperature was 65℃, the liquid flow rate was 40 L / h, and the hydrolysis reaction time was 30 min. The specific operating procedure is as follows:

[0028] (1) Turn on the chlorine recycling reaction device and set the stirring rate to 1000 r / min; close the exhaust valve and the feed valve to ensure the airtightness of the system.

[0029] (2) Turn on the chlorine flow meter to the set gas flow rate of 100 ml / min, and simultaneously turn on the high-salt solution magnetic pump to ensure that the liquid flow rate is stably controlled at about 40 L / h; control the amount of chlorine to be 3.3 times the molar ratio of cobalt ions.

[0030] A high-salt solution of nickel chloride and nickel sulfate with a pH of 4.0-5.0, along with chlorine gas, enters a Venturi gas-liquid mixer. After a preliminary gas-liquid mixing reaction, the unreacted chlorine gas and high-salt solution sequentially enter the primary, secondary, and tertiary chlorine recycling reactors through the inlet pipes. Deep gas-liquid mixing occurs in these reactors. To ensure the reuse of residual gas, the unreacted residual gas is circulated from the top to the bottom of the reactor via an external circulation system. The residual gas then re-enters the reactor body through the exhaust port, external gas circulation pipe, and residual gas inlet pipe for reuse. Under the vigorous stirring action of the agitator, the chlorine-containing solution and residual chlorine come into contact again and react fully. After passing through the multi-stage chlorine recycling reactors, the high-salt solution enters a hydrolysis precipitation tank for heavy metal hydrolysis precipitation.

[0031] (3) When the solution overflows from the three-stage chlorine recycling reaction device to the hydrolysis precipitation tank, adjust the sodium hydroxide solution addition rate to maintain the pH of the reaction solution at about 5.0 and control the hydrolysis reaction time at about 30 min.

[0032] (4) Unreacted chlorine tail gas enters the tail gas absorption device, is absorbed by sodium hydroxide solution, and the chlorine content is measured.

[0033] (5) After the reaction was completed, the solution was filtered through slow-speed filter paper, and the lead and cobalt ion content of the solution and the nickel and cobalt content of the solid slag were measured. The analysis showed that the cobalt ion content in the solution was 0.00085 g / L and the lead ion content was 0.00011 g / L, which met the requirements for purification of high-salt aqueous solutions. In addition, the nickel content in the solid slag was 0.6%, and the nickel-cobalt ratio of 0.02 was far lower than the actual production requirement of 3.0. At the same time, the chlorine utilization rate was 95%.

[0034] (6) After the operation stops, the liquid in the chlorine recycling reactor is discharged into the reactor through the feed pipe.

[0035] Example 2

[0036] Reaction apparatus: Same as in Example 1.

[0037] Reaction process: Intermittent deep cobalt and manganese removal experiments were conducted on the hydrochloric acid leaching solution of lateritic nickel ore at pH 4.0 using the aforementioned equipment (cobalt ion concentration 0.15 g / L, manganese ion concentration 0.03 g / L in the high-salt solution). The chlorine gas flow rate was set to 10% of the high-salt solution liquid flow rate, and the reaction temperature was 65°C. o C, the liquid flow rate is 40 L / h, and the hydrolysis reaction time is 30 min; the specific operating procedure is as follows:

[0038] (1) Turn on the chlorine recycling reaction device and set the stirring rate to 1000 r / min; close the exhaust valve and the feed valve to ensure the airtightness of the system;

[0039] (2) Turn on the chlorine flow meter to the set gas flow rate of 84 ml / min, and simultaneously turn on the high-salt solution magnetic pump to ensure that the liquid flow rate is stably controlled at about 40 L / h; control the amount of chlorine to be 2.2 times the molar ratio of cobalt ions;

[0040] (3) When the solution overflows from the three-stage chlorine recycling reaction device to the hydrolysis precipitation tank, adjust the sodium bicarbonate solution addition rate to maintain the pH of the reaction solution at around 5.0;

[0041] (4) Unreacted chlorine tail gas enters the tail gas absorption device, is absorbed by sodium hydroxide solution, and the chlorine content is measured;

[0042] (5) After the reaction was completed, the solution was filtered through slow-speed filter paper, and the cobalt and manganese ion content of the solution and the nickel and cobalt content of the solid slag were measured. Analysis showed that the cobalt ion content in the solution decreased from 0.15 g / L to 0.0002 g / L, and the manganese ion content decreased from 0.03 g / L to 0.00016 g / L, meeting the purification requirements for high-salt aqueous solutions. Furthermore, the nickel content in the solid slag was 0.8%, and the nickel-cobalt ratio was 0.025; simultaneously, the chlorine utilization rate was 97%.

[0043] (6) After the operation stops, the liquid in the chlorine recycling reactor is discharged into the reactor through the feed pipe.

[0044] Example 3

[0045] Reaction apparatus: Same as in Example 1.

[0046] Reaction process: Using the above equipment, wastewater from an electrolysis workshop (Ni: 1.36 g / L; Na: 40.85 g / L) with a pH of 4.5 was treated. The chlorine gas flow rate was set to 78% of the high-salt solution liquid flow rate, and the reaction temperature was 65°C. o C, the liquid flow rate is 40 L / h, and the hydrolysis reaction time is 30 min; the specific operating procedure is as follows:

[0047] (1) Turn on the chlorine recycling reaction device and set the stirring rate to 1000 r / min; close the exhaust valve and the feed valve to ensure the airtightness of the system;

[0048] (2) Turn on the chlorine flow meter to the set gas flow rate of 520 ml / min, and simultaneously turn on the high-salt solution magnetic pump to ensure that the liquid flow rate is stably controlled at about 40 L / h; control the amount of chlorine to be 1.5 times the nickel ion molar ratio;

[0049] (3) When the solution overflows from the three-stage chlorine recycling reaction device to the hydrolysis precipitation tank, adjust the sodium carbonate solution addition rate to maintain the pH of the reaction solution at around 5.0;

[0050] (4) Unreacted chlorine tail gas enters the tail gas absorption device, is absorbed by sodium hydroxide solution, and the chlorine content is measured;

[0051] (5) After the reaction was completed, the solution was filtered through slow-speed filter paper, and the nickel ion content of the filtrate was measured. The analysis showed that the nickel ion content in the solution was 0.00020 g / L, and the chlorine utilization rate was 97%.

[0052] (6) After the operation stops, the liquid in the chlorine recycling reactor is discharged into the vessel through the liquid outlet.

[0053] Comparative Example 1

[0054] Reaction apparatus: Same as in Example 1

[0055] Reaction Process: Using the aforementioned equipment, an intermittent deep lead and cobalt removal experiment was conducted on a mixed high-salt solution of nickel chloride and nickel sulfate at pH 4.5 (lead and cobalt ion concentrations in the high-salt solution were 0.012 g / L and 0.30 g / L, respectively). The chlorine gas flow rate was set to 15% of the high-salt solution liquid flow rate, and the reaction temperature was 65°C. o C, the liquid flow rate is 40 L / h, and the hydrolysis reaction time is 30 min; the specific operating procedure is as follows:

[0056] (1) Turn on the chlorine recycling reaction device and set the stirring rate to 0 r / min; close the exhaust valve and the feed valve to ensure the airtightness of the system;

[0057] (2) Turn on the chlorine flow meter to the set gas flow rate of 100 ml / min, and simultaneously turn on the high-salt solution magnetic pump to ensure that the liquid flow rate is stably controlled at about 40 L / h; control the amount of chlorine to be 3.3 times the molar ratio of cobalt ions;

[0058] (3) When the solution overflows from the three-stage chlorine recycling reaction device to the hydrolysis precipitation tank, adjust the sodium hydroxide solution addition rate to maintain the pH of the reaction solution at around 5.0;

[0059] (4) Unreacted chlorine tail gas enters the tail gas absorption device, is absorbed by sodium hydroxide solution, and the chlorine content is measured;

[0060] (5) After the reaction was completed, the solution was filtered through slow-speed filter paper, and the lead and cobalt ion content of the solution and the nickel and cobalt content of the solid slag were measured. Analysis showed that the cobalt ion content in the solution was 0.012 g / L and the lead ion content was 0.0011 g / L, which did not meet the purification requirements for high-salt aqueous solutions. Furthermore, the nickel content in the solid slag was 42.5%, with a nickel-cobalt ratio of 2.75; simultaneously, the chlorine utilization rate was only 75%.

[0061] (6) After the operation stops, the liquid in the chlorine recycling reactor is discharged into the vessel through the liquid outlet.

Claims

1. A method for efficiently purifying heavy metal ions in high-salt water using chlorine gas, comprising the following apparatus and process: The reaction apparatus includes a Venturi gas-liquid mixer, which is sequentially connected to a primary chlorine recycling reactor, a secondary chlorine recycling reactor, and a tertiary chlorine recycling reactor. The primary, secondary, and tertiary chlorine recycling reactors have identical structures and employ an external circulation self-priming design. Each reactor includes a vessel body containing a stirring paddle composed of a porous titanium paddle and a stirring rod. The stirring paddle is powered by a variable frequency motor located at the top of the reactor. The bottom of the reactor body has a liquid inlet pipe and a residual gas inlet pipe, with the residual gas inlet pipe nested inside the liquid inlet pipe. A T-junction is installed on the liquid inlet pipe. The upper part of the reactor body has a liquid outlet, and the top of the reactor body has a flange cover with an exhaust port. The exhaust port is connected to the residual gas inlet pipe via an external gas circulation pipe, which is equipped with a vent pipe. The gas-liquid outlet of the Venturi gas-liquid mixer is connected to the inlet pipe of the primary chlorine recycling reactor via a three-way pipe. The outlet of the primary chlorine recycling reactor is connected to the inlet pipe of the secondary chlorine recycling reactor via a pipe. The outlet of the secondary chlorine recycling reactor is connected to the inlet pipe of the tertiary chlorine recycling reactor via a pipe. The outlet of the tertiary chlorine recycling reactor is connected to the hydrolysis sedimentation tank. Reaction process: The above-mentioned device is used to perform deep removal of lead, cobalt, manganese, and nickel from a high-salt solution with a pH of 4.0-5.

0. The chlorine gas flow rate is set to 15% of the high-salt solution liquid flow rate, the high-salt solution liquid flow rate is 40 L / h, the reaction temperature in the chlorine recycling reactor is 65℃, and the hydrolysis reaction time is 25-35 min. The specific operation procedure is as follows: (1) Turn on the chlorine recycling reaction device and set the stirring rate to 1000 r / min; close the exhaust valve and the feed valve to ensure the airtightness of the system; (2) Set the chlorine gas flow rate into the Venturi gas-liquid mixer to 100 ml / min, and stably control the liquid flow rate of the high-salt solution to 40 L / h; control the chlorine gas usage to be 3.3 times the molar amount of cobalt ions; the lead ion and cobalt ion concentrations in the high-salt solution are 0.012 g / L and 0.30 g / L, respectively; A high-salt solution with a pH of 4.0-5.0 and chlorine gas enter a Venturi gas-liquid mixer. After the initial gas-liquid mixing reaction, the unreacted chlorine gas and high-salt solution enter the primary, secondary, and tertiary chlorine recycling reactors through the inlet pipes. In the chlorine recycling reactors, a deep gas-liquid mixing reaction takes place. To ensure the recycling of residual gas, the unreacted residual gas is led from the top of the reactor to the bottom through an external circulation system. The residual gas then re-enters the reactor body through the exhaust port, the external gas circulation pipe, and the residual gas inlet pipe for recycling. After passing through the multi-stage chlorine recycling reactors, the high-salt solution enters a hydrolysis precipitation tank for heavy metal hydrolysis precipitation. (3) When the solution overflows from the three-stage chlorine recycling reaction device to the hydrolysis precipitation tank, add alkali solution to adjust the pH of the reaction solution to 4.5~5.5; control the hydrolysis reaction time to 25~35 min; (4) Unreacted chlorine tail gas enters the tail gas absorption device, is absorbed by sodium hydroxide solution, and the chlorine content is measured; (5) After the hydrolysis precipitation tank reaction is completed, the solution is filtered through slow filter paper, and the lead and cobalt ion content of chlorine gas and the nickel and cobalt content of solid slag are measured. The analysis shows that the cobalt ion content in the solution is less than 0.001 g / L, the lead ion content is less than 0.0002 g / L, and the nickel content in the solid slag is as low as 0.65%, with a nickel-cobalt ratio of 0.

02. (6) After the operation stops, the liquid in the chlorine recycling reactor is discharged into the reactor through the feed pipe.

2. The method for efficiently purifying heavy metal ions in high-salt water using chlorine gas according to claim 1, characterized in that: The agitator is made of a large-page porous titanium plate, and the agitator has 4-6 blades.

3. The method for efficiently purifying heavy metal ions in high-salt water with chlorine gas according to claim 1, characterized in that: The agitator and the reactor body are sealed with a PTFE mechanical seal plug.

4. The method for efficiently purifying heavy metal ions in high-salt water with chlorine gas according to claim 1, characterized in that: An exhaust valve is installed on the vent pipe.

5. The method for efficiently purifying heavy metal ions in high-salt water with chlorine gas according to claim 1, characterized in that: The first pipe of the three-way connector is connected to the liquid inlet pipe, the second pipe is connected to the gas-liquid outlet of the Venturi gas-liquid mixer, and the third pipe serves as the discharge pipe, which is equipped with a discharge valve.

6. The method for efficiently purifying heavy metal ions in high-salt water with chlorine gas according to claim 1, characterized in that: The inlet of the Venturi gas-liquid mixer is connected to a high-salt solution pipeline, and the gas inlet is connected to a chlorine pipeline; a chlorine flow meter is installed on the chlorine pipeline, and a magnetic pump is installed on the high-salt solution pipeline.

7. The method for efficiently purifying heavy metal ions in high-salt water with chlorine gas according to claim 1, characterized in that: The alkaline solution is a sodium hydroxide, sodium carbonate, sodium bicarbonate, or ammonium carbonate solution.

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