Organic salt leaching separation method of thallium-chlorine-containing solid waste

Abstract

The invention provides an organic salt leaching separation method for thallium-chlorine-containing solid waste. The method comprises the following steps: providing the thallium-chlorine-containing solid waste; preparing alkaline leaching liquid from the thallium-chlorine-containing solid waste, alkaline liquor and organic salt, carrying out alkaline leaching separation on thallium in the thallium-chlorine-containing solid waste, and carrying out solid-liquid separation to obtain leaching liquid; the organic salt comprises one or more of oxalate and acetate. According to the method, the alkaline leaching separation efficiency of thallium in the thallium-chlorine-containing solid waste is improved; when oxalate is adopted as an additive, the thallium leaching rate of 90% or above can be achieved only at the leaching temperature of about 50 DEG C; when acetate is adopted as an additive, the thallium leaching rate of 95% or above can be achieved only at the leaching temperature of about 60 DEG C; compared with conventional alkaline leaching separation, the method has the advantage that the leaching effect of thallium is remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of solid waste treatment, and particularly relates to a method for separating organic salts by alkaline leaching of thallium-containing solid waste. Background Technology

[0002] Thallium-containing chlorine-laden flue dust is produced by multi-hearth furnaces in zinc smelting enterprises. This flue dust contains both thallium and chlorine; it also contains elements such as lead, zinc, and cadmium. Therefore, when leaching thallium from this flue dust, it is not only easily affected by chlorine but may also cause the simultaneous leaching of large amounts of lead, zinc, cadmium, and other elements.

[0003] In wet processing, sodium hydroxide alkaline leaching is commonly used to treat thallium-containing chlorine-laden flue dust. Although this method can leach thallium from thallium-containing chlorine-laden flue dust, the leaching rates of lead, zinc, and cadmium are relatively low, achieving selective leaching of thallium. However, when using alkaline solutions such as sodium hydroxide for alkaline leaching separation of thallium from thallium-containing chlorine-laden flue dust, saturated precipitation of TlOH is likely to occur. Furthermore, due to the presence of chlorine, supersaturated precipitation of TlCl due to chloride ions is also likely to occur, resulting in a low thallium leaching rate under alkaline leaching alone.

[0004] Therefore, it is necessary to provide a method for separating thallium from thallium-containing solid waste by alkaline leaching, in order to solve or at least alleviate the technical problem of how to improve the alkaline leaching separation efficiency of thallium in thallium-containing solid waste. Summary of the Invention

[0005] The main objective of this invention is to provide a method for separating thallium from thallium-containing solid waste by alkaline leaching, aiming to solve or at least alleviate the technical problem of how to improve the alkaline leaching separation efficiency of thallium in thallium-containing solid waste.

[0006] To achieve the above objectives, the present invention provides a method for separating thallium-containing chlorine solid waste by organic salt leaching, comprising: providing thallium-containing chlorine solid waste; preparing an alkali leaching solution by mixing the thallium-containing chlorine solid waste with an alkaline solution and an organic salt; performing alkali leaching separation of thallium in the thallium-containing chlorine solid waste; and obtaining a leachate after solid-liquid separation; wherein the organic salt comprises one or more of oxalate and acetate.

[0007] Furthermore, the oxalate includes one or more of sodium oxalate and potassium oxalate; the acetate includes one or more of sodium acetate and potassium acetate.

[0008] Furthermore, the concentration of the organic salt in the alkaline leaching solution is not less than 0.2 mol / L.

[0009] Further, the organic salt includes the oxalate, the concentration of which in the alkaline leaching solution is 0.2-1.0 mol / L; or, the organic salt includes the acetate, the concentration of which in the alkaline leaching solution is 0.6-1.0 mol / L.

[0010] Furthermore, the alkaline leaching separation temperature is 45-85℃.

[0011] Further, the organic salt includes the oxalate, and the alkaline leaching separation temperature is 50-80°C; or, the organic salt includes the acetate, and the alkaline leaching separation temperature is 55-65°C.

[0012] Furthermore, the alkaline leaching separation time is not less than 60 minutes.

[0013] Further, the organic salt includes the oxalate, and the mass-to-volume ratio of the thallium-chloride-containing solid waste to the alkaline solution is 1g:5-6mL; the organic salt includes the acetate, and the mass-to-volume ratio of the thallium-chloride-containing solid waste to the alkaline solution is 1g:4-6mL.

[0014] Furthermore, the concentration of hydroxide ions in the alkaline leaching solution is not less than 0.5 mol / L; the alkaline solution includes a strongly alkaline hydroxide; the strongly alkaline hydroxide includes one or more of sodium hydroxide and potassium hydroxide.

[0015] Furthermore, the thallium-containing chlorine solid waste also contains one or more of lead, zinc, and cadmium; the thallium-containing chlorine solid waste includes thallium-containing chlorine dust.

[0016] Compared with the prior art, the present invention has at least the following advantages:

[0017] This invention improves the alkaline leaching separation efficiency of thallium in thallium-containing chlorine solid waste; during the alkaline leaching separation process, the Tl in the thallium-containing chlorine dust... + With Cl - Thallium readily forms stable TlCl, which is a slightly soluble substance. In such cases, a significant increase in temperature is typically attempted to improve the leaching rate of thallium. However, this not only increases energy consumption considerably but also easily leads to the co-leaching of other metals, thus affecting the selective and efficient leaching of thallium. This invention utilizes the reaction of thallium ions and a slightly soluble thallium chloride phase with oxalate or acetate, and free oxalate or acetate ions, to form a stable and dissolved TlC₂O₄. -Alternatively, CH3COOTl(aq) can be used to achieve efficient thallium release. In this invention, when oxalate is used as an additive, a leaching temperature of only about 50°C is required to achieve a thallium leaching rate of over 90%; when acetate is used as an additive, a leaching temperature of only about 60°C is required to achieve a thallium leaching rate of over 95%. Compared with conventional alkaline leaching separation, the thallium leaching effect of this invention is significantly improved. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0019] Figure 1 This is the XRD pattern of thallium-chlorine-containing flue dust in Example 1 of the present invention.

[0020] The realization of the objective, functional characteristics and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0023] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in the present invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention, as well as the prior art known to those skilled in the art and the description of this invention, may be implemented using any prior art methods, devices, and materials similar to or equivalent to those described, used, or made of materials in the embodiments of this invention.

[0024] This invention provides a method for separating thallium-containing chlorine solid waste from organic salts by alkaline leaching, comprising: providing thallium-containing chlorine solid waste; preparing an alkaline leaching solution by mixing the thallium-containing chlorine solid waste with an alkaline solution and organic salts; performing alkaline leaching separation of thallium in the thallium-containing chlorine solid waste; obtaining a leachate and a leachate residue after solid-liquid separation; wherein the organic salts include one or more of oxalates and acetates.

[0025] In this invention, the alkaline leaching solution is obtained by: mixing the thallium-containing chlorine solid waste, the alkaline solution, and the organic salt, and continuing to mix them; the alkaline leaching separation is based on the alkaline leaching solution, and the alkaline leaching separation process is a mixing process of the thallium-containing chlorine solid waste, the alkaline solution, and the organic salt; during the alkaline leaching separation process, thallium in the thallium-containing chlorine solid waste is released, so that a large amount of thallium in the thallium-containing chlorine solid waste enters the leaching solution; after the alkaline leaching separation is completed, the reaction product is subjected to solid-liquid separation.

[0026] The thallium-containing chlorine solid waste of the present invention contains thallium and chlorine; the thallium content in the thallium-containing chlorine solid waste is 0.5-0.7 wt%, and the chlorine content is 4-6 wt%; the thallium-containing chlorine solid waste also contains one or more of lead, zinc, and cadmium; further, the thallium-containing chlorine solid waste also contains lead and zinc. The lead content in the thallium-containing chlorine solid waste is 20-23 wt%, and the zinc content is 28-31 wt%; the cadmium content in the thallium-containing chlorine solid waste is 2-3 wt%. The phases in the thallium-containing chlorine solid waste include zinc sulfate, lead sulfate, lead chloride, and cadmium oxide; the phase forms in the thallium-containing chlorine dust include crystalline and amorphous states. The thallium-containing chlorine solid waste includes thallium-containing chlorine dust, specifically thallium-containing chlorine dust generated during zinc smelting; the thallium element in the thallium-containing chlorine dust (corresponding to the thallium-containing chlorine solid waste) includes or is monovalent thallium.

[0027] In this invention, the thallium-containing solid waste is in granular form; specifically, before obtaining the alkaline leaching solution, the thallium-containing solid waste is dried, ground, and sieved; the sieve mesh size is 100 mesh.

[0028] In this invention, the oxalate is readily soluble in water; the oxalate includes one or more of sodium oxalate and potassium oxalate. The acetate is readily soluble in water; the acetate includes one or more of sodium acetate and potassium acetate. In this invention, the organic salt preferably includes or is the oxalate.

[0029] In this invention, the concentration of the organic salt in the alkaline leaching solution is not less than 0.2 mol / L or not less than 0.6 mol / L. As another illustration, the organic salt includes or is the oxalate, and the concentration of the oxalate in the alkaline leaching solution is not less than 0.2 mol / L, more specifically 0.2-1.0 mol / L, more specifically 0.2-0.6 mol / L or 0.6-1.0 mol / L; or, the organic salt includes or is the acetate, and the concentration of the acetate in the alkaline leaching solution is not less than 0.6 mol / L, more specifically 0.6-1.0 mol / L, more specifically 0.6-0.8 mol / L or 0.8-1.0 mol / L.

[0030] In this invention, the alkaline leaching separation temperature is 45-85℃. As a supplementary explanation, the organic salt includes or is the oxalate, and the alkaline leaching separation temperature is 45-85℃, further 50-80℃, 50-60℃, 60-70℃, 70-80℃, 60-80℃, 50-70℃, 45-55℃, or 55-65℃; or, the organic salt includes or is the acetate, and the alkaline leaching separation temperature is 45-85℃, further 50-80℃, 45-65℃, 45-55℃, 55-65℃, 58-62℃, 60-65℃, 60-62℃, 50-60℃, or 60-80℃.

[0031] In this invention, the mass-to-volume ratio of the thallium-chloride-containing solid waste to the alkaline solution is no greater than 1g:4mL or no greater than 1g:5mL; or, the mass-to-volume ratio of the thallium-chloride-containing solid waste to the alkaline solution is 1g:4-6mL or 1g:5-7mL. As another embodiment, the organic salt includes or is the oxalate, and the mass-to-volume ratio of the thallium-chloride-containing solid waste to the alkaline solution is 1g:5-6mL, 1g:4.9-5.5mL, 1g:4.9-5.1mL, or 1g:4.5-5.5mL; the organic salt includes or is the acetate, and the mass-to-volume ratio of the thallium-chloride-containing solid waste to the alkaline solution is 1g:4-6mL, 1g:4.5-5.5mL, 1g:5-5.5mL, 1g:4-5mL, or 1g:5-6mL.

[0032] In this invention, the alkaline leaching separation time is not less than 60 min or not less than 120 min, or it can be 60-200 min, 100-150 min, 120-150 min, or 120-200 min.

[0033] In the alkaline leaching solution or alkaline solution of the present invention, the concentration of hydroxide ions is not less than 0.5 mol / L, and more specifically 0.5-0.8 mol / L, 0.6-0.8 mol / L, 0.55-0.65 mol / L, 0.6-0.7 mol / L, 0.75-0.85 mol / L, or 0.7-0.8 mol / L; the hydroxide ions are provided by the alkaline solution; the alkaline solution includes a strongly alkaline hydroxide, specifically, the alkaline substance in the alkaline solution can be the strongly alkaline hydroxide. The strong alkaline hydroxide includes one or more of sodium hydroxide and potassium hydroxide; the alkaline solution includes one or more of sodium hydroxide solution and potassium hydroxide solution; in the alkaline solution, the concentration of the strong alkaline hydroxide is not less than 0.5 mol / L, further being 0.5-0.8 mol / L, 0.6-0.8 mol / L, 0.55-0.65 mol / L, 0.6-0.7 mol / L, 0.75-0.85 mol / L, or 0.7-0.8 mol / L.

[0034] The main reasons for choosing sodium acetate or sodium oxalate as the additive in this invention include: to achieve the separation of thallium from valuable metals in thallium-containing chlorine dust, selective leaching of thallium under alkaline conditions is employed, allowing the valuable metals to exist as precipitates in the solid slag. Controlling the endpoint pH to 8-10 can achieve good separation results. However, in the alkaline leaching separation process using NaOH alone, Tl in the thallium-containing chlorine dust... + With Cl - Thallium readily forms stable TlCl, which is only slightly soluble, making thallium leaching difficult. The solution involves reacting thallium ions and the slightly soluble thallium chloride phase with oxalate or acetate, and free oxalate or acetate ions, to form a stable and dissolved TlC₂O₄. - Alternatively, CH3COOTl(aq) can be used to release thallium, which not only reduces the leaching temperature and time but also improves the separation efficiency. Furthermore, this invention forms a stable dissolved TlC2O4. - Alternatively, CH3COOTl(aq) can also be used to avoid the saturation precipitation of TlOH.

[0035] Compared with conventional alkaline leaching and other treatment methods, the thallium leaching rate of this invention is significantly improved; under controlled reaction conditions, the selective separation of thallium can be further guaranteed; this invention has strong industrial applicability, and the thallium-free slag obtained after separation can be returned to the lead-zinc smelting system for secondary use, which greatly reduces the environmental risk of thallium-containing solid waste while ensuring thallium recovery.

[0036] The following are specific examples of the present invention:

[0037] Example 1

[0038] Sampling and analysis of thallium-containing chlorine dust:

[0039] Thallium-containing chlorine-containing dust generated during zinc smelting was dried (in an 80°C forced-air drying oven) to constant weight and then ground (until it could pass through a 100-mesh sieve). The ground thallium-containing chlorine-containing dust was digested, and the elemental content in the thallium-containing chlorine-containing dust was measured. In this embodiment, phase analysis of the thallium-containing chlorine-containing dust was also performed.

[0040] The specific results are as follows:

[0041] 1. In this embodiment, the main phases present in the thallium-containing chlorine-laden dust include zinc sulfate (water-soluble zinc), lead sulfate, lead chloride, cadmium oxide, etc.; the phase morphologies in the thallium-containing chlorine-laden dust include crystalline and amorphous states. XRD analysis of the thallium-containing chlorine-laden dust is described in [reference needed]. Figure 1 As shown.

[0042] 2. In this embodiment, the mass percentage of the main elements in the thallium-chlorine-containing dust is detailed in the table below:

[0043] element Zn Pb S Cd F Tl Cl O content(%) 29.8 21.8 7.06 2.61 2.32 0.59 4.92 27.55

[0044] As can be seen from the table above, thallium-containing chlorine dust mainly contains valuable metal elements such as Zn and Pb.

[0045] Analysis example 1

[0046] Take 1 kg of dried (80℃ forced-air drying oven) thallium-chlorine-containing dust sample (same as in Example 1) to constant weight and grind it (grind until it can pass through a 100-mesh sieve) to obtain the grinding product.

[0047] Leaching of the grinding product: Take 10g of the grinding product and put it into a beaker. Add 50mL of 0.6mol / L NaOH solution to obtain an alkaline leaching solution. Stir and leach at 50℃ for 120min. Then perform solid-liquid separation, collect the leaching solution and use ICP-OES to determine the elemental contents of thallium, lead, zinc and cadmium.

[0048] In this analysis, the pH of the leachate was 8.34, the thallium leaching rate was 74.30%, the lead leaching rate was 0.008%, the zinc leaching rate was 0.002%, and the cadmium leaching rate was 0.48%.

[0049] Example 2

[0050] Concentration experiment of sodium oxalate system:

[0051] Take 1 kg of dried (80℃ forced-air drying oven) thallium-chlorine-containing dust sample (same as in Example 1) to constant weight and grind it (grind until it can pass through a 100-mesh sieve) to obtain the grinding product.

[0052] Leaching of the grinding product: Take 10g of the grinding product and put it into a beaker. Add 50mL of 0.6mol / L NaOH solution and immediately add sodium oxalate solid while stirring to obtain an alkaline leaching solution. Stir and leach at 50℃ for 120min. Then perform solid-liquid separation, collect the leaching solution and use ICP-OES to determine the elemental contents of thallium, lead, zinc and cadmium.

[0053] In this embodiment, the sodium oxalate solid is at a predetermined concentration in the alkaline leaching solution; the predetermined concentrations of sodium oxalate solid in this embodiment are 0.2 mol / L, 0.6 mol / L, and 1 mol / L, respectively; leaching is performed at the above-mentioned different predetermined concentrations in this embodiment.

[0054] When the concentrations of sodium oxalate solid were 0.2 mol / L, 0.6 mol / L, and 1 mol / L, the thallium leaching rates were 91.19%, 92.51%, and 92.88%, respectively.

[0055] When the concentrations of sodium oxalate solid were 0.2 mol / L, 0.6 mol / L, and 1 mol / L, the lead leaching rates were 0.10%, 0.10%, and 0.09%, respectively.

[0056] When the concentrations of sodium oxalate solid were 0.2 mol / L, 0.6 mol / L, and 1 mol / L, the zinc leaching rates were 0.16%, 0.21%, and 0.20%, respectively.

[0057] When the concentrations of sodium oxalate solid were 0.2 mol / L, 0.6 mol / L, and 1 mol / L, the cadmium leaching rates were 1.26%, 1.62%, and 1.49%, respectively.

[0058] Example 3

[0059] Liquid-to-solid ratio experiment of sodium oxalate system:

[0060] Take 1 kg of dried (80℃ forced-air drying oven) thallium-chlorine-containing dust sample (same as in Example 1) to constant weight and grind it (grind until it can pass through a 100-mesh sieve) to obtain the grinding product.

[0061] Leaching of the ground product: Take 10g of the ground product and put it into a beaker. Add a predetermined volume of 0.6mol / L NaOH solution and immediately add sodium oxalate solid while stirring to obtain an alkaline leaching solution. The concentration of sodium oxalate solid in the alkaline leaching solution is 0.6mol / L. Stir and leach at 50℃ for 120min. Then perform solid-liquid separation, collect the leaching solution and use ICP-OES to determine the elemental contents of thallium, lead, zinc and cadmium.

[0062] In this embodiment, the preset volumes of NaOH solution are 40 mL, 50 mL, 60 mL, and 70 mL; leaching is performed at the above different preset volumes.

[0063] When the volumes of NaOH solution were 40 mL, 50 mL, 60 mL, and 70 mL, the thallium leaching rates were 76.81%, 92.51%, 86.41%, and 79.89%, respectively.

[0064] When the volumes of NaOH solution were 40 mL, 50 mL, 60 mL, and 70 mL, the lead leaching rates were 0.20%, 0.10%, 0.29%, and 3.48%, respectively.

[0065] When the volumes of NaOH solution were 40 mL, 50 mL, 60 mL, and 70 mL, the zinc leaching rates were 0.84%, 0.21%, 0.04%, and 0.17%, respectively.

[0066] When the volumes of NaOH solution were 40 mL, 50 mL, 60 mL, and 70 mL, the cadmium leaching rates were 2.11%, 1.62%, 0.10%, and 0.05%, respectively.

[0067] Example 4

[0068] Temperature experiment of sodium oxalate system:

[0069] Take 1 kg of dried (80℃ forced-air drying oven) thallium-chlorine-containing dust sample (same as in Example 1) to constant weight and grind it (grind until it can pass through a 100-mesh sieve) to obtain the grinding product.

[0070] Leaching of the ground product: Take 10g of the ground product and put it into a beaker. Add 50mL of 0.6mol / L NaOH solution and immediately add sodium oxalate solid while stirring to obtain an alkaline leaching solution. The concentration of sodium oxalate solid in the alkaline leaching solution is 0.6mol / L. Stir and leach for 120min at a preset temperature. Then perform solid-liquid separation, collect the leaching solution and use ICP-OES to determine the elemental contents of thallium, lead, zinc and cadmium.

[0071] In this embodiment, the preset temperatures are 50℃, 60℃, 70℃, and 80℃ respectively; leaching is carried out at the above different preset temperatures.

[0072] At preset temperatures of 50℃, 60℃, 70℃, and 80℃, the thallium leaching rates were 92.51%, 99.29%, 98.19%, and 99.60%, respectively.

[0073] At preset temperatures of 50℃, 60℃, 70℃, and 80℃, the lead leaching rates were 0.10%, 0.30%, 0.51%, and 0.88%, respectively.

[0074] At preset temperatures of 50℃, 60℃, 70℃, and 80℃, the zinc leaching rates were 0.21%, 0.83%, 1.19%, and 1.78%, respectively.

[0075] At preset temperatures of 50℃, 60℃, 70℃, and 80℃, the cadmium leaching rates were 1.62%, 3.62%, 3.84%, and 4.52%, respectively.

[0076] Example 5

[0077] Concentration experiment of sodium acetate system:

[0078] Take 1 kg of dried (80℃ forced-air drying oven) thallium-chlorine-containing dust sample (same as in Example 1) to constant weight and grind it (grind until it can pass through a 100-mesh sieve) to obtain the grinding product.

[0079] Leaching of the ground product: Take 10g of the ground product and put it into a beaker. Add 50mL of 0.6mol / L NaOH solution and immediately add sodium acetate solid while stirring to obtain an alkaline leaching solution. Stir and leach at 50℃ for 120min. Then perform solid-liquid separation, collect the leaching solution and use ICP-OES to determine the elemental contents of thallium, lead, zinc and cadmium.

[0080] In this embodiment, the sodium acetate solid is at a predetermined concentration in the alkaline leaching solution; the predetermined concentrations of sodium acetate solid in this embodiment are 0.6 mol / L, 0.8 mol / L, and 1 mol / L; leaching is performed at the above-mentioned different predetermined concentrations.

[0081] When the concentrations of sodium acetate solid were 0.6 mol / L, 0.8 mol / L, and 1 mol / L, the thallium leaching rates were 80.20%, 80.62%, and 81.84%, respectively.

[0082] When the concentrations of sodium acetate solid were 0.6 mol / L, 0.8 mol / L, and 1 mol / L, the lead leaching rates were 0.04%, 0.05%, and 0.06%, respectively.

[0083] When the concentrations of sodium acetate solid were 0.6 mol / L, 0.8 mol / L, and 1 mol / L, the zinc leaching rates were 0.003%, 0.004%, and 0.005%, respectively.

[0084] When the concentrations of sodium acetate solid were 0.6 mol / L, 0.8 mol / L, and 1 mol / L, the cadmium leaching rates were 0.25%, 0.36%, and 0.40%, respectively.

[0085] Example 6

[0086] Liquid-to-solid ratio experiment of sodium acetate system:

[0087] Take 1 kg of dried (80℃ forced-air drying oven) thallium-chlorine-containing dust sample (same as in Example 1) to constant weight and grind it (grind until it can pass through a 100-mesh sieve) to obtain the grinding product.

[0088] Leaching of the ground product: Take 10g of the ground product and put it into a beaker. Add a predetermined volume of 0.6mol / L NaOH solution and immediately add sodium acetate solid while stirring to obtain an alkaline leaching solution. The concentration of sodium acetate solid in the alkaline leaching solution is 1mol / L. Stir and leach at 50℃ for 120min. Then perform solid-liquid separation, collect the leaching solution and use ICP-OES to determine the elemental contents of thallium, lead, zinc and cadmium.

[0089] In this embodiment, the preset volumes of NaOH solution are 40 mL, 50 mL, and 60 mL; leaching is performed at the above different preset volumes.

[0090] When the volumes of NaOH solution were 40 mL, 50 mL, and 60 mL, the thallium leaching rates were 82.28%, 81.84%, and 77.46%, respectively.

[0091] When the volumes of NaOH solution were 40 mL, 50 mL, and 60 mL, the lead leaching rates were 0.14%, 0.06%, and 0.07%, respectively.

[0092] When the volumes of NaOH solution were 40 mL, 50 mL, and 60 mL, the zinc leaching rates were 0.020%, 0.005%, and 0.007%, respectively.

[0093] When the volumes of NaOH solution were 40 mL, 50 mL, and 60 mL, the cadmium leaching rates were 7.37%, 0.40%, and 0.16%, respectively.

[0094] Example 7

[0095] Temperature experiment of sodium acetate system:

[0096] Take 1 kg of dried (80℃ forced-air drying oven) thallium-chlorine-containing dust sample (same as in Example 1) to constant weight and grind it (grind until it can pass through a 100-mesh sieve) to obtain the grinding product.

[0097] Leaching of the ground product: Take 10g of the ground product and put it into a beaker. Add 50mL of 0.6mol / L NaOH solution and immediately add sodium acetate solid while stirring to obtain an alkaline leaching solution. The concentration of sodium acetate solid in the alkaline leaching solution is 1mol / L. Stir and leach for 120min at a preset temperature. Then perform solid-liquid separation, collect the leaching solution and use ICP-OES to determine the elemental contents of thallium, lead, zinc and cadmium.

[0098] In this embodiment, the preset temperatures are 50℃, 60℃, 70℃, and 80℃ respectively; leaching is carried out at the above different preset temperatures.

[0099] At preset temperatures of 50℃, 60℃, 70℃, and 80℃, the thallium leaching rates were 81.84%, 97.37%, 98.17%, and 98.68%, respectively.

[0100] At preset temperatures of 50℃, 60℃, 70℃, and 80℃, the lead leaching rates were 0.06%, 0.15%, 0.38%, and 0.39%, respectively.

[0101] At preset temperatures of 50℃, 60℃, 70℃, and 80℃, the zinc leaching rates were 0.005%, 0.01%, 0.16%, and 0.37%, respectively.

[0102] At preset temperatures of 50℃, 60℃, 70℃, and 80℃, the cadmium leaching rates were 0.40%, 3.82%, 38.41%, and 60.15%, respectively.

[0103] Comparative Example 1

[0104] Comparative experiment of sodium carbonate system:

[0105] Take 1 kg of dried (80℃ forced-air drying oven) thallium-chlorine-containing dust sample (same as in Example 1) to constant weight and grind it (grind until it can pass through a 100-mesh sieve) to obtain the grinding product.

[0106] Leaching of the ground product: 10g of the ground product was placed in a beaker, 50mL of 0.6mol / L NaOH solution was added, and sodium carbonate solid was immediately added under stirring to obtain an alkaline leaching solution. The sodium carbonate solid was stirred and leached at 60℃ for 120min under the conditions of 0.6mol / L and 1mol / L concentrations in the alkaline leaching solution. Then the solid and liquid were separated, the leaching solution was collected, and the elemental contents of thallium, lead, zinc, and cadmium were determined by ICP-OES.

[0107] In this comparative example, when the concentrations of sodium carbonate solid in the alkaline leaching solution were 0.6 mol / L and 1 mol / L, the corresponding thallium leaching rates were 73.18% and 75.42%, lead leaching rates were 0.09% and 0.54%, zinc leaching rates were 0.29% and 0.31%, and cadmium leaching rates were 1.24% and 1.11%.

[0108] Comparative Example 2

[0109] Comparative experiment of sodium citrate system:

[0110] Take 1 kg of dried (80℃ forced-air drying oven) thallium-chlorine-containing dust sample (same as in Example 1) to constant weight and grind it (grind until it can pass through a 100-mesh sieve) to obtain the grinding product.

[0111] Leaching of the ground product: 10g of the ground product was placed in a beaker, 50mL of 0.6mol / L NaOH solution was added, and sodium citrate solid was immediately added under stirring to obtain an alkaline leaching solution; the sodium citrate solid was stirred and leached at 60℃ for 120min under the conditions of 0.6mol / L and 1mol / L concentrations in the alkaline leaching solution; then the solid and liquid were separated, the leaching solution was collected, and the elemental contents of thallium, lead, zinc, and cadmium were determined by ICP-OES.

[0112] In this comparative example, when the concentrations of sodium citrate solid in the alkaline leaching solution were 0.6 mol / L and 1 mol / L, the corresponding thallium leaching rates were 71.52% and 82.11%, lead leaching rates were 11.05% and 17.99%, zinc leaching rates were 2.46% and 5.18%, and cadmium leaching rates were 13.33% and 28.49%.

[0113] The above technical solutions of the present invention are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made under the technical concept of the present invention using the contents of the present invention specification and drawings, or direct / indirect applications in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A method for separating organic salts from thallium-chlorine-containing solid waste by alkaline leaching, characterized in that, include: Provide thallium-containing chlorine solid waste; prepare an alkaline leaching solution by mixing the thallium-containing chlorine solid waste with an alkaline solution and organic salts, and perform alkaline leaching separation of thallium in the thallium-containing chlorine solid waste, and obtain a leachate after solid-liquid separation; the organic salts include one or more of oxalate and acetate.

2. The organic salt alkali leaching separation method according to claim 1, characterized in that, The oxalate includes one or more of sodium oxalate and potassium oxalate; the acetate includes one or more of sodium acetate and potassium acetate.

3. The organic salt alkali leaching separation method according to claim 1, characterized in that, The concentration of the organic salt in the alkaline leaching solution is not less than 0.2 mol / L.

4. The organic salt alkali leaching separation method according to claim 3, characterized in that, The organic salt includes the oxalate, the concentration of which in the alkaline leaching solution is 0.2-1.0 mol / L; or, the organic salt includes the acetate, the concentration of which in the alkaline leaching solution is 0.6-1.0 mol / L.

5. The organic salt alkali leaching separation method according to claim 1, characterized in that, The alkaline leaching separation temperature is 45-85℃.

6. The organic salt alkali leaching separation method according to claim 5, characterized in that, The organic salt includes the oxalate, and the alkaline leaching separation temperature is 50-80℃; or, the organic salt includes the acetate, and the alkaline leaching separation temperature is 55-65℃.

7. The organic salt alkali leaching separation method according to claim 1, characterized in that, The alkaline leaching separation time shall not be less than 60 minutes.

8. The organic salt leaching and separation method according to claim 1, characterized in that, The organic salt includes the oxalate, and the mass-to-volume ratio of the thallium-chloride-containing solid waste to the alkaline solution is 1g:5-6mL; the organic salt includes the acetate, and the mass-to-volume ratio of the thallium-chloride-containing solid waste to the alkaline solution is 1g:4-6mL.

9. The method for enhancing alkaline leaching separation of thallium from thallium-containing chlorine solid waste according to claim 1, characterized in that, The concentration of hydroxide ions in the alkaline leaching solution is not less than 0.5 mol / L; the alkaline solution includes a strongly alkaline hydroxide; the strongly alkaline hydroxide includes one or more of sodium hydroxide and potassium hydroxide.

10. The method for separating organic salts by alkaline leaching according to any one of claims 1-9, characterized in that, The thallium-containing chlorine solid waste also contains one or more of lead, zinc, and cadmium; the thallium-containing chlorine solid waste includes thallium-containing chlorine dust.

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