Method for comprehensive recovery of tellurium residues

Abstract

The present application relates to non-ferrous smelting technical field, specifically to a kind of tellurium slag comprehensive recovery method, steps include: tellurium slag is broken, ball milling to 100 mesh below particle size, by sulfuric acid leaching, leaching solution recovers copper, leaching residue is oxidized by hydrochloric acid and leaching, leaching solution is purified and recovered selenium tellurium by impurity removal, leaching residue is recovered gold and silver by water washing and neutralization and oxygen gas inclined-blowing rotary converter.The tellurium slag comprehensive recovery method disclosed in the present application, copper and tellurium in tellurium slag are leached into liquid phase in two stages, lead, gold and silver are in slag phase, so that copper and tellurium are effectively separated from lead, gold and silver, and the leaching rate of copper and tellurium is more than 90%, gold and silver are enriched in slag phase, which can be matched with pressurized copper removal anode mud into oxygen gas inclined-blowing rotary converter.The tellurium slag comprehensive recovery method disclosed in the present application can effectively recover copper, tellurium, gold, silver and other metal elements in tellurium slag, has the advantages of high treatment efficiency, and is worth popularization and application.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of non-ferrous smelting, in particular to a method for comprehensive recovery of tellurium residue. BACKGROUND

[0002] Currently, the advanced Kaldo furnace smelting process is widely used at home and abroad to treat copper anode slime to extract gold and silver. This process produces a tellurium residue, which mainly contains copper, lead, antimony, bismuth, gold and silver, with contents of 5-15%, 1-7%, 0-4%, 0-2%, 60-200 g / t and 40,000-150,000 g / t, respectively, and has a high recovery value.

[0003] There are generally two methods for treating the tellurium residue. One is to directly return the residue to the copper anode slime smelting system for treatment, which has the following problems. First, it causes a large amount of residue to be returned, increasing the blowing operation time. Second, the copper and tellurium impurities are continuously enriched in the system, leading to increased difficulty in removing impurities in the Kaldo furnace, increased consumption of auxiliary materials and fuel, and partial loss of tellurium metal. The other method is to separately treat and recover the residue, i.e., crushing the anode slime tellurium residue, ball milling, alkali leaching, purification, tellurium precipitation, calcination, electrolysis and refined tellurium. In this process, the leaching rate of tellurium is low (only 40-50%), and copper is not leached at all, resulting in a high tellurium content of 3-8% and a high copper content of 6-18% in the alkali leaching residue. The alkali leaching residue is returned to the oxygen inclined blowing rotary converter and the pressurized copper removal anode slime to re-enrich the slag, thus leading to low recovery rate and long recovery cycle of tellurium, and enrichment of copper in the system. SUMMARY

[0004] In view of the problems in the prior art, the present application provides a method for comprehensive recovery of tellurium residue, which specifically includes the following contents.

[0005] A method for comprehensive recovery of tellurium residue includes the following steps:

[0006] (1) First-stage leaching: adding tellurium residue powder with a particle size of ≤100 mesh into a sulfuric acid solution for first-stage leaching to obtain a first-stage leaching solution and a first-stage leaching residue;

[0007] (2) Copper precipitation: adding an excess of a precipitant to the first-stage leaching solution for copper precipitation to obtain a copper-containing residue and a solution after copper precipitation;

[0008] (3) Second-stage leaching: adding the first-stage leaching residue into a hydrochloric acid solution, and then slowly adding an oxidizing agent for oxidative leaching to obtain a second-stage leaching solution and a second-stage leaching residue;

[0009] (4) Purification and impurity removal: adding an impurity removal agent to the second-stage leaching solution for impurity removal to obtain a purified residue and a solution after purification;

[0010] (5) First-stage reduction: adding a reducing agent to the solution after purification for first-stage reduction to obtain crude selenium and a solution after first-stage reduction;

[0011] (6) Secondary reduction: a reducing agent is added to the liquid after the first reduction to perform a secondary reduction reaction to obtain crude tellurium and a liquid after the secondary reduction.

[0012] Preferably, in the step (1), the concentration of the sulfuric acid solution is 100-200 g / L; the liquid-solid ratio of the first leaching is (3-6):1, the reaction time is 3-5 h, the reaction temperature is 60-80℃, and the pH value at the end of the first leaching reaction is controlled to be 3-5. The chemical reaction occurring in the step (1) is CuO+H2SO4=CuSO4+H2O.

[0013] Preferably, in the step (2), the precipitant is one or more of sodium sulfide and hydrogen sulfide, and the amount of the precipitant added is 1.1-1.3 times the theoretical amount; the reaction temperature of the copper precipitation reaction is 80-90℃, and the reaction time is 2-3 h. The chemical reaction occurring in the step (2) is Cu 2+ +S 2- =CuS↓.

[0014] Preferably, in the step (3), the concentration of the hydrochloric acid solution is 4-6 mol / L; the oxidant is one or more of hydrogen peroxide, sodium chlorate, and manganese dioxide, and the amount of the oxidant added is 150-250 g / (kg of tellurium residue); the reaction time of the oxidizing leaching is 3-5 h, the reaction temperature is 60-80℃, and the liquid-solid ratio is (3-5):1. The chemical reactions occurring in the step (3) are TeO2+HCl=TeCl4+H2O and CuO+2HCl=CuCl2+H2O.

[0015] Preferably, in the step (4), the impurity removing agent is one or more of oxalic acid and oxalate; the reaction temperature of the impurity removing is 30-50℃, the reaction time is 45-90 min, and the amount of the impurity removing agent added is 1.5-3 times the theoretical amount. The chemical reaction occurring in the step (4) is Cu 2+ +H2C2O4=CuC2O4↓+2H + .

[0016] Preferably, in the step (5), the reducing agent is one or more of sodium sulfite, sodium bisulfite, and sulfur dioxide; the end point of the reduction reaction is detected by thiourea without red precipitate; the reaction time of the first reduction reaction is 2-4 h, and the reaction temperature is 80-90℃.

[0017] Preferably, in the step (6), the reducing agent is one or more of sodium sulfite, sodium bisulfite, and sulfur dioxide; the amount of the reducing agent added is 1.05-1.1 times the theoretical amount; the reaction time of the secondary reduction reaction is 2-4 h, and the reaction temperature is 80-90℃.

[0018] Preferably, the method further comprises a step (7) of recovering gold and silver: smelting the second-stage leaching residue obtained in step (3) to recover gold and silver.

[0019] Preferably, the method of smelting the second-stage leaching residue in step (7) is as follows: the second-stage leaching residue is slurried and then subjected to a neutralization reaction, and then is added into an oxygen inclined-blowing rotary converter together with a pressurized copper-depleted anode mud to be smelted, thereby producing a gold-silver alloy; finally, the gold-silver alloy is cast into silver anode plates to further recover gold and silver.

[0020] The present application has the following advantages:

[0021] (1) The method for comprehensive recovery of tellurium residue disclosed in the present application uses a sulfuric acid solution for first-stage acid leaching and controls the end-point pH value, thereby ensuring the leaching rate of copper and enriching tellurium, gold, silver and lead in the first-stage leaching residue;

[0022] (2) The method for comprehensive recovery of tellurium residue disclosed in the present application uses a hydrochloric acid solution for second-stage oxidative leaching, thereby improving the leaching rate of tellurium and making the leaching rate of tellurium reach more than 90%;

[0023] (3) The method for comprehensive recovery of tellurium residue disclosed in the present application uses oxalic acid or oxalate for purification and impurity removal, because oxalate does not react with tellurium and the copper precipitation by oxalic acid is complete, so that the copper removal effect of purification and impurity removal is better, thereby ensuring the removal of copper impurities without loss; selenium and tellurium are separated by twice reduction;

[0024] (4) The method for comprehensive recovery of tellurium residue disclosed in the present application makes copper and tellurium in the tellurium residue enter the liquid phase through two-stage leaching, and makes lead, gold and silver enter the residue phase, thereby effectively separating copper and tellurium from lead, gold and silver, and making the leaching rates of copper and tellurium both reach more than 90% and gold and silver being enriched in the residue phase to be combined with pressurized copper-depleted anode mud to enter an oxygen inclined-blowing rotary converter. The method for comprehensive recovery of tellurium residue disclosed in the present application can effectively recover copper, tellurium, gold, silver and other metal elements in the tellurium residue, has the advantages of high treatment efficiency and the like, and is worth popularization and application. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 The present application discloses a process flow chart. DETAILED DESCRIPTION

[0026] The present application will be described in detail below with reference to the accompanying drawings and specific embodiments. The embodiments shown below do not limit the invention described in the claims in any way. In addition, the entire content of the configuration represented in the following embodiments is not limited to what is necessary as a solution to the invention described in the claims.

[0027] A method for comprehensive recovery of tellurium residue, comprising the following steps:

[0028] (1) First-stage leaching: Te residue powder with a particle size of ≤100 mesh (e.g., 50 mesh, 60 mesh, 70 mesh, 80 mesh, 90 mesh, etc.) is added to a sulfuric acid solution with a concentration of 100-200 g / L (e.g., 120 g / L, 140 g / L, 160 g / L, 180 g / L, etc.), and the liquid-solid ratio is controlled to be (3-6): 1 (e.g., 3.5: 1, 4: 1, 4.5: 1, 5: 1, 5.5: 1, etc.), the reaction temperature is controlled to be 60-80°C (e.g., 62°C, 65°C, 68°C, 70°C, 75°C, 78°C, etc.), and the reaction is carried out for 3-5 h (e.g., 3.5 h, 4 h, 4.5 h, 5 h, etc.), and the pH value at the end of the reaction is controlled to be 3-5 (e.g., 3.2, 3.5, 3.8, 4.0, 4.5, 4.8, etc.), and after the reaction is completed, solid-liquid separation is performed to obtain a first-stage leaching solution and a first-stage leaching residue;

[0029] (2) Copper precipitation: one or more of sodium sulfide and hydrogen sulfide in an amount of 1.1-1.3 times (e.g., 1.15 times, 1.20 times, 1.25 times, 1.28 times, etc.) the theoretical amount (the theoretical amount is the amount calculated based on just complete reaction) is added to the first-stage leaching solution as a precipitant, and a copper precipitation reaction is carried out at a temperature of 80-90°C (e.g., 82°C, 84°C, 86°C, 88°C, 89°C, etc.) for 2-3 h (e.g., 2.2 h, 2.4 h, 2.5 h, 2.6 h, 2.8 h, etc.), and solid-liquid separation is performed to obtain a copper-containing residue and a post-copper precipitation solution;

[0030] (3) Second-stage leaching: the first-stage leaching residue is added to a hydrochloric acid solution with a concentration of 4-6 mol / L (e.g., 4.2 mol / L, 4.5 mol / L, 4.8 mol / L, 5.0 mol / L, 5.2 mol / L, 5.5 mol / L, 5.8 mol / L, etc.), and then one or more of hydrogen peroxide, sodium chlorate, and manganese dioxide is slowly added as an oxidant at a ratio of 150-250 g / (kg of Te residue) (e.g., 160 g / (kg of Te residue), 180 g / (kg of Te residue), 200 g / (kg of Te residue), 220 g / (kg of Te residue), 240 g / (kg of Te residue), etc.), the liquid-solid ratio is controlled to be (3-5): 1 (e.g., 3.5: 1, 4: 1, 4.5: 1, etc.), the reaction temperature is controlled to be 60-80°C (e.g., 62°C, 64°C, 66°C, 68°C, 70°C, 75°C, 78°C, etc.), and an oxidative leaching reaction is carried out, and the reaction time is 3-5 h (e.g., 3.5 h, 3.8 h, 4.0 h, 4.2 h, 4.6 h, etc.), and after the reaction is completed, solid-liquid separation is performed to obtain a second-stage leaching solution and a second-stage leaching residue;

[0031] (4) Purification and impurity removal: one or more of oxalic acid and oxalate in an amount of 1.5-3 times (e.g. 1.6 times, 1.8 times, 1.9 times, 2.0 times, 2.2 times, 2.5 times, 2.8 times, etc.) of the theoretical amount is added to the secondary leaching solution as an impurity removal agent, and impurity removal is performed, with the reaction temperature for impurity removal controlled at 30-50°C (e.g. 32°C, 35°C, 38°C, 40°C, 42°C, 45°C, 48°C, etc.), and the reaction time controlled at 45-90 min (e.g. 48 min, 50 min, 55 min, 60 min, 65 min, 70 min, 80 min, 85 min, etc.). After the reaction is completed, solid-liquid separation is performed, and a purified residue and a purified solution are obtained.

[0032] (5) Primary reduction: one or more of sodium sulfite, sodium bisulfite, or sulfur dioxide is added to the purified solution as a reducing agent, and primary reduction is performed, with the reaction time controlled at 2-4 h (e.g. 2.5 h, 3 h, 3.5 h, 3.8 h, etc.), and the reaction temperature controlled at 80-90°C (82°C, 84°C, 86°C, 88°C). The reaction is completed when no red precipitate is produced when thiocyanate is used for detection, and solid-liquid separation is performed, and a crude selenium and a primary reduction solution are obtained.

[0033] (6) Secondary reduction: one or more of sodium sulfite, sodium bisulfite, or sulfur dioxide is added to the primary reduction solution in an amount of 1.05-1.1 times (1.06 times, 1.07 times, 1.08 times, 1.09 times, etc.) of the theoretical amount as a reducing agent, and secondary reduction is performed, with the reaction time controlled at 2-4 h (e.g. 2.2 h, 2.5 h, 2.8 h, 3.0 h, 3.5 h, 3.8 h, etc.), and the reaction temperature controlled at 80-90°C (82°C, 84°C, 86°C, 88°C). After the reaction is completed, solid-liquid separation is performed, and a crude tellurium and a secondary reduction solution are obtained.

[0034] (7) Recovery of gold and silver: the secondary leaching residue obtained in step (3) is slurried and then subjected to a neutralization reaction, and then is added to an oxygen inclined-blowing rotary converter together with a pressurized copper removal anode mud to produce a gold and silver alloy. Finally, the gold and silver alloy is cast into silver anode plates to further recover gold and silver.

[0035] Example 1

[0036] Tellurium residue composition: tellurium 11.4%, copper 12.3%, lead 6.6%, selenium 3.45%, gold 237 g / t, and silver 62124 g / t.

[0037] (1) Take tellurium residue 100 g, particle size 100 mesh, add 180 g / L sulfuric acid solution according to liquid-solid ratio 5:1, temperature control at 60℃, reaction 3h, end point pH=4, filter separation of the first stage leaching liquid and the first stage leaching residue rich in tellurium, selenium, lead, gold and silver, get the first stage leaching residue 65 g, copper 1.5% in the first stage leaching residue, lead 10.0%, selenium 4.6%, tellurium 14.6%, gold 360 g / t, silver 95560 g / t.

[0038] (2) The above obtained leaching residue is added into 4 mol / L hydrochloric acid solution according to liquid-solid ratio 4:1, then slowly add hydrogen peroxide, hydrogen peroxide addition amount is 15 g, reaction temperature 60℃, reaction 4h, filter separation of the second stage leaching liquid and the second stage leaching residue rich in lead, gold and silver, get the second stage leaching residue 45 g, copper 1.4% in the second stage leaching residue, lead 14.4%, selenium 2.0%, tellurium 1.2%, gold 510 g / t, silver 135000 g / t.

[0039] (3) The first stage leaching liquid is added into theoretical amount 1.1 times of sodium sulfide for copper precipitation, reaction 2h, reaction temperature is 80℃, filter separation to get copper-containing residue (copper sulfide residue) and post-copper precipitation liquid, copper content in the post-copper precipitation liquid is 0.2 g / L.

[0040] (4) The above obtained second stage leaching liquid is added into theoretical amount 2 times of oxalic acid for impurity removal, normal temperature, reaction time 45 min, filter separation to get purified residue and post-purification liquid, tellurium content in the post-purification liquid is 35.8 g / L, selenium content is 11.8 g / L.

[0041] (5) The post-purification liquid is added into sodium sulfite solution for reduction, reaction temperature is 90℃, reaction time 4h, no red precipitate is detected by using thiourea, filter separation of crude selenium powder and post-first reduction liquid, selenium content in the crude selenium after washing is 98%, selenium content in the post-first reduction liquid is 0.3 g / L, tellurium content is 33 g / L.

[0042] (6) The post-first reduction liquid is added into theoretical amount 1.05 times of sodium bisulfite solution for reduction, reaction temperature is 90℃, reaction time 4h, tellurium content in the crude tellurium powder is 97%, selenium content in the post-neutralization liquid is 0.15 g / L, tellurium content is 0.15 g / L.

[0043] (7) The second stage leaching residue is slurried and then subjected to neutralization reaction, and then is added into an oxygen inclined-blowing rotary converter together with a pressurized copper removal anode mud for smelting to produce gold-silver alloy; finally, the gold-silver alloy is cast into silver anode plates for further recovery of gold and silver.

[0044] Example 2

[0045] Composition of tellurium residue: tellurium 11.4%, copper 12.3%, lead 6.6%, selenium 3.45%, gold 237 g / t, silver 62124 g / t.

[0046] (1)Take tellurium residue 100 g, particle size 100 mesh, add 200 g / L sulfuric acid solution according to liquid-solid ratio 4:1, temperature control at 75℃, reaction for 4h, end point pH=4.5, filter separation to obtain a first leaching solution and a first leaching residue rich in tellurium, selenium, lead, gold and silver, obtain first leaching residue 68 g, copper 1.65% in first leaching residue, lead 9.6%, selenium 4.7%, tellurium 15.3%, gold 348 g / t, silver 90800 g / t.

[0047] (2)Add the first leaching residue to 5 mol / L hydrochloric acid solution according to liquid-solid ratio 5:1, then slowly add 20 g hydrogen peroxide, reaction temperature 65℃, reaction for 3h, filter separation of second leaching solution and second leaching residue rich in lead, gold and silver, obtain second leaching residue 42 g, copper 1.8% in second leaching residue, lead 14.6%, selenium 1.8%, tellurium 1.0%, gold 555 g / t, silver 146000 g / t.

[0048] (3)Add the first leaching solution to theoretical amount 1.2 times of sodium sulfide to precipitate copper, filter separation of copper sulfide residue and copper precipitation after liquid, copper precipitation after liquid contains 0.15 g / L of copper.

[0049] (4)Add the second leaching solution to theoretical amount 2.5 times of oxalic acid to remove impurities, normal temperature, reaction time 60 min, filter separation of purification residue and purification after liquid, purification after liquid contains 29.7 g / L of tellurium and 9.0 g / L of selenium.

[0050] (5)Add the purification after liquid to sodium sulfite solution for reduction, reaction temperature 90℃, reaction time 4h, no red precipitate is detected by using thiourea, filter separation of crude selenium powder and first reduction after liquid, crude selenium contains 97% of selenium, first reduction after liquid contains 0.3 g / L of selenium and 28 g / L of tellurium.

[0051] (6)Add the first reduction after liquid to theoretical amount 1.1 times of sodium bisulfite solution for reduction, reaction temperature 90℃, reaction time 4h, crude tellurium powder contains 98% of tellurium, neutralization after liquid contains 0.15 g / L of tellurium and 0.15 g / L of selenium.

[0052] Example 3

[0053] Tellurium residue composition: tellurium 11.4%, copper 12.3%, lead 6.6%, selenium 3.45%, gold 237 g / t, silver 62124 g / t.

[0054] (1)Take tellurium residue 100g, particle size is 100 mesh, add 160g / L sulfuric acid solution according to liquid-solid ratio 6:1, temperature control at 80℃, reaction 5h, end point PH=4, filter separation first stage leaching liquid and rich tellurium, selenium, lead, gold, silver first stage leaching residue, get first stage leaching residue 62g, copper 1.6% in first stage leaching residue, lead 10.5%, selenium 5.0%, tellurium 16.8%, gold 380g / t, silver 99000g / t.

[0055] (2)Put first stage leaching residue into 6mol / L hydrochloric acid solution according to liquid-solid ratio 3:1, then slowly add 25g hydrogen peroxide, reaction temperature 80℃, reaction 5h, filter separation second stage leaching liquid and rich lead, gold, silver second stage leaching residue, get second stage leaching residue 40g, copper 2.0% in second stage leaching residue, lead 14.8%, selenium 2.0%, tellurium 1.2%, gold 590g / t, silver 152000g / t.

[0056] (3)Put first stage leaching liquid into theoretical dosage 1.2 times of sodium sulfide to precipitate copper, filter separation copper sulfide residue and post-copper precipitation liquid, copper content in post-copper precipitation liquid is 0.5g / L.

[0057] (4)Put second stage leaching liquid into theoretical dosage 3 times of oxalic acid to remove impurities, normal temperature, reaction time 45min, filter separation purification residue and post-purification liquid, tellurium content in post-purification liquid is 50g / L, selenium content is 15g / L.

[0058] (5)Put post-purification liquid into sodium sulfite solution to reduce, reaction temperature is 90℃, reaction time 4h, no red precipitate is generated by using thiourea detection, filter separation crude selenium powder and post-first reduction liquid, selenium content in crude selenium after washing is 97%, selenium content in post-first reduction liquid is 0.2g / L, tellurium content is 45g / L.

[0059] (6)Put post-first reduction liquid into theoretical dosage 1.15 times of sodium bisulfite solution to reduce, reaction temperature is 90℃, reaction time 4h, tellurium content in crude tellurium powder is 98%, tellurium content in neutralized post-liquid is 0.1g / L, selenium content is 0.1g / L.

[0060] The above description of disclosed embodiments enables those skilled in the art to carry out or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for comprehensive recovery of tellurium slag, characterized in that, Includes the following steps: (1) First-stage leaching: Add tellurium slag powder with a particle size ≤100 mesh to sulfuric acid solution for first-stage leaching. Control the pH value at the end of the first-stage leaching reaction to be 3-5 to obtain first-stage leachate and first-stage leaching residue. (2) Copper precipitation: Add an excess of precipitant to the first-stage leaching solution to carry out the copper precipitation reaction, and obtain copper-containing slag and copper-precipitated liquid; the precipitant is one or more of sodium sulfide and hydrogen sulfide, and the amount of precipitant added is 1.1-1.3 times the theoretical amount; the reaction temperature of the copper precipitation reaction is 80-90℃ and the reaction time is 2-3h; (3) Second-stage leaching: Add the first-stage leaching residue to hydrochloric acid solution, and then slowly add an oxidant to carry out oxidative leaching, and obtain the second-stage leaching solution and the second-stage leaching residue; the oxidant is one or more of hydrogen peroxide, sodium chlorate, and manganese dioxide, and the amount of oxidant added is 150-250g / kg tellurium slag; (4) Purification and impurity removal: Add impurity removal agent to the second stage leachate to remove impurities and obtain purified residue and purified liquid; the reaction temperature for impurity removal is 30-50℃, and the amount of impurity removal agent added is 1.5-3 times the theoretical amount; (5) Primary reduction: Add a reducing agent to the purified liquid and carry out a primary reduction reaction to obtain crude selenium and a primary reduction liquid; the reducing agent is one or more of sodium sulfite, sodium bisulfite or sulfur dioxide; the endpoint of the reduction reaction is tested with thiourea and no red precipitate is produced; the reaction time of the primary reduction reaction is 2-4 hours and the reaction temperature is 80-90℃; (6) Secondary reduction: Add a reducing agent to the liquid after primary reduction to carry out a secondary reduction reaction to obtain crude tellurium and a liquid after secondary reduction; the reducing agent is one or more of sodium sulfite, sodium bisulfite or sulfur dioxide; the amount of reducing agent added is 1.05-1.1 times the theoretical amount; the reaction time of the secondary reduction reaction is 2-4 hours and the reaction temperature is 80-90℃.

2. The method for comprehensive recovery of tellurium slag according to claim 1, characterized in that, In step (1): the concentration of the sulfuric acid solution is 100-200 g / L; the liquid-to-solid ratio of the first leaching stage is (3-6):1; the reaction time is 3-5 h; and the reaction temperature is 60-80 °C.

3. The method for comprehensive recovery of tellurium slag according to claim 1, characterized in that, In step (3): the concentration of the hydrochloric acid solution is 4-6 mol / L; the oxidative leaching reaction time is 3-5 h, the reaction temperature is 60-80 °C, and the liquid-solid ratio is (3-5):

1.

4. The method for comprehensive recovery of tellurium slag according to claim 1, characterized in that, In step (4): the impurity removal agent is one or more of oxalic acid and oxalate; the reaction time is 45-90 min.

5. The method for comprehensive recovery of tellurium slag according to any one of claims 1-4, characterized in that, It also includes step (7) to recover gold and silver: smelting the two-stage leaching residue obtained in step (3) to recover gold and silver.

6. The method for comprehensive recovery of tellurium slag according to claim 5, characterized in that, The method for smelting the second-stage leaching residue in step (7) is as follows: the second-stage leaching residue is slurried and then neutralized, and then added together with the pressurized copper-removing anode mud into an oxygen inclined rotary furnace for smelting to produce a gold-silver alloy; finally, the gold-silver alloy is cast into a silver anode plate for further recovery of gold and silver.

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