ELECTROCHEMICAL METALLURGICAL PROCESS FOR EXTRACTING METALS AND SULFUR FROM METALLIC SULFIDES

Abstract

This invention presents an electrochemical metallurgical technique for extracting metals and sulfur from metal sulfides, offering an adjustable composition and mechanical properties during electrode preparation. The metal sulfide anode, submerged in an electrolyte with a cathode made of materials like titanium, copper, stainless steel, lead, zinc, aluminum or graphite, undergoes electrolysis. This process oxidizes sulfur in the metal sulfide to the anode and releases metal ions into the electrolyte, where they're reduced at the cathode. The method yields metal at the cathode and sulfur at the anode, with minimal environmental impact, low investment, and straightforward process.

Claims

1. An electrochemical metallurgical process for extracting metals and sulfur from metal sulfides, characterized by the following steps: (1) Metal sulfide is transformed into an electrode, known as a metal sulfide electrode; (2) The metal sulfide electrode serves as the anode, alongside the insertion of both anode and cathode into the electrolyte at intervals to establish an electrode array for electrolysis, during this process, the sulfur element within the metal sulfide undergoes oxidation and is absorbed in the form of sulfur onto the anode, simultaneously, metal ions migrate into the electrolyte, initiating reduction reactions on the cathode surface, resulting in the formation of metal elements, cathode materials may include titanium, copper, stainless steel, lead, zinc, aluminum, or graphite.

2. According to the electrochemical metallurgical method for extracting metal and sulfur from metal sulfide as described in claim 1, it is distinguished by the adjustment of metal sulfide composition through the addition of elements during the preparation phase, as well as the modification of mechanical properties by incorporating enhancers, these additional elements may include one or more of copper, manganese, cobalt, sulfur, molybdenum, tin, bismuth, lead, zinc, selenium, antimony, tellurium, cadmium, and the reinforcing agent is carbon fiber, stainless steel fiber, copper fiber or lead fiber; Metal sulfide can exist as a pure substance or a mixture, pure substances encompass various compounds, including but not limited to lithium sulfide, sodium sulfide, magnesium sulfide, aluminum sulfide, potassium sulfide, calcium sulfide, manganese sulfide, iron sulfide, ferrous sulfide, cobalt sulfide, copper sulfide, cuprous sulfide, zinc sulfide, molybdenum sulfide, silver sulfide, cadmium sulfide, tin sulfide, antimony sulfide, lead sulfide, and bismuth sulfide; Mixtures of metal sulfides include natural sulfide concentrates, metallurgical intermediates, or by-products, examples of natural sulfide concentrates consist of, but are not limited to, pyrite, green vanadite, chalcopyrite, bornite, chalcocite, cuprite, fahlerite, arsenophenite, cobaltite, quartzite, wolframite, sulfotin, tetrahedrite, columnite, sulfotinite, antiantimonite, disulfide tin, trapezite, manganese sulfite, and pyroxene. Additionally, mixtures may comprise metallurgical intermediates or by-products such as copper matte, cobalt matte, lead matte, antimony matte, iron matte, copper matte, and bismuth matte.

3. Claim 2's electrochemical metallurgical method for extracting metals and sulfur from metal sulfides is characterized by employing various preparation methods for metal sulfide electrodes, these methods include thermal spraying, hot plating, physical vapor deposition (such as vacuum evaporation and magnetron sputtering), chemical vapor deposition, casting (such as sand casting and solid casting), and powder metallurgy (such as pressing and centrifugal forming).

4. Electrochemical metallurgical method for extracting metals and sulfur from metal sulfides in accordance with claim 3, characterized by: Thermal spraying method: the use of heat sources to melt the metal sulfide powder, by controlling the pressure of the protective gas is sprayed to the surface of the substrate to form a metal sulfide electrode, where the pressure is 1?20 MPa; Vacuum evaporation method: the metal sulfide powder is added to the evaporation container, adjust the vacuum degree, heating the powder deposited on the substrate to obtain the metal sulfide electrode, where the vacuum degree is 10.sup.?6?10.sup.2 Pa; In the magnetron sputtering method, the substrate is linked to the anode while the metal sulfide target is connected to the cathode, the vacuum is reduced to below 10.sup.?3 Pa, followed by filling with argon to maintain the vacuum within the range of 10.sup.?2 to 10 Pa, power is then activated, leading to the deposition of the metal sulfide electrode through magnetron sputtering; The material composition of the sulfide target encompasses, but is not restricted to, magnesium sulfide, zinc sulfide, calcium sulfide, aluminum sulfide, and cadmium sulfide; In the chemical vapor deposition method, the metal powder and sulfur powder are placed in an evaporator within a chemical vapor deposition chamber filled with protective gas, upon heating, the metal and sulfur powders evaporate and react in the chamber, depositing onto the substrate and forming the metal sulfide electrode; In the hot plating method, the metal sulfide is melted within a melting furnace, and the substrate is immersed into the molten metal sulfide for hot plating, resulting in the formation of the metal sulfide electrode; The sand casting method involves preparing a cavity using mold sand and core sand, the metal sulfide is melted in a furnace, poured into the prepared cavity, and left to cool and solidify, the metal sulfide electrode is obtained through sand removal and cleaning; For the solid casting method, foam is buried in sand, and the metal sulfide is melted in a furnace, the molten metal sulfide replaces the foam, and upon cooling and solidification, the metal sulfide electrode is obtained through sand removal and cleaning; In the press method, metal sulfide powder and forming agent are mixed and pressed into a mold to obtain a green form, the green form is then sintered to obtain the metal sulfide electrode, pressing parameters include a molding pressure of 10 to 30 MPa, pressing speed of 1 to 15 mm/s, and pressure holding time of 0.1 to 10 hours; Similarly, in the centrifugal forming method, metal sulfide powder and forming agent are mixed and centrifugally formed in a mold to obtain a green form, the green form is then sintered to obtain the metal sulfide electrode, centrifugal forming speed typically ranges from 500 to 4500 r/min; Sintering is typically conducted in a protective gas atmosphere, with temperatures ranging from 400 to 1200? C. and sintering times from 0.1 to 10 hours, protective gases used include but are not limited to argon, nitrogen, and carbon dioxide.

5. Claim 4's electrochemical metallurgical method for extracting metals and sulfur from metal sulfides is distinguished by the average particle size of the metal sulfide powder, which ranges from 1 nm to 1 mm.

6. In accordance with claim 4, the electrochemical metallurgical method for extracting metals and sulfur from metal sulfides is characterized by the substrate material, which can be metal, graphite, or composite material: Metal substrate materials include, but are not limited to, copper, zinc, lead, tin, aluminum, titanium, stainless steel, aluminum alloy, lead alloy, titanium alloy, manganese alloy, copper alloy, zinc alloy, tin alloy, tungsten alloy, and molybdenum alloy, composite substrate materials include, but are not limited to, conductive silicone rubber, conductive plastic, and conductive fiber.

7. As per claim 4, the electrochemical metallurgical method for extracting metals and sulfur from metal sulfides is distinguished by the dimensions of the substrate: The longitudinal cross-section area ranges from 1 cm.sup.2 to 10 m.sup.2, while the thickness or radius ranges from 1 to 2000 mm, additionally, the adhesion thickness of metal sulfide on the substrate ranges from 1 to 30 mm.

8. According to claim 4, the electrochemical metallurgical method for extracting metals and sulfur from metal sulfides is characterized by the forming agent, which includes but is not limited to starch, sulfur, molybdenum disulfide, graphite powder, paraffin wax, and rosin.

9. The electrochemical metallurgical method for extracting metals and sulfur from metal sulfides described in claim 1 is characterized by the composition of the electrolyte, which contains solvents, electrolytes, oxidants, and additives, the solvent can be water or an organic solvent, where the organic solvent includes one or more of anhydrous acetic acid, methanol, acetonitrile, and tetrahydrofuran; The electrolyte utilized in the electrochemical metallurgical method for extracting metals and sulfur from metal sulfides, as described in claim 1, includes sulfuric acid, perchloric acid, hydrobromic acid, hydrochloric acid, silofluoric acid, carbonic acid, phosphoric acid, nitrite, hydroiodic acid, tartaric acid, oxalic acid, citric acid, hydrofluoric acid, acetic acid, hypochloric acid, boric acid, bismuth chloride, bismuth sulfate, bismuth fluorosilicate, sodium chloride, lithium perchlorate, magnesium perchlorate, molybdenum chloride, sodium sulfate, aluminum chloride, sodium nitrate, molybdenum sulfate, copper chloride, copper sulfate, lead chloride, lead fluosilicate, cadmium chloride, antimony chloride, silver nitrate, stannous sulfate, zinc chloride, sodium acetate, sodium nitrite, sodium borate, zinc sulfate, manganese chloride, cobalt chloride, ammonium sulfate, cobalt sulfate, sodium oxalate, sodium tetrafluoroborate, sodium sulfide, sodium hydroxide, calcium sulfonate, potassium methanol, aluminum stearate, ammonium chloride, tetraethyl tetrafluoroborate, and ammonium tetrafluoroborate; The content of the electrolyte in the solution ranges from 0.1 to 1000 g/L; The oxidizer employed in the process includes ferric chloride, potassium permanganate, oxygen, hydrogen peroxide, fluorine, ozone, ferric sulfate, chlorine, bromine vapor, sodium dichromate, either singly or in combination, when the oxidizer is a gas, the flow rate ranges from 0.01 to 5 L/min; when it is not a gas, the content of the oxidizer in the electrolyte ranges from 0.1 to 1000 g/L; Various additives are incorporated into the electrolyte, such as gelatin, bone glue, leather glue, thiourea, ?-phenol, powder glue, sodium lignosulfonate, carbolic acid, tannin, diphenylamine, phenol, borax, and casein, The content of additives in the electrolyte ranges from 0 to 1000 g/L.

10. The electrochemical metallurgical method for extracting metals and sulfur from metal sulfides, in accordance with claim 1, is characterized by specific operational parameters: The distance between the plates ranges from 1 to 1000 mm, the voltage applied to the tank ranges from 0.1 to 10 V, the control range of current density is 1 to 1000 A/m.sup.2, the temperature of the electrolyte ranges from 25 to 100? C., the circulation speed ranges from 1 to 100 L/min, and the anode residue rate ranges from 1% to 25%.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0101] In order to more clearly illustrate technical solutions of embodiments of the invention or the prior art, drawings will be used in the description of embodiments or the prior art will be given a brief description below. Apparently, the drawings in the following description only are some of embodiments of the invention, the ordinary skill in the art can obtain other drawings according to these illustrated drawings without creative effort.

[0102] FIG. 1 shows the typical polarization curves of N-type semiconductors and P-type semiconductors;

[0103] FIG. 2 shows the cyclic voltammetry curve of embodiment 13 metal sulfide in electrolyte;

[0104] FIG. 3 shows the morphology of cathode product copper in Embodiment 13 under scanning electron microscope;

[0105] FIG. 4 is the Raman diagram of anode product of Embodiment 13 copper;

[0106] FIG. 5 is the XRD pattern of anode product sulfur in Embodiment 13.

[0107] A method for improving liquid crystal rotation obstacle according to the first embodiment of the invention specifically includes steps as follows.

[0108] Step one: The metal sulfide is transformed into an electrode, referred to as a metal sulfide electrode. Throughout the preparation process, the composition of the metal sulfide can be tailored by incorporating additional elements, while the mechanical properties can be enhanced by introducing reinforcing agents. Potential elements that can be added include copper, manganese, cobalt, sulfur, molybdenum, tin, bismuth, lead, zinc, selenium, antimony, tellurium, and cadmium. The mass of the added element ranges from 0% to 50% of the mass of the metal sulfide. Additionally, reinforcing agents such as carbon fiber, stainless steel fiber, copper fiber, or lead fiber can be introduced, with the mass of the reinforcing agent ranging from 0% to 10% of the mass of the metal sulfide.

[0109] Preferably, the additive element is one or more kinds of copper, sulfur, tin, and the additive element mass is 5% to 15% of the mass of metal sulfide;

[0110] Preferably, the reinforcing agent is carbon fiber or stainless steel fiber, and the reinforcing agent quality is 0.5%?1% of the quality of metal sulfide;

[0111] Metal sulfide primarily behaves as a semiconductor, with N-type semiconductor characteristics when used as the anode. However, its conductivity at the anode is often limited due to intrinsic properties. To facilitate smooth electrolysis at the anode, adjustments are made to its composition to transform it into a P-type semiconductor. When utilizing natural sulfide concentrates, metallurgical intermediates, or by-products as the anode, their high impurity content and poor electrical conductivity pose challenges. To ensure smooth electrolysis, the content of elements within them is adjusted to enhance their electrical conductivity. Moreover, metal sulfides tend to be brittle, leading to electrode breakage during the electrolytic process. Adjustments are made to the elemental proportions or additional materials, such as carbon fiber, are incorporated during the preparation process to augment its mechanical strength.

[0112] Step two: The metal sulfide electrode anode, along with the anode and cathode, is placed into the electrolyte to establish an electrode array. Parameters such as the distance between electrodes, tank voltage, current density, electrolyte temperature, and cycling speed are adjusted for the electrolysis process. During this process, the sulfur element within the metal sulfide is oxidized and adsorbed in elemental sulfur form at the anode, while metal ions migrate into the electrolyte. Reduction reactions occur on the surface of the cathode, resulting in the production of pure metal substances. The products from the anode and cathode are then stripped. The cathode materials may include titanium, copper, stainless steel, lead, zinc, aluminum, or graphite. The vertical section shape of the cathode corresponds to that of the anode, while the longitudinal section shape may vary, such as square, round, triangle, trapezoid, pentagon, or fan. The longitudinal section area of the cathode typically ranges from 1 cm.sup.2 to 10 m.sup.2. The thickness or radius of the cathode ranges from 0.2 mm to 3000 mm.

[0113] Parameters such as the distance between electrodes, tank voltage, current density, electrolyte temperature, and cycling speed are adjusted for the electrolysis process. During this process, the sulfur element within the metal sulfide is oxidized and adsorbed in elemental sulfur form at the anode, while metal ions migrate into the electrolyte. Reduction reactions occur on the surface of the cathode, resulting in the production of pure metal substances. The products from the anode and cathode are then stripped. The cathode materials may include titanium, copper, stainless steel, lead, zinc, aluminum, or graphite. The vertical section shape of the cathode corresponds to that of the anode, while the longitudinal section shape may vary, such as square, round, triangle, trapezoid, pentagon, or fan. The longitudinal section area of the cathode typically ranges from 1 cm.sup.2 to 10 m.sup.2. The thickness or radius of the cathode ranges from 0.2 mm to 3000 mm.

[0114] Preferably, the cathode is titanium, copper, stainless steel, lead or aluminum, the longitudinal section shape is square, the longitudinal section area is 200 cm.sup.2?0.6 m.sup.2, the thickness of the cathode is 1.5?6 mm;

[0115] The number n of the anode ranges from 1 to 1000, and the number of cathodes is n+1; Preferably, the number of anodes n ranges from 35 to 350;

[0116] The metal sulfide can exist in a pure form or as a mixture, encompassing various compounds such as lithium sulfide, sodium sulfide, magnesium sulfide, aluminum sulfide, potassium sulfide, calcium sulfide, manganese sulfide, iron sulfide, ferrous sulfide, cobalt sulfide, copper sulfide, cuprous sulfide, zinc sulfide, molybdenum sulfide, silver sulfide, cadmium sulfide, tin sulfide, antimony sulfide, lead sulfide, and bismuth sulfide. Mixtures of metal sulfides may include natural sulfide concentrates, metallurgical intermediate products, or by-products. Examples of natural sulfide concentrates comprise, but are not limited to, pyrite, green vanadite, chalcopyrite, bornite, chalcocite, cuprite, fahlerite, arsenophenite, cobaltite, quartzite, wolframite, sulfotin, tetrahedrite, columnite, sulfotinite, antiantimonite, disulfide tin, trapezite, manganese sulfite, and pyroxene. Additionally, metallurgical intermediate products or by-products may include copper matte, cobalt matte, lead matte, antimony matte, iron matte, copper matte, and bismuth matte.

[0117] Preferably, metal sulfides: sodium sulfide, tin sulfide, aluminum sulfide, antimony sulfide, bismuthite, manganese sulfide, sphalerite, galena, copper matte.

[0118] The preparation of the metal sulfide electrode can be accomplished through various methods, including the thermal spraying method, hot plating method, physical vapor deposition method, chemical vapor deposition method, casting method, or powder metallurgy method. Specifically, the physical vapor deposition method encompasses techniques such as vacuum evaporation method and magnetron sputtering method, while the casting method includes approaches like sand casting method and solid casting method. Additionally, the powder metallurgy method involves techniques like the press method and centrifugal forming method.

[0119] Preferably, the thermal spraying method involves melting the metal sulfide powder using a heat source and forming the metal sulfide electrode on the substrate's surface by controlling the pressure of the protective gas. The pressure typically ranges from 1 to 20 MPa. Plasma arc heating is a preferred heat source, and the pressure is preferably maintained between 5 to 15 MPa for optimal results.

[0120] In the vacuum evaporation method, the metal sulfide powder is introduced into the evaporation container, and the vacuum is adjusted. The powder is then heated to deposit metal sulfide electrodes onto the substrate. The vacuum level typically ranges from 10.sup.?6 to 10.sup.2 Pa. Resistance heating is the preferred heating method for this process.

[0121] In the magnetron sputtering method, the substrate is connected to the anode, while the metal sulfide target is connected to the cathode. The vacuum is pumped below 10.sup.?3 Pa, and argon gas is introduced to maintain the vacuum within the range of 10.sup.?2 to 10 Pa. Power is then applied to obtain metal sulfide electrodes through magnetron sputtering. The material of the sulfide target may include magnesium sulfide, zinc sulfide, calcium sulfide, aluminum sulfide, or cadmium sulfide, with aluminum sulfide being preferred.

[0122] In the chemical vapor deposition method, a protective gas is filled in the chemical vapor deposition setting. Metal powder and sulfur powder are placed in the evaporator and heated to evaporate into the reaction chamber, where they react and deposit on the substrate to form the metal sulfide electrode. Argon gas is preferred as the protective gas in this method.

[0123] The hot plating method involves melting the metal sulfide in a melting furnace, and the substrate is then immersed in the liquid metal sulfide for hot plating to produce the metal sulfide electrode.

[0124] In the sand casting method, a cavity is prepared using mold sand and core sand. The molten metal sulfide is poured into the cavity from a melting furnace, followed by cooling and solidification. The metal sulfide electrode is obtained through sand cleaning.

[0125] Similarly, in the solid casting method, foam is buried in sand, and the metal sulfide is melted in a furnace. The molten metal sulfide replaces the foam, and upon cooling and solidification, the metal sulfide electrode is obtained by removing the sand.

[0126] When employing the hot plating method, sand casting method, or solid casting method, it is preferable to use a vacuum induction furnace, vacuum arc furnace, induction furnace, or reverberatory furnace.

[0127] In the press method, metal sulfide powder and forming agent are mixed evenly into a mold, pressed to form a green body, and then sintered to obtain the metal sulfide electrode. The pressing molding pressure typically ranges from 10 to 30 MPa, with a pressing speed of 1 to 15 mm/s and a pressure holding time of 0.1 to 10 hours. Preferred parameters include a pressure of 20 to 25 MPa, a pressing speed of 10 to 12 mm/s, and a holding time of 1.5 to 2 hours.

[0128] In the centrifugal forming method, the metal sulfide powder and forming agent are uniformly mixed and placed into a mold. Centrifugal force is then applied to the mold to achieve shaping, resulting in a green body. This green body is subsequently sintered to obtain the metal sulfide electrode. The centrifugal forming speed typically ranges from 500 to 4500 revolutions per minute (r/min), with preferred speeds falling between 3000 and 3500 r/min.

[0129] During sintering, the atmosphere is maintained as a protective gas environment. The sintering temperature typically ranges from 400 to 1200 degrees Celsius (? C.), with preferred temperatures falling between 750 and 1200? C. The duration of sintering ranges from 0.1 to 10 hours, with preferred sintering times being 1.5 to 2 hours.

[0130] Protective gases include but are not limited to argon, nitrogen, carbon dioxide;

[0131] The average particle size of the metal sulfide powder is 1 nm?1 mm.

[0132] The substrate material for the metal sulfide electrode can be chosen from metals, graphite, or composite materials. For metal substrates, options include but are not limited to copper, zinc, lead, tin, aluminum, titanium, stainless steel, aluminum alloy, lead alloy, titanium alloy, manganese alloy, copper alloy, zinc alloy, tin alloy, tungsten alloy, and molybdenum alloy. Composite substrates can include conductive materials such as conductive silicone rubber, conductive plastic, and conductive fiber. Preferred substrate materials include titanium, stainless steel, titanium alloy, lead alloy, or conductive fiber due to their suitability for electrochemical processes and their ability to withstand harsh conditions during electrolysis.

[0133] The substrate can feature various longitudinal section shapes such as square, circular, triangular, palisade, or porous. Its longitudinal section area typically ranges from 1 cm.sup.2 to 10 m.sup.2. with a thickness or radius of 1 mm to 2000 mm. The adhesion thickness of the metal sulfide on the substrate usually falls between 1 mm to 30 mm.

[0134] Preferred longitudinal section shapes for the substrate include square, circular, triangular, palisade, or porous, with a longitudinal section area preferably ranging from 180 cm.sup.2 to 0.35 m.sup.2 and a thickness or radius ranging from 1 mm to 3 mm. The adhesion thickness of the metal sulfide on the substrate is preferably 3 mm to 20 mm.

[0135] For metal sulfide electrodes prepared by casting or powder metallurgy methods, they typically take the shape of a cuboid with two ears. The length can range from 100 mm to 2500 mm, the width from 100 mm to 2000 mm, and the thickness from 1 mm to 100 mm. Preferably, the length is between 800 mm to 1200 mm, the width is between 500 mm to 700 mm, and the thickness is between 45 mm to 60 mm.

[0136] Forming agents used in the process include but are not limited to starch, sulfur, molybdenum disulfide, graphite powder, paraffin wax, and rosin. Among these, sulfur or graphite powder is preferred.

[0137] The electrolyte contains a solvent, electrolyte, oxidizer, additive, the solvent is water or organic solvent, organic solvent is anhydrous acetic acid, methanol, acetonitrile, tetrahydrofuran one or more; Preferably, the organic solvent is one or more of methanol, acetonitrile, tetrahydrofuran;

[0138] The electrolytes used in the process include sulfuric acid, perchloric acid, hydrobromic acid, hydrochloric acid, silofluoric acid, carbonic acid, phosphoric acid, nitrite, hydroiodic acid, tartaric acid, oxalic acid, citric acid, hydrofluoric acid, acetic acid, hypochloric acid, boric acid, bismuth chloride, bismuth sulfate, bismuth fluorosilicate, sodium chloride, lithium perchlorate, magnesium perchlorate, molybdenum chloride, sodium sulfate, aluminum chloride, sodium nitrate, molybdenum sulfate, copper chloride, copper sulfate, lead chloride, lead fluosilicate, cadmium chloride, antimony chloride, silver nitrate, stannous sulfate, zinc chloride, sodium acetate, sodium nitrite, sodium borate, zinc sulfate, manganese chloride, cobalt chloride, ammonium sulfate, cobalt sulfate, sodium oxalate, sodium tetrafluoroborate, sodium sulfide, sodium hydroxide, calcium sulfonate, potassium methanol, aluminum stearate, ammonium chloride, tetraethyl tetrafluoroborate, and ammonium tetrafluoroborate. The concentration of the electrolyte in the solution typically ranges from 0.1 g/L to 1000 g/L.

[0139] Preferably, the electrolyte comprises one or more of sulfuric acid, hydrochloric acid, silicofluoric acid, sodium tetrafluoroborate, sodium chloride, stannous sulfate, aluminum chloride, ammonium chloride, sodium sulfide, sodium hydroxide, bismuth chloride, bismuth silicofluorate, manganese chloride, ammonium sulfate, zinc sulfate, zinc chloride, lead chloride, lead fluorosilicate, copper sulfate, and copper chloride. The concentration of the electrolyte typically ranges from 10 g/L to 240 g/L.

[0140] As for the oxidizer, it can be ferric chloride, potassium permanganate, oxygen, hydrogen peroxide, fluorine, ozone, ferric sulfate, chlorine, bromine vapor, sodium dichromate, or a combination thereof. The oxidizer can either be in gas form or non-gas form, with a flow rate of 0.01 L/min to 5 L/min for gas and a concentration of 0.1 g/L to 1000 g/L for non-gas oxidizers.

[0141] Preferably, the oxidizer includes sodium perchlorate, ferric chloride, potassium permanganate, oxygen, hydrogen peroxide, ferric sulfate, or sodium hypochlorite. When using oxygen as the oxidizer, the flow rate ranges from 0.1 L/min to 0.15 L/min, and when using a non-gas oxidizer, the concentration in the electrolyte ranges from 10 g/L to 45 g/L.

[0142] Additionally, additives such as gelatin, bone glue, leather glue, thiourea, ?-phenol, powder glue, sodium lignosulfonate, carbolic acid, tannin, diphenylamine, phenol, or borax can be used. The content of additives in the electrolyte ranges from 0 g/L to 1000 g/L. If the additive content is 0, then the electrolyte does not contain any additives.

[0143] Preferably, the additive is gelatin, bone glue, thiourea, ?-phenol, cresol sulfonic acid, sodium lignosulfonate, casein one or more.

[0144] When the electrolyte contains additives, the preferred content of additives is 8?30 mg/L;

[0145] The distance between the same plate is 1?1000 mm, the tank voltage range is 0.1?10V, the current density control range is 1?1000 A/m.sup.2, the electrolyte temperature range is 25?100? C., the cycle speed range is 1?100 L/min, the anode residue rate is 1%? 25%;

[0146] Preferably, the distance between the same plate is 18?120 mm, the tank voltage range is 1.5?3.5V, the current density control range is 150?450 A/m.sup.2, the electrolyte temperature range is 25?60? C., the cycle speed range is 5?30 L/min, the anode residue rate is 5%?20%;

[0147] The method of stripping the product is ultrasonic method, mechanical method or manual method.

[0148] The principle of extracting metals and sulfur from metal sulfides relies on semiconductor electrochemistry. From a physical perspective, semiconductor behavior determines the electrochemical reactions occurring at the electrode interfaces. In semiconductor electrochemistry, when a semiconductor is of N-type, the charge carriers are free electrons. When the cathode is polarized, the abundance of free electrons in the conduction band increases, facilitating reaction occurrence. However, when the anode is polarized in an N-type semiconductor, few subsequent holes in the valence band participate in the reaction at the semiconductor/electrolyte interface. Instead, many subsequent electrons in the conduction band are repelled and flow away from the interface. As polarization increases, the rate (ic) of electrons participating in the cathode reaction increases. However, the electron concentration at the semiconductor/electrolyte interface can become even lower than the hole concentration. This phenomenon leads to a self-limiting effect on the current, where the current reaches a saturated value (is). Therefore, in electrolysis involving semiconductor anodes, N-type semiconductors are not suitable due to this self-limiting effect. Conversely, when cathode polarization occurs in the valence band of P-type semiconductors, a similar self-limiting effect and saturation current can be observed. However, when a P-type semiconductor electrode is oxidized, there is no self-limiting effect, allowing smooth anodic polarization reaction in the valence band. Hence, in the electrolytic process, P-type semiconductors are more suitable for use as anodes.

[0149] The typical polarization curves of N-type and P-type semiconductors illustrate these behaviors. In FIG. 1, iv indicates the rate at which holes in the valence band participate in the electrode reaction.

[0150] From a chemical point of view, when oxidizing agents (such as hydrogen peroxide) are higher than S.sup.2? in metal sulfide (Me.sub.2Sx), the oxidizing agent can oxidize S.sup.2? to sulfur, the relevant reaction equation is (1); At the same time, when the metal sulfide is an anode, a positive voltage is applied, and the anode oxidizes, and the relevant reaction equation is (2); The sulfur element in the metal sulfide is oxidized and adsorbed on the anode plate in the form of sulfur element. As the sulfur element is oxidized, the metal ions enter the electrolyte, and the reduction reaction occurs on the cathode surface to form the metal. The relevant reaction equation is shown in (3).

Me.sub.2S.sub.x+xH.sub.2O.sub.2+2xH+.fwdarw.2Mex++xS+2xH.sub.2O(1)

Me.sub.2Sx-2xe?.fwdarw.2Mex++xS(2)

Mex++xe?.fwdarw.Me(3)