Tin metal refining method

Abstract

The invention discloses a tin metal refining method, which belongs to the technical field of resource recycling and reutilization, and comprises the following steps: adding tin-containing waste powder and hydrogen peroxide into a hydrochloric acid solution for acid leaching, enabling all metals to enter the solution in the form of ions with the highest valence state, regulating the pH value of the solution to 4.8-5.2 by using sodium hydroxide, depositing and enriching the metals, uniformly mixing filter residues, fused salt and a reducing agent, and carrying out solid-liquid separation to obtain the tin metal. The method comprises the following steps: smelting, reducing, removing impurity elements such as iron, further purifying the tin alloy, carrying out vacuum distillation to volatilize impurity metals with a boiling point lower than that of tin, further purifying the tin alloy to obtain crude tin, and finally electrolyzing to obtain metallic tin, and the purity of the tin metal is high and can reach 4.5 N level.

Description

Technical Field

[0001] The invention relates to the technical field of resource recovery and reuse, and in particular to a method for refining tin metal. Background Art

[0002] Tin is a silvery-white metal with a melting point of 231.9°C and a density of 7.3g / cm2. It is relatively soft and has good ductility but poor ductility. Tin has a low melting point, is non-toxic, and can form alloys with many metals.

[0003] Tin is often mixed with indium metal in proportion to form ITO targets, but the target utilization rate is only about 60%. A large amount of waste ITO targets contain tin metal, so recovering tin metal from them has become one of the important ways to recycle tin resources.

[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 tin metal refining method, which can effectively recover tin metal from tin-containing waste materials and effectively improve the purity of tin metal.

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

[0007] A method for refining tin metal comprises the following steps:

[0008] (1) crushing the tin-containing waste to obtain tin-containing waste powder, adding the tin-containing waste powder and hydrogen peroxide to a hydrochloric acid solution, reacting, adding sodium hydroxide to adjust the pH to 4.8-5.2, filtering, and obtaining a filter residue;

[0009] (2) uniformly mixing the filter residue, molten salt and reducing agent, and smelting to obtain an alloy ingot;

[0010] (3) vacuum distilling the alloy ingot to obtain a tin ingot;

[0011] (4) using the tin ingot obtained in step (3) as an anode, using refined tin as a cathode, and using a tin-containing liquid as an electrolyte to perform electrolysis to obtain tin metal.

[0012] The present invention creatively adds tin-containing waste powder and hydrogen peroxide into a hydrochloric acid solution for acid leaching, so that all metals enter the solution in the highest valence state ions, and then uses sodium hydroxide to adjust the pH value of the solution to 4.8-5.2 to allow the metal to precipitate and enrich, and then evenly mix the filter residue, molten salt and reducing agent, smelt and reduce, remove impurity elements such as iron, and further purify the tin alloy, and then perform vacuum distillation to volatilize the impurity metals with a lower boiling point than tin, further purify the tin alloy to obtain crude tin, and finally electrolyze to obtain metallic tin, wherein the purity of the tin metal is high and can reach the 4.5N level.

[0013] As a preferred embodiment of the present invention, the tin-containing waste includes at least one of waste ITO targets, waste solder, and waste tin-containing electronic components.

[0014] As a preferred embodiment of the present invention, the tin content in the tin-containing waste is 30-44.98%.

[0015] As a preferred embodiment of the present invention, the main metal components of the tin-containing waste are: 30-44.98% tin, 5-15.91% indium, 0.5-1.47% iron, 2-9.41% lead, 5-15% bismuth, and 1-3.71% copper.

[0016] As a preferred embodiment of the present invention, the particle size of the tin-containing waste powder is 30 to 80 meshes.

[0017] As a preferred embodiment of the present invention, the dosage ratio of the tin-containing waste powder, hydrogen peroxide and hydrochloric acid solution is 1 kg: (10-20) mL: (3-6) L. By controlling the dosage ratio of the tin-containing waste powder, hydrogen peroxide and hydrochloric acid solution within this range, all the metals can be oxidized to the highest valence state and completely leached into the solution, so that when sodium hydroxide is subsequently added to adjust the pH to 4.8-5.2, the tin metal is completely precipitated.

[0018] As a preferred embodiment of the present invention, the concentration of the hydrogen peroxide is 27.5 to 60 wt %;

[0019] The concentration of the hydrochloric acid solution is 2-4 mol / L.

[0020] As a preferred embodiment of the present invention, the reaction temperature is 50-60° C., and the reaction time is 1-2 h.

[0021] As a preferred embodiment of the present invention, the mass ratio of the filter residue, molten salt and reducing agent is 100:(5-10):(3-5). By controlling the mass ratio of the filter residue, molten salt and reducing agent within this range, the reaction can be thorough. If too little molten salt is added, slag formation is less, which may easily lead to the formation of a large amount of oxidized slag on the surface of the metal liquid. If too much molten salt is added, the main metal may be entrained and lost. If too little reducing agent is added, the miscellaneous metals cannot be completely reduced, resulting in the main metal and the impurity metal still existing in the form of oxidized alloys. If too much reducing agent is added, a mixture may be formed with the molten salt, entraining a large amount of metal, which is difficult to separate and causes the loss of the main metal. If the temperature is too high, part of the metal may volatilize and entrain the main metal, and the service life of the equipment may be greatly reduced. If the temperature is too low, the reaction is incomplete and the purity of the main metal is reduced.

[0022] As a preferred embodiment of the present invention, the molten salt includes at least one of calcium oxide, magnesium fluoride, sodium borate and quartz stone;

[0023] The reducing agent includes at least one of coke, anthracite and charcoal.

[0024] As a preferred embodiment of the present invention, the distillation temperature is 1400-1600° C. and the distillation time is 4-6 hours.

[0025] As a preferred embodiment of the present invention, the current density of the electrolysis is 100 to 300 A / m 2 , temperature is 30~50℃, voltage is 2~4V.

[0026] As a preferred embodiment of the present invention, the electrolyte comprises the following components: 30-50 g / L SnSO4, 50-70 g / L H2SO4, 0.1-0.3 g / L 2-naphthyl, 0.5-2 g / L gelatin, 1.5-2.5 g / L potassium dichromate, and 2-5 g / L organic additives;

[0027] The organic additive includes at least one of cresol sulfonic acid, phenol sulfonic acid and ethyl sulfonic acid.

[0028] The beneficial effects of the present invention are as follows: the present invention adds tin-containing waste powder and hydrogen peroxide into a hydrochloric acid solution for acid leaching, so that all metals enter the solution in the highest valence state ions, and then uses sodium hydroxide to adjust the pH value of the solution to 4.8-5.2 to allow metal deposition and enrichment, and then evenly mixes the filter residue, molten salt and reducing agent, smelts and reduces, removes impurity elements such as iron, and further purifies the tin alloy, and then performs vacuum distillation to volatilize impurity metals with a lower boiling point than tin, further purifies the tin alloy to obtain crude tin, and finally electrolyzes to obtain metallic tin, wherein the purity of the tin metal is high and can reach the 4.5N level. DETAILED DESCRIPTION

[0029] 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.

[0030] 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.

[0031] 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.

[0032] In the present application, there is no particular limitation on the specific dispersion and stirring treatment methods.

[0033] 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.

[0034] The following examples are provided to facilitate understanding of the present invention. These examples are not provided to limit the scope of the claims.

[0035] Example 1

[0036] A method for refining tin metal comprises the following steps:

[0037] (1) crushing the tin-containing waste into 50 meshes, removing the plastic particles, and obtaining tin-containing waste powder; the main metal components of the tin-containing waste are: 60.50% tin, 22.69% indium, 1.25% iron, 0.51% lead, 0.89% bismuth, and 1.72% copper.

[0038] (2) adding tin-containing waste powder and 27.85 wt% hydrogen peroxide to a 4 mol / L hydrochloric acid solution, reacting at 55° C. for 1.5 h, adding sodium hydroxide to adjust the pH to 5, filtering, and obtaining a filter residue;

[0039] The usage ratio of the tin-containing waste powder, hydrogen peroxide and hydrochloric acid solution is 1kg:20mL:4L.

[0040] (3) mixing the filter residue, calcium oxide and coke in a mass ratio of 100:10:3, smelting at 1200° C. for 4 h, removing the surface scum, cooling, and obtaining an alloy ingot;

[0041] (4) subjecting the alloy ingot to vacuum distillation at a vacuum degree of 1 Pa to obtain a tin ingot; the distillation temperature is 1600° C. and the time is 6 h;

[0042] (5) Casting the tin ingot of step (4) into an anode, using 4N refined tin as a cathode, and using a tin-containing liquid as an electrolyte, electrolyzing to obtain tin metal.

[0043] The current density of the electrolysis is 200A / m2 , temperature is 35℃, voltage is 2.5V.

[0044] The electrolyte includes the following components: 40 g / L SnSO4, 60 g / L H2SO4, 0.2 g / L 2-naphthyl, 1 g / L gelatin, 2 g / L potassium dichromate, and 4 g / L phenolsulfonic acid.

[0045] Example 2

[0046] A method for refining tin metal comprises the following steps:

[0047] (1) crushing the tin-containing waste into 50 meshes, removing the plastic particles, and obtaining tin-containing waste powder; the main metal components of the tin-containing waste are: 60.50% tin, 22.69% indium, 1.25% iron, 0.51% lead, 0.89% bismuth, and 1.72% copper.

[0048] (2) adding tin-containing waste powder and 27.85 wt% hydrogen peroxide to a 4 mol / L hydrochloric acid solution, reacting at 55° C. for 1.5 h, adding sodium hydroxide to adjust the pH to 5, filtering, and obtaining a filter residue;

[0049] The usage ratio of the tin-containing waste powder, hydrogen peroxide and hydrochloric acid solution is 1kg:20mL:4L.

[0050] (3) mixing the filter residue, calcium oxide and coke in a mass ratio of 100:5:5, smelting at 1200° C. for 4 h, removing the surface scum, cooling, and obtaining an alloy ingot;

[0051] (4) subjecting the alloy ingot to vacuum distillation at a vacuum degree of 1 Pa to obtain a tin ingot; the distillation temperature is 1600° C. and the time is 6 h;

[0052] (5) Casting the tin ingot of step (4) into an anode, using 4N refined tin as a cathode, and using a tin-containing liquid as an electrolyte, electrolyzing to obtain tin metal.

[0053] The current density of the electrolysis is 200A / m 2 , temperature is 35℃, voltage is 2.5V.

[0054] The electrolyte includes the following components: 40 g / L SnSO4, 60 g / L H2SO4, 0.2 g / L 2-naphthyl, 1 g / L gelatin, 2 g / L potassium dichromate, and 4 g / L phenolsulfonic acid.

[0055] Example 3

[0056] A method for refining tin metal comprises the following steps:

[0057] (1) crushing the tin-containing waste into 50 meshes, removing the plastic particles, and obtaining tin-containing waste powder; the main metal components of the tin-containing waste are: 60.50% tin, 22.69% indium, 1.25% iron, 0.51% lead, 0.89% bismuth, and 1.72% copper.

[0058] (2) adding tin-containing waste powder and 27.85 wt% hydrogen peroxide to a 4 mol / L hydrochloric acid solution, reacting at 55° C. for 1.5 h, adding sodium hydroxide to adjust the pH to 5, filtering, and obtaining a filter residue;

[0059] The usage ratio of the tin-containing waste powder, hydrogen peroxide and hydrochloric acid solution is 1kg:20mL:4L.

[0060] (3) mixing the filter residue, calcium oxide and coke in a mass ratio of 100:10:3, smelting at 1000° C. for 4 h, removing the surface scum, cooling, and obtaining an alloy ingot;

[0061] (4) subjecting the alloy ingot to vacuum distillation at a vacuum degree of 1 Pa to obtain a tin ingot; the distillation temperature is 1600° C. and the time is 6 h;

[0062] (5) Casting the tin ingot of step (4) into an anode, using 4N refined tin as a cathode, and using a tin-containing liquid as an electrolyte, electrolyzing to obtain tin metal.

[0063] The current density of the electrolysis is 200A / m 2 , temperature is 35℃, voltage is 2.5V.

[0064] The electrolyte includes the following components: 40 g / L SnSO4, 60 g / L H2SO4, 0.2 g / L 2-naphthyl, 1 g / L gelatin, 2 g / L potassium dichromate, and 4 g / L phenolsulfonic acid.

[0065] Example 4

[0066] A method for refining tin metal comprises the following steps:

[0067] (1) crushing the tin-containing waste into 50 meshes, removing the plastic particles, and obtaining tin-containing waste powder; the main metal components of the tin-containing waste are: 60.50% tin, 22.69% indium, 1.25% iron, 0.51% lead, 0.89% bismuth, and 1.72% copper.

[0068] (2) adding tin-containing waste powder and 27.85 wt% hydrogen peroxide to a 4 mol / L hydrochloric acid solution, reacting at 55° C. for 1.5 h, adding sodium hydroxide to adjust the pH to 5, filtering, and obtaining a filter residue;

[0069] The usage ratio of the tin-containing waste powder, hydrogen peroxide and hydrochloric acid solution is 1kg:20mL:4L.

[0070] (3) mixing the filter residue, calcium oxide and coke in a mass ratio of 100:10:3, smelting at 1200° C. for 4 h, removing the surface scum, cooling, and obtaining an alloy ingot;

[0071] (4) subjecting the alloy ingot to vacuum distillation at a vacuum degree of 1 Pa to obtain a tin ingot; the distillation temperature is 1600° C. and the time is 6 h;

[0072] (5) Casting the tin ingot of step (4) into an anode, using 4N refined tin as a cathode, and using a tin-containing liquid as an electrolyte, electrolyzing to obtain tin metal.

[0073] The current density of the electrolysis is 200A / m 2 , temperature is 35℃, voltage is 2.5V.

[0074] The electrolyte includes the following components: 30 g / L SnSO4, 70 g / L H2SO4, 0.1 g / L 2-naphthyl, 2 g / L gelatin, 1.5 g / L potassium dichromate, and 5 g / L phenolsulfonic acid.

[0075] Example 5

[0076] A method for refining tin metal comprises the following steps:

[0077] (1) crushing the tin-containing waste into 50 meshes, removing the plastic particles, and obtaining tin-containing waste powder; the main metal components of the tin-containing waste are: 60.50% tin, 22.69% indium, 1.25% iron, 0.51% lead, 0.89% bismuth, and 1.72% copper.

[0078] (2) adding tin-containing waste powder and 27.85 wt% hydrogen peroxide to a 4 mol / L hydrochloric acid solution, reacting at 55° C. for 1.5 h, adding sodium hydroxide to adjust the pH to 5, filtering, and obtaining a filter residue;

[0079] The usage ratio of the tin-containing waste powder, hydrogen peroxide and hydrochloric acid solution is 1kg:20mL:4L.

[0080] (3) mixing the filter residue, calcium oxide and coke in a mass ratio of 100:10:3, smelting at 1200° C. for 4 h, removing the surface scum, cooling, and obtaining an alloy ingot;

[0081] (4) subjecting the alloy ingot to vacuum distillation at a vacuum degree of 1 Pa to obtain a tin ingot; the distillation temperature is 1600° C. and the time is 6 h;

[0082] (5) Casting the tin ingot of step (4) into an anode, using 4N refined tin as a cathode, and using a tin-containing liquid as an electrolyte, electrolyzing to obtain tin metal.

[0083] The current density of the electrolysis is 200A / m 2 , temperature is 35℃, voltage is 2.5V.

[0084] The electrolyte includes the following components: 50 g / L SnSO4, 50 g / L H2SO4, 0.3 g / L 2-naphthyl, 1.5 g / L gelatin, 2.5 g / L potassium dichromate, and 2 g / L phenolsulfonic acid.

[0085] Comparative Example 1

[0086] A method for refining tin metal comprises the following steps:

[0087] (1) crushing the tin-containing waste into 50 meshes, removing the plastic particles, and obtaining tin-containing waste powder; the main metal components of the tin-containing waste are: 60.50% tin, 22.69% indium, 1.25% iron, 0.51% lead, 0.89% bismuth, and 1.72% copper.

[0088] (2) adding the tin-containing waste powder to a hydrochloric acid solution with a concentration of 4 mol / L, reacting at 55° C. for 1.5 h, adding sodium hydroxide to adjust the pH to 5, filtering, and obtaining a filter residue;

[0089] The usage ratio of the tin-containing waste powder and the hydrochloric acid solution is 1kg:4L.

[0090] (3) mixing the filter residue, calcium oxide and coke in a mass ratio of 100:10:3, smelting at 1200° C. for 4 h, removing the surface scum, cooling, and obtaining an alloy ingot;

[0091] (4) subjecting the alloy ingot to vacuum distillation at a vacuum degree of 1 Pa to obtain a tin ingot; the distillation temperature is 1600° C. and the time is 6 h;

[0092] (5) Casting the tin ingot of step (4) into an anode, using 4N refined tin as a cathode, and using a tin-containing liquid as an electrolyte, electrolyzing to obtain tin metal.

[0093] The current density of the electrolysis is 200A / m 2 , temperature is 35℃, voltage is 2.5V.

[0094] The electrolyte includes the following components: 40 g / L SnSO4, 60 g / L H2SO4, 0.2 g / L 2-naphthyl, 1 g / L gelatin, 2 g / L potassium dichromate, and 4 g / L phenolsulfonic acid.

[0095] Comparative Example 2

[0096] A method for refining tin metal comprises the following steps:

[0097] (1) crushing the tin-containing waste into 50 meshes, removing the plastic particles, and obtaining tin-containing waste powder; the main metal components of the tin-containing waste are: 60.50% tin, 22.69% indium, 1.25% iron, 0.51% lead, 0.89% bismuth, and 1.72% copper.

[0098] (2) adding tin-containing waste powder and 27.85 wt% hydrogen peroxide to a 4 mol / L hydrochloric acid solution, reacting at 55° C. for 1.5 h, adding sodium hydroxide to adjust the pH to 5, filtering, and obtaining a filter residue;

[0099] The usage ratio of the tin-containing waste powder, hydrogen peroxide and hydrochloric acid solution is 1kg:20mL:4L.

[0100] (3) mixing the filter residue, calcium oxide and coke in a mass ratio of 100:20:1, smelting at 1200° C. for 4 h, removing the surface scum, cooling, and obtaining an alloy ingot;

[0101] (4) subjecting the alloy ingot to vacuum distillation at a vacuum degree of 1 Pa to obtain a tin ingot; the distillation temperature is 1600° C. and the time is 6 h;

[0102] (5) Casting the tin ingot of step (4) into an anode, using 4N refined tin as a cathode, and using a tin-containing liquid as an electrolyte, electrolyzing to obtain tin metal.

[0103] The current density of the electrolysis is 200A / m 2 , temperature is 35℃, voltage is 2.5V.

[0104] The electrolyte includes the following components: 40 g / L SnSO4, 60 g / L H2SO4, 0.2 g / L 2-naphthyl, 1 g / L gelatin, 2 g / L potassium dichromate, and 4 g / L phenolsulfonic acid.

[0105] Comparative Example 3

[0106] A method for refining tin metal comprises the following steps:

[0107] (1) crushing the tin-containing waste into 50 meshes, removing the plastic particles, and obtaining tin-containing waste powder; the main metal components of the tin-containing waste are: 60.50% tin, 22.69% indium, 1.25% iron, 0.51% lead, 0.89% bismuth, and 1.72% copper.

[0108] (2) adding tin-containing waste powder and 27.85 wt% hydrogen peroxide to a 4 mol / L hydrochloric acid solution, reacting at 55° C. for 1.5 h, adding sodium hydroxide to adjust the pH to 5, filtering, and obtaining a filter residue;

[0109] The usage ratio of the tin-containing waste powder, hydrogen peroxide and hydrochloric acid solution is 1kg:20mL:4L.

[0110] (3) mixing the filter residue, calcium oxide and coke in a mass ratio of 100:2:10, smelting at 1200° C. for 4 h, removing the surface scum, cooling, and obtaining an alloy ingot;

[0111] (4) subjecting the alloy ingot to vacuum distillation at a vacuum degree of 1 Pa to obtain a tin ingot; the distillation temperature is 1600° C. and the time is 6 h;

[0112] (5) Casting the tin ingot of step (4) into an anode, using 4N refined tin as a cathode, and using a tin-containing liquid as an electrolyte, electrolyzing to obtain tin metal.

[0113] The current density of the electrolysis is 200A / m 2 , temperature is 35℃, voltage is 2.5V.

[0114] The electrolyte includes the following components: 40 g / L SnSO4, 60 g / L H2SO4, 0.2 g / L 2-naphthyl, 1 g / L gelatin, 2 g / L potassium dichromate, and 4 g / L phenolsulfonic acid.

[0115] Comparative Example 4

[0116] A method for refining tin metal comprises the following steps:

[0117] (1) crushing the tin-containing waste into 50 meshes, removing the plastic particles, and obtaining tin-containing waste powder; the main metal components of the tin-containing waste are: 60.50% tin, 22.69% indium, 1.25% iron, 0.51% lead, 0.89% bismuth, and 1.72% copper.

[0118] (2) adding tin-containing waste powder and 27.85 wt% hydrogen peroxide to a 4 mol / L hydrochloric acid solution, reacting at 55° C. for 1.5 h, adding sodium hydroxide to adjust the pH to 5, filtering, and obtaining a filter residue;

[0119] The usage ratio of the tin-containing waste powder, hydrogen peroxide and hydrochloric acid solution is 1kg:20mL:4L.

[0120] (3) mixing the filter residue, calcium oxide and coke in a mass ratio of 100:10:3, smelting at 1300° C. for 4 h, removing the surface scum, cooling and obtaining an alloy ingot;

[0121] (4) subjecting the alloy ingot to vacuum distillation at a vacuum degree of 1 Pa to obtain a tin ingot; the distillation temperature is 1600° C. and the time is 6 h;

[0122] (5) Casting the tin ingot of step (4) into an anode, using 4N refined tin as a cathode, and using a tin-containing liquid as an electrolyte, electrolyzing to obtain tin metal.

[0123] The current density of the electrolysis is 200A / m 2 , temperature is 35℃, voltage is 2.5V.

[0124] The electrolyte includes the following components: 40 g / L SnSO4, 60 g / L H2SO4, 0.2 g / L 2-naphthyl, 1 g / L gelatin, 2 g / L potassium dichromate, and 4 g / L phenolsulfonic acid.

[0125] Comparative Example 5

[0126] A method for refining tin metal comprises the following steps:

[0127] (1) crushing the tin-containing waste into 50 meshes, removing the plastic particles, and obtaining tin-containing waste powder; the main metal components of the tin-containing waste are: 60.50% tin, 22.69% indium, 1.25% iron, 0.51% lead, 0.89% bismuth, and 1.72% copper.

[0128] (2) adding tin-containing waste powder and 27.85 wt% hydrogen peroxide to a 4 mol / L hydrochloric acid solution, reacting at 55° C. for 1.5 h, adding sodium hydroxide to adjust the pH to 5, filtering, and obtaining a filter residue;

[0129] The usage ratio of the tin-containing waste powder, hydrogen peroxide and hydrochloric acid solution is 1kg:20mL:4L.

[0130] (3) mixing the filter residue, calcium oxide and coke in a mass ratio of 100:10:3, smelting at 900° C. for 4 h, removing the surface scum, cooling, and obtaining an alloy ingot;

[0131] (4) subjecting the alloy ingot to vacuum distillation at a vacuum degree of 1 Pa to obtain a tin ingot; the distillation temperature is 1600° C. and the time is 6 h;

[0132] (5) Casting the tin ingot of step (4) into an anode, using 4N refined tin as a cathode, and using a tin-containing liquid as an electrolyte, electrolyzing to obtain tin metal.

[0133] The current density of the electrolysis is 200A / m 2 , temperature is 35℃, voltage is 2.5V.

[0134] The electrolyte includes the following components: 40 g / L SnSO4, 60 g / L H2SO4, 0.2 g / L 2-naphthyl, 1 g / L gelatin, 2 g / L potassium dichromate, and 4 g / L phenolsulfonic acid.

[0135] Comparative Example 6

[0136] A method for refining tin metal comprises the following steps:

[0137] (1) crushing the tin-containing waste into 50 meshes, removing the plastic particles, and obtaining tin-containing waste powder; the main metal components of the tin-containing waste are: 60.50% tin, 22.69% indium, 1.25% iron, 0.51% lead, 0.89% bismuth, and 1.72% copper.

[0138] (2) adding tin-containing waste powder and 27.85 wt% hydrogen peroxide to a 4 mol / L hydrochloric acid solution, reacting at 55° C. for 1.5 h, adding sodium hydroxide to adjust the pH to 5, filtering, and obtaining a filter residue;

[0139] The usage ratio of the tin-containing waste powder, hydrogen peroxide and hydrochloric acid solution is 1kg:20mL:4L.

[0140] (3) mixing the filter residue, calcium oxide and coke in a mass ratio of 100:10:3, smelting at 1200° C. for 4 h, removing the surface scum, cooling, and obtaining an alloy ingot;

[0141] (4) subjecting the alloy ingot to vacuum distillation at a vacuum degree of 1 Pa to obtain a tin ingot; the distillation temperature is 1600° C. and the time is 6 h;

[0142] (5) Casting the tin ingot of step (4) into an anode, using 4N refined tin as a cathode, and using a tin-containing liquid as an electrolyte, electrolyzing to obtain tin metal.

[0143] The current density of the electrolysis is 200A / m 2 , temperature is 35℃, voltage is 2.5V.

[0144] The electrolyte includes the following components: 40 g / L SnSO4.

[0145] Comparative Example 7

[0146] A method for refining tin metal comprises the following steps:

[0147] (1) crushing the tin-containing waste into 50 meshes, removing the plastic particles, and obtaining tin-containing waste powder; the main metal components of the tin-containing waste are: 60.50% tin, 22.69% indium, 1.25% iron, 0.51% lead, 0.89% bismuth, and 1.72% copper.

[0148] (2) adding tin-containing waste powder and 27.85 wt% hydrogen peroxide to a 4 mol / L hydrochloric acid solution, reacting at 55° C. for 1.5 h, adding sodium hydroxide to adjust the pH to 5, filtering, and obtaining a filter residue;

[0149] The usage ratio of the tin-containing waste powder, hydrogen peroxide and hydrochloric acid solution is 1kg:20mL:4L.

[0150] (3) mixing the filter residue, calcium oxide and coke in a mass ratio of 100:10:3, smelting at 1200° C. for 4 h, removing the surface scum, cooling, and obtaining an alloy ingot;

[0151] (4) subjecting the alloy ingot to vacuum distillation at a vacuum degree of 1 Pa to obtain a tin ingot; the distillation temperature is 1600° C. and the time is 6 h;

[0152] (5) Casting the tin ingot of step (4) into an anode, using 4N refined tin as a cathode, and using a tin-containing liquid as an electrolyte, electrolyzing to obtain tin metal.

[0153] The current density of the electrolysis is 200A / m 2 , temperature is 35℃, voltage is 2.5V.

[0154] The electrolyte includes the following components: 20 g / L SnSO4, 80 g / L H2SO4, 0.05 g / L 2-naphthyl, 4 g / L gelatin, 1 g / L potassium dichromate, and 8 g / L phenolsulfonic acid.

[0155] Comparative Example 8

[0156] A method for refining tin metal comprises the following steps:

[0157] (1) crushing the tin-containing waste into 50 meshes, removing the plastic particles, and obtaining tin-containing waste powder; the main metal components of the tin-containing waste are: 60.50% tin, 22.69% indium, 1.25% iron, 0.51% lead, 0.89% bismuth, and 1.72% copper.

[0158] (2) adding tin-containing waste powder and 27.85 wt% hydrogen peroxide to a 4 mol / L hydrochloric acid solution, reacting at 55° C. for 1.5 h, adding sodium hydroxide to adjust the pH to 5, filtering, and obtaining a filter residue;

[0159] The usage ratio of the tin-containing waste powder, hydrogen peroxide and hydrochloric acid solution is 1kg:20mL:4L.

[0160] (3) mixing the filter residue, calcium oxide and coke in a mass ratio of 100:10:3, smelting at 1200° C. for 4 h, removing the surface scum, cooling, and obtaining an alloy ingot;

[0161] (4) subjecting the alloy ingot to vacuum distillation at a vacuum degree of 1 Pa to obtain a tin ingot; the distillation temperature is 1600° C. and the time is 6 h;

[0162] (5) Casting the tin ingot of step (4) into an anode, using 4N refined tin as a cathode, and using a tin-containing liquid as an electrolyte, electrolyzing to obtain tin metal.

[0163] The current density of the electrolysis is 200A / m 2 , temperature is 35℃, voltage is 2.5V.

[0164] The electrolyte includes the following components: 60 g / L SnSO4, 20 g / L H2SO4, 0.5 g / L 2-naphthyl, 0.1 g / L gelatin, 4 g / L potassium dichromate, and 1 g / L phenolsulfonic acid.

[0165] Test Case

[0166] The purity and recovery of tin metal in the embodiments and comparative examples are shown in Table 1.

[0167] Table 1

[0168]

[0169]

[0170] The invention adds tin-containing waste powder and hydrogen peroxide into a hydrochloric acid solution for acid leaching, so that all metals enter the solution in the highest valence state ions, and then uses sodium hydroxide to adjust the pH value of the solution to 4.8-5.2 to allow the metal to precipitate and enrich, and then evenly mix the filter residue, molten salt and reducing agent, smelt and reduce, remove impurity elements such as iron, and further purify the tin alloy, and then perform vacuum distillation to volatilize the impurity metals with a lower boiling point than tin, further purify the tin alloy to obtain crude tin, and finally electrolyze to obtain metallic tin, wherein the purity of the tin metal is high and can reach the 4.5N level.

[0171] 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 refining tin metal, characterized in that: The following steps are involved: (1) crushing the tin-containing waste to obtain tin-containing waste powder, adding the tin-containing waste powder and hydrogen peroxide to a hydrochloric acid solution, reacting, adding sodium hydroxide to adjust the pH to 4.8-5.2, filtering, and obtaining a filter residue; (2) uniformly mixing the filter residue, molten salt and reducing agent, and smelting to obtain an alloy ingot; (3) subjecting the alloy ingot to vacuum distillation to obtain a tin ingot; (4) using the tin ingot obtained in step (3) as an anode, using refined tin as a cathode, and using a tin-containing liquid as an electrolyte to perform electrolysis to obtain tin metal.

2. The tin metal refining method according to claim 1, characterized in that: The particle size of the tin-containing waste powder is 30 to 80 meshes.

3. The tin metal refining method according to claim 1, characterized in that: The usage ratio of the tin-containing waste powder, hydrogen peroxide and hydrochloric acid solution is 1kg: (10-20)mL: (3-6)L.

4. The tin metal refining method according to claim 1, characterized in that: The concentration of the hydrogen peroxide is 27.5-60wt%; The concentration of the hydrochloric acid solution is 2-4 mol / L.

5. The tin metal refining method according to claim 1, characterized in that: The reaction temperature is 50-60° C., and the reaction time is 1-2 hours.

6. The tin metal refining method according to claim 1, characterized in that: The mass ratio of the filter residue, the molten salt and the reducing agent is 100:(5-10):(3-5).

7. The tin metal refining method according to claim 1, characterized in that: The molten salt includes at least one of calcium oxide, magnesium fluoride, sodium borate and quartz stone; The reducing agent includes at least one of coke, anthracite and charcoal.

8. The tin metal refining method according to claim 1, characterized in that: The distillation temperature is 1400-1600° C. and the distillation time is 4-6 hours.

9. The tin metal refining method according to claim 1, characterized in that: The current density of the electrolysis is 100-300A / m 2 , temperature is 30~50℃, voltage is 2~4V.

10. The tin metal refining method according to claim 1, characterized in that: The electrolyte comprises the following components: 30-50 g / L SnSO4, 50-70 g / L H2SO4, 0.1-0.3 g / L 2-naphthyl, 0.5-2 g / L gelatin, 1.5-2.5 g / L potassium dichromate, and 2-5 g / L organic additives; The organic additive includes at least one of cresol sulfonic acid, phenol sulfonic acid and ethyl sulfonic acid.

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