A method for separating and recovering tellurium copper material

Abstract

The present invention provides a separation and recovery method of tellurium copper material, comprising: S1, preparing tellurium copper material into slurry, adding acid and oxidant, adjusting pH value of slurry to 1-2, and potential of slurry to 450-550mV, leaching, and then solid-liquid separation to obtain solution A and crude tellurium; S2, adding sodium sulfite and / or sulfur dioxide to solution A, and adjusting pH value of solution A to 0.5-1.5, reacting, and solid-liquid separation to obtain solution B and copper-containing product; S3, adjusting pH value of solution B to 4-5, reacting, and then solid-liquid separation to obtain tellurium-containing product. The method has mild reaction, less reagents, low cost, simple equipment, short process, safety, environmental friendliness, and is suitable for industrial application. The method has high separation effect on tellurium and copper, and the recovery rate of tellurium and copper is both above 96%, and has considerable industrial application prospect.

Description

Technical Field

[0001] The invention belongs to the technical field of nonferrous metal hydrometallurgy, and in particular relates to a method for separating and recovering tellurium copper materials. Background Art

[0002] Tellurium has the chemical formula Te and a molecular weight of 127.6. It is a black powder or a silvery white cubic crystal. 80% of tellurium consumption is used in the metallurgical industry: adding a small amount of tellurium to steel and copper alloys can improve their cutting performance and increase their hardness; in white cast iron, tellurium is used as a carbide stabilizer to make the surface strong and wear-resistant; lead containing a small amount of tellurium can improve the corrosion resistance, wear resistance and strength of the material and is used as a sheath for submarine cables; adding tellurium to lead can increase the hardness of lead and is used to make battery plates and printing type. Tellurium can be used as an additive for petroleum cracking catalysts and a catalyst for the production of ethylene glycol. Tellurium oxide is used as a colorant for glass. High-purity tellurium can be used as an alloy component of thermoelectric materials. Bismuth telluride is a good refrigeration material. Tellurium and several tellurides are semiconductor materials. Ultrapure tellurium single crystals are new infrared materials.

[0003] Thirty years ago, someone used SO2 to reduce tellurium from H2SO4 solution containing copper and tellurium to obtain copper telluride. The Russian Horilskiy Joint Enterprise processed copper electrolysis anode mud and used nickel powder to convert tellurium from H2SO4 solution containing copper to obtain an intermediate product, a conversion precipitate containing tellurium. X-ray phase analysis showed that the main phase in the conversion precipitate containing tellurium was Cu. 2－ x Te. Copper replaces tellurium in the H2SO4 system but does not produce tellurium. Instead, it forms a Cu2Te compound with tellurium.

[0004] The main sources of tellurium copper materials are copper telluride produced in the process of removing tellurium from copper electrolyte, tellurium-containing copper alloy waste, and tellurium-containing copper by-products in production.

[0005] The existing methods for separating tellurium copper materials mainly include:

[0006] ① High acidity oxidation leaching → filter pressing → tellurium reduction → filter pressing → alkaline copper precipitation. This method requires tellurium copper to be leached, consumes a lot of acid, alkali and oxidant, and is costly.

[0007] ② High acidity oxidation leaching → filter pressing → alkaline copper precipitation → filter pressing → neutral tellurium precipitation. This method requires tellurium copper to be leached, consumes a large amount of acid, alkali and oxidant, and is costly.

[0008] ③ Sulfate roasting → water leaching copper → filter press → alkaline copper precipitation → filter press → alkaline tellurium leaching → neutral tellurium precipitation. This method has a long process and it is difficult to completely oxidize tellurium copper, and it is also necessary to add sulfuric acid roasting equipment.

[0009] ④ Low acidity oxidation copper removal → filter press → alkaline copper precipitation of copper removal solution → filter press → neutral tellurium precipitation. This method consumes a lot of acid and alkali and is costly; neutral tellurium precipitation first and then alkaline copper precipitation is low in cost, but a large amount of copper will precipitate during tellurium precipitation, and the tellurium-copper separation effect is not good.

[0010] It can be seen that the existing methods for separating tellurium copper materials have technical problems such as high cost, large amount of reagents, long process flow, high equipment requirements, and poor tellurium copper separation effect. Summary of the invention

[0011] In order to solve the above problems, the present invention provides a method for separating and recovering tellurium copper materials.

[0012] In order to achieve the above objectives, the following solutions are proposed:

[0013] A method for separating and recovering tellurium copper materials, comprising:

[0014] S1. Prepare tellurium copper material into slurry, add acid and oxidant, adjust the pH value of the slurry to 1-2, and the potential of the slurry to 450-550 mV, perform leaching, and then perform solid-liquid separation to obtain solution A and crude tellurium;

[0015] S2. Add sodium sulfite or sulfur dioxide to solution A, and adjust the pH value of solution A to 0.5-1.5, and react until the supernatant changes from green to light yellow, accompanied by a large amount of grayish white insoluble matter, and perform solid-liquid separation to obtain solution B and a copper-containing product;

[0016] S3. Adjust the pH value of solution B to 4-5, carry out reaction, and then separate the solid from the liquid to obtain a tellurium-containing product and solution C.

[0017] Preferably, in step S1, the acid is hydrochloric acid, or a mixed acid of hydrochloric acid and sulfuric acid.

[0018] Preferably, in step S1, the oxidant is one or more of sodium chlorate, sodium hypochlorite, potassium chlorate, potassium hypochlorite, chloric acid and hydrogen peroxide.

[0019] Preferably, in step S1, the solid-to-liquid ratio of the slurry is 1:3-5 g / mL.

[0020] In step S2, when the added reducing agent is sodium sulfite, the amount of sodium sulfite added is 1.0-~1.2 times the mass of copper metal in the solution; when the added reducing agent is sulfur dioxide, the amount of sulfur dioxide added is added according to the molar ratio of copper to sulfur dioxide in the solution of 1:0.5~0.6; when the added reducing agent is a mixture of sodium sulfite and sulfur dioxide, the amount added is calculated according to the corresponding ratio.

[0021] Preferably, in step S1, the leaching time is 0.5-3h, more preferably 0.8-2.5h; the leaching temperature is 40-90°C, more preferably 70-90°C.

[0022] Preferably, in step S2, the reaction time is 0.5-3 h, more preferably 1-2.5 h.

[0023] Preferably, in step S3, the reaction time is 20 min-2 h, more preferably 30 min-1.5 h.

[0024] Preferably, in step S1, before the tellurium copper material is prepared into slurry, the tellurium copper material is also crushed, ball-milled, and sieved.

[0025] Preferably, the tellurium copper material is at least one of copper telluride, a tellurium copper alloy and a tellurium copper byproduct material.

[0026] Preferably, in step S2, the reagent for adjusting the pH value is at least one of sodium hydroxide, potassium hydroxide and ammonia water.

[0027] Preferably, in step S3, the reagent for adjusting pH is at least one of sodium hydroxide, potassium hydroxide and ammonia water.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. In the present invention, a specific oxidation acid leaching is performed on the tellurium copper material to leach copper and a small amount of tellurium, so that copper is separated from most of the tellurium, and then a reduction reaction is performed under the condition of pH 0.5-1.5 to reduce the copper in the solution and precipitate it in the form of cuprous chloride. After filtration, tellurium and copper are effectively separated. The obtained cuprous chloride can be sold directly, and finally the pH is adjusted to neutrally precipitate tellurium, which can effectively separate the tellurium and copper in the solution. The tellurium and copper contents in the solution after the removal of copper and tellurium are extremely low. Compared with the strong acid and strong base separation conditions of the conventional method, this method has a mild reaction and uses less reagents, which can effectively reduce the input of auxiliary materials and labor. The recovery method of the present invention has simple equipment, short process, low cost, safety, environmental friendliness, and is suitable for industrial application.

[0030] 2. The method of the present invention has a high separation effect on tellurium and copper, and the total recovery rates of tellurium and copper are both above 96%, which has considerable application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 1 is a process flow chart of the separation and recovery method of tellurium copper materials according to various embodiments of the present invention. DETAILED DESCRIPTION

[0032] The present invention provides a method for separating and recovering tellurium copper materials, comprising:

[0033] S1. Prepare tellurium copper material into slurry, add acid and oxidant, adjust the pH value of slurry to 1-2, the potential of slurry to 450-550mV, perform leaching, and then perform solid-liquid separation to obtain solution A and crude tellurium; no matter the copper in tellurium copper material is in elemental state, oxidized state or alloy form, copper can be leached by controlling the potential by adding oxidant. This patent controls pH to make the acidity lower than the leaching acidity of tellurium, and leaches as little tellurium as possible while leaching copper, so as to achieve the effect of tellurium copper separation. When sodium chlorate is selected as oxidant, the reaction formula is as follows:

[0034] 3Cu+6HCl+NaClO3=3CuCl2+NaCl+3H2O (1)

[0035] CuO+2HCl= CuCl2+H2O (2)

[0036] 3Te+2NaClO3=3TeO2+2NaCl (3)

[0037] 3Cu2Te+12HCl+4NaClO3=3TeO2+ 6CuCl2+4NaCl+6H2O (4)

[0038] In the above reaction, only a small amount of tellurium participates in the reaction due to the acidity and the amount of sodium chlorate added as the oxidant. If the pH is too low or an excessive amount of oxidant is added, a large amount of tellurium will be leached out. The reaction formula is as follows:

[0039] 3Te+12HCl+2NaClO3=3TeCl4+2NaCl+6H2O (5)

[0040] TeO2+4HCl=TeCl4+2H2O (6)

[0041] 3Cu2Te+24HCl+4NaClO3=3TeCl4+ 6CuCl2+4NaCl+12H2O (7)

[0042] S2, adding sodium sulfite and / or sulfur dioxide to solution A, and adjusting the pH value of solution A to 0.5-1.5, reacting until the supernatant changes from green to light yellow, accompanied by a large amount of grayish white insoluble matter, and performing solid-liquid separation to obtain solution B and copper-containing products; this step controls the pH and reducing agent to make Cu 2+ Reduction to Cu + , cuprous chloride precipitate is generated. When sodium sulfite is used as a reducing agent, the reaction formula is as follows:

[0043] 2CuCl2+Na2SO3+H2O= 2CuCl+Na2SO4+2HCl (8)

[0044] The reduction potential of tellurium is higher than that of copper. Tellurium is easier to reduce than copper, but the acidity of copper reduction is much lower than that of tellurium. However, when copper is reduced, HCl is generated, the acidity of the system increases and the pH decreases. If the pH is not controlled, tellurium will be reduced, affecting the separation of tellurium and copper. The specific reaction formula is as follows:

[0045] TeCl4+ 2Na2SO3+2H2O=Te+2Na2SO4+ 4HCl (9)

[0046] S3. Adjust the pH value of solution B to 4-5, react, and then separate the solid and liquid to obtain a tellurium-containing product and solution C. The contents of tellurium and copper in solution C are both extremely low.

[0047] As some preferred specific implementations, in step S1, the acid is hydrochloric acid, or a mixed acid of hydrochloric acid and sulfuric acid, more preferably hydrochloric acid.

[0048] As some preferred specific implementations, in step S1, the oxidant is one or more of sodium chlorate, sodium hypochlorite, potassium chlorate, potassium hypochlorite, chloric acid and hydrogen peroxide.

[0049] As some preferred specific implementations, in step S1, the solid-to-liquid ratio of the slurry is 1:3~5g / mL.

[0050] As some preferred specific implementation methods, in step S2, when the added reducing agent is sodium sulfite, the amount of sodium sulfite added is 1.0-~1.2 times the mass of copper metal in the solution; when the added reducing agent is sulfur dioxide, the amount of sulfur dioxide added is calculated according to the molar ratio of copper to sulfur dioxide in the solution = 1:0.5~0.6 (that is, 11.2~13.4L of sulfur dioxide under standard conditions is added for every 1 mol of copper); when the added reducing agent is a mixture of sodium sulfite and sulfur dioxide, the amount added is calculated according to the corresponding ratio.

[0051] As some preferred specific implementation methods, in step S1, the leaching time is 0.5-3h, for example, 0.5h, 0.8h, 1h, 1.5h, 2h, 2.5h, etc.; the leaching temperature is 40-90°C, more preferably 70-90°C, for example, 70°C, 75°C, 80°C, 85°C, 90°C, etc.

[0052] As some preferred specific implementation methods, in step S2, the reaction time is 0.5-3 h, more preferably 1-2.5 h, such as 1 h, 1.5 h, 2 h, 2.5 h, etc.

[0053] As some preferred specific implementation methods, in step S3, the reaction time is 20 min-2 h, more preferably 30 min-1.5 h, for example 30 min, 35 min, 40 min, 50 min, 60 min, 70 min, 80 min, etc.

[0054] As some preferred embodiments, in step S1, before the tellurium copper material is prepared into slurry, the tellurium copper material is crushed, ball-milled, and sieved. The sieve may be selected but is not limited to a 30-60 mesh sieve, and the purpose of the sieve is to remove large particles of the material.

[0055] As some specific implementations, the tellurium copper material is at least one of copper telluride, a tellurium copper alloy, and a tellurium copper byproduct material.

[0056] As some specific implementations, in step S2, the reagent for adjusting the pH value is at least one of sodium hydroxide, potassium hydroxide and ammonia water.

[0057] As some specific implementations, in step S3, the reagent for adjusting pH is at least one of sodium hydroxide, potassium hydroxide and ammonia water.

[0058] The present invention will be further described below in conjunction with specific embodiments and accompanying drawings, but the present invention is not limited to the following embodiments. Unless otherwise defined, all professional terms used hereinafter have the same meaning as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0059] The experimental methods described in the following examples are conventional methods unless otherwise specified; the reagents and materials described are commercially available unless otherwise specified.

[0060] The copper telluride materials used in all the following embodiments and comparative examples are the same. In addition to tellurium and copper, the materials also contain impurities such as Pb, Sn, and Bi.

[0061] Example 1

[0062] The separation and recovery method of tellurium copper materials is shown in the process flow chart Figure 1 As shown, including:

[0063] (1) The copper telluride material containing 34% tellurium and 29% copper is crushed and ball-milled by a crushing ball mill and passed through a 30-mesh sieve;

[0064] (2) Add 400 mL of water to the reactor, add 100 g of the powder obtained in step (1) at a stirring rate of 300 r / min, add hydrochloric acid to adjust the pH to 1.2, heat to 40-80°C and slowly add sodium chlorate (avoid adding too quickly to cause the solution temperature to rise too high), adjust the solution potential to 520 mv, and add hydrochloric acid to maintain the pH (add a total of 115 g of hydrochloric acid and 20 g of sodium chlorate). After the pH stabilizes, react at 70-90°C for 1 h and filter to obtain solution A and tellurium-containing product ①.

[0065] (3) Sodium sulfite was added to solution A, and sodium hydroxide was added to maintain the pH value at 0.5-1.5, until the supernatant changed from green to light yellow and clear (30 g sodium sulfite and 9.2 g sodium hydroxide were added in total), accompanied by the generation of a large amount of grayish white insoluble matter. The reaction was continued for 1 hour and filtered to obtain solution B and copper-containing product ①.

[0066] (4) Add 6 g of sodium hydroxide to solution B to adjust the pH to 4.7. Allow to react for 1 h and filter to obtain solution C and tellurium-containing product ②.

[0067] Example 2

[0068] The separation and recovery method of tellurium copper materials is shown in the process flow chart Figure 1 As shown, including:

[0069] (1) The copper telluride material containing 34% tellurium and 29% copper is crushed and ball-milled by a crushing ball mill and passed through a 30-mesh sieve;

[0070] (2) Add 400 mL of water to the reactor, add 100 g of the powder obtained in step (1) at a stirring rate of 300 r / min, add hydrochloric acid to adjust the pH to 1.1, heat to 40-80°C and slowly add sodium chlorate (avoid adding too quickly to cause the solution temperature to rise too high), adjust the solution potential to 502 mv, and add hydrochloric acid to maintain the pH (add a total of 115 g of hydrochloric acid and 20 g of sodium chlorate). After the pH stabilizes, react at 70-90°C for 1 h and filter to obtain solution A and tellurium-containing product ①.

[0071] (3) Sodium sulfite was added to solution A, and sodium hydroxide was added to maintain the pH value at 0.5-1.5, until the supernatant changed from green to light yellow and clear (30 g sodium sulfite and 9.2 g sodium hydroxide were added in total), accompanied by the generation of a large amount of grayish white insoluble matter. The reaction was continued for 1 hour and filtered to obtain solution B and copper-containing product ①.

[0072] (4) Add 5.8 g of sodium hydroxide to solution B to adjust the pH to 4.5. React for 1 h and filter to obtain solution C and tellurium-containing product ②.

[0073] Example 3

[0074] The separation and recovery method of tellurium copper materials is shown in the process flow chart Figure 1 As shown, including:

[0075] (1) The copper telluride material containing 34% tellurium and 29% copper is crushed and ball-milled by a crushing ball mill and passed through a 30-mesh sieve;

[0076] (2) Add 400 mL of water to the reactor, add 100 g of the powder obtained in step (1) at a stirring rate of 300 r / min, add hydrochloric acid to adjust the pH to 1.5, heat to 40-80°C and slowly add sodium chlorate (avoid adding too quickly to cause the solution temperature to rise too high), adjust the solution potential to 488 mv, and add hydrochloric acid to maintain the pH (add a total of 110 g of hydrochloric acid and 18 g of sodium chlorate). After the pH stabilizes, react at 70-90°C for 1 h and filter to obtain solution A and tellurium-containing product ①.

[0077] (3) Sodium sulfite was added to solution A, and sodium hydroxide was added to maintain the pH value at 0.5-1.5, until the supernatant changed from green to light yellow and clear (a total of 28 g sodium sulfite and 9 g sodium hydroxide were added), accompanied by the generation of a large amount of grayish white insoluble matter. The reaction was continued for 1 h and filtered to obtain solution B and copper-containing product ①.

[0078] (4) Add 5.5 g of sodium hydroxide to solution B to adjust the pH to 4.9. React for 1 h and filter to obtain solution C and tellurium-containing product ②.

[0079] Note: In Examples 1 to 3, the tellurium-containing product ① is crude tellurium, the tellurium-containing product ② is tellurium dioxide, and the copper-containing product ① is cuprous chloride.

[0080] Comparative Example 1

[0081] Comparative Example 1 is substantially the same as Example 1, except that when sodium sulfite is added in step (3), no sodium hydroxide is added to maintain the pH, and the pH at the end of the reaction is -0.3.

[0082] Comparative Example 2

[0083] Comparative Example 1 is substantially the same as Example 1, except that sodium chlorate is added in step (2) until the solution potential reaches E=632 mv.

[0084] Comparative Example 3

[0085] A method for separating and recovering tellurium copper materials, comprising:

[0086] (1) The copper telluride material containing 34% tellurium and 29% copper is crushed and ball-milled by a crushing ball mill and passed through a 30-mesh sieve;

[0087] (2) Add 200 mL of water and 200 mL of hydrochloric acid into the reactor, add 100 g of the powder obtained in step (1) at a stirring rate of 300 r / min, raise the temperature to 80°C, slowly add sodium chlorate to adjust the solution potential to 554 mv (a total of 70 g of sodium chlorate is added), react for 1 h, and filter to obtain a leachate and acid leaching residue.

[0088] (3) Add 220 g of sodium sulfite (3.5 times the amount of copper tellurium metal) to the leaching solution, react for 1 hour, and filter to obtain tellurium reduction solution and reduced tellurium powder.

[0089] (4) Add 140 g of sodium hydroxide to the tellurium reduction solution to adjust the pH to 13.2, react for 1 hour, and filter to obtain a copper precipitation solution and copper hydroxide.

[0090] Comparative Example 4

[0091] A method for separating and recovering tellurium copper materials, comprising:

[0092] (1) The copper telluride material containing 34% tellurium and 29% copper is crushed and ball-milled by a crushing ball mill and passed through a 30-mesh sieve;

[0093] (2) Add 200 mL of water and 200 mL of hydrochloric acid into the reactor, add 100 g of the powder obtained in step (1) at a stirring rate of 300 r / min, raise the temperature to 80°C, slowly add sodium chlorate to adjust the solution potential to 554 mv (a total of 70 g of sodium chlorate is added), react for 1 h, and filter to obtain a leachate and acid leaching residue.

[0094] (3) Add 170 g of sodium hydroxide to the leaching solution to adjust the pH to 13.5, react for 1 hour, and filter to obtain copper precipitation solution and copper hydroxide.

[0095] (4) Add 38 g of sulfuric acid to the copper precipitation solution to adjust the pH to 4.2, react for 1 hour, and filter to obtain tellurium precipitation solution and tellurium dioxide.

[0096] Comparative Example 5

[0097] A method for separating and recovering tellurium copper materials, comprising:

[0098] (1) The copper telluride material containing 34% tellurium and 29% copper is crushed and ball-milled by a crushing ball mill and passed through a 30-mesh sieve;

[0099] (2) Add 400 mL of water to the reactor, add 100 g of the powder obtained in step (1) at a stirring rate of 300 r / min, add hydrochloric acid to adjust the pH to 1.1, raise the temperature to 80°C, slowly add sodium chlorate to adjust the solution potential to 475 mv, and simultaneously add hydrochloric acid to maintain the pH (a total of 115 g of hydrochloric acid and 20 g of sodium chlorate are added). After the pH stabilizes, react at 70-90°C for 1 h and filter to obtain a decopperized solution and crude tellurium.

[0100] (3) Add 45.5 g of sodium hydroxide to the decoppering solution to adjust the pH to 13.4, react for 1 hour, filter, and obtain the copper precipitation solution and copper hydroxide.

[0101] (4) Add 8.4 g of sulfuric acid to the decopperizing solution to adjust the pH to 4.8. Allow to react for 1 h and filter to obtain tellurium precipitate and tellurium dioxide.

[0102] Table 1 Analytical data of step (2) of Examples 1 to 3 and Comparative Examples 1 to 2

[0103]

[0104] Table 2 Analysis data of step (3) of Examples 1 to 3 and Comparative Examples 1 to 2

[0105]

[0106] Table 3 Analysis data of step (4) of Examples 1 to 3 and Comparative Examples 1 to 2

[0107]

[0108] The experimental data of Examples 1 to 3 and Comparative Examples 1 to 2 are shown in Tables 1 to 3, from which it can be seen that:

[0109] ① In Examples 1 to 3, the copper removal rates in step (2) are all above 98%, in step (3) copper is reduced, and the total recovery rate of copper is higher than 96%, and in step (4) tellurium is precipitated, and the total recovery rate of tellurium is higher than 97%. Tellurium and copper have high recovery rates and can be effectively separated.

[0110] ② In Comparative Example 1, due to the decrease in pH, tellurium participated in the reduction and the copper reduction rate decreased. Tellurium and copper co-precipitated in the reduction step, and the tellurium and copper separation effect was poor.

[0111] ③ In comparative example 2, excessive sodium chlorate was added, and part of the tellurium was oxidized to hexavalent telluric acid soluble in water, resulting in incomplete recovery when the pH was adjusted to precipitate the tellurium, and the tellurium yield was reduced.

[0112] The experimental data for analyzing each step in Comparative Examples 3-5 are shown in Tables 4-6.

[0113] Table 4 Analysis data of each step of Comparative Example 3

[0114]

[0115] Table 5 Analysis data of each step of Comparative Example 4

[0116]

[0117] Table 6 Analysis data of each step of Comparative Example 5

[0118]

[0119] As can be seen from Table 4-6, the tellurium copper precipitation rates of Comparative Examples 3 to 5 are all above 94%, indicating that the tellurium copper precipitation effect is very good at the corresponding pH. However, since the tellurium in the solution will first form tellurium dioxide precipitation during alkaline copper precipitation and then react with sodium hydroxide to form sodium tellurite and dissolve in the solution, a small amount of tellurium dioxide is wrapped in copper hydroxide and cannot participate in the reaction, and eventually enters the copper product, resulting in poor tellurium copper separation effect in the copper precipitation step, thus affecting its total yield, the tellurium total yield is higher than 95%, and the copper total yield is higher than 94%. Compared with Examples 1 to 3, the tellurium copper total yield of the embodiment is slightly higher; by comparison, it can be seen that the tellurium content in the copper products of Examples 1 to 3 and the copper content in the tellurium-containing products are lower than those of Comparative Examples 3 to 5, indicating that the tellurium copper separation effect of Examples 1 to 3 is better than that of Comparative Examples 3 to 5.

[0120] Table 5

[0121]

[0122] The amounts of auxiliary materials and costs of Examples 1 to 3 and Comparative Examples 3 to 5 are shown in Table 5. The method used in the present invention is to oxidatively remove copper at low acidity, then reduce copper under the acidity conditions, and finally adjust the pH with a small amount of alkali to precipitate tellurium to achieve tellurium-copper separation. Comparative Example 3 leaches tellurium-copper at high acidity oxidation, reduces tellurium, and then alkaline copper precipitation; Comparative Example 4 leaches tellurium-copper at high acidity oxidation, alkaline copper precipitation in the leaching solution, and neutral tellurium precipitation in the copper precipitation solution. The costs of these two separation methods are much higher than the method of the present invention. Comparative Example 5 oxidatively removes copper at low acidity, strongly precipitates copper, and then neutrally precipitates tellurium in the copper precipitation solution. The cost of this method is also higher than the method of the present invention.

[0123] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for separating and recovering tellurium copper materials, characterized in that: include: S1. Prepare tellurium copper material into slurry, add acid and oxidant, adjust the pH value of the slurry to 1-2, the potential of the slurry to 450-550 mV, perform leaching, and then perform solid-liquid separation to obtain solution A and crude tellurium; the leaching temperature is 40-90°C; S2, adding sodium sulfite and / or sulfur dioxide to solution A, and adjusting the pH value of solution A to 0.5-1.5, reacting until the supernatant changes from green to light yellow, accompanied by a large amount of grayish white insoluble matter, performing solid-liquid separation, and obtaining solution B and a copper-containing product; when the added reducing agent is sodium sulfite, the addition amount of the sodium sulfite is 1.0-1.2 times the mass of copper in the solution; when the added reducing agent is sulfur dioxide, the addition amount of sulfur dioxide is added according to the molar ratio of copper to sulfur dioxide in the solution of 1:0.5-0.6; when the added reducing agent is a mixture of sodium sulfite and sulfur dioxide, the addition amount is calculated according to the corresponding ratio; S3. Adjust the pH value of solution B to 4-5, carry out reaction, and then obtain a tellurium-containing product through solid-liquid separation.

2. The method for separating and recovering tellurium copper materials according to claim 1, characterized in that: In step S1, the oxidant is one or more of sodium chlorate, sodium hypochlorite, potassium chlorate, potassium hypochlorite, chloric acid and hydrogen peroxide.

3. The method for separating and recovering tellurium copper materials according to claim 1, characterized in that: In step S1, the acid is hydrochloric acid or a mixed acid of hydrochloric acid and sulfuric acid.

4. The method for separating and recovering tellurium copper materials according to any one of claims 1 to 3, characterized in that: In step S1, the solid-liquid ratio of the slurry is 1:3~5g / mL.

5. The method for separating and recovering tellurium copper materials according to any one of claims 1 to 3, characterized in that: In step S1, the leaching time is 0.5 to 3 hours.

6. The method for separating and recovering tellurium copper materials according to any one of claims 1 to 3, characterized in that: In step S2, the reaction time is 0.5-3h; In step S3, the reaction time is 20 min-2 h.

7. The method for separating and recovering tellurium copper materials according to any one of claims 1 to 3, characterized in that: In step S1, before the tellurium copper material is prepared into slurry, the tellurium copper material is crushed, ball-milled, and sieved.

8. The method for separating and recovering tellurium copper materials according to any one of claims 1 to 3, characterized in that: The tellurium copper material is at least one of copper telluride, a tellurium copper alloy and a tellurium copper byproduct material.

9. The method for separating and recovering tellurium copper materials according to any one of claims 1 to 3, characterized in that: In step S2, the reagent for adjusting the pH value is at least one of sodium hydroxide, potassium hydroxide and ammonia water; In step S3, the reagent for adjusting pH is at least one of sodium hydroxide, potassium hydroxide and ammonia water.

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