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CN-117230491-B - Method and system for removing fluorine and chlorine from zinc hydrometallurgy electrolyte circulation liquid

CN117230491BCN 117230491 BCN117230491 BCN 117230491BCN-117230491-B

Abstract

The invention relates to the technical field of hydrometallurgy, in particular to a method and a system for removing fluorine and chlorine from a zinc hydrometallurgy electrolyte circulating solution, and provides a method and a corresponding system for removing only fluorine and chlorine without changing other components of a waste electrolyte, wherein the method comprises the following steps of (1) pumping the waste electrolyte into a concentration tower for concentration and heating; the method comprises the steps of (1) conveying waste electrolyte to a defluorination chlorine circulation tank, (3) pumping the waste electrolyte in the tank to a defluorination chlorine tower, enabling the waste electrolyte to fall in a spray shape in the defluorination chlorine tower, blowing off fluoride ions and chloride ions in falling liquid drops by introducing hot air at 160-220 ℃ into the defluorination chlorine tower, simultaneously, refluxing the falling liquid drops to the defluorination chlorine circulation tank, pumping the waste electrolyte to the defluorination chlorine tower again for blowing off for a plurality of times, and obtaining finished acid when the sulfuric acid mass content in acid liquor reaches 65-75%, b, introducing the rising flue gas containing fluorine and chloride ions into an alkaline washing tower, washing the flue gas by introducing sodium hydroxide solution into the alkaline washing tower, discharging the generated sodium salt solution to a sewage treatment station, and discharging the washed gas.

Inventors

  • YANG SHUYAN

Assignees

  • 江苏恒丰伟业玻璃钢有限公司

Dates

Publication Date
20260505
Application Date
20230928

Claims (9)

  1. 1. The method for removing fluorine and chlorine from the zinc hydrometallurgy electrolyte circulation liquid is characterized by comprising the following steps of: (1) Pumping the waste electrolyte to a concentration tower, introducing hot gas into the concentration tower, evaporating water to increase the mass content of sulfuric acid in the waste electrolyte to 15-25%, and increasing the temperature of the waste electrolyte to 60-65 ℃; (2) Conveying the waste electrolyte to a defluorination chlorine circulation tank; (3) Pumping waste electrolyte in a defluorination chlorine circulation tank to a defluorination chlorine tower, wherein the waste electrolyte falls in a spray shape in the defluorination chlorine tower, and blowing out fluoride ions and chloride ions in the falling liquid drops by introducing 160-220 ℃ hot air into the defluorination chlorine tower, wherein the process simultaneously comprises the following steps: a. The dropped liquid drops flow back to the defluorination and chlorine circulation tank, waste electrolyte in the defluorination and chlorine circulation tank is pumped to the defluorination and chlorine tower again for blowing off, and after a plurality of times of circulation, the finished acid for the wet workshop is obtained when the sulfuric acid mass content in the acid liquor in the defluorination and chlorine circulation tank is detected to reach 65-75%; b. The rising flue gas containing fluoride ions and chloride ions is connected into an alkaline washing tower, sodium hydroxide solution is introduced into the alkaline washing tower to wash the flue gas, the washed gas is emptied, and sodium salt solution generated by reaction is discharged to a sewage treatment station after a plurality of times of circulation; (4) And arranging a clear water supply device, and flushing the drip catcher in the defluorination chlorine tower and the alkaline washing tower in stages.
  2. 2. The method for removing fluorine and chlorine from zinc hydrometallurgy electrolyte circulation liquid according to claim 1, wherein the hot gas is introduced into the concentration tower in the process (1), and the hot flue gas discharged from the rotary kiln is introduced into the concentration tower.
  3. 3. The method for removing fluorine and chlorine from zinc hydrometallurgy electrolyte circulation liquid according to claim 1, wherein a process of filtering the waste electrolyte in a filter press is further arranged between the processes (1) and (2), the filtered waste electrolyte enters the process (2), and filtered filter residues are sent to the rotary kiln.
  4. 4. The method for removing fluorine and chlorine from zinc hydrometallurgy electrolyte circulation liquid according to claim 1, wherein the hot air at 160-220 ℃ introduced into the defluorination chlorine tower in the process (3) is fed into the defluorination chlorine tower after the hot air in the acid making conversion section is subjected to heat compensation by a heat compensation furnace.
  5. 5. The method for removing fluorine and chlorine from zinc hydrometallurgy electrolyte circulation liquid according to claim 1, wherein the mass content of sodium hydroxide in the sodium hydroxide solution fed into the alkaline washing tower in the process (3) is 8-12%.
  6. 6. A system for removing fluorine and chlorine from zinc hydrometallurgy electrolyte circulation liquid is characterized in that the system is a system for intensively removing fluorine and chlorine after collecting waste electrolyte, and is provided with a concentration tower, a defluorination chlorine circulation tank, a defluorination chlorine tower, an alkaline washing tower and a sodium hydroxide configuration tank communicated with an alkaline washing tower pipeline; the concentration tower is provided with a heating device for concentrating the evaporation water of the waste electrolyte, and is communicated with the defluorination chlorine circulating tank; The defluorination and chlorine removal device comprises a defluorination and chlorine removal tower, wherein a first spray device is arranged in the defluorination and chlorine removal tower, the first spray device is connected to a defluorination and chlorine removal circulating tank through a first circulating pump outside the defluorination and chlorine removal tower, a hot air inlet is arranged on the defluorination and chlorine removal tower and below the first spray device, the hot air inlet is connected with the hot air device, a fluorine and chlorine blowing off opening is arranged at the top of the defluorination and chlorine removal tower above the first spray device, and a first reflux opening communicated with a defluorination and chlorine removal circulating tank pipeline is arranged at the bottom of the defluorination and chlorine removal tower; The alkaline washing tower is provided with a flue gas inlet, the flue gas inlet is connected with a fluorine-chlorine stripping port pipeline of the defluorination chlorine tower, a second spraying device is arranged above the flue gas inlet, the second spraying device is communicated with a second reflux port pipeline at the bottom of the alkaline washing tower through a second circulating pump outside the alkaline washing tower, and the top of the alkaline washing tower is provided with an emptying port; The first circulating pump is provided with two states of leading to the first spraying device and leading to the finished acid tank, and the second circulating pump is provided with two states of leading to the second spraying device and leading to the sewage outlet; the system is also provided with a clear water supply device, wherein the clear water supply device supplies configuration clear water to the sodium hydroxide configuration groove, flushing clear water to the drip catcher of the defluorination chlorine tower and flushing clear water to the drip catcher of the alkaline washing tower.
  7. 7. The system for removing fluorine and chlorine from zinc hydrometallurgy electrolyte circulation liquid according to claim 6, wherein the heating device is a heat exchange tube communicated with an external rotary kiln smoke exhaust system.
  8. 8. The system for removing fluorine and chlorine from zinc hydrometallurgy electrolyte circulation liquid according to claim 6, wherein a filter press and a liquid storage tank are connected between the concentration tower and the defluorination chlorine circulation tank in sequence through pipelines, and a liquid suction pump is arranged between the liquid storage tank and the defluorination chlorine circulation tank.
  9. 9. The system for removing fluorine and chlorine from zinc hydrometallurgy electrolyte circulation liquid according to claim 6, wherein the hot air device comprises a heat supplementing furnace, a fan and a pipeline connected with a hot air discharge system of an external acid making conversion section.

Description

Method and system for removing fluorine and chlorine from zinc hydrometallurgy electrolyte circulation liquid Technical Field The invention relates to the technical field of hydrometallurgy, in particular to a method and a system for removing fluorine and chlorine from a zinc hydrometallurgy electrolyte circulating solution. Background Zinc hydrometallurgy is to melt zinc in zinc-containing materials (such as zinc calcine, zinc smoke dust, zinc oxide ore and the like) by dilute sulfuric acid to form zinc sulfate, the clarified zinc sulfate solution enters an electrowinning tank, zinc ions are reduced to metal zinc and gradually deposited on an aluminum cathode under the action of current, electrolyte in the electrowinning tank is used as a solvent to be continuously recycled for melting the zinc-containing materials, so that fluorine and chlorine naturally contained in the zinc-containing materials can be accumulated to a harm degree, the biggest harm is to corrode polar plates, the quality of zinc ingots is reduced, the current efficiency is also influenced, the energy consumption is improved, and therefore, the concentration of fluorine ions in the electrolyte is generally required to be not more than 50mg/l, and the concentration of chloride ions is generally required to be not more than 100mg/l. Chinese patent publication No. CN112877736A discloses a method for removing fluorine and chlorine from zinc hydrometallurgy electrolyte, which comprises the steps of adding calcium oxide into the electrolyte, heating to react to obtain calcium fluoride precipitate and fluorine-precipitating solution, adding copper slag into the fluorine-precipitating solution, heating to react to obtain copper chloride precipitate and fluorine-chlorine-removing electrolyte, this method uses copper materials in the copper slag, but the components in the copper slag are complex, and cannot ensure that no new pollutants are brought into the electrolyte, including the addition of calcium oxide to the electrolyte circulation, which is not a pure fluorine and chlorine removal process. Disclosure of Invention The invention aims to solve the technical problems of providing a method for removing fluorine and chlorine from a zinc hydrometallurgy electrolyte circulation solution without changing other components of the waste electrolyte solution and providing a corresponding removal system. The technical scheme adopted for solving the technical problems is as follows: the method for removing fluorine and chlorine from the zinc hydrometallurgy electrolyte circulation liquid is a method for intensively removing fluorine and chlorine after collecting waste electrolyte, and comprises the following steps: (1) Pumping the waste electrolyte to a concentration tower, introducing hot gas into the concentration tower, evaporating water to increase the mass content of sulfuric acid in the waste electrolyte to 15-25%, and increasing the temperature of the waste electrolyte to 60-65 ℃; (2) Conveying the waste electrolyte to a defluorination chlorine circulation tank; (3) Pumping waste electrolyte in a defluorination chlorine circulation tank to a defluorination chlorine tower, wherein the waste electrolyte falls in a spray shape in the defluorination chlorine tower, and blowing out fluoride ions and chloride ions in the falling liquid drops by introducing 160-220 ℃ hot air into the defluorination chlorine tower, wherein the process simultaneously comprises the following steps: a. The dropped liquid drops flow back to the defluorination and chlorine circulation tank, waste electrolyte in the defluorination and chlorine circulation tank is pumped to the defluorination and chlorine tower again for blowing off, and after a plurality of times of circulation, the finished acid for the wet workshop is obtained when the sulfuric acid mass content in the acid liquor in the defluorination and chlorine circulation tank is detected to reach 65-75%; b. And (3) introducing the rising flue gas containing fluoride ions and chloride ions into an alkaline washing tower, introducing sodium hydroxide solution into the alkaline washing tower to wash the flue gas, discharging the sodium salt solution generated by the reaction to a sewage treatment station, and exhausting the washed gas. Specifically, in order to save energy, hot gas is introduced into the concentration tower in the process (1), and hot flue gas exhausted from the rotary kiln is connected into the concentration tower. Specifically, a process of filtering the waste electrolyte by connecting the waste electrolyte to a filter press is further arranged between the processes (1) and (2), the filtered waste electrolyte enters the process (2), and the filtered filter residues are sent to the rotary kiln. In order to save energy, the hot air at 160-220 ℃ is introduced into the defluorination and chlorine removal tower in the process (3), and the hot air in the acid making conversion section is fed into the defluorin