Electrochemical metallurgy method for extracting copper and tellurium from copper tellurium slag
Patent Information
- Application Number
- CN202511292264.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-10
- Publication Date
- 2025-11-18
Smart Images
Figure CN120967447A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of metallurgical and chemical technology, specifically relating to an electrochemical metallurgical method for extracting copper and tellurium from copper tellurium slag. Background Technology
[0002] Tellurium is extremely rare in the Earth's crust and is mainly used in four high-end fields: photovoltaic industry (such as cadmium telluride thin-film batteries), thermoelectric conversion devices (such as bismuth-tellurium thermoelectric power generation modules), infrared detection (such as mercury-cadmium-tellurium semiconductor detectors), and special alloys (such as superhard cutting materials). Currently, tellurium resource supply is highly dependent on secondary resource recycling, among which copper tellurium slag produced by copper anode mud treatment process has become the core raw material carrier.
[0003] Copper tellurium slag is an industrial waste residue mainly containing copper and tellurium, produced during the reduction and displacement of copper powder in the smelting process of copper anode mud. Related technologies for extracting copper and tellurium from copper tellurium slag mainly include atmospheric pressure oxidation-alkali leaching, oxidation-acid leaching, sulfation roasting, pressure acid leaching, and extraction separation. These methods generally have significant drawbacks: the tellurium recovery rate of the oxidation-alkali leaching process is low; oxidation-acid leaching generates a large amount of arsenic-containing wastewater; sulfation roasting has excessively high energy consumption; pressure acid leaching accelerates equipment corrosion; and extraction separation technology suffers from the problem of easy organic phase failure. With the rapid development of 5G communication and the cadmium telluride photovoltaic industry, the market demand for high-purity tellurium continues to grow rapidly. Developing short-process, high-recovery, and environmentally friendly copper tellurium slag treatment technologies has become a key path to overcome the bottleneck of tellurium resource supply.
[0004] The related technology discloses a method for efficiently separating copper tellurium from copper telluride materials. The method processes copper telluride slag (Te content 22.8–33.4 wt%, Cu content 33.8–40.0 wt%) generated from copper smelting anode mud treatment. The process involves simultaneous leaching of copper tellurium and enrichment of precious metals through acidic catalytic oxidation dissolution (sulfuric acid system, 60–95℃, 0.5–5.0 h, with the addition of 100–500 ppm catalytic activator and 5–50 ppm surfactant). The leaching solution (slag rate ≤ 1.21%) is separated by electrodeposition (tank voltage 1.7~5.5V, 20~65℃, inert anode / stainless steel cathode) to directly precipitate tellurium powder (purity 94.2~98.8%). The residual electrolyte is then replaced with copper powder to recover copper. This method achieves short-process separation through integrated catalytic oxidation-electrodeposition. However, the strong acid system (hydrochloric acid / nitric acid) easily leads to the dissolution and loss of precious metals, and the oxidant (sodium chlorate / sodium hypochlorite) introduces chloride ions, which aggravates equipment corrosion. Summary of the Invention
[0005] In view of this, the purpose of this invention is to provide an electrochemical metallurgical method for extracting copper and tellurium from copper tellurium slag. This method can achieve one-step electrolytic separation and purification of copper and tellurium elements, with the purity of the obtained copper and tellurium elements ≥99.9% and the direct recovery rate ≥99%.
[0006] To achieve the above objectives, the present invention provides the following technical solution:
[0007] This invention provides an electrochemical metallurgical method for extracting copper and tellurium from copper-tellurium slag, comprising the following steps:
[0008] The copper tellurium slag powder and the electrolyte base are mixed, and the resulting electrolyte is subjected to constant voltage electrolysis treatment. A reduction reaction occurs on the cathode surface to generate metallic copper, and an oxidation reaction occurs on the anode surface to generate metallic tellurium, thus obtaining cathode deposited copper and anode precipitated tellurium, respectively.
[0009] The electrolyte base liquid includes hydrogen bond donors, hydrogen bond acceptors, and conductive salts.
[0010] Preferably, the hydrogen bond donor includes organic hydrogen bond donors and / or inorganic hydrogen bond donors; the organic hydrogen bond donors include one or more of alcohols, carboxylic acids, quaternary ammonium salts, primary amines, secondary amines, amides, and phenols; the inorganic hydrogen bond donors include one or more of water, ammonia, hydrogen fluoride, and inorganic acids.
[0011] Preferably, the hydrogen bond acceptor includes organic hydrogen bond acceptors and / or inorganic hydrogen bond acceptors; the organic hydrogen bond acceptors include one or more of alcohols, ethers, aldehydes, ketones, amides, organic acids, esters, and tertiary amines; the inorganic hydrogen bond acceptors include one or more of water, ammonia, hydrogen fluoride, inorganic substances containing halogen anions, inorganic substances containing cyanide ions, and inorganic substances containing oxoanions.
[0012] Preferably, the conductive salt includes one or more of sodium salt, potassium salt, and ammonium salt.
[0013] Preferably, when the hydrogen bond donor and the hydrogen bond acceptor are different types of substances, the mass ratio of the hydrogen bond donor and the hydrogen bond acceptor is 1:0.5 to 4, and the molar ratio of the hydrogen bond donor to the conductive salt is 1:0.1 to 0.5; when the hydrogen bond donor and the hydrogen bond acceptor are the same type of substance, the molar ratio of the hydrogen bond donor to the conductive salt is 1.5 to 4:1.
[0014] Preferably, the constant voltage electrolysis treatment is performed at a voltage of 0.5–1.5V for 2–8 hours.
[0015] Preferably, the distance between the anode and the cathode is 2 to 5 cm.
[0016] Preferably, during the constant voltage electrolysis process, the temperature of the electrolyte is maintained at 50–80°C.
[0017] Preferably, the current density of the cathode is 180–240 A / m.2 .
[0018] Preferably, the current density of the anode is 180–240 A / m. 2 .
[0019] This invention provides an electrochemical metallurgical method for extracting copper and tellurium from copper tellurium slag, comprising the following steps: mixing copper tellurium slag powder with an electrolyte base solution, subjecting the resulting electrolyte to constant voltage electrolysis treatment, generating metallic copper through a reduction reaction on the cathode surface and metallic tellurium through an oxidation reaction on the anode surface, thereby obtaining cathode-deposited copper and anode-deposited tellurium, respectively; the electrolyte base solution comprises a hydrogen bond donor, a hydrogen bond acceptor, and a conductive salt.
[0020] This invention employs an electrolyte composed of hydrogen bond donors, hydrogen bond acceptors, and conductive salts, wherein the hydrogen bond donors and acceptors form a complexing agent through chemical bonding. The effective component (complexing agent) in this electrolyte can react with the Cu produced by the dissolution of copper tellurium slag. + and Te 2- Ions undergo selective complexation, forming easily reducible copper-containing complex anions and easily oxidized tellurium-containing complex cations, respectively. Electrolysis is then performed under a constant voltage; in the cathode region, the complexed Cu... + It is preferentially reduced and deposited as high-purity elemental copper; simultaneously, in the anode region, the complexed Te... 2- The copper and tellurium are oxidized in a specific direction to precipitate high-purity tellurium, thus achieving simultaneous one-step electrolytic separation and purification of copper and tellurium.
[0021] Compared with existing technologies for treating copper-tellurium slag, this invention achieves a technological breakthrough by constructing an electrolyte system containing hydrogen bond donors, hydrogen bond acceptors, and conductive salts, enabling the simultaneous one-step electrolytic separation and purification of elemental copper-tellurium from copper-tellurium slag. Compared to traditional copper-tellurium slag treatment processes, this method boasts significant advantages such as greatly simplified processes, substantial reduction in energy consumption, outstanding environmental friendliness, and superior overall economic efficiency. The electrolyte system used in this invention, with its low environmental impact, high metal recovery efficiency, wide operating temperature window, and strong component controllability, shows promising application prospects in the field of metal resource recovery. Through continuous optimization of the electrolyte formulation and process parameters, this invention is expected to play a key role in the circular economy and promote the sustainable development of the non-ferrous metals industry. Attached Figure Description
[0022] Figure 1 This is a schematic diagram of the electrochemical metallurgical method for extracting copper and tellurium from copper tellurium slag in an embodiment of the present invention. Detailed Implementation
[0023] This invention provides an electrochemical metallurgical method for extracting copper and tellurium from copper-tellurium slag, comprising the following steps:
[0024] The copper tellurium slag powder and the electrolyte base are mixed, and the resulting electrolyte is subjected to constant voltage electrolysis treatment. A reduction reaction occurs on the cathode surface to generate metallic copper, and an oxidation reaction occurs on the anode surface to generate metallic tellurium, thus obtaining cathode deposited copper and anode precipitated tellurium, respectively.
[0025] The electrolyte base liquid includes hydrogen bond donors, hydrogen bond acceptors, and conductive salts.
[0026] Unless otherwise specified, the present invention does not have special requirements on the source of raw materials used, and commercially available products well known to those skilled in the art can be used.
[0027] In one embodiment, the copper tellurium slag originates from the copper powder reduction and replacement process during the copper anode mud smelting process; by mass percentage, the copper tellurium slag comprises: Cu 30-50%, Te 30-40%, and the remainder being metallic impurities, including one or more of Pb, Bi, As, and Se.
[0028] As one embodiment, the method for preparing the copper tellurium slag powder is as follows: crushing the copper tellurium slag; the particle size distribution of the copper tellurium slag powder is D. 90 ≤100μm.
[0029] In one embodiment, the electrolyte base liquid includes a hydrogen bond donor, a hydrogen bond acceptor, and a conductive salt; the hydrogen bond donor includes organic hydrogen bond donors and / or inorganic hydrogen bond donors, with organic hydrogen bond donors being used in a specific embodiment; the organic hydrogen bond donor includes one or more of alcohols, carboxylic acids, quaternary ammonium salts, primary amines, secondary amines, amides, and phenols, with alcohols being used in a specific embodiment; the alcohol includes methanol (CH3OH) and / or ethanol (CH3CH2OH), with methanol being used in a specific embodiment; the quaternary ammonium salt is choline chloride (HOCH2CH2N(CH3)3). + The carboxylic acid compounds include acetic acid (CH3COOH); the primary amine is methylamine (CH3NH2); the secondary amine is dimethylamine ((CH3)2NH); the amide compounds are acetamide (CH3CONH2) and / or urea (H2NCONH2); the phenolic compounds are phenol (C6H5OH); the inorganic hydrogen bond donors include one or more of water (H2O), ammonia (NH3), hydrogen fluoride (HF), and inorganic acids, with water being the specific example; the inorganic acids include one or more of sulfuric acid (H2SO4), phosphoric acid (H3PO4), and hydrochloric acid (HCl), with sulfuric acid being the specific example.
[0030] The hydrogen bond donors described in this invention refer to chemical groups or substances containing hydrogen atoms (H) that are directly bonded to electronegative atoms (such as oxygen (O), nitrogen (N), and fluorine (F)). Typical hydrogen bond donors include: in organic compounds: hydroxyl groups (-OH, e.g., methanol CH3OH, ethanol CH3CH2OH), choline chloride HOCH2CH2N(CH3)3 + The hydroxyl groups in amines include: hydroxyl groups in the carboxyl groups of carboxylic acids (-COOH, e.g., acetic acid CH3COOH); amino groups in primary and secondary amines (-NH2, -NH-, e.g., methylamine CH3NH2, dimethylamine (CH3)2NH); amino groups in urea H2NCONH2; NH bonds in the amide groups of amides (-CONH-, e.g., acetamide CH3CONH2); and phenolic hydroxyl groups in phenolic compounds (-OH, e.g., phenol C6H5OH). In inorganic compounds: OH bonds in water molecules (H2O), NH bonds in ammonia molecules (NH3), HF bonds in hydrogen fluoride molecules (HF), and hydrogen atoms bonded to oxygen or halogen atoms in inorganic acid molecules (e.g., sulfuric acid H2SO4, phosphoric acid H3PO4, hydrochloric acid HCl).
[0031] In one embodiment, the hydrogen bond acceptor includes organic hydrogen bond acceptors and / or inorganic hydrogen bond acceptors, with organic hydrogen bond acceptors being a specific embodiment. The organic hydrogen bond acceptor includes one or more of alcohols, ethers, aldehydes, ketones, amides, organic acids, esters, and tertiary amines, with alcohols being a specific embodiment. The alcohol includes one or more of methanol (CH3OH), ethanol (CH3CH2OH), and ethylene glycol (HOCH2CH2OH); the ether is diethyl ether (CH3CH2OCH2CH3); the aldehyde is acetaldehyde (CH3CHO); the ketone is acetone ((CH3)2C=O); the amide is urea (H2NCONH2); and the organic... The acid is one or more of formic acid (HCOOH), acetic acid (CH3COOH), and trifluoroacetic acid (CF3COOH); the ester compound is ethyl acetate (CH3COOCH2CH3); the tertiary amine organic compound is triethylamine ((CH3CH2)3N); the inorganic hydrogen bond acceptor includes one or more of water (H2O), ammonia (NH3), hydrogen fluoride (HF), inorganic substances containing halide anions, inorganic substances containing cyanide ions, and inorganic substances containing oxoanions, specifically water in this embodiment; the inorganic substances containing halide anions include inorganic substances containing fluoride ions and / or inorganic substances containing chloride ions, specifically chloride-containing inorganic substances in this embodiment; the inorganic substances containing chloride ions include sodium chloride (NaCl) and choline chloride ([CH3CH2N(CH3)3)). +Cl - The inorganic substances containing fluoride ions include one or more of sodium fluoride (NaF), ammonium fluoride (NH4F), and sodium tetrafluoroborate (NaBF4); the inorganic substances containing oxyanions include those containing nitrate ions (NO3). - Inorganic substances containing sulfate ions (SO4) 2- Inorganic substances and phosphate-containing substances (PO4) 3- One or more of the inorganic substances, specifically those containing nitrate ions (NO3) in the embodiments. - Inorganic substances containing nitrate ions (NO3); - The inorganic substances include one or more of sodium nitrate (NaNO3), ammonium nitrate (NH4NO3), and nitric acid (HNO3); the sulfate-containing substances (SO4) 2- The inorganic substances include one or more of sodium sulfate (Na₂SO₄), ammonium sulfate ((NH₄)₂SO₄), and sulfuric acid (H₂SO₄); the phosphate-containing (PO₄) 3- The inorganic substances include one or more of sodium dihydrogen phosphate (NaH2PO4), disodium hydrogen phosphate (Na2HPO4), and phosphoric acid (H3PO4).
[0032] In this invention, a hydrogen bond acceptor refers to a chemical group or substance containing an electronegative atom with a lone pair of electrons (such as oxygen (O), nitrogen (N), fluorine (F), chlorine (Cl), etc.). Typical hydrogen bond acceptors include: in organic compounds: oxygen atoms (-OH) in alcohol hydroxyl groups, oxygen atoms (-O-, e.g., diethyl ether CH3CH2OCH2CH3) in ether bonds, carbonyl oxygen atoms (-CHO, e.g., acetaldehyde CH3CHO) in aldehyde groups, carbonyl oxygen atoms (-C=O, e.g., acetone (CH3)2C=O) in ketone groups, carbonyl oxygen atoms in urea H2NCONH2, carbonyl oxygen atoms and hydroxyl oxygen atoms (-COOH) in carboxylic acids, carbonyl oxygen atoms and ether bond oxygen atoms (-COOR, e.g., ethyl acetate CH3COOCH2CH3) in esters, carbonyl oxygen atoms and amino nitrogen atoms (-CON-) in amides, and nitrogen atoms with lone pairs of electrons in tertiary amines (e.g., triethylamine (CH3CH2)3N). In inorganic substances: oxygen atoms in water molecules (H2O), nitrogen atoms in ammonia molecules (NH3), fluorine atoms in hydrogen fluoride molecules (HF, with weak acceptor ability), and halogen anions (e.g., fluoride ions F). - chloride ions Cl - ), nitrogen atom (CN) in cyanide ion - ), and oxygen atoms in oxygen-containing anions (e.g., nitrate ions NO3-). - sulfate ions SO42- 2- phosphate ions PO43- ).
[0033] In one embodiment, the conductive salt includes one or more of sodium salt, potassium salt, and ammonium salt, with sodium salt being a specific example; the sodium salt includes sodium sulfate (Na2SO4) and / or sodium chloride (NaCl), with sodium chloride being a specific example; the potassium salt includes potassium sulfate (K2SO4) and / or potassium chloride (KCl), with potassium chloride being a specific example; the ammonium salt includes ammonium sulfate ((NH4)2SO4) and / or ammonium chloride (NH4Cl), with ammonium chloride being a specific example.
[0034] In one implementation, when the hydrogen bond donor and hydrogen bond acceptor are different types of substances, the mass ratio of the hydrogen bond donor to the hydrogen bond acceptor is 1:0.5 to 4, and in a specific embodiment it is 1:1.5; the molar ratio of the hydrogen bond donor to the conductive salt is 1:0.1 to 0.5, and in a specific embodiment it is 1:0.25. When the hydrogen bond donor and hydrogen bond acceptor are the same type of substance, the molar ratio of the hydrogen bond donor to the conductive salt is 1.5 to 4:1, and in specific embodiments it is 2:1 and 2.5:1.
[0035] As one embodiment, the preparation method of the electrolyte base solution is as follows: after dehydrating and drying the hydrogen bond donor, hydrogen bond acceptor, and conductive salt, the mixture is stirred at a constant temperature to obtain the electrolyte base solution; the vacuum degree of the dehydration and drying is 30-100 Pa, specifically 30 Pa, 50 Pa, or 80 Pa in the embodiment; the temperature is 60-90℃, specifically 75℃, 80℃, or 85℃ in the embodiment; the time is 18-36 h, specifically 20 h, 24 h, or 28 h in the embodiment; the temperature of the constant temperature stirring is 60-90℃, specifically 70℃, 75℃, or 80℃ in the embodiment; the speed is 200-500 rpm, specifically 300 rpm, 350 rpm, or 400 rpm in the embodiment; the time is 24-48 h, specifically 30 h, 36 h, or 40 h in the embodiment.
[0036] In one embodiment, the conductivity of the electrolyte base liquid is 10-15 mS / cm, specifically 11.8 mS / cm, 12.3 mS / cm, or 13.5 mS / cm in specific embodiments.
[0037] As one implementation method, the ratio of the mass of the copper tellurium slag powder to the volume of the electrolyte base liquid is 1g:(16-24)mL, and in specific embodiments it is 1g:18mL, 1g:20mL or 1g:22mL.
[0038] In one implementation method, after mixing the copper tellurium slag powder and the electrolyte base liquid, the method further includes: sequentially dehydrating and drying the mixture of the obtained copper tellurium slag powder and the electrolyte base liquid, stirring, and filtering to obtain electrolyte and filter residue, respectively; the dehydration and drying temperature is 60-100℃, specifically 75℃, 85℃, or 80℃ in this embodiment, and the time is 2-5h, specifically 2.5h, 3h, or 3.5h in this embodiment; the dehydration and drying is vacuum drying; the equipment used for vacuum drying is a vacuum drying oven; the vacuum degree of vacuum drying is 10-100Pa, specifically 40Pa, 60Pa, or 70Pa in this embodiment; the stirring temperature is 50-100℃, specifically 75℃, 80℃, or 85℃ in this embodiment, the stirring speed is 200-1200rpm, specifically 400rpm, 450rpm, or 380rpm in this embodiment, and the time is 2-5h, specifically 2.5h, 3h, or 4h in this embodiment.
[0039] In one implementation, the conductivity of the electrolyte fluctuates by <1% / h, specifically <0.8% / h, <0.7% / h, or <0.9% / h in specific embodiments.
[0040] In one embodiment, the constant voltage electrolysis treatment is carried out in an electrolytic cell; the cathode is a titanium plate; and the effective area of the cathode is 40–200 cm². 2 In the specific embodiment, it is 80cm 2 100cm 2 Or 120cm 2 The anode is a porous graphite anode, and the effective area of the anode is 40–200 cm². 2 In the specific embodiment, it is 80cm 2 100cm 2 Or 120cm 2 The porosity is 10-20%, with specific examples showing 12%, 15%, or 18%.
[0041] In one implementation, the constant voltage electrolysis treatment voltage is 0.5–1.5V, specifically 1.0V, 1.2V, or 1.4V in some embodiments, and the time is 2–8 hours, specifically 3.5 hours, 4 hours, or 5 hours in some embodiments; the distance between the anode and cathode is 2–5 cm, specifically 2.5 cm, 3 cm, or 3.5 cm in some embodiments; and the cathode current density is 180–240 A / m. 2 In a specific embodiment, it is 195A / m 2 210A / m 2 Or 225A / m 2 The current density of the anode is 180–240 A / m. 2 In a specific embodiment, it is 190A / m 2205A / m 2 Or 220A / m 2 .
[0042] In one embodiment, during the constant voltage electrolysis process, the temperature of the electrolyte is maintained at 50-80°C, specifically 72±1°C, 75±1°C, or 78±1°C in the embodiment; the temperature of the electrolyte is controlled by a thermostat; the thermostat is an oil bath.
[0043] As one implementation method, after the constant voltage electrolysis treatment, the method further includes: sequentially subjecting the cathode deposited copper and the anode precipitated tellurium to ultrasonic washing, vacuum filtration and vacuum drying to obtain copper powder and tellurium crystals.
[0044] In one embodiment, the ultrasonic washing is performed in an antioxidant solution; the antioxidant solution includes an antioxidant and a solvent; the antioxidant includes one or more of ascorbic acid (vitamin C), vitamin E, tea polyphenols, glutathione, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), sodium thiosulfate, and ascorbyl palmitate, with ascorbic acid being used in a specific embodiment; the solvent includes water and / or ethanol, with water being used in a specific embodiment; the mass concentration of the antioxidant in the antioxidant solution is 0.5–2.0 wt%, with 1.0%, 1.5%, or 0.8% being used in a specific embodiment.
[0045] In one embodiment, the ultrasonic washing uses an ultrasonic power of 200–500W, specifically 350W, 400W, or 300W, for a duration of 15–30 minutes, specifically 20 minutes, 25 minutes, or 28 minutes; the vacuum filtration uses a vacuum degree of 0.08–0.1MPa, specifically 0.09MPa, 0.085MPa, or 0.095MPa; the vacuum drying uses a vacuum degree of 50–100Pa, specifically 70Pa, 60Pa, or 90Pa, at a temperature of 50–70°C, specifically 60°C, 55°C, or 65°C, for a duration of 4–8 hours, specifically 6 hours, 5.5 hours, or 7 hours.
[0046] In one embodiment, the purity of the cathode deposited copper is ≥99.9%, specifically 99.987%, 99.992%, or 99.995% in the embodiments; the purity of the anode deposited tellurium is ≥99.9%, specifically 99.978%, 99.983%, or 99.989% in the embodiments; and the direct recovery rate of the copper powder and tellurium crystals is ≥99%, specifically 99.1%, 99.2%, or 99.5% in the embodiments.
[0047] Figure 1 This is a schematic diagram of the electrochemical metallurgical method for extracting copper and tellurium from copper-tellurium slag in an embodiment of the present invention. Figure 1 As shown, in this invention, an electrolyte base solution is added to copper tellurium slag, stirred and filtered to obtain an electrolyte and a filter residue. The electrolyte is electrolyzed in a constant-temperature heated electrolytic cell using a DC power supply at a constant voltage for 2-8 hours. The product is collected, cleaned and dried to obtain elemental copper and tellurium.
[0048] This invention achieves simultaneous and efficient extraction of copper at the cathode and tellurium at the anode by directly preparing an electrolyte solution from dissolved copper-tellurium slag and then electrolyzing it. This method is characterized by its simple process, low investment, and minimal environmental pollution. The purity of the obtained copper and tellurium is ≥99.9%, and the direct recovery rate is ≥99%.
[0049] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments thereof, but they should not be construed as limiting the scope of protection of the present invention.
[0050] Example 1
[0051] An electrochemical metallurgical method for extracting copper and tellurium from copper-tellurium slag includes the following steps:
[0052] Using 99.9% pure copper tellurium slag raw material (total impurities ≤0.1wt%), after crushing, particle size D is obtained. 90 Powder with a particle size of 85μm is available for use;
[0053] The electrolyte base solution is composed of a quaternary ammonium salt (choline chloride), an amide-containing compound (urea), and a conductive salt (sodium chloride) in a mass ratio of 1:1.5. The molar ratio of the quaternary ammonium salt to the conductive salt is 1:0.25. The selected quaternary ammonium salt, amide-containing compound, and conductive salt are dehydrated and dried at 50 Pa vacuum and 80 °C for 24 h, and then electromagnetically stirred at 350 rpm for 36 h at a constant temperature of 75 °C to form a homogeneous and transparent electrolyte base solution (conductivity 12.3 mS / cm).
[0054] Copper tellurium slag powder was added to the above electrolyte base at a solid-liquid ratio of 1:20 (g / mL). The mixture was dehydrated and dried for 2.5 h under a vacuum of 40 Pa and a temperature of 75 °C. Then, it was continuously stirred and activated at 80 °C and 400 rpm for 3 h. After filtration, the filter residue was removed to obtain a phase-stable electrolyte with a conductivity fluctuation of <0.8% / h.
[0055] The electrolytic cell is equipped with a polished titanium plate cathode (effective area 100 cm²). 2 ) and porous graphite anode (effective area 100cm²) 2 Porosity 15%, electrode spacing 3cm, constant temperature control throughout 75±1℃;
[0056] Electrolysis was performed at a constant voltage of 1.2V for 4 hours, with a cathode current density of 210A / m. 2Anode current density 205 A / m 2 After electrolysis, copper deposited at the cathode and tellurium deposited at the anode were directly obtained. They were placed in an antioxidant solution (ascorbic acid as the antioxidant, water as the solvent, and the mass concentration of the antioxidant was 1.0%) and ultrasonically washed for 20 min with an ultrasonic power of 350 W. They were then vacuum filtered under a vacuum of 0.09 MPa and finally vacuum dried for 6 h under a vacuum of 70 Pa and a temperature of 60 °C to obtain copper powder and tellurium crystals.
[0057] ICP-MS testing showed that the purity of the cathode copper reached 99.992%, the purity of the anode tellurium reached 99.983%, and the direct recovery rate was 99.2%.
[0058] Example 2
[0059] An electrochemical metallurgical method for extracting copper and tellurium from copper-tellurium slag includes the following steps:
[0060] Using 99.5% pure copper tellurium slag raw material (total impurities ≤0.5wt%), after crushing, particle size D is obtained. 90 Powder with a particle size of 75μm is available for use;
[0061] The electrolyte base solution is composed of conductive salt (potassium chloride) and nitrogen-containing organic matter (urea) in a molar ratio of 1:2. The selected conductive salt and nitrogen-containing organic matter are dehydrated and dried at 30 Pa vacuum and 85 °C for 20 h, and then electromagnetically stirred at 400 rpm for 30 h at a constant temperature of 70 °C to form a homogeneous and transparent electrolyte base solution (conductivity 11.8 mS / cm).
[0062] Copper tellurium slag powder was added to the above electrolyte base at a solid-liquid ratio of 1:18 (g / mL). The mixture was dehydrated and dried for 3 hours under a vacuum of 60 Pa and a temperature of 85 °C. Then, it was continuously stirred and activated at 85 °C and 450 rpm for 2.5 hours. After filtration, the filter residue was removed to obtain a phase-stable electrolyte with a conductivity fluctuation of <0.7% / h.
[0063] The electrolytic cell is equipped with a polished titanium plate cathode (effective area 80cm²). 2 ) and porous graphite anode (effective area 80cm²) 2 Porosity 12%, electrode spacing 2.5cm, constant temperature control throughout 78±1℃;
[0064] Electrolysis was performed at a constant voltage of 1.0V for 3.5 hours, with a cathode current density of 195A / m. 2 Anode current density 190A / m 2After electrolysis, copper deposited at the cathode and tellurium deposited at the anode were directly obtained. They were placed in an antioxidant solution (ascorbic acid as the antioxidant, water as the solvent, and the mass concentration of the antioxidant was 1.5 wt%) and ultrasonically washed for 25 min with an ultrasonic power of 400 W. They were then vacuum filtered under a vacuum of 0.085 MPa and finally vacuum dried for 5.5 h under a vacuum of 60 Pa and a temperature of 55 °C to obtain copper powder and tellurium crystals.
[0065] ICP-MS testing showed that the purity of the cathode copper reached 99.995%, the purity of the anode tellurium reached 99.989%, and the direct recovery rate was 99.5%.
[0066] Example 3
[0067] An electrochemical metallurgical method for extracting copper and tellurium from copper-tellurium slag includes the following steps:
[0068] Using copper tellurium slag raw material with a purity of 99.0% (total impurities ≤ 1.0 wt%), after crushing, particle size D is obtained. 90 Powder with a particle size of 120μm is available for use;
[0069] The electrolyte base solution is composed of a conductive salt (sodium chloride) and a polyhydroxy compound (ethylene glycol) in a molar ratio of 1:2.5. The selected conductive salt and polyhydroxy compound are dehydrated and dried at 80 Pa vacuum and 75 °C for 28 h, and then electromagnetically stirred at 300 rpm for 40 h at a constant temperature of 80 °C to form a homogeneous and transparent electrolyte base solution (conductivity 13.5 mS / cm).
[0070] Copper tellurium slag powder was added to the above electrolyte base at a solid-liquid ratio of 1:22 (g / mL). The mixture was dehydrated and dried for 3.5 h under a vacuum of 70 Pa and a temperature of 80 °C. Then, it was continuously stirred and activated at 380 rpm at 75 °C for 4 h. After filtration, the filter residue was removed to obtain a phase-stable electrolyte with a conductivity fluctuation of <0.9% / h.
[0071] The electrolytic cell is equipped with a polished titanium plate cathode (effective area 120 cm²). 2 ) and porous graphite anode (effective area 120cm²) 2 Porosity 18%, electrode spacing 3.5cm, constant temperature control throughout 72±1℃;
[0072] Electrolysis was performed at a constant voltage of 1.4V for 5 hours, with a cathode current density of 225A / m. 2 Anode current density 220A / m 2After electrolysis, copper deposited at the cathode and tellurium deposited at the anode were directly obtained. They were placed in an antioxidant solution (ascorbic acid as the antioxidant, water as the solvent, and the antioxidant concentration of 0.8 wt%) and ultrasonically washed for 28 min with an ultrasonic power of 300 W. They were then vacuum filtered under a vacuum of 0.095 MPa and finally vacuum dried for 7 h under a vacuum of 90 Pa and a temperature of 65 °C to obtain copper powder and tellurium crystals.
[0073] ICP-MS testing showed that the purity of the cathode copper reached 99.987%, the purity of the anode tellurium reached 99.978%, and the direct recovery rate was 99.1%.
[0074] Comparative Example 1
[0075] A conventional metallurgical method for extracting copper and tellurium from copper-tellurium slag includes the following steps:
[0076] The raw material is copper tellurium slag with a purity of 99.9% (total impurities ≤ 0.1 wt%), crushed to a particle size D. 90 =100μm, 400mL of distilled water and 280mL of concentrated sulfuric acid were added to a 2L glass reactor to prepare a sulfuric acid leachate (initial acidity approximately 250g / L). 200g of crushed raw material was added, and the temperature was maintained at 90℃. Hydrogen peroxide was added as an oxidant at 1.3 times the theoretical amount, and the reaction was continuously stirred for 3 hours. After the reaction, the solution was grass-green. The leachate (approximately 1.2L in volume, containing Cu) was obtained through vacuum filtration with qualitative filter paper. 2+ 36.5g / L, Te 4+ 33.4 g / L) and leaching residue containing precious metals (residue rate 1.2%);
[0077] The leachate was transferred to an electrolytic cell, and sulfuric acid was added to adjust the acidity to 200 g / L. A lead plate was used as the anode and a stainless steel plate as the cathode (both with an effective area of 100 cm²). 2 The electrolysis was performed under constant voltage conditions, with an electrode spacing of 15 mm, a cell voltage of 2.0 V, and a temperature of 35 °C, until Te was dissolved in the solution. 4+ The electrolysis process was terminated when the concentration dropped to 5 g / L, and black tellurium powder was deposited at the cathode. ICP-MS analysis showed that the tellurium powder purity was 95.5%, with copper (3.2 wt%) and trace lead (0.3 wt%) as the main impurities, and a direct recovery rate of 88%. Residual copper in the electrolyte residue was recovered by zinc powder replacement, and the filtrate after replacement was returned to the copper electrolysis system.
[0078] Through comparative verification, the method of this application achieves three breakthroughs in the field of copper tellurium slag resource utilization: It constructs a novel electrolyte system that simultaneously completes the deposition of high-purity copper at the cathode and the precipitation of high-purity tellurium at the anode through one-step electrolysis, significantly simplifying the traditional multi-step separation process; the entire process produces no harmful gas emissions or chemical pollutants, and the electrolyte can be recycled, fundamentally eliminating the burden of waste treatment; the electrolysis voltage is significantly reduced, driving energy consumption is optimized year-on-year, and pretreatment steps such as pyrometallurgical smelting and hydrometallurgical leaching are reduced. Through technological innovation (one-step electrolysis simultaneous separation + green electrolyte), the production system is completely restructured, eliminating high-cost modules (pyrometallurgical / hydrometallurgical pretreatment, multi-step separation, and waste treatment), fundamentally changing the cost structure and significantly reducing the total cost.
[0079] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.
Claims
1. An electrochemical metallurgical process for the extraction of copper and tellurium from copper tellurium dross, characterized in that, The method comprises the following steps: The powder of copper-tellurium slag is mixed with electrolyte base solution, and the obtained electrolyte is subjected to constant voltage electrolysis treatment, so that reduction reaction occurs on the surface of the cathode to generate elemental copper, and oxidation reaction occurs on the surface of the anode to generate elemental tellurium, thereby obtaining cathode deposited copper and anode precipitated tellurium, respectively; The electrolyte base solution comprises a hydrogen bond donor, a hydrogen bond acceptor and a conductive salt.
2. The electrochemical metallization process according to claim 1, characterized in that The hydrogen bond donor comprises an organic hydrogen bond donor and / or an inorganic hydrogen bond donor; the organic hydrogen bond donor comprises one or more of alcohol compounds, carboxylic acid compounds, quaternary ammonium salt organic compounds, primary amines, secondary amines, amide compounds and phenolic compounds; and the inorganic hydrogen bond donor comprises one or more of water, ammonia, hydrogen fluoride and inorganic acids.
3. The electrochemical metallization process of claim 1, wherein, The hydrogen bond acceptor comprises an organic hydrogen bond acceptor and / or an inorganic hydrogen bond acceptor; the organic hydrogen bond acceptor comprises one or more of alcohol compounds, ether compounds, aldehyde compounds, ketone compounds, amide organic compounds, organic acids, ester compounds and tertiary amine organic compounds; and the inorganic hydrogen bond acceptor comprises one or more of water, ammonia, hydrogen fluoride, inorganic substances containing halide anions, inorganic substances containing cyanide ions and inorganic substances containing oxygen anions.
4. The electrochemical metallization process of claim 1, wherein, The conductive salt comprises one or more of sodium salts, potassium salts and ammonium salts.
5. The electrochemical metallizing process according to any one of claims 1 to 4, characterized in that, When the hydrogen bond donor and the hydrogen bond acceptor are different substances, the mass ratio of the hydrogen bond donor to the hydrogen bond acceptor is 1:0.5-4, and the molar ratio of the hydrogen bond donor to the conductive salt is 1:0.1-0.5; when the hydrogen bond donor and the hydrogen bond acceptor are the same substance, the molar ratio of the hydrogen bond donor to the conductive salt is 1.5-4:
1.
6. The electrochemical metallization process of claim 1, wherein, The voltage of the constant voltage electrolysis treatment is 0.5-1.5 V, and the time is 2-8 h.
7. The electrochemical metallization process of claim 1, wherein, The distance between the anode and the cathode is 2-5 cm.
8. The electrochemical metallization process of claim 1, wherein, During the constant voltage electrolysis treatment, the temperature of the electrolyte is maintained at 50-80 °C.
9. The electrochemical metallization process of claim 1, wherein, The cathode has a current density of 180 to 240 A / m 2 .
10. The electrochemical metallization process of claim 1, wherein, The current density of the anode is 180-240 A / m 2 .