Method for recovering high-purity zinc from electric furnace ash containing secondary zinc oxide

Abstract

The invention discloses a method for recovering high-purity zinc from secondary zinc oxide-containing electric furnace ash, which comprises the following steps: firstly, treating by sodium carbonate to form a precipitate containing zinc and other metal elements so as to separate chlorine and fluorine ions in the electric furnace ash, and fixing soluble zinc salt in the electric furnace ash to reduce the loss of zinc. Subsequently, zinc and other metal elements form soluble ions through sulfuric acid treatment; adding hydrogen peroxide to remove iron, and adding potassium permanganate to remove manganese, so as to obtain a primary leaching solution; the primary leachate is treated by ethylenediamine, tea saponin and urea, and reacts with zinc ions to form a stable complex, so that the zinc ions are prevented from being continuously precipitated by ammonia water, and hydroxide precipitates of other ions are separated. Subsequently, a dilute sulfuric acid solution is used for decomposing the complex, zinc is precipitated through sodium carbonate, and recovery of the zinc element is completed. By adopting the method disclosed by the invention, the zinc in the secondary zinc oxide-containing electric furnace ash recovery product has a relatively high leaching rate, and the purity of the zinc-containing product zinc carbonate in the obtained product is relatively high.

Description

Technical Field

[0001] The invention relates to the technical field of zinc recovery, and in particular to a method for recovering high-purity zinc from electric furnace ash containing secondary zinc oxide. Background Art

[0002] Secondary zinc oxide powder mainly comes from the smoke dust of zinc leaching slag in rotary kiln, the smoke dust of zinc concentrate boiling furnace roasting, and the smoke dust of pyrometallurgical lead smelting and ironworks, etc., and is an extremely important zinc resource. Secondary zinc oxide powder not only contains a large amount of valuable metals such as zinc, copper, lead, and silver, but also contains a large amount of impurities such as fluorine and chlorine. If it is not handled in time and abandoned at will, it will cause very serious pollution to the surrounding soil and water bodies, directly affect the living environment of animals and plants, destroy local biodiversity and ecological environment, and endanger human health. There are many methods for processing secondary zinc oxide at present, but the existing methods have the disadvantages of complex process, harsh operating environment, and large environmental pollution. Summary of the invention

[0003] To this end, the present invention provides a method for recovering high-purity zinc from electric furnace ash containing secondary zinc oxide, the steps comprising:

[0004] (1) preparing an aqueous solution of sodium carbonate; adding electric furnace ash containing zinc oxide to the aqueous solution of sodium carbonate, rapidly stirring at a stirring speed of 200 to 500 r / min for more than 10 min, separating the solid and liquid after the stirring is completed, and drying the solid phase to obtain a primary treatment product;

[0005] (2) adding the primary treatment product to a sulfuric acid solution to form a mixture, heating the mixture to 75±5°C for insulation, stirring and leaching at a constant temperature for more than 60 minutes, then adding hydrogen peroxide to the mixture, stirring at a constant temperature of 75±5°C for more than 30 minutes after the addition is completed, adding ammonia water to adjust the pH to 5-5.5 after the stirring is completed, then adding potassium permanganate powder under stirring, stirring at a constant temperature of 75±5°C for more than 30 minutes after the addition is completed, separating the solid and liquid to remove the precipitate phase, and obtaining a primary leachate;

[0006] (3) preparing a composite ethanol aqueous solution of tea saponin and urea; stirring the primary leachate, then adding an aqueous solution of ethylenediamine to the primary leachate under stirring, continuing to stir the solution for more than 30 minutes after the addition is completed, then adding the composite ethanol aqueous solution of tea saponin and urea to the solution under stirring, stirring for more than 2 hours after the addition, then adding ammonia water to adjust the pH of the solution to 10-10.5, stirring the solution for more than 20 minutes, and removing the precipitate phase by solid-liquid separation to obtain a secondary leachate;

[0007] (4) adding a dilute sulfuric acid solution to the secondary leachate under stirring, and after the addition is completed, the temperature is kept constant at 60±5° C. in a water bath, and the solution is stirred at the constant temperature for more than 30 minutes, and then a sodium hydroxide solution is added to the solution to adjust the pH value of the solution to neutral, and then a sodium carbonate solution is added dropwise until no precipitation is generated to form a zinc-containing precipitate, which is then dried to obtain a zinc-containing product.

[0008] Furthermore, in the step (1), the concentration of sodium carbonate in the aqueous solution of sodium carbonate is 50-60 g / L, and the solvent is water; the solid-liquid mass ratio of the electric furnace ash containing zinc oxide to the aqueous solution of sodium carbonate is electric furnace ash containing zinc oxide: sodium carbonate aqueous solution = 1:7-8.

[0009] Furthermore, in the step (2), the mass ratio of the primary treatment product added to the sulfuric acid solution is primary treatment product: sulfuric acid solution = 1:4-5; wherein the mass percentage of the solute in the sulfuric acid is 20%-25%; the mass ratio of the added mass of the hydrogen peroxide, the added mass of the potassium permanganate powder and the mass ratio of the primary treatment product added to the mixture is hydrogen peroxide: potassium permanganate powder: primary treatment product = 1-2:0.05-0.08:1, wherein the mass percentage of the solute in the hydrogen peroxide is 10%.

[0010] Furthermore, in the step (3), in the composite ethanol aqueous solution of tea saponin and urea, the concentration of tea saponin is 26-30 g / L, the concentration of urea is 80-85 g / L, and the solvent is an ethanol aqueous solution with a volume percentage of 30%-40%; the mass percentage of ethylenediamine in the aqueous solution of ethylenediamine is 20%-25%, and the solvent is water; the volume ratio of the aqueous solution of ethylenediamine and the composite ethanol aqueous solution of tea saponin and urea added to the primary leaching solution is primary leaching solution: aqueous solution of ethylenediamine: composite ethanol aqueous solution of tea saponin and urea = 10:1-3:1-5.

[0011] Furthermore, in step (4), the mass percentage of the solute in the dilute sulfuric acid solution is 8% to 10%, and the solvent is water; the volume ratio of the added volume of the dilute sulfuric acid solution to the secondary leaching solution is dilute sulfuric acid solution: secondary leaching solution = 2 to 3:10; the mass percentage of the solute in the sodium hydroxide solution is 5% to 10%.

[0012] The beneficial effect of the present invention is that the zinc in the product recovered from the electric furnace ash containing secondary zinc oxide by the method of the present invention has a high leaching rate, and the purity of the zinc carbonate product containing zinc in the product is high, and the recovery efficiency is significantly improved. This is mainly because: the present invention first forms a precipitate containing zinc and other metal elements by sodium carbonate treatment to separate the chlorine and fluorine ions in the electric furnace ash, and fixes the soluble zinc salt in the electric furnace ash to reduce the loss of zinc. Subsequently, the zinc and other metal elements are formed into soluble ions by sulfuric acid treatment, which is convenient for leaching and separation; hydrogen peroxide is added to remove iron, and potassium permanganate is added to remove manganese to obtain a primary leachate. The primary leachate is treated with ethylenediamine, tea saponin, and urea, and the structural units of ethylenediamine, tea saponin, and urea react with zinc ions to form a stable complex, preventing it from being precipitated by ammonia water, thereby separating the hydroxide precipitates of other ions. Subsequently, the complex is decomposed by a dilute sulfuric acid solution, and zinc is precipitated by sodium carbonate to complete the recovery of the zinc element. DETAILED DESCRIPTION

[0013] The present invention will be further described below in conjunction with the embodiments.

[0014] Example 1

[0015] A method for recovering high-purity zinc from electric furnace ash containing secondary zinc oxide, comprising the following steps:

[0016] (1) preparing an aqueous solution of sodium carbonate; in the aqueous solution of sodium carbonate, the concentration of sodium carbonate is 50 g / L, and the solvent is water; adding electric furnace ash containing zinc oxide (all embodiments and comparative examples are made from the same batch of electric furnace ash raw materials) to the aqueous solution of sodium carbonate, and the solid-liquid mass ratio of the electric furnace ash containing zinc oxide to the aqueous solution of sodium carbonate is electric furnace ash containing zinc oxide: aqueous solution of sodium carbonate = 1:7; rapidly stirring, the stirring speed is 300 r / min, the stirring time is 10 min, after the stirring is completed, the solid-liquid separation is carried out, and the solid phase is dried to obtain a primary treatment product;

[0017] (2) adding the primary treatment product to a sulfuric acid solution to form a mixture, wherein the mass ratio of the primary treatment product to the sulfuric acid solution is primary treatment product: sulfuric acid solution = 1:4; wherein the mass percentage of the solute in the sulfuric acid is 25%; the mixture is heated to 75°C for insulation, stirred at a constant temperature for leaching for 60 minutes, and then hydrogen peroxide is added to the mixture, and after the addition is completed, stirring is continued at a constant temperature of 75°C for 30 minutes, and after the stirring is completed, ammonia water (the mass percentage of the solute is 20%) is added to adjust the pH to 5, and then potassium permanganate powder is added under stirring, and the mass ratio of the added mass of the hydrogen peroxide, the added mass of the potassium permanganate powder and the mass of the primary treatment product added to the mixture is hydrogen peroxide: potassium permanganate powder: primary treatment product = 1:0.05:1, wherein the mass percentage of the solute in the hydrogen peroxide is 10%; after the addition is completed, stirring is continued at a constant temperature of 75°C for 30 minutes, and the precipitate phase is removed by solid-liquid separation to obtain a primary leachate;

[0018] (3) preparing a composite ethanol aqueous solution of tea saponin and urea; in the composite ethanol aqueous solution of tea saponin and urea, the concentration of tea saponin is 26 g / L, the concentration of urea is 80 g / L, and the solvent is an ethanol aqueous solution with a volume percentage of 30% ethanol; stirring the primary leaching solution, and then adding an aqueous solution of ethylenediamine to the primary leaching solution under stirring, wherein the mass percentage of ethylenediamine in the aqueous solution of ethylenediamine is 20%, and the solvent is water; after the addition is completed, the solution is stirred for 30 minutes, and then The composite ethanol aqueous solution of tea saponin and urea is added to the solution under stirring, and the volume ratio of the aqueous solution of ethylenediamine and the composite ethanol aqueous solution of tea saponin and urea is added to the primary leaching solution: the aqueous solution of ethylenediamine: the composite ethanol aqueous solution of tea saponin and urea = 10:1:1; after adding the materials, stirring for another 2 hours, then adding ammonia water (the mass percentage of the solute is 20%) to adjust the pH of the solution to 10, stirring the solution for 20 minutes, and removing the precipitate phase by solid-liquid separation to obtain a secondary leaching solution;

[0019] (4) adding a dilute sulfuric acid solution to the secondary leachate under stirring, wherein the mass percentage of the solute in the dilute sulfuric acid solution is 8%, and the solvent is water; the volume ratio of the added volume of the dilute sulfuric acid solution to the secondary leachate is dilute sulfuric acid solution: secondary leachate = 2:10; after the addition is completed, the water bath is kept at a constant temperature of 60° C., and then stirred at the constant temperature for 30 minutes, and then sodium hydroxide solution is added to the solution to adjust the pH of the solution to neutral, and the mass percentage of the solute in the sodium hydroxide solution is 10%; then sodium carbonate solution (solute concentration is 80 g / L) is added dropwise until no precipitation is generated, forming a zinc-containing precipitate, and drying is performed to obtain a zinc-containing product.

[0020] Example 2

[0021] A method for recovering high-purity zinc from electric furnace ash containing secondary zinc oxide, comprising the following steps:

[0022] (1) preparing an aqueous solution of sodium carbonate; in the aqueous solution of sodium carbonate, the concentration of sodium carbonate is 53 g / L, and the solvent is water; adding electric furnace ash containing zinc oxide (all embodiments and comparative examples are made from the same batch of electric furnace ash raw materials) to the aqueous solution of sodium carbonate, and the solid-liquid mass ratio of the electric furnace ash containing zinc oxide to the aqueous solution of sodium carbonate is electric furnace ash containing zinc oxide: aqueous solution of sodium carbonate = 1:7; rapidly stirring, the stirring speed is 300 r / min, the stirring time is 10 min, after the stirring is completed, the solid-liquid separation is carried out, and the solid phase is dried to obtain a primary treatment product;

[0023] (2) adding the primary treatment product to a sulfuric acid solution to form a mixture, wherein the mass ratio of the primary treatment product to the sulfuric acid solution is primary treatment product: sulfuric acid solution = 1:4; wherein the mass percentage of the solute in the sulfuric acid is 25%; the mixture is heated to 75°C for insulation, stirred and leached at a constant temperature for 60 minutes, and then hydrogen peroxide is added to the mixture, and after the addition is completed, stirring is continued at a constant temperature of 75°C for 30 minutes, and after the stirring is completed, ammonia water (the mass percentage of the solute is 20%) is added to adjust the pH to 5, and then potassium permanganate powder is added under stirring, and the mass ratio of the added mass of the hydrogen peroxide, the added mass of the potassium permanganate powder and the mass of the primary treatment product added to the mixture is hydrogen peroxide: potassium permanganate powder: primary treatment product = 1:0.06:1, wherein the mass percentage of the solute in the hydrogen peroxide is 10%; after the addition is completed, stirring is continued at a constant temperature of 75°C for 30 minutes, and the precipitate phase is removed by solid-liquid separation to obtain a primary leachate;

[0024] (3) preparing a composite ethanol aqueous solution of tea saponin and urea; in the composite ethanol aqueous solution of tea saponin and urea, the concentration of tea saponin is 28 g / L, the concentration of urea is 82 g / L, and the solvent is an ethanol aqueous solution with a volume percentage of 30% ethanol; stirring the primary leaching solution, and then adding an aqueous solution of ethylenediamine to the primary leaching solution under stirring, wherein the mass percentage of ethylenediamine in the aqueous solution of ethylenediamine is 20%, and the solvent is water; after the addition is completed, the solution is stirred for 30 minutes, and then The composite ethanol aqueous solution of tea saponin and urea is added to the solution under stirring, and the volume ratio of the aqueous solution of ethylenediamine and the composite ethanol aqueous solution of tea saponin and urea is added to the primary leaching solution: the aqueous solution of ethylenediamine: the composite ethanol aqueous solution of tea saponin and urea = 10:2:3; after adding the materials, stirring for another 2 hours, then adding ammonia water (the mass percentage of the solute is 20%) to adjust the pH of the solution to 10, stirring the solution for 20 minutes, and removing the precipitate phase by solid-liquid separation to obtain a secondary leaching solution;

[0025] (4) adding a dilute sulfuric acid solution to the secondary leachate under stirring, wherein the mass percentage of the solute in the dilute sulfuric acid solution is 8%, and the solvent is water; the volume ratio of the added volume of the dilute sulfuric acid solution to the secondary leachate is dilute sulfuric acid solution: secondary leachate = 2:10; after the addition is completed, the water bath is kept at a constant temperature of 60° C., and then stirred at the constant temperature for 30 minutes, and then sodium hydroxide solution is added to the solution to adjust the pH of the solution to neutral, and the mass percentage of the solute in the sodium hydroxide solution is 10%; then sodium carbonate solution (solute concentration is 80 g / L) is added dropwise until no precipitation is generated, forming a zinc-containing precipitate, and drying is performed to obtain a zinc-containing product.

[0026] Example 3

[0027] A method for recovering high-purity zinc from electric furnace ash containing secondary zinc oxide, comprising the following steps:

[0028] (1) preparing an aqueous solution of sodium carbonate; in the aqueous solution of sodium carbonate, the concentration of sodium carbonate is 58 g / L, and the solvent is water; adding electric furnace ash containing zinc oxide (all embodiments and comparative examples are made from the same batch of electric furnace ash raw materials) to the aqueous solution of sodium carbonate, and the solid-liquid mass ratio of the electric furnace ash containing zinc oxide to the aqueous solution of sodium carbonate is electric furnace ash containing zinc oxide: aqueous solution of sodium carbonate = 1:8; rapidly stirring, the stirring speed is 300 r / min, the stirring time is 10 min, after the stirring is completed, the solid-liquid separation is carried out, and the solid phase is dried to obtain a primary treatment product;

[0029] (2) adding the primary treatment product to a sulfuric acid solution to form a mixture, wherein the mass ratio of the primary treatment product to the sulfuric acid solution is primary treatment product: sulfuric acid solution = 1:5; wherein the mass percentage of the solute in the sulfuric acid is 20%; the mixture is heated to 75°C for insulation, stirred at a constant temperature for leaching for 60 minutes, and then hydrogen peroxide is added to the mixture, and after the addition is completed, stirring is continued at 75°C for 30 minutes, and after the stirring is completed, ammonia water (the mass percentage of the solute is 20%) is added to adjust the pH to 5, and then potassium permanganate powder is added under stirring, and the mass ratio of the added mass of the hydrogen peroxide, the added mass of the potassium permanganate powder and the mass of the primary treatment product added to the mixture is hydrogen peroxide: potassium permanganate powder: primary treatment product = 2:0.07:1, wherein the mass percentage of the solute in the hydrogen peroxide is 10%; after the addition is completed, stirring is continued at 75°C for 30 minutes, and the precipitate phase is removed by solid-liquid separation to obtain a primary leachate;

[0030] (3) preparing a composite ethanol aqueous solution of tea saponin and urea; in the composite ethanol aqueous solution of tea saponin and urea, the concentration of tea saponin is 28 g / L, the concentration of urea is 83 g / L, and the solvent is an ethanol aqueous solution with a volume percentage of 40% ethanol; stirring the primary leaching solution, and then adding an aqueous solution of ethylenediamine to the primary leaching solution under stirring, wherein the mass percentage of ethylenediamine in the aqueous solution of ethylenediamine is 25%, and the solvent is water; after the addition is completed, the solution is stirred for 30 minutes, and then The composite ethanol aqueous solution of tea saponin and urea is added to the solution under stirring, and the volume ratio of the aqueous solution of ethylenediamine and the composite ethanol aqueous solution of tea saponin and urea is added to the primary leaching solution: the aqueous solution of ethylenediamine: the composite ethanol aqueous solution of tea saponin and urea = 10:2:3; after adding the materials, stirring for another 2 hours, then adding ammonia water (the mass percentage of the solute is 20%) to adjust the pH of the solution to 10, stirring the solution for 20 minutes, and removing the precipitate phase by solid-liquid separation to obtain a secondary leaching solution;

[0031] (4) adding a dilute sulfuric acid solution to the secondary leachate under stirring, wherein the mass percentage of the solute in the dilute sulfuric acid solution is 10%, and the solvent is water; the volume ratio of the added volume of the dilute sulfuric acid solution to the secondary leachate is dilute sulfuric acid solution: secondary leachate = 3:10; after the addition is completed, the water bath is kept at a constant temperature of 60° C., and then stirred at the constant temperature for 30 minutes, and then sodium hydroxide solution is added to the solution to adjust the pH of the solution to neutral, and the mass percentage of the solute in the sodium hydroxide solution is 10%; then sodium carbonate solution (solute concentration is 80 g / L) is added dropwise until no precipitation is generated, forming a zinc-containing precipitate, and drying is performed to obtain a zinc-containing product.

[0032] Example 4

[0033] A method for recovering high-purity zinc from electric furnace ash containing secondary zinc oxide, comprising the following steps:

[0034] (1) preparing an aqueous solution of sodium carbonate; in the aqueous solution of sodium carbonate, the concentration of sodium carbonate is 60 g / L, and the solvent is water; adding electric furnace ash containing zinc oxide (all embodiments and comparative examples are made from the same batch of electric furnace ash raw materials) to the aqueous solution of sodium carbonate, and the solid-liquid mass ratio of the electric furnace ash containing zinc oxide to the aqueous solution of sodium carbonate is electric furnace ash containing zinc oxide: aqueous solution of sodium carbonate = 1:8; rapidly stirring, the stirring speed is 300 r / min, the stirring time is 10 min, after the stirring is completed, the solid-liquid separation is carried out, and the solid phase is dried to obtain a primary treatment product;

[0035] (2) adding the primary treatment product to a sulfuric acid solution to form a mixture, wherein the mass ratio of the primary treatment product to the sulfuric acid solution is primary treatment product: sulfuric acid solution = 1:5; wherein the mass percentage of the solute in the sulfuric acid is 20%; the mixture is heated to 75°C for insulation, stirred at a constant temperature for leaching for 60 minutes, and then hydrogen peroxide is added to the mixture, and after the addition is completed, stirring is continued at a constant temperature of 75°C for 30 minutes, and after the stirring is completed, ammonia water (the mass percentage of the solute is 20%) is added to adjust the pH to 5, and then potassium permanganate powder is added under stirring, and the mass ratio of the added mass of the hydrogen peroxide, the added mass of the potassium permanganate powder and the mass of the primary treatment product added to the mixture is hydrogen peroxide: potassium permanganate powder: primary treatment product = 2:0.08:1, wherein the mass percentage of the solute in the hydrogen peroxide is 10%; after the addition is completed, stirring is continued at a constant temperature of 75°C for 30 minutes, and the precipitate phase is removed by solid-liquid separation to obtain a primary leachate;

[0036] (3) preparing a composite ethanol aqueous solution of tea saponin and urea; in the composite ethanol aqueous solution of tea saponin and urea, the concentration of tea saponin is 30 g / L, the concentration of urea is 85 g / L, and the solvent is an ethanol aqueous solution with a volume percentage of 40% ethanol; stirring the primary leaching solution, and then adding an aqueous solution of ethylenediamine to the primary leaching solution under stirring, wherein the mass percentage of ethylenediamine in the aqueous solution of ethylenediamine is 25%, and the solvent is water; after the addition is completed, the solution is stirred for 30 minutes, and then The composite ethanol aqueous solution of tea saponin and urea is added to the solution under stirring, and the volume ratio of the aqueous solution of ethylenediamine and the composite ethanol aqueous solution of tea saponin and urea is added to the primary leaching solution: the aqueous solution of ethylenediamine: the composite ethanol aqueous solution of tea saponin and urea = 10:3:5; after adding the materials, stirring for another 2 hours, then adding ammonia water (the mass percentage of the solute is 20%) to adjust the pH of the solution to 10, stirring the solution for 20 minutes, and removing the precipitate phase by solid-liquid separation to obtain a secondary leaching solution;

[0037] (4) adding a dilute sulfuric acid solution to the secondary leachate under stirring, wherein the mass percentage of the solute in the dilute sulfuric acid solution is 10%, and the solvent is water; the volume ratio of the added volume of the dilute sulfuric acid solution to the secondary leachate is dilute sulfuric acid solution: secondary leachate = 3:10; after the addition is completed, the water bath is kept at a constant temperature of 60° C., and then stirred at the constant temperature for 30 minutes, and then sodium hydroxide solution is added to the solution to adjust the pH of the solution to neutral, and the mass percentage of the solute in the sodium hydroxide solution is 10%; then sodium carbonate solution (solute concentration is 80 g / L) is added dropwise until no precipitation is generated, forming a zinc-containing precipitate, and drying is performed to obtain a zinc-containing product.

[0038] Comparative Example 1

[0039] A comparative method for recovering zinc from electric furnace ash containing secondary zinc oxide comprises the following steps:

[0040] (1) preparing an aqueous solution of sodium carbonate; in the aqueous solution of sodium carbonate, the concentration of sodium carbonate is 58 g / L, and the solvent is water; adding electric furnace ash containing zinc oxide (all embodiments and comparative examples are made from the same batch of electric furnace ash raw materials) to the aqueous solution of sodium carbonate, and the solid-liquid mass ratio of the electric furnace ash containing zinc oxide to the aqueous solution of sodium carbonate is electric furnace ash containing zinc oxide: aqueous solution of sodium carbonate = 1:8; rapidly stirring, the stirring speed is 300 r / min, the stirring time is 10 min, after the stirring is completed, the solid-liquid separation is carried out, and the solid phase is dried to obtain a primary treatment product;

[0041] (2) adding the primary treatment product to a sulfuric acid solution to form a mixture, wherein the mass ratio of the primary treatment product to the sulfuric acid solution is primary treatment product: sulfuric acid solution = 1:5; wherein the mass percentage of the solute in the sulfuric acid is 20%; the mixture is heated to 75°C for insulation, stirred at a constant temperature for leaching for 60 minutes, and then hydrogen peroxide is added to the mixture, and after the addition is completed, stirring is continued at 75°C for 30 minutes, and after the stirring is completed, ammonia water (the mass percentage of the solute is 20%) is added to adjust the pH to 5, and then potassium permanganate powder is added under stirring, and the mass ratio of the added mass of the hydrogen peroxide, the added mass of the potassium permanganate powder and the mass of the primary treatment product added to the mixture is hydrogen peroxide: potassium permanganate powder: primary treatment product = 2:0.07:1, wherein the mass percentage of the solute in the hydrogen peroxide is 10%; after the addition is completed, stirring is continued at 75°C for 30 minutes, and the precipitate phase is removed by solid-liquid separation to obtain a primary leachate;

[0042] (3) stirring the primary leachate, and then adding an aqueous solution of ethylenediamine to the primary leachate under stirring, wherein the mass percentage of ethylenediamine in the aqueous solution of ethylenediamine is 25%, and the solvent is water; after the addition is completed, the solution is stirred for 2 hours, and the volume ratio of the aqueous solution of ethylenediamine added to the primary leachate is primary leachate: aqueous solution of ethylenediamine = 10:2; then adding ammonia water (the mass percentage of the solute is 20%) to adjust the pH of the solution to 10, stirring the solution for 20 minutes, and removing the precipitate phase by solid-liquid separation to obtain the secondary leachate of this comparative example;

[0043] (4) adding a dilute sulfuric acid solution to the secondary leachate under stirring, wherein the mass percentage of the solute in the dilute sulfuric acid solution is 10%, and the solvent is water; the volume ratio of the added volume of the dilute sulfuric acid solution to the secondary leachate is dilute sulfuric acid solution: secondary leachate = 3:10; after the addition is completed, the water bath is kept at a constant temperature of 60° C., and then stirred at the constant temperature for 30 minutes, and then sodium hydroxide solution is added to the solution to adjust the pH of the solution to neutral, and the mass percentage of the solute in the sodium hydroxide solution is 10%; then sodium carbonate solution (solute concentration is 80 g / L) is added dropwise until no precipitation is generated to form a zinc-containing precipitate, which is dried to obtain the zinc-containing product of this comparative example.

[0044] Comparative Example 2

[0045] A comparative method for recovering zinc from electric furnace ash containing secondary zinc oxide comprises the following steps:

[0046] (1) preparing an aqueous solution of sodium carbonate; in the aqueous solution of sodium carbonate, the concentration of sodium carbonate is 58 g / L, and the solvent is water; adding electric furnace ash containing zinc oxide (all embodiments and comparative examples are made from the same batch of electric furnace ash raw materials) to the aqueous solution of sodium carbonate, and the solid-liquid mass ratio of the electric furnace ash containing zinc oxide to the aqueous solution of sodium carbonate is electric furnace ash containing zinc oxide: aqueous solution of sodium carbonate = 1:8; rapidly stirring, the stirring speed is 300 r / min, the stirring time is 10 min, after the stirring is completed, the solid-liquid separation is carried out, and the solid phase is dried to obtain a primary treatment product;

[0047] (2) adding the primary treatment product to a sulfuric acid solution to form a mixture, wherein the mass ratio of the primary treatment product to the sulfuric acid solution is primary treatment product: sulfuric acid solution = 1:5; wherein the mass percentage of the solute in the sulfuric acid is 20%; the mixture is heated to 75°C for insulation, stirred at a constant temperature for leaching for 60 minutes, and then hydrogen peroxide is added to the mixture, and after the addition is completed, stirring is continued at 75°C for 30 minutes, and after the stirring is completed, ammonia water (the mass percentage of the solute is 20%) is added to adjust the pH to 5, and then potassium permanganate powder is added under stirring, and the mass ratio of the added mass of the hydrogen peroxide, the added mass of the potassium permanganate powder and the mass of the primary treatment product added to the mixture is hydrogen peroxide: potassium permanganate powder: primary treatment product = 2:0.07:1, wherein the mass percentage of the solute in the hydrogen peroxide is 10%; after the addition is completed, stirring is continued at 75°C for 30 minutes, and the precipitate phase is removed by solid-liquid separation to obtain a primary leachate;

[0048] (3) preparing an ethanol aqueous solution of tea saponin; in the ethanol aqueous solution of tea saponin, the concentration of tea saponin is 28 g / L, and the solvent is an ethanol aqueous solution with a volume percentage of 40% ethanol; stirring the primary leachate, and then adding an aqueous solution of ethylenediamine to the primary leachate under stirring, wherein the mass percentage of ethylenediamine in the aqueous solution of ethylenediamine is 25%, and the solvent is water; after the addition is completed, the solution is stirred for 30 minutes, and then the ethanol aqueous solution of tea saponin is added to the solution under stirring, and the volume ratio of the aqueous solution of ethylenediamine and the ethanol aqueous solution of tea saponin added to the primary leachate is primary leachate: aqueous solution of ethylenediamine: ethanol aqueous solution of tea saponin = 10:2:3; stirring for another 2 hours after the addition, and then adding ammonia water (solute mass percentage is 20%) to adjust the pH of the solution to 10, stirring the solution for 20 minutes, and removing the precipitate phase by solid-liquid separation to obtain a secondary leachate;

[0049] (4) adding a dilute sulfuric acid solution to the secondary leachate under stirring, wherein the mass percentage of the solute in the dilute sulfuric acid solution is 10%, and the solvent is water; the volume ratio of the added volume of the dilute sulfuric acid solution to the secondary leachate is dilute sulfuric acid solution: secondary leachate = 3:10; after the addition is completed, the water bath is kept at a constant temperature of 60° C., and then stirred at the constant temperature for 30 minutes, and then sodium hydroxide solution is added to the solution to adjust the pH of the solution to neutral, and the mass percentage of the solute in the sodium hydroxide solution is 10%; then sodium carbonate solution (solute concentration is 80 g / L) is added dropwise until no precipitation is generated to form a zinc-containing precipitate, which is dried to obtain the zinc-containing product of this comparative example.

[0050] Comparative Example 3

[0051] A comparative method for recovering zinc from electric furnace ash containing secondary zinc oxide comprises the following steps:

[0052] (1) preparing an aqueous solution of sodium carbonate; in the aqueous solution of sodium carbonate, the concentration of sodium carbonate is 58 g / L, and the solvent is water; adding electric furnace ash containing zinc oxide (all embodiments and comparative examples are made from the same batch of electric furnace ash raw materials) to the aqueous solution of sodium carbonate, and the solid-liquid mass ratio of the electric furnace ash containing zinc oxide to the aqueous solution of sodium carbonate is electric furnace ash containing zinc oxide: aqueous solution of sodium carbonate = 1:8; rapidly stirring, the stirring speed is 300 r / min, the stirring time is 10 min, after the stirring is completed, the solid-liquid separation is carried out, and the solid phase is dried to obtain a primary treatment product;

[0053] (2) adding the primary treatment product to a sulfuric acid solution to form a mixture, wherein the mass ratio of the primary treatment product to the sulfuric acid solution is primary treatment product: sulfuric acid solution = 1:5; wherein the mass percentage of the solute in the sulfuric acid is 20%; the mixture is heated to 75°C for insulation, stirred at a constant temperature for leaching for 60 minutes, and then hydrogen peroxide is added to the mixture, and after the addition is completed, stirring is continued at 75°C for 30 minutes, and after the stirring is completed, ammonia water (the mass percentage of the solute is 20%) is added to adjust the pH to 5, and then potassium permanganate powder is added under stirring, and the mass ratio of the added mass of the hydrogen peroxide, the added mass of the potassium permanganate powder and the mass of the primary treatment product added to the mixture is hydrogen peroxide: potassium permanganate powder: primary treatment product = 2:0.07:1, wherein the mass percentage of the solute in the hydrogen peroxide is 10%; after the addition is completed, stirring is continued at 75°C for 30 minutes, and the precipitate phase is removed by solid-liquid separation to obtain a primary leachate;

[0054] (3) preparing an ethanol aqueous solution of urea; in the ethanol aqueous solution of urea, the concentration of urea is 83 g / L, and the solvent is an ethanol aqueous solution with a volume percentage of 40% of ethanol; stirring the primary leachate, and then adding an aqueous solution of ethylenediamine to the primary leachate under stirring, wherein the mass percentage of ethylenediamine in the aqueous solution of ethylenediamine is 25%, and the solvent is water; after the addition is completed, continuing to stir the solution for 30 minutes, and then adding the ethanol aqueous solution of urea to the solution under stirring, the volume ratio of the aqueous solution of ethylenediamine and the ethanol aqueous solution of urea added to the primary leachate is primary leachate: aqueous solution of ethylenediamine: ethanol aqueous solution of urea = 10:2:3; stirring for another 2 hours after the addition, and then adding ammonia water (solute mass percentage is 20%) to adjust the pH of the solution to 10, stirring the solution for 20 minutes, and removing the precipitate phase by solid-liquid separation to obtain a secondary leachate;

[0055] (4) adding a dilute sulfuric acid solution to the secondary leachate under stirring, wherein the mass percentage of the solute in the dilute sulfuric acid solution is 10%, and the solvent is water; the volume ratio of the added volume of the dilute sulfuric acid solution to the secondary leachate is dilute sulfuric acid solution: secondary leachate = 3:10; after the addition is completed, the water bath is kept at a constant temperature of 60° C., and then stirred at the constant temperature for 30 minutes, and then sodium hydroxide solution is added to the solution to adjust the pH of the solution to neutral, and the mass percentage of the solute in the sodium hydroxide solution is 10%; then sodium carbonate solution (solute concentration is 80 g / L) is added dropwise until no precipitation is generated to form a zinc-containing precipitate, which is dried to obtain the zinc-containing product of this comparative example.

[0056] Example 5

[0057] The zinc content in the zinc-containing products obtained by the methods described in the above embodiments and comparative examples was tested respectively, and the zinc leaching rate and the purity of zinc carbonate in the products were calculated. The results are shown in Table 1.

[0058] As shown in Table 1, the zinc in the product recovered from the electric furnace ash containing secondary zinc oxide by the method of the present invention has a high leaching rate, and the purity of the zinc carbonate product containing zinc in the product is high, and the recovery efficiency is significantly improved. This is mainly due to: the present invention first forms a precipitate containing zinc and other metal elements by sodium carbonate treatment to separate the chlorine and fluorine ions in the electric furnace ash, and fixes the soluble zinc salt in the electric furnace ash to reduce the loss of zinc. Subsequently, zinc and other metal elements are formed into soluble ions by sulfuric acid treatment, which is convenient for leaching and separation; hydrogen peroxide is added to remove iron, and potassium permanganate is added to remove manganese to obtain a primary leachate. The primary leachate is treated with ethylenediamine, tea saponin, and urea, and the structural units of ethylenediamine, tea saponin, and urea react with zinc ions to form a stable complex, preventing it from being precipitated by ammonia water, thereby separating the hydroxide precipitates of other ions. Subsequently, the complex is decomposed with a dilute sulfuric acid solution, and zinc is precipitated by sodium carbonate to complete the recovery of the zinc element.

[0059] Table 1

[0060] Experimental Group Zinc leaching rate Purity of zinc carbonate Example 1 91.5％ 99.0％ Example 2 92.3％ 99.3％ Example 3 92.6％ 99.3％ Example 4 91.8％ 99.2％ Comparative Example 1 79.2％ 93.7％ Comparative Example 2 83.7％ 96.1％ Comparative Example 3 82.0％ 95.9％

[0061] The technical solution provided by the present invention is introduced in detail above. For those skilled in the art, according to the concept of the embodiments of the present invention, there may be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for recovering high-purity zinc from electric furnace ash containing secondary zinc oxide, characterized in that the steps include: (1) preparing an aqueous solution of sodium carbonate; adding electric furnace ash containing zinc oxide to the aqueous solution of sodium carbonate, rapidly stirring at a stirring speed of 200 to 500 r / min for more than 10 min, separating the solid and liquid after the stirring is completed, and drying the solid phase to obtain a primary treatment product; (2) adding the primary treatment product to a sulfuric acid solution to form a mixture, heating the mixture to 75±5°C for insulation, stirring and leaching at a constant temperature for more than 60 minutes, then adding hydrogen peroxide to the mixture, stirring at a constant temperature of 75±5°C for more than 30 minutes after the addition is completed, adding ammonia water to adjust the pH to 5-5.5 after the stirring is completed, then adding potassium permanganate powder under stirring, stirring at a constant temperature of 75±5°C for more than 30 minutes after the addition is completed, separating the solid and liquid to remove the precipitate phase, and obtaining a primary leachate; (3) preparing a composite ethanol aqueous solution of tea saponin and urea; stirring the primary leachate, then adding an aqueous solution of ethylenediamine to the primary leachate under stirring, continuing to stir the solution for more than 30 minutes after the addition is completed, then adding the composite ethanol aqueous solution of tea saponin and urea to the solution under stirring, stirring for more than 2 hours after the addition, then adding ammonia water to adjust the pH of the solution to 10-10.5, stirring the solution for more than 20 minutes, and removing the precipitate phase by solid-liquid separation to obtain a secondary leachate; (4) adding a dilute sulfuric acid solution to the secondary leachate under stirring, and after the addition is completed, the temperature is kept constant at 60±5° C. in a water bath, and the solution is stirred at the constant temperature for more than 30 minutes, and then a sodium hydroxide solution is added to the solution to adjust the pH value of the solution to neutral, and then a sodium carbonate solution is added dropwise until no precipitation is generated to form a zinc-containing precipitate, which is then dried to obtain a zinc-containing product.

2. The method for recovering high-purity zinc from electric furnace ash containing secondary zinc oxide according to claim 1, characterized in that: In the step (1), the concentration of sodium carbonate in the aqueous solution of sodium carbonate is 50-60 g / L, and the solvent is water; the solid-liquid mass ratio of the electric furnace ash containing zinc oxide to the aqueous solution of sodium carbonate is electric furnace ash containing zinc oxide: sodium carbonate aqueous solution = 1:7-8.

3. The method for recovering high-purity zinc from electric furnace ash containing secondary zinc oxide according to claim 1, characterized in that: In the step (2), the mass ratio of the primary treatment product added to the sulfuric acid solution is primary treatment product: sulfuric acid solution = 1:4-5; wherein the mass percentage of the solute in the sulfuric acid is 20%-25%; the mass ratio of the added mass of the hydrogen peroxide, the added mass of the potassium permanganate powder and the mass ratio of the primary treatment product added to the mixture is hydrogen peroxide: potassium permanganate powder: primary treatment product = 1-2:0.05-0.08:1, wherein the mass percentage of the solute in the hydrogen peroxide is 10%.

4. The method for recovering high-purity zinc from electric furnace ash containing secondary zinc oxide according to claim 1, characterized in that: In the step (3), in the composite ethanol aqueous solution of tea saponin and urea, the concentration of tea saponin is 26-30 g / L, the concentration of urea is 80-85 g / L, and the solvent is an ethanol aqueous solution with a volume percentage of 30%-40%; the mass percentage of ethylenediamine in the aqueous solution of ethylenediamine is 20%-25%, and the solvent is water; the volume ratio of the aqueous solution of ethylenediamine and the composite ethanol aqueous solution of tea saponin and urea added to the primary leaching solution is primary leaching solution: aqueous solution of ethylenediamine: composite ethanol aqueous solution of tea saponin and urea = 10:1-3:1-5.

5. The method for recovering high-purity zinc from electric furnace ash containing secondary zinc oxide according to claim 1, characterized in that: In the step (4), the mass percentage of the solute in the dilute sulfuric acid solution is 8% to 10%, and the solvent is water; the volume ratio of the added volume of the dilute sulfuric acid solution to the volume of the secondary leaching solution is the dilute sulfuric acid solution: Secondary leaching solution = 2-3:10; the mass percentage of the solute in the sodium hydroxide solution is 5%-10%.