Recycling method of fluorine-containing and indium-containing waste liquid

Abstract

The invention discloses a recycling method of fluorine-containing and indium-containing waste liquid, and belongs to the technical field of resource recycling, the method comprises the following steps: adjusting the pH value of the fluorine-containing and indium-containing waste liquid to 3-5, effectively precipitating indium, reducing the precipitation of other ions, calcining the precipitate, promoting the decomposition of indium oxide, and carrying out reduction calcination to obtain high-purity crude indium; the pH value of the supernatant is adjusted to 1-2, impurity metal elements are effectively removed, the activity of the additive is improved, side reactions are reduced, finally, step-by-step flocculation is conducted, filtrate and waste residues containing chromium and fluorine are obtained, metal elements and fluorine elements in the filtrate are effectively removed, the waste residues containing chromium and fluorine can serve as by-products to be directly sold, and the cost is reduced. And the economic benefit is effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of resource recycling, and in particular to a method for recycling fluorine-containing and indium-containing waste liquid. Background Art

[0002] Indium is a rare metal with atomic number 49, relative atomic weight 114.82, melting point 429.76K, boiling point 2353.15K. It is a silvery white metal with strong ductility, extremely soft texture, low melting point, high boiling point, and located in Group III A of the periodic table. The original indium resources that can be directly mined in the earth's crust are less than 30,000 tons, and are often associated with zinc, copper and other metal veins.

[0003] In industry, metallic indium is often extracted, separated and purified from recycled indium resources. Common recycled indium resources include smelting waste slag containing indium (lead-zinc smelting waste slag, steel dust, flue ash, etc.) and wastewater (indium etching waste liquid, indium electrolysis waste liquid, raffinate, etc.).

[0004] In view of this, this application is filed. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method for recycling fluorine-containing and indium-containing waste liquid. The method described in the present invention not only removes the harmful elements of chromium and fluorine in the waste liquid, but also can effectively recover indium metal, and has extremely high economic benefits and application prospects.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] A method for recycling fluorine-containing and indium-containing waste liquid comprises the following steps:

[0008] (1) adding a sodium hydroxide solution to a fluorine-containing and indium-containing waste liquid, adjusting the pH to 3 to 5, stirring evenly, filtering to obtain a supernatant and a precipitate, and calcining the precipitate to obtain crude indium oxide;

[0009] (2) mixing crude indium oxide and anthracite uniformly, and calcining to obtain crude indium;

[0010] (3) adding sulfuric acid solution to the supernatant of step (1), adjusting the pH to 1-2, adding additives, adjusting the solution temperature to 45-55° C., adjusting the pH to 7-8 with sodium hydroxide solution, adding polyaluminum chloride solution, stirring evenly, adding polyacrylamide solution, stirring evenly, filtering, and taking the supernatant;

[0011] (4) adding calcium oxide to the supernatant of step (3), then adding the polyaluminium chloride solution, stirring evenly, filtering, and obtaining a filtrate and chromium- and fluorine-containing waste residue.

[0012] The present invention adjusts the pH value of fluorine-containing and indium-containing waste liquid to 3-5, which can effectively precipitate indium and reduce the precipitation of other ions; then the precipitate is calcined to promote the decomposition of indium oxide, and then reduction calcination is performed to obtain high-purity crude indium; the pH value of the supernatant is adjusted to 1-2, the impurity metal elements are effectively removed, the activity of the additive is improved, and the occurrence of side reactions is reduced; finally, after step-by-step flocculation, a filtrate and chromium- and fluorine-containing waste residues are obtained, wherein the metal elements and fluorine elements in the filtrate are effectively removed, and the chromium- and fluorine-containing waste residues can be directly sold as by-products. The method described in the present invention not only removes the harmful elements of chromium and fluorine in the waste liquid, but also can effectively recover indium metal, and has extremely high economic effect and application prospects.

[0013] The method for recycling fluorine-containing and indium-containing waste liquid described in the present invention takes "green, efficient and deep purification" as the recycling and purification purpose, improves the utilization efficiency of indium metal of recycled indium resources, reduces the pollution and damage of other ions in the wastewater to the environment and equipment, and increases the profits of the enterprise.

[0014] As a preferred embodiment of the present invention, the fluorine-containing and indium-containing waste liquid mainly includes the following components: indium 600-1200 mg / L, Zn 100-200 mg / L, Cr 200-300 mg / L, F 100-300 mg / L, As50-200 mg / L, Sn 1000-1500 mg / L, Fe 500-700 mg / L, especially when the content of each component is within this range, the purity of indium and the removal effect of fluorine and chromium can be more effectively improved.

[0015] As a preferred embodiment of the present invention, the calcination temperature in step (1) is 500-600° C. and the time is 6-8 hours. The calcination is carried out in an oxygen atmosphere. Controlling the calcination temperature within this range can promote the decomposition of indium oxide. If the temperature is too high, indium monoxide will be generated, resulting in a decrease in product purity. If the temperature is too low, the indium oxide will not be completely decomposed.

[0016] As a preferred embodiment of the present invention, the mass ratio of the crude indium oxide to anthracite is 1:(3-5).

[0017] As a preferred embodiment of the present invention, the calcination temperature in step (1) is 1000-1100° C. and the time is 4-6 hours. By using anthracite as a reducing agent and controlling the amount of the reducing agent, the calcination temperature and time, the reduction can be thorough, the adhesion of anthracite and indium metal can be avoided, and the yield can be improved.

[0018] Wherein, the mass fraction of the sodium hydroxide solution is 35-50%.

[0019] Wherein, the mass fraction of the sulfuric acid solution is 10-20%.

[0020] As a preferred embodiment of the present invention, the additive includes at least one of iron powder, sodium sulfite, sodium thiosulfate, ferrous sulfate, and sodium bisulfite, and the additive is added in an amount of 5 to 10 g / L.

[0021] As a preferred embodiment of the present invention, the mass fraction of the polyaluminium chloride solution is 5-15%; the mass fraction of the polyaluminium chloride solution is 2-8%.

[0022] As a preferred embodiment of the present invention, in step (4), the amount of the polyaluminium chloride solution added is 100-300 mg / L, and the amount of the polyacrylamide solution added is 10-30 mg / L.

[0023] As a preferred embodiment of the present invention, the amount of calcium oxide added is 200-300 mg / L.

[0024] As a preferred embodiment of the present invention, in step (4), the amount of the polyaluminium chloride solution added is 100-300 mg / L, and the amount of the polyacrylamide solution added is 20-50 mg / L.

[0025] Wherein, the reaction equation in step (4) is: Ca 2+ +F - =CaF2.

[0026]

[0027] The beneficial effects of the present invention are as follows: (1) The present invention adjusts the pH of the fluorine-containing and indium-containing waste liquid to 3-5, which can effectively precipitate indium and reduce the precipitation of other ions, and then calcines the precipitate to promote the decomposition of indium oxide, and then performs reduction calcination to obtain high-purity crude indium; the pH of the supernatant is adjusted to 1-2, which effectively removes impure metal elements, improves the activity of the additive, and reduces the occurrence of side reactions, and finally obtains filtrate and chromium- and fluorine-containing waste residues through step-by-step flocculation, wherein the metal elements and fluorine elements in the filtrate are effectively removed, and the chromium- and fluorine-containing waste residues can be directly sold as by-products. The method described in the present invention not only removes the harmful elements of chromium and fluorine in the waste liquid, but also can effectively recover indium metal, which has extremely high economic effects and application prospects. (2) The recycling and utilization method of the fluorine-containing and indium-containing waste liquid described in the present invention takes "green, efficient, and deep purification" as the recycling and purification purpose, improves the utilization efficiency of indium metal in the recycled indium resource, reduces the pollution and damage of other ions in the waste water to the environment and equipment, and increases the benefits of the enterprise. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application are described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0029] In the present application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0030] In this application, when it comes to numerical ranges, unless otherwise specified, the above numerical ranges are deemed to be continuous and include the minimum and maximum values ​​of the range, as well as each value between such minimum and maximum values. Further, when a range refers to an integer, each integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges included therein.

[0031] In the present application, there is no particular limitation on the specific dispersion and stirring treatment methods.

[0032] Unless otherwise specified, the components, raw materials or instruments used in the embodiments and comparative examples of the present invention are all commercially available raw materials or instruments, and the components and raw materials used in each parallel experiment are all of the same kind.

[0033] The following examples are provided to facilitate understanding of the present invention. These examples are not provided to limit the scope of the claims.

[0034] Example 1

[0035] A method for recycling fluorine-containing and indium-containing waste liquid comprises the following steps:

[0036] (1) Fluorine-containing and indium-containing waste liquids are added to an enamel reactor #1 equipped with an electromagnetic stirrer at a rate of 10 L / min, and the liquid level in the container does not exceed 2 / 3 of the container volume;

[0037] The fluorine-containing and indium-containing waste liquid mainly includes the following components: 912 mg / L indium, 160 mg / L Zn, 257 mg / L Cr, 200 mg / L F, 100 mg / L As, 1289 mg / L Sn, and 630 mg / L Fe.

[0038] (2) adding a 46 wt % sodium hydroxide solution to the fluorine-containing and indium-containing waste liquid, adjusting the pH to 5, stirring evenly at 30° C., and filtering after the supernatant and the precipitate in the reaction kettle are clearly separated, and calcining the precipitate at 500° C. for 8 h in an oxygen atmosphere to obtain crude indium oxide;

[0039] (3) mixing crude indium oxide and anthracite in a mass ratio of 1:4, and calcining at 1100° C. for 4 h to obtain crude indium;

[0040] (4) adding a 160 g / L sulfuric acid solution to the supernatant of step (2), adjusting the pH to 1, adding sodium sulfite in an amount of 8 g / L, adjusting the solution temperature to 50° C., stirring evenly, adjusting the pH to 8 with a 46 wt % sodium hydroxide solution, then adding a polyaluminium chloride solution in an amount of 200 mg / L, stirring evenly, then adding a polyacrylamide solution in an amount of 20 to 50 mg / L, stirring evenly, filtering, and taking the supernatant;

[0041] (5) Calcium oxide is added to the supernatant of step (4) in an amount of 300 mg / L, and then a polyaluminium chloride solution is added in an amount of 200 mg / L, the mixture is stirred evenly, and filtered to obtain a filtrate and chromium- and fluorine-containing waste residue.

[0042] The concentration of the polyaluminium chloride solution is 10wt%; the concentration of the polyaluminium chloride solution is 5wt%.

[0043] Example 2

[0044] A method for recycling fluorine-containing and indium-containing waste liquid comprises the following steps:

[0045] (1) Fluorine-containing and indium-containing waste liquids are added to an enamel reactor #1 equipped with an electromagnetic stirrer at a rate of 10 L / min, and the liquid level in the container does not exceed 2 / 3 of the container volume;

[0046] The fluorine-containing and indium-containing waste liquid mainly includes the following components: 912 mg / L indium, 160 mg / L Zn, 257 mg / L Cr, 200 mg / L F, 100 mg / L As, 1289 mg / L Sn, and 630 mg / L Fe.

[0047] (2) adding a 46 wt % sodium hydroxide solution to the fluorine-containing and indium-containing waste liquid, adjusting the pH to 3, stirring evenly at 30° C., and filtering after the supernatant and the precipitate in the reaction kettle are clearly separated, to obtain a supernatant and a precipitate, and calcining the precipitate at 500° C. for 8 h in an oxygen atmosphere to obtain crude indium oxide;

[0048] (3) mixing crude indium oxide and anthracite in a mass ratio of 1:4, and calcining at 1100° C. for 4 h to obtain crude indium;

[0049] (4) adding a 160 g / L sulfuric acid solution to the supernatant of step (2), adjusting the pH to 1, adding 8 g / L of sodium sulfite, adjusting the solution temperature to 50° C., stirring evenly, adjusting the pH to 8 with a 46 wt % sodium hydroxide solution, adding 200 mg / L of polyaluminium chloride solution, stirring evenly, adding 200 mg / L of polyacrylamide solution, stirring evenly, filtering, and taking the supernatant;

[0050] (5) Calcium oxide is added to the supernatant of step (4) in an amount of 300 mg / L, and then a polyaluminium chloride solution is added in an amount of 200 mg / L, the mixture is stirred evenly, and filtered to obtain a filtrate and chromium- and fluorine-containing waste residue.

[0051] The concentration of the polyaluminium chloride solution is 10wt%; the concentration of the polyaluminium chloride solution is 5wt%.

[0052] Example 3

[0053] A method for recycling fluorine-containing and indium-containing waste liquid comprises the following steps:

[0054] (1) Fluorine-containing and indium-containing waste liquids are added to an enamel reactor #1 equipped with an electromagnetic stirrer at a rate of 10 L / min, and the liquid level in the container does not exceed 2 / 3 of the container volume;

[0055] The fluorine-containing and indium-containing waste liquid mainly includes the following components: 912 mg / L indium, 160 mg / L Zn, 257 mg / L Cr, 200 mg / L F, 100 mg / L As, 1289 mg / L Sn, and 630 mg / L Fe.

[0056] (2) adding a 46 wt % sodium hydroxide solution to the fluorine-containing and indium-containing waste liquid, adjusting the pH to 5, stirring evenly at 30° C., and filtering after the supernatant and the precipitate in the reaction kettle are clearly separated, and calcining the precipitate at 600° C. for 4 h under an oxygen atmosphere to obtain crude indium oxide;

[0057] (3) mixing crude indium oxide and anthracite in a mass ratio of 1:4, and calcining at 1100° C. for 4 h to obtain crude indium;

[0058] (4) adding a 160 g / L sulfuric acid solution to the supernatant of step (2), adjusting the pH to 1, adding 8 g / L of sodium sulfite, adjusting the solution temperature to 50° C., stirring evenly, adjusting the pH to 8 with a 46 wt % sodium hydroxide solution, adding 200 mg / L of polyaluminium chloride solution, stirring evenly, adding 200 mg / L of polyacrylamide solution, stirring evenly, filtering, and taking the supernatant;

[0059] (5) Calcium oxide is added to the supernatant of step (4) in an amount of 300 mg / L, and then a polyaluminium chloride solution is added in an amount of 200 mg / L, the mixture is stirred evenly, and filtered to obtain a filtrate and chromium- and fluorine-containing waste residue.

[0060] The concentration of the polyaluminium chloride solution is 10wt%; the concentration of the polyaluminium chloride solution is 5wt%.

[0061] Example 4

[0062] A method for recycling fluorine-containing and indium-containing waste liquid comprises the following steps:

[0063] (1) Fluorine-containing and indium-containing waste liquids are added to an enamel reactor #1 equipped with an electromagnetic stirrer at a rate of 10 L / min, and the liquid level in the container does not exceed 2 / 3 of the container volume;

[0064] The fluorine-containing and indium-containing waste liquid mainly includes the following components: 912 mg / L indium, 160 mg / L Zn, 257 mg / L Cr, 200 mg / L F, 100 mg / L As, 1289 mg / L Sn, and 630 mg / L Fe.

[0065] (2) adding a 46 wt % sodium hydroxide solution to the fluorine-containing and indium-containing waste liquid, adjusting the pH to 5, stirring evenly at 30° C., and filtering after the supernatant and the precipitate in the reaction kettle are clearly separated, and calcining the precipitate at 500° C. for 8 h in an oxygen atmosphere to obtain crude indium oxide;

[0066] (3) mixing crude indium oxide and anthracite in a mass ratio of 1:4, and calcining at 1100° C. for 4 h to obtain crude indium;

[0067] (4) adding a 160 g / L sulfuric acid solution to the supernatant of step (2), adjusting the pH to 2, adding 8 g / L of sodium sulfite, adjusting the solution temperature to 50° C., stirring evenly, adjusting the pH to 8 with a 46 wt % sodium hydroxide solution, adding 200 mg / L of polyaluminium chloride solution, stirring evenly, adding 200 mg / L of polyacrylamide solution, stirring evenly, filtering, and taking the supernatant;

[0068] (5) Calcium oxide is added to the supernatant of step (4) in an amount of 300 mg / L, and then a polyaluminium chloride solution is added in an amount of 200 mg / L, the mixture is stirred evenly, and filtered to obtain a filtrate and chromium- and fluorine-containing waste residue.

[0069] The concentration of the polyaluminium chloride solution is 10wt%; the concentration of the polyaluminium chloride solution is 5wt%.

[0070] Example 5

[0071] A method for recycling fluorine-containing and indium-containing waste liquid comprises the following steps:

[0072] (1) Fluorine-containing and indium-containing waste liquids are added to an enamel reactor #1 equipped with an electromagnetic stirrer at a rate of 10 L / min, and the liquid level in the container does not exceed 2 / 3 of the container volume;

[0073] The fluorine-containing and indium-containing waste liquid mainly includes the following components: 912 mg / L indium, 160 mg / L Zn, 257 mg / L Cr, 200 mg / L F, 100 mg / L As, 1289 mg / L Sn, and 630 mg / L Fe.

[0074] (2) adding a 46 wt % sodium hydroxide solution to the fluorine-containing and indium-containing waste liquid, adjusting the pH to 5, stirring evenly at 30° C., and filtering after the supernatant and the precipitate in the reaction kettle are clearly separated, and calcining the precipitate at 500° C. for 8 h in an oxygen atmosphere to obtain crude indium oxide;

[0075] (3) mixing crude indium oxide and anthracite in a mass ratio of 1:4, and calcining at 1100° C. for 4 h to obtain crude indium;

[0076] (4) adding a 160 g / L sulfuric acid solution to the supernatant of step (2), adjusting the pH to 1, adding 8 g / L of sodium sulfite, adjusting the solution temperature to 50° C., stirring evenly, adjusting the pH to 7 with a 46 wt % sodium hydroxide solution, adding 200 mg / L of polyaluminium chloride solution, stirring evenly, adding 200 mg / L of polyacrylamide solution, stirring evenly, filtering, and taking the supernatant;

[0077] (5) Calcium oxide is added to the supernatant of step (4) in an amount of 300 mg / L, and then a polyaluminium chloride solution is added in an amount of 200 mg / L, the mixture is stirred evenly, and filtered to obtain a filtrate and chromium- and fluorine-containing waste residue.

[0078] The concentration of the polyaluminium chloride solution is 10wt%; the concentration of the polyaluminium chloride solution is 5wt%.

[0079] Comparative Example 1

[0080] A method for recycling fluorine-containing and indium-containing waste liquid comprises the following steps:

[0081] (1) Fluorine-containing and indium-containing waste liquids are added to an enamel reactor #1 equipped with an electromagnetic stirrer at a rate of 10 L / min, and the liquid level in the container does not exceed 2 / 3 of the container volume;

[0082] The fluorine-containing and indium-containing waste liquid mainly includes the following components: 912 mg / L indium, 160 mg / L Zn, 257 mg / L Cr, 200 mg / L F, 100 mg / L As, 1289 mg / L Sn, and 630 mg / L Fe.

[0083] (2) adding a 46 wt % sodium hydroxide solution to the fluorine-containing and indium-containing waste liquid, adjusting the pH to 5, stirring evenly at 30° C., and filtering after the supernatant and the precipitate in the reaction kettle are clearly separated, and calcining the precipitate at 500° C. for 8 h in an oxygen atmosphere to obtain crude indium oxide;

[0084] (3) mixing crude indium oxide and anthracite in a mass ratio of 1:4, and calcining at 1100° C. for 4 h to obtain crude indium;

[0085] (4) adding a 160 g / L sulfuric acid solution to the supernatant of step (2), adjusting the pH to 1, adjusting the solution temperature to 50° C., stirring evenly, adjusting the pH to 8 with a 46 wt % sodium hydroxide solution, then adding a 200 mg / L polyaluminium chloride solution, stirring evenly, then adding a 200 mg / L polyacrylamide solution, stirring evenly, filtering, and taking the supernatant;

[0086] (5) Calcium oxide is added to the supernatant of step (4) in an amount of 300 mg / L, and then a polyaluminium chloride solution is added in an amount of 200 mg / L, the mixture is stirred evenly, and filtered to obtain a filtrate and chromium- and fluorine-containing waste residue.

[0087] The concentration of the polyaluminium chloride solution is 10wt%; the concentration of the polyaluminium chloride solution is 5wt%.

[0088] Comparative Example 2

[0089] A method for recycling fluorine-containing and indium-containing waste liquid comprises the following steps:

[0090] (1) Fluorine-containing and indium-containing waste liquids are added to an enamel reactor #1 equipped with an electromagnetic stirrer at a rate of 10 L / min, and the liquid level in the container does not exceed 2 / 3 of the container volume;

[0091] The fluorine-containing and indium-containing waste liquid mainly includes the following components: 912 mg / L indium, 160 mg / L Zn, 257 mg / L Cr, 200 mg / L F, 100 mg / L As, 1289 mg / L Sn, and 630 mg / L Fe.

[0092] (2) adding a 46 wt % sodium hydroxide solution to the fluorine-containing and indium-containing waste liquid, adjusting the pH to 5, stirring evenly at 30° C., and filtering after the supernatant and the precipitate in the reaction kettle are clearly separated, and calcining the precipitate at 500° C. for 8 h in an oxygen atmosphere to obtain crude indium oxide;

[0093] (3) mixing crude indium oxide and anthracite in a mass ratio of 1:4, and calcining at 1100° C. for 4 h to obtain crude indium;

[0094] (4) adding a 160 g / L sulfuric acid solution to the supernatant of step (2), adjusting the pH to 1, adding 8 g / L of sodium sulfite, adjusting the solution temperature to 50° C., stirring evenly, adjusting the pH to 8 with a 46 wt % sodium hydroxide solution, adding 200 mg / L of polyaluminium chloride solution, stirring evenly, adding 200 mg / L of polyacrylamide solution, stirring evenly, filtering, and taking the supernatant;

[0095] (5) Add 200 mg / L of polyaluminium chloride solution, stir evenly, and filter to obtain a filtrate and chromium- and fluorine-containing waste residue.

[0096] The concentration of the polyaluminium chloride solution is 10wt%; the concentration of the polyaluminium chloride solution is 5wt%.

[0097] Comparative Example 3

[0098] A method for recycling fluorine-containing and indium-containing waste liquid comprises the following steps:

[0099] (1) Fluorine-containing and indium-containing waste liquids are added to an enamel reactor #1 equipped with an electromagnetic stirrer at a rate of 10 L / min, and the liquid level in the container does not exceed 2 / 3 of the container volume;

[0100] The fluorine-containing and indium-containing waste liquid mainly includes the following components: 912 mg / L indium, 160 mg / L Zn, 257 mg / L Cr, 200 mg / L F, 100 mg / L As, 1289 mg / L Sn, and 630 mg / L Fe.

[0101] (2) adding a 46 wt % sodium hydroxide solution to the fluorine-containing and indium-containing waste liquid, adjusting the pH to 5, stirring evenly at 30° C., and filtering after the supernatant and the precipitate in the reaction kettle are clearly separated, and calcining the precipitate at 500° C. for 8 h in an oxygen atmosphere to obtain crude indium oxide;

[0102] (3) mixing crude indium oxide and anthracite in a mass ratio of 1:4, and calcining at 1100° C. for 4 h to obtain crude indium;

[0103] (4) adding a 160 g / L sulfuric acid solution to the supernatant of step (2), adjusting the pH to 1, adding 8 g / L of sodium sulfite, adjusting the solution temperature to 50° C., stirring evenly, adjusting the pH to 8 with a 46 wt % sodium hydroxide solution, adding 200 mg / L of polyaluminium chloride solution, stirring evenly, adding 200 mg / L of polyacrylamide solution, stirring evenly, filtering, and taking the supernatant;

[0104] (5) adding calcium oxide in an amount of 300 mg / L to the supernatant of step (4), stirring evenly, filtering, and obtaining a filtrate and chromium- and fluorine-containing waste residue.

[0105] The concentration of the polyaluminium chloride solution is 10wt%; the concentration of the polyaluminium chloride solution is 5wt%.

[0106] Comparative Example 4

[0107] A method for recycling fluorine-containing and indium-containing waste liquid comprises the following steps:

[0108] (1) Fluorine-containing and indium-containing waste liquids are added to an enamel reactor #1 equipped with an electromagnetic stirrer at a rate of 10 L / min, and the liquid level in the container does not exceed 2 / 3 of the container volume;

[0109] The fluorine-containing and indium-containing waste liquid mainly includes the following components: 912 mg / L indium, 160 mg / L Zn, 257 mg / L Cr, 200 mg / L F, 100 mg / L As, 1289 mg / L Sn, and 630 mg / L Fe.

[0110] (2) adding a 46 wt % sodium hydroxide solution to the fluorine-containing and indium-containing waste liquid, adjusting the pH to 2, stirring evenly at 30° C., and filtering after the supernatant and the precipitate in the reaction kettle are clearly separated, to obtain a supernatant and a precipitate, and calcining the precipitate at 500° C. for 8 h in an oxygen atmosphere to obtain crude indium oxide;

[0111] (3) mixing crude indium oxide and anthracite in a mass ratio of 1:4, and calcining at 1100° C. for 4 h to obtain crude indium;

[0112] (4) adding a 160 g / L sulfuric acid solution to the supernatant of step (2), adjusting the pH to 1, adding 8 g / L of sodium sulfite, adjusting the solution temperature to 50° C., stirring evenly, adjusting the pH to 8 with a 46 wt % sodium hydroxide solution, adding 200 mg / L of polyaluminium chloride solution, stirring evenly, adding 200 mg / L of polyacrylamide solution, stirring evenly, filtering, and taking the supernatant;

[0113] (5) Calcium oxide is added to the supernatant of step (4) in an amount of 300 mg / L, and then a polyaluminium chloride solution is added in an amount of 200 mg / L, the mixture is stirred evenly, and filtered to obtain a filtrate and chromium- and fluorine-containing waste residue.

[0114] The concentration of the polyaluminium chloride solution is 10wt%; the concentration of the polyaluminium chloride solution is 5wt%.

[0115] Comparative Example 5

[0116] A method for recycling fluorine-containing and indium-containing waste liquid comprises the following steps:

[0117] (1) Fluorine-containing and indium-containing waste liquids are added to an enamel reactor #1 equipped with an electromagnetic stirrer at a rate of 10 L / min, and the liquid level in the container does not exceed 2 / 3 of the container volume;

[0118] The fluorine-containing and indium-containing waste liquid mainly includes the following components: 912 mg / L indium, 160 mg / L Zn, 257 mg / L Cr, 200 mg / L F, 100 mg / L As, 1289 mg / L Sn, and 630 mg / L Fe.

[0119] (2) adding a 46 wt % sodium hydroxide solution to the fluorine-containing and indium-containing waste liquid, adjusting the pH to 7, stirring evenly at 30° C., and filtering after the supernatant and the precipitate in the reaction kettle are clearly separated, to obtain a supernatant and a precipitate, and calcining the precipitate at 500° C. for 8 h in an oxygen atmosphere to obtain crude indium oxide;

[0120] (3) mixing crude indium oxide and anthracite in a mass ratio of 1:4, and calcining at 1100° C. for 4 h to obtain crude indium;

[0121] (4) adding a 160 g / L sulfuric acid solution to the supernatant of step (2), adjusting the pH to 1, adding 8 g / L of sodium sulfite, adjusting the solution temperature to 50° C., stirring evenly, adjusting the pH to 8 with a 46 wt % sodium hydroxide solution, adding 200 mg / L of polyaluminium chloride solution, stirring evenly, adding 200 mg / L of polyacrylamide solution, stirring evenly, filtering, and taking the supernatant;

[0122] (5) Calcium oxide is added to the supernatant of step (4) in an amount of 300 mg / L, and then a polyaluminium chloride solution is added in an amount of 200 mg / L, the mixture is stirred evenly, and filtered to obtain a filtrate and chromium- and fluorine-containing waste residue.

[0123] The concentration of the polyaluminium chloride solution is 10wt%; the concentration of the polyaluminium chloride solution is 5wt%.

[0124] Comparative Example 6

[0125] A method for recycling fluorine-containing and indium-containing waste liquid comprises the following steps:

[0126] (1) Fluorine-containing and indium-containing waste liquids are added to an enamel reactor #1 equipped with an electromagnetic stirrer at a rate of 10 L / min, and the liquid level in the container does not exceed 2 / 3 of the container volume;

[0127] The fluorine-containing and indium-containing waste liquid mainly includes the following components: 912 mg / L indium, 160 mg / L Zn, 257 mg / L Cr, 200 mg / L F, 100 mg / L As, 1289 mg / L Sn, and 630 mg / L Fe.

[0128] (2) adding a 46 wt % sodium hydroxide solution to the fluorine-containing and indium-containing waste liquid, adjusting the pH to 5, stirring evenly at 30° C., and filtering after the supernatant and the precipitate in the reaction kettle are clearly separated, and calcining the precipitate at 500° C. for 8 h in an oxygen atmosphere to obtain crude indium oxide;

[0129] (3) mixing crude indium oxide and anthracite in a mass ratio of 1:4, and calcining at 1100° C. for 4 h to obtain crude indium;

[0130] (4) adding a 160 g / L sulfuric acid solution to the supernatant of step (2), adjusting the pH to 0.5, adding 8 g / L of sodium sulfite, adjusting the solution temperature to 50° C., stirring evenly, adjusting the pH to 8 with a 46 wt % sodium hydroxide solution, adding 200 mg / L of polyaluminium chloride solution, stirring evenly, adding 200 mg / L of polyacrylamide solution, stirring evenly, filtering, and taking the supernatant;

[0131] (5) Calcium oxide is added to the supernatant of step (4) in an amount of 300 mg / L, and then a polyaluminium chloride solution is added in an amount of 200 mg / L, the mixture is stirred evenly, and filtered to obtain a filtrate and chromium- and fluorine-containing waste residue.

[0132] The concentration of the polyaluminium chloride solution is 10wt%; the concentration of the polyaluminium chloride solution is 5wt%.

[0133] Comparative Example 7

[0134] A method for recycling fluorine-containing and indium-containing waste liquid comprises the following steps:

[0135] (1) Fluorine-containing and indium-containing waste liquids are added to an enamel reactor #1 equipped with an electromagnetic stirrer at a rate of 10 L / min, and the liquid level in the container does not exceed 2 / 3 of the container volume;

[0136] The fluorine-containing and indium-containing waste liquid mainly includes the following components: 912 mg / L indium, 160 mg / L Zn, 257 mg / L Cr, 200 mg / L F, 100 mg / L As, 1289 mg / L Sn, and 630 mg / L Fe.

[0137] (2) adding a 46 wt % sodium hydroxide solution to the fluorine-containing and indium-containing waste liquid, adjusting the pH to 5, stirring evenly at 30° C., and filtering after the supernatant and the precipitate in the reaction kettle are clearly separated, and calcining the precipitate at 500° C. for 8 h in an oxygen atmosphere to obtain crude indium oxide;

[0138] (3) mixing crude indium oxide and anthracite in a mass ratio of 1:4, and calcining at 1100° C. for 4 h to obtain crude indium;

[0139] (4) adding a 160 g / L sulfuric acid solution to the supernatant of step (2), adjusting the pH to 3, adding 8 g / L of sodium sulfite, adjusting the solution temperature to 50° C., stirring evenly, adjusting the pH to 8 with a 46 wt % sodium hydroxide solution, adding 200 mg / L of polyaluminium chloride solution, stirring evenly, adding 200 mg / L of polyacrylamide solution, stirring evenly, filtering, and taking the supernatant;

[0140] (5) Calcium oxide is added to the supernatant of step (4) in an amount of 300 mg / L, and then a polyaluminium chloride solution is added in an amount of 200 mg / L, the mixture is stirred evenly, and filtered to obtain a filtrate and chromium- and fluorine-containing waste residue.

[0141] The concentration of the polyaluminium chloride solution is 10wt%; the concentration of the polyaluminium chloride solution is 5wt%.

[0142] Comparative Example 8

[0143] A method for recycling fluorine-containing and indium-containing waste liquid comprises the following steps:

[0144] (1) Fluorine-containing and indium-containing waste liquids are added to an enamel reactor #1 equipped with an electromagnetic stirrer at a rate of 10 L / min, and the liquid level in the container does not exceed 2 / 3 of the container volume;

[0145] The fluorine-containing and indium-containing waste liquid mainly includes the following components: 912 mg / L indium, 160 mg / L Zn, 257 mg / L Cr, 200 mg / L F, 100 mg / L As, 1289 mg / L Sn, and 630 mg / L Fe.

[0146] (2) adding a 46 wt % sodium hydroxide solution to the fluorine-containing and indium-containing waste liquid, adjusting the pH to 5, stirring evenly at 30° C., and filtering after the supernatant and the precipitate in the reaction kettle are clearly separated, and calcining the precipitate at 400° C. for 8 h in an oxygen atmosphere to obtain crude indium oxide;

[0147] (3) mixing crude indium oxide and anthracite in a mass ratio of 1:4, and calcining at 1100° C. for 4 h to obtain crude indium;

[0148] (4) adding a 160 g / L sulfuric acid solution to the supernatant of step (2), adjusting the pH to 1, adding 8 g / L of sodium sulfite, adjusting the solution temperature to 50° C., stirring evenly, adjusting the pH to 8 with a 46 wt % sodium hydroxide solution, adding 200 mg / L of polyaluminium chloride solution, stirring evenly, adding 200 mg / L of polyacrylamide solution, stirring evenly, filtering, and taking the supernatant;

[0149] (5) Calcium oxide is added to the supernatant of step (4) in an amount of 300 mg / L, and then a polyaluminium chloride solution is added in an amount of 200 mg / L, the mixture is stirred evenly, and filtered to obtain a filtrate and chromium- and fluorine-containing waste residue.

[0150] The concentration of the polyaluminium chloride solution is 10wt%; the concentration of the polyaluminium chloride solution is 5wt%.

[0151] Comparative Example 9

[0152] A method for recycling fluorine-containing and indium-containing waste liquid comprises the following steps:

[0153] (1) Fluorine-containing and indium-containing waste liquids are added to an enamel reactor #1 equipped with an electromagnetic stirrer at a rate of 10 L / min, and the liquid level in the container does not exceed 2 / 3 of the container volume;

[0154] The fluorine-containing and indium-containing waste liquid mainly includes the following components: 912 mg / L indium, 160 mg / L Zn, 257 mg / L Cr, 200 mg / L F, 100 mg / L As, 1289 mg / L Sn, and 630 mg / L Fe.

[0155] (2) adding a 46 wt % sodium hydroxide solution to the fluorine-containing and indium-containing waste liquid, adjusting the pH to 5, stirring evenly at 30° C., and filtering after the supernatant and the precipitate in the reaction kettle are clearly separated, and calcining the precipitate at 700° C. for 8 h in an oxygen atmosphere to obtain crude indium oxide;

[0156] (3) mixing crude indium oxide and anthracite in a mass ratio of 1:4, and calcining at 1100° C. for 4 h to obtain crude indium;

[0157] (4) adding a 160 g / L sulfuric acid solution to the supernatant of step (2), adjusting the pH to 1, adding 8 g / L of sodium sulfite, adjusting the solution temperature to 50° C., stirring evenly, adjusting the pH to 8 with a 46 wt % sodium hydroxide solution, adding 200 mg / L of polyaluminium chloride solution, stirring evenly, adding 200 mg / L of polyacrylamide solution, stirring evenly, filtering, and taking the supernatant;

[0158] (5) Calcium oxide is added to the supernatant of step (4) in an amount of 300 mg / L, and then a polyaluminium chloride solution is added in an amount of 200 mg / L, the mixture is stirred evenly, and filtered to obtain a filtrate and chromium- and fluorine-containing waste residue.

[0159] The concentration of the polyaluminium chloride solution is 10wt%; the concentration of the polyaluminium chloride solution is 5wt%.

[0160] Test Case

[0161] The purity, chromium removal rate, and fluorine removal rate of the crude indium obtained in Example 1 and the comparative example are shown in Table 1, respectively.

[0162] Table 1

[0163]

[0164]

[0165] As can be seen from Table 1, the method described in the present invention not only removes harmful elements of chromium and fluorine in the waste liquid, but also can effectively recover indium metal, and has extremely high economic benefits and application prospects.

[0166] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A method for recycling fluorine-containing and indium-containing waste liquid, characterized in that: The following steps are involved: (1) adding a sodium hydroxide solution to a fluorine-containing and indium-containing waste liquid, adjusting the pH to 3 to 5, stirring evenly, filtering to obtain a supernatant and a precipitate, and calcining the precipitate to obtain crude indium oxide; (2) mixing crude indium oxide and anthracite uniformly, and calcining to obtain crude indium; (3) adding sulfuric acid solution to the supernatant of step (1), adjusting the pH to 1-2, adding additives, adjusting the solution temperature to 45-55° C., adjusting the pH to 7-8 with sodium hydroxide solution, adding polyaluminum chloride solution, stirring evenly, adding polyacrylamide solution, stirring evenly, filtering, and taking the supernatant; (4) adding calcium oxide to the supernatant of step (3), then adding polyaluminium chloride solution, stirring evenly, filtering, and obtaining a filtrate and chromium- and fluorine-containing waste residue.

2. The method for recycling fluorine-containing and indium-containing waste liquid according to claim 1, characterized in that: The fluorine-containing and indium-containing waste liquid mainly includes the following components: 600-1200 mg / L of indium, 100-200 mg / L of Zn, 200-300 mg / L of Cr, 100-300 mg / L of F, 50-200 mg / L of As, 1000-1500 mg / L of Sn, and 500-700 mg / L of Fe.

3. The method for recycling fluorine-containing and indium-containing waste liquid according to claim 1, characterized in that: The calcination temperature in step (1) is 500-600° C. and the calcination time is 6-8 hours.

4. The method for recycling fluorine-containing and indium-containing waste liquid according to claim 1, characterized in that: The mass ratio of the crude indium oxide to anthracite is 1:(3-5).

5. The method for recycling fluorine-containing and indium-containing waste liquid according to claim 1, characterized in that: In step (1), the calcination temperature is 1000-1100°C and the calcination time is 4-6 hours.

6. The method for recycling fluorine-containing and indium-containing waste liquid according to claim 1, characterized in that: The additive comprises at least one of iron powder, sodium sulfite, sodium thiosulfate, ferrous sulfate and sodium bisulfite, and the additive amount is 5-10 g / L.

7. The method for recycling fluorine-containing and indium-containing waste liquid according to claim 1, characterized in that: The mass fraction of the polyaluminium chloride solution is 5-15%; the mass fraction of the polyaluminium chloride solution is 2-8%.

8. The method for recycling fluorine-containing and indium-containing waste liquid according to claim 1, characterized in that: In step (4), the amount of polyaluminium chloride solution added is 100-300 mg / L, and the amount of polyacrylamide solution added is 10-30 mg / L.

9. The method for recycling fluorine-containing and indium-containing waste liquid according to claim 1, characterized in that: The added amount of calcium oxide is 200-300 mg / L.

10. The method for recycling fluorine-containing and indium-containing waste liquid according to claim 1, characterized in that: In step (4), the amount of polyaluminium chloride solution added is 100-300 mg / L, and the amount of polyacrylamide solution added is 20-50 mg / L.

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