A method for quickly filtering an acidic mixed solution containing tin, antimony and silicon

Abstract

The present invention provides a method for rapidly filtering an acidic mixed solution containing tin, antimony, and silicon, belonging to the technical field of rapid filtration of difficult-to-filter solutions. A filter aid is added to the acidic mixed solution containing tin, antimony, and silicon. The filter aid reacts with oxalic acid and / or sulfuric acid in the acidic mixed solution containing tin, antimony, and silicon to form a large, loose solid precipitate. This destroys the colloid formed by the tin, antimony, and silicon in the solution, reduces the viscosity of the acidic mixed solution containing tin, antimony, and silicon, loosens the filter residue layer, and greatly improves the efficiency of solid-liquid separation. Furthermore, the added filter aid does not react with the tin in the acidic mixed solution containing tin, antimony, and silicon, and has no or minimal effect on tin recovery.

Description

Technical Field

[0001] The invention belongs to the technical field of rapid filtration of difficult-to-filter solutions, and particularly relates to a method for rapid filtration of an acidic mixed solution containing tin, antimony, and silicon. Background Art

[0002] Tin is one of the earliest metals used by humans and one of the most widely used in industry. Along with tungsten, antimony, and rare earth elements, tin is considered one of the "four strategic resources." As a key strategic resource, the efficient and clean recycling of tin from secondary sources such as tin-containing waste is becoming increasingly important, as primary mineral resources become scarcer and national environmental protection standards are tightened.

[0003] Low-grade tin-containing secondary resources (tin content less than 5%) are generally recovered by acid leaching. During the wet tin recovery process, Sn, Sb, and Si in the raw materials are leached into the solution. Under acidic conditions, these elements will form colloids, which will clog the filter cloth during liquid-solid separation, hinder filtration, and seriously reduce filtration efficiency.

[0004] Currently, the main methods for addressing this issue include centrifugation, colloidal coagulation, and flocculation. Centrifugation is primarily used for small-scale solid-liquid separation in the laboratory. Colloidal coagulation causes valuable metals such as tin and antimony leached into the solution to settle back into the slag, failing to achieve the desired leaching and separation. Adding flocculants also causes valuable metals such as tin and antimony to settle into the slag and introduce impurities. Therefore, these methods are unsuitable for treating difficult-to-filter solutions containing valuable metals such as tin and antimony. Summary of the Invention

[0005] In view of this, the present invention aims to provide a method for rapidly filtering an acidic mixture containing tin, antimony and silicon. The method provided by the present invention is simple to operate, greatly improves the filtration speed, and has no or minimal impact on tin recovery.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides a method for quickly filtering an acidic mixed solution containing tin, antimony and silicon, comprising the following steps:

[0008] The filter aid is mixed with the acidic mixed solution containing tin, antimony and silicon and then filtered;

[0009] The filter aid is a calcium-containing compound;

[0010] The acid in the acidic mixed solution containing tin, antimony and silicon is sulfuric acid and / or oxalic acid.

[0011] Preferably, the calcium-containing compound includes CaO, Ca(OH)2 or CaCl2.

[0012] Preferably, the concentration of Sn in the acidic mixed solution containing tin, antimony and silicon is 0.5-5 g / L, the concentration of Sb is 0.1-1 g / L, and the concentration of Si is 0.1-1 g / L.

[0013] Preferably, the concentration of sulfuric acid in the acidic mixed solution containing tin, antimony and silicon is 0-200 g / L, and the concentration of oxalic acid is 0-100 g / L, and the concentrations of sulfuric acid and oxalic acid are not both 0.

[0014] Preferably, the temperature of the acidic mixed solution containing tin, antimony and silicon is 10-90°C.

[0015] Preferably, the temperature of the acidic mixed solution containing tin, antimony and silicon is 20-70°C.

[0016] Preferably, the pH value of the acidic mixed solution containing tin, antimony and silicon is -2 to 4.

[0017] Preferably, the volume ratio of the mass of the filter aid to the acidic mixed solution containing tin, antimony and silicon is (7-80) g:1 L.

[0018] Preferably, the mixing is carried out under stirring conditions, with a stirring speed of 20 to 200 r / min and a stirring time of 1 to 10 min.

[0019] Preferably, the filtering method includes vacuum filtration or pressure filtration.

[0020] The present invention provides a method for rapidly filtering an acidic mixture containing tin, antimony, and silicon, comprising the following steps: mixing a filter aid with the acidic mixture containing tin, antimony, and silicon, followed by filtration; the filter aid being a calcium-containing compound; and the acid in the acidic mixture containing tin, antimony, and silicon being sulfuric acid and / or oxalic acid. Under acidic conditions, the tin, antimony, and silicon in the solution will form a colloid, which will clog the filter cloth during filtration and make solid-liquid separation difficult. The present invention adds a cheap and readily available calcium-containing filter aid to the acidic mixture containing tin, antimony, and silicon. The calcium reacts with the oxalic acid and / or sulfuric acid in the acidic mixture to form large, loose particles of calcium oxalate and / or calcium sulfate, which destroy the colloid in the solution, reduce the viscosity of the acidic mixture containing tin, and loosen the filter residue layer, greatly improving the solid-liquid separation efficiency. Furthermore, the added calcium-containing filter aid does not react with the tin in the acidic mixture containing tin, antimony, and silicon, and has no or minimal effect on tin recovery. The method provided by the present invention has high solid-liquid separation efficiency, low cost, and simple operation.

[0021] In addition, the filter aid of the present invention is a calcium-containing compound, which can generate calcium oxalate with oxalic acid, and can further generate oxalic acid and calcium sulfate by adding sulfuric acid in the later stage, thereby realizing the recycling of oxalic acid; the pH of the acidic mixed solution containing tin, antimony and silicon can be increased, and the consumption of sodium hydroxide can be reduced during the later hydrolysis and precipitation of tin, thereby reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 The present invention provides a flow chart for the rapid filtration of an acidic mixed solution containing tin, antimony and silicon. DETAILED DESCRIPTION

[0024] The present invention provides a method for quickly filtering an acidic mixed solution containing tin, antimony and silicon, comprising the following steps:

[0025] The filter aid is mixed with the acidic mixed solution containing tin, antimony and silicon and then filtered;

[0026] The filter aid is a calcium-containing compound;

[0027] The acid in the acidic mixed solution containing tin, antimony and silicon is sulfuric acid and / or oxalic acid.

[0028] In the present invention, the acidic mixture containing tin, antimony, and silicon is preferably obtained by acid leaching a tin-containing material with oxalic acid and / or sulfuric acid, or by dissolving tin oxide or tin hydroxide to prepare an acidic solution. The tin content of the tin-containing material is preferably less than 5% by weight. The present invention has no particular requirements for the acid leaching process or the process of dissolving tin oxide or tin hydroxide to prepare the acidic solution; processes well known in the art may be employed.

[0029] In the present invention, the concentration of Sn in the acidic mixed solution containing tin, antimony and silicon is preferably 0.5-5 g / L, more preferably 1-3.5 g / L, more preferably 1.2-3 g / L; the concentration of Sb is 0.1-1 g / L, 0.2-0.7 g / L, more preferably 0.3-0.5 g / L; the concentration of Si is preferably 0.1-1 g / L, more preferably 0.12-0.7 g / L, more preferably 0.2-0.5 g / L.

[0030] In the present invention, the acid in the acidic mixed solution containing tin, antimony, and silicon is sulfuric acid and / or oxalic acid, preferably sulfuric acid and oxalic acid. In the present invention, the concentration of the sulfuric acid is preferably 0 to 200 g / L, more preferably 20 to 180 g / L, and more preferably 50 to 120 g / L; the concentration of the oxalic acid is preferably 0 to 100 g / L, more preferably 20 to 95 g / L, and more preferably 30 to 70 g / L, and the concentrations of the sulfuric acid and oxalic acid are not both zero. In the present invention, the pH of the acidic mixed solution containing tin, antimony, and silicon is preferably -2 to 4.

[0031] In the present invention, the temperature of the acidic mixed solution containing tin, antimony, and silicon is preferably 10 to 90°C, more preferably 20 to 70°C, and even more preferably 40 to 60°C. In the present invention, the calcium-containing filter aid reacts with oxalic acid to form calcium oxalate. If the temperature is above 90°C, the oxalic acid will decompose, affecting the filtration effect. Therefore, the temperature of the acidic mixed solution containing tin, antimony, and silicon is controlled to be 10 to 90°C.

[0032] In the present invention, the calcium-containing compound preferably includes CaO, Ca(OH)2, or CaCl2, more preferably CaO or Ca(OH)2, and even more preferably CaO. In the present invention, the volume ratio of the filter aid to the acidic mixed solution containing tin, antimony, and silicon is preferably (7-80) g:1 L, more preferably (10-60) g:1 L, and even more preferably (20-50) g:1 L.

[0033] In the present invention, the acidic mixed solution containing tin, antimony and silicon is preferably obtained by acid leaching a tin-containing material with oxalic acid and / or sulfuric acid; under acidic conditions, the tin, antimony and silicon in the solution will form a colloid, which will clog the filter cloth during filtration, resulting in difficulty in solid-liquid separation. The present invention adds a calcium-containing filter aid to the acidic mixed solution containing tin, antimony and silicon. The calcium reacts with the oxalic acid and / or sulfuric acid in the acidic mixed solution containing tin, antimony and silicon to form large-particle, relatively loose calcium oxalate and / or calcium sulfate, destroying the colloid in the solution, reducing the viscosity of the acidic mixed solution containing tin, antimony and silicon, making the filter residue layer loose, and greatly improving the solid-liquid separation efficiency; and the added calcium-containing filter aid does not react with the tin in the acidic mixed solution containing tin, antimony and silicon, and will not affect or has minimal effect on the recovery of tin. The method provided by the present invention has high solid-liquid separation efficiency, low cost, and simple operation.

[0034] The filter aid of the present invention is a calcium-containing compound, which can generate calcium oxalate with oxalic acid, and can further generate oxalic acid and calcium sulfate by adding sulfuric acid in the later stage, thereby realizing the recycling of oxalic acid; the filter aid can increase the pH of the acidic mixed solution containing tin, antimony and silicon, and can reduce the consumption of sodium hydroxide during the later hydrolysis and precipitation of tin, thereby reducing costs.

[0035] In the present invention, the mixing is preferably carried out under stirring conditions, and the stirring speed is preferably 20 to 200 r / min, more preferably 50 to 150 r / min, and more preferably 80 to 120 r / min; the stirring time is preferably 1 to 10 min, more preferably 3 to 8 min, and more preferably 4 to 7 min. In the present invention, mechanical stirring is preferably used to control the rotation speed. In the present invention, the filtration method includes vacuum filtration or filter press. In an embodiment of the present invention, the filtration is carried out in a suction flask equipped with a Buchner funnel.

[0036] Figure 1 The figure is a flow chart of the rapid filtration of the acidic mixed solution containing tin, antimony and silicon according to the present invention. Figure 1As shown, the present invention mixes the acidic mixed solution containing tin, antimony and silicon obtained by acid leaching the tin-containing material with a filter aid and then filters to obtain filter residue and a tin-antimony-silicon solution, and then recovers tin in the tin-antimony-silicon solution to obtain a tin product.

[0037] To further illustrate the present invention, the method for rapid filtration of an acidic mixed solution containing tin, antimony and silicon provided by the present invention is described in detail below with reference to the accompanying drawings and examples, but they should not be construed as limiting the scope of protection of the present invention.

[0038] Example 1

[0039] In the acidic mixed solution containing tin, antimony and silicon described in this embodiment, the concentration of Sn is 1.32 g / L, the concentration of Sb is 0.39 g / L, the concentration of Si is 0.15 g / L, the concentration of oxalic acid is 90 g / L, and the rest is sulfuric acid and a small amount of Fe and Cd. The temperature of the acidic mixed solution containing tin, antimony and silicon is 65°C and the pH value is 0.13.

[0040] Take 500mL of the acidic mixture containing tin, antimony and silicon, add 7g of calcium oxide according to the volume ratio of the filter aid mass to the acidic mixture containing tin, antimony and silicon of 14g:1L, stir for 5min, and the stirring speed is 100r / min. Use an 80mm Buchner funnel and a 1L suction bottle, pad two layers of medium-speed filter paper, turn on the circulating water multi-purpose vacuum pump to start filtration, and record the filtration time.

[0041] The filtration was completed, and the filtration time was 21 minutes. Compared with Comparative Example 1, the filtration speed was increased by 13 times, and the filtrate was clear and transparent. The tin concentration in the filtrate was 1.31 g / L.

[0042] Example 2

[0043] In the acidic mixed solution containing tin, antimony and silicon described in this embodiment, the concentration of Sn is 1.32 g / L, the concentration of Sb is 0.39 g / L, the concentration of Si is 0.15 g / L, the concentration of oxalic acid is 90 g / L, and the rest is sulfuric acid and a small amount of Fe and Cd. The temperature of the acidic mixed solution containing tin, antimony and silicon is 65°C and the pH value is 0.13.

[0044] Take 500mL of the acidic mixed solution containing tin, antimony and silicon, add 14g of calcium hydroxide according to the volume ratio of the mass of the filter aid to the acidic mixed solution containing tin, antimony and silicon of 28g:1L, stir for 5min, and the stirring speed is 100r / min. Use an 80mm Buchner funnel and a 1L suction bottle, pad two layers of medium-speed filter paper, turn on the circulating water multi-purpose vacuum pump to start filtration, and record the filtration time.

[0045] The filtration was completed, and the filtration time was 6 minutes. Compared with Comparative Example 1, the filtration speed was increased by 45 times, and the filtrate was clear and transparent, and the tin concentration in the filtrate was 1.29 g / L.

[0046] Example 3

[0047] In the acidic mixed solution containing tin, antimony and silicon described in this embodiment, the concentration of Sn is 1.32 g / L, the concentration of Sb is 0.39 g / L, the concentration of Si is 0.15 g / L, the concentration of oxalic acid is 90 g / L, and the rest is sulfuric acid and a small amount of Fe and Cd. The temperature of the acidic mixed solution containing tin, antimony and silicon is 65°C and the pH value is 0.13.

[0048] Take 500mL of the acidic mixed solution containing tin, antimony and silicon, add 14g of calcium chloride according to the volume ratio of the mass of the filter aid to the acidic mixed solution containing tin, antimony and silicon of 28g:1L, stir for 5min, and the stirring speed is 100r / min. Use an 80mm Buchner funnel and a 1L suction bottle, pad two layers of medium-speed filter paper, turn on the circulating water multi-purpose vacuum pump to start filtration, and record the filtration time.

[0049] The filtration was completed, and the filtration time was 8 minutes. Compared with Comparative Example 1, the filtration speed was increased by 34 times, and the filtrate was clear and transparent. The tin concentration in the filtrate was 1.30 g / L.

[0050] Example 4

[0051] In the acidic mixed solution containing tin, antimony and silicon described in this embodiment, the concentration of Sn is 2.24 g / L, the concentration of Sb is 0.45 g / L, the concentration of Si is 0.18 g / L, the concentration of oxalic acid is 90 g / L, and the rest is sulfuric acid and a small amount of Fe and Cd. The temperature of the acidic mixed solution containing tin, antimony and silicon is 65°C and the pH value is 0.02.

[0052] Take 15L of the acidic mixed solution containing tin, antimony and silicon, add 840g of calcium oxide according to the volume ratio of the mass of the filter aid to the acidic mixed solution containing tin, antimony and silicon of 56g:L, stir for 5 minutes, and the stirring speed is 100r / min. Use a 300mm Buchner funnel and a 20L suction bottle, pad two layers of medium-speed filter paper, turn on the circulating water multi-purpose vacuum pump to start filtration, and record the filtration time.

[0053] The filtration was completed, and the filtration time was 45 minutes. Compared with Comparative Example 2, the filtration speed was increased by 80 times, and the filtrate was clear and transparent. The tin concentration in the filtrate was 2.21 g / L.

[0054] Comparative Example 1

[0055] In the acidic mixed solution containing tin, antimony and silicon described in this embodiment, the concentration of Sn is 1.32 g / L, the concentration of Sb is 0.39 g / L, the concentration of Si is 0.15 g / L, the concentration of oxalic acid is 90 g / L, and the rest is sulfuric acid and a small amount of Fe and Cd. The temperature of the acidic mixed solution containing tin, antimony and silicon is 65°C and the pH value is 0.13.

[0056] Take 500 mL of the acidic mixture containing tin, antimony and silicon without adding filter aids, use an 80 mm Buchner funnel and a 1 L suction flask, pad two layers of medium-speed filter paper, turn on the circulating water multi-purpose vacuum pump to start filtration, and record the filtration time.

[0057] The filtration was completed, the filtration time was 270 min, and the filtrate was turbid and opaque.

[0058] Comparative Example 2

[0059] In the acidic mixed solution containing tin, antimony and silicon described in this embodiment, the concentration of Sn is 2.24 g / L, the concentration of Sb is 0.45 g / L, the concentration of Si is 0.18 g / L, the concentration of oxalic acid is 90 g / L, and the rest is sulfuric acid and a small amount of Fe and Cd. The temperature of the acidic mixed solution containing tin, antimony and silicon is 65°C and the pH value is 0.02.

[0060] Take 15L of acidic mixed solution containing tin, antimony and silicon, without adding filter aid, use a 300mm Buchner funnel and a 20L suction flask, pad two layers of medium-speed filter paper, turn on the circulating water multi-purpose vacuum pump to start filtration, and record the filtration time.

[0061] The filtration was completed, the filtration time was 3600 min, and the filtrate was turbid and opaque.

[0062] Although the above embodiment provides a detailed description of the present invention, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the scope of protection of the present invention.

Claims

1. A method for rapid filtration of an acidic mixture containing tin, antimony and silicon, characterized in that: The following steps are involved: Mixing the filter aid with the acidic mixed solution containing tin, antimony and silicon and filtering the mixture; the temperature of the acidic mixed solution containing tin, antimony and silicon is 10 to 65° C.; the pH value of the acidic mixed solution containing tin, antimony and silicon is -2 to 4; The filter aid is a calcium-containing compound; the calcium-containing compound is CaO, Ca(OH)2 or CaCl2; The acid in the acidic mixed solution containing tin, antimony and silicon is sulfuric acid and oxalic acid or oxalic acid.

2. The method according to claim 1, characterized in that In the acidic mixed solution containing tin, antimony and silicon, the concentration of Sn is 0.5-5 g / L, the concentration of Sb is 0.1-1 g / L, and the concentration of Si is 0.1-1 g / L.

3. The method according to claim 1, characterized in that The concentration of oxalic acid in the acidic mixed solution containing tin, antimony and silicon is 0-100 g / L, and the concentration of oxalic acid is not zero.

4. The method according to claim 1 or 2, characterized in that The volume ratio of the mass of the filter aid to the acidic mixed liquid containing tin, antimony and silicon is (7-80) g:1L.

5. The method according to claim 1, characterized in that The mixing is carried out under stirring conditions, with a stirring speed of 20 to 200 r / min and a stirring time of 1 to 10 minutes.

6. The method according to claim 1, characterized in that The filtering method includes vacuum filtration or pressure filtration.

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