A method for recovering valuable metals by short-process pyrometallurgical zinc smelting

Abstract

The present application provides a method for recovering valuable metals by short-process pyrometallurgical zinc smelting, which comprises the following steps: A mixed material formed by zinc sulfide material and flux reacts with oxygen-rich gas in the oxidation smelting zone of the furnace cavity to carry out the first oxidation desulfurization reaction, obtaining a preliminarily oxidized material and a matte material; The preliminarily oxidized material is subjected to a second oxidation desulfurization reaction in the oxidation smelting zone to form a high-zinc material and a high-cadmium soot; The high-zinc material is reduced in the reduction smelting zone and the volume ratio of CO to CO2 is controlled to be 20-35:1; An iron-containing metal material and zinc vapor are obtained; The zinc vapor is condensed to produce crude zinc, and the crude zinc is rectified to obtain zinc metal. The present application realizes the recovery of zinc metal and other valuable metals in the zinc sulfide material by using a reasonable oxidation and reduction method, and has good social benefits and production economic benefits.

Description

Technical Field

[0001] This application relates to the field of metal reduction and recycling, and particularly to a method for short-process pyrometallurgical zinc smelting to recover valuable metals. Background Art

[0002] Pyrometallurgical zinc smelting has the characteristics of processing complex raw materials and a simple process, and has been widely applied to the smelting of lead and zinc metals. Among them, the pyrometallurgical methods mainly include blast furnace, shaft furnace, and electric furnace processes. Blast furnace zinc smelting can only process lead-zinc mixed ores with a certain lead-zinc ratio, and the raw materials must be sintered before being charged into the furnace. The final slag of the blast furnace contains 5%-7% zinc, and the recovery rates of valuable metals such as zinc are low; for shaft furnace zinc smelting, zinc sulfide materials must be subjected to desulfurization and shaping treatments such as roasting and pelletizing before being charged into the furnace. The requirements for the raw material composition are relatively high, and the stock preparation process is complex. The final slag contains 5%-10% zinc, and the recovery rates of valuable metals such as zinc, copper, gold, and silver are all relatively low; for electric furnace zinc smelting, zinc sulfide materials need to be subjected to desulfurization treatments such as roasting before being charged into the furnace. During the smelting process after being charged into the furnace, the atmosphere and temperature in the furnace need to be controlled. The final slag contains 3%-6% zinc, and the recovery rate of valuable metals is relatively low. Summary of the Invention

[0003] This application aims to solve at least one of the technical problems in the related technologies to some extent. This application proposes a method for short-process pyrometallurgical zinc smelting to recover valuable metals. The method directly adds to the oxidation smelting zone of the zinc smelting furnace, and successively conducts the first oxidation desulfurization reaction and the second oxidation desulfurization reaction to form high-zinc materials and high-cadmium fumes; then, during the reduction process of the high-zinc materials, the volume ratio of CO to CO2 is 20-35:1 to achieve high-temperature reduction, producing iron-containing metal materials and zinc vapor. The zinc vapor is condensed to produce crude zinc, and the crude zinc is rectified to obtain zinc metal, cadmium metal, and lead metal. This application realizes the recovery of zinc metal and other valuable metals in zinc sulfide materials by using reasonable oxidation and reduction methods, and has good social benefits and production economic benefits.

[0004] According to an embodiment of this application, a method for short-process pyrometallurgical zinc smelting to recover valuable metals is proposed, including the following steps:

[0005] A mixed material formed by zinc sulfide materials and fluxes reacts with oxygen-enriched gas in the oxidation smelting zone of the furnace cavity to conduct the first oxidation desulfurization reaction, obtaining preliminarily oxidized materials and copper matte materials;

[0006] The preliminarily oxidized materials are subjected to the second oxidation desulfurization reaction in the oxidation smelting zone to form high-zinc materials and high-cadmium fumes; wherein the temperature of the first oxidation desulfurization reaction is t1, and the oxygen-to-material ratio is OM1; the temperature of the second oxidation desulfurization reaction is t2, and the oxygen-to-material ratio is OM2; 50°C ≤ t2 - t1 ≤ 450°C; 50 Nm 3 / t ≤ OM2 - OM1 ≤ 400 Nm 3 / t;

[0007] Reduce the high-zinc material in the reduction smelting zone and control the volume ratio of CO to CO2 to 20 - 35:1; obtain iron-containing metal material and zinc-containing vapor;

[0008] Condense the zinc-containing vapor to produce crude zinc, and rectify the crude zinc to obtain zinc metal, cadmium metal and lead metal.

[0009] In some embodiments, the particle size of the mixed material is D, where 0.05 mm ≤ D ≤ 5 mm;

[0010] And / or, the mass ratio of the zinc sulfide material to the flux in the mixed material is 5 - 20:1;

[0011] And / or, the flux includes at least one of quartz sand, quicklime and limestone;

[0012] And / or, the temperature of the first oxidation desulfurization reaction is 1100 - 1300 °C, and the oxygen-to-material ratio is 100 - 250 Nm 3 / t;

[0013] And / or, the temperature of the second oxidation desulfurization reaction is 1350 - 1550 °C, and the oxygen-to-material ratio is 300 - 500 Nm 3 / t;

[0014] And / or, the mass percentage content of cadmium element in the high-cadmium soot is greater than 12%.

[0015] In some embodiments, the reduction smelting zone includes a first reduction zone and a second reduction zone;

[0016] The high-zinc material and the first reducing agent are preliminarily reduced in the first reduction zone to obtain a preliminarily reduced material; the preliminarily reduced material is subjected to a deep reduction reaction in the second reduction zone with oxygen-rich gas and carbonaceous reducing agent injected through jet injection.

[0017] In some embodiments, based on the high-zinc material, by mass percentage, the sulfur element content in the high-zinc material is less than 1%, and the Zn element content is 40% - 60%;

[0018] And / or, the first reduction zone is electrically heated for reduction, which uses electrode heat compensation, and the reduction smelting temperature is 1200 - 1300 °C;

[0019] And / or, the first reducing agent includes at least one of coke lumps, crushed coke and anthracite lumps; it is added through the feeding port of the first reduction zone;

[0020] And / or, the molar ratio of carbon element in the first reducing agent to zinc element in the high-zinc material is 0.8 - 1.2:1.

[0021] In some embodiments, the second reduction zone is jet injection combustion reduction, and the reduction smelting temperature is 1350 - 1500 °C;

[0022] And / or, the carbonaceous reducing agent includes coke powder and / or pulverized coal; the molar ratio of carbon element in the carbonaceous reducing agent to zinc element in the high-zinc material is 0.2 - 0.5:1;

[0023] And / or, the injection amount of the oxygen-enriched gas is 0.1 - 0.5 of the total volume of oxygen required for complete combustion of the carbonaceous reducing agent in the second reduction zone.

[0024] In some embodiments, the time for the preliminary reduction and deep reduction reaction of the high-zinc material is 2 - 6 h per furnace charge;

[0025] And / or, the time for the preliminary reduction of the high-zinc material is 1 - 3 h per furnace charge;

[0026] And / or, the time for the deep reduction reaction of the preliminarily reduced material is 1 - 3 h per furnace charge.

[0027] In some embodiments, the heat supplement ratio between the first reduction zone and the second reduction zone is 2 - 5:1.

[0028] In some embodiments, the oxygen concentration of the oxygen-enriched gas is 23 - 99.8%, and the pressure is 0.2 - 0.5 MPa;

[0029] And / or, the oxygen-enriched gas and the carbonaceous reducing agent are injected into the second reduction zone, and the injection amount of the oxygen-enriched gas is 0.1 - 0.5 of the total volume of oxygen required for complete combustion of the carbonaceous reducing agent.

[0030] In some embodiments, during the crude zinc rectification process: first, control the vapor temperature at 900 - 950 °C to separate and recover lead metal; then control the vapor temperature at 500 - 600 °C to obtain refined zinc, and at the same time, enrich cadmium metal, indium metal, and germanium metal to hard zinc;

[0031] And / or, the recovery rate of zinc in the high-zinc material is 97% - 98%, the recovery rate of lead is 97% - 98%, the recovery rate of copper is 90% - 95%, the recovery rate of cadmium is 90% - 95%, the recovery rate of gold is 90% - 95%, the recovery rate of silver is 90% - 95%, the recovery rate of indium is 90% - 95%, and the recovery rate of germanium is 90% - 95%;

[0032] And / or, the purity of the refined zinc > 99.995%.

[0033] In some embodiments, the injection methods in the oxidation smelting zone and the second reduction zone include single side blowing, single bottom blowing, or a combination of side blowing and bottom blowing.

[0034] The zinc sulfide material of the present application does not require complicated preparation and processing. The mixed material has a suitable particle size, is fully contacted with the oxygen-rich gas in the oxidation smelting zone of the furnace chamber, and undergoes the first oxidation desulfurization reaction under low temperature and low oxygen potential conditions to obtain a preliminary oxide material and a copper matte material. The copper matte material is discharged from a siphon port set in the oxidation smelting zone; and the preliminary oxide material continues to undergo deep oxidation desulfurization in the oxidation smelting zone under high temperature and high oxygen potential conditions to form a high-zinc material and high-cadmium smoke. The above-mentioned oxidation desulfurization method of the zinc sulfide material does not require complicated preparation and processing of the zinc sulfide material, and can effectively improve the recovery rate of valuable metals in the zinc sulfide material.

[0035] The high-zinc material of the present application is reduced at high temperature by controlling the volume ratio of CO to CO2 to 20-35:1 during the reduction process, and produces iron-containing metal material and zinc-containing vapor, wherein the iron-containing metal material also includes copper, gold, and silver elements enriched therein to achieve recovery; the zinc element in the high-zinc material is reduced to form zinc-containing vapor, wherein valuable metals such as cadmium, lead, indium, and germanium in the high-zinc material volatilize into the zinc-containing vapor, and the zinc-containing vapor is condensed to produce crude zinc, and the crude zinc is distilled to obtain zinc metal, cadmium metal, and lead metal. The present application achieves the complete reduction of high-zinc materials and the recovery of iron-containing metal materials, while greatly improving the overflow rate of zinc metal, and has good social benefits and production economic benefits.

[0036] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0038] Figure 1 The present invention is a flow chart of a method for recovering valuable metals by short-process pyrometallurgical zinc smelting according to an embodiment of the present application. DETAILED DESCRIPTION

[0039] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be construed as limiting the present application. On the contrary, the present application includes all changes, modifications and equivalents that fall within the spirit and connotation of the appended claims.

[0040] The existing hydrometallurgical zinc smelting technology has a long process flow, complex processes, huge investment, and relatively high energy consumption. Most importantly, a large amount of leaching residue, iron slag, etc. are generated during the hydrometallurgical process, and their output rate exceeds 50%. They all belong to hazardous wastes and need to be treated harmlessly, which causes a large amount of energy consumption and brings new pollution. The existing pyrometallurgical zinc smelting technology generally has high energy consumption, complex batching processes, low direct zinc recovery rate and recovery rate, small single-series production capacity, and cannot meet the requirements of modern large-scale industrial production.

[0041] In the current related technologies, a lead-zinc ore smelting method is mentioned. The lead-zinc ore is melted in an oxidation smelting furnace, and the melt is sent to a power frequency electric heating reduction furnace for reduction. Zinc vapor is condensed with traditional lead rain or zinc rain to obtain crude zinc; or zinc sulfide materials are melted in an oxygen bottom-blown smelting furnace, and the melt is sent to a side-blown reduction furnace for reduction. Zinc vapor is condensed with traditional lead rain or zinc rain to obtain crude zinc; zinc sulfide materials are melted in an oxygen bottom-blown smelting furnace, and then cast into blocks and sent to a blast furnace for reduction. Zinc vapor is condensed with traditional lead rain or zinc rain to obtain crude zinc. The above methods have solved many problems existing in hydrometallurgical zinc smelting. However, compared with the existing pyrometallurgical zinc smelting methods, they only mainly solve the problem of complex batching systems, and there is no obvious improvement in the smelting process and the recovery of valuable metals.

[0042] To solve the problem of low recovery rate of valuable metals, some related technologies mention the use of blast furnace smelting. The molten slag needs to be cast and cooled, the batching process is complex, the energy consumption is relatively high, the zinc recovery rate has not been improved compared with the traditional pyrometallurgical zinc smelting technology, and there is room for further improvement in the recovery rate of valuable metal recovery. Some other related technologies mention the use of two metallurgical furnaces. The molten slag flows from the bottom-blown furnace into the side-blown furnace, inevitably resulting in heat loss and increasing the smoke emission points. The side-blown furnace reduction belongs to bath smelting and requires a large amount of oxygen-enriched air to be blown in, resulting in a low concentration of zinc vapor, which is more likely to cause secondary oxidation of zinc vapor and reduce the direct zinc recovery rate. The smelting temperature of the side-blown furnace is 1200 - 1250 °C, the zinc content in the slag is relatively high, the direct zinc recovery rate and recovery rate are relatively low, iron cannot be recovered, the subsequent flue gas treatment cost is high, and there is room for further improvement in the recovery rate of valuable metal recovery. In addition, some related technologies mention the use of two metallurgical furnaces. The molten slag flows from the oxidation smelting furnace into the power frequency electric heating reduction furnace, inevitably resulting in heat loss and increasing the smoke emission points. The smelting temperature of the power frequency electric heating reduction furnace is limited, which will cause a relatively high zinc content in the slag, low zinc recovery rate, and iron cannot be recovered. The single-series production capacity of the power frequency electric heating reduction furnace is limited and it is difficult to adapt to large-scale industrial production, and there is room for further improvement in the recovery rate of valuable metal recovery.

[0043] Based on this, the technical solution of the embodiment of the present application provides a method for short-process pyrometallurgical zinc smelting to recover valuable metals. The zinc sulfide material does not require complex preparation and treatment, and is directly added to the oxidation smelting zone of the zinc smelting furnace, and the first oxidation desulfurization reaction and the second oxidation desulfurization reaction are carried out in sequence to form a high-zinc material and a high-cadmium dust; then the high-zinc material is subjected to high-temperature reduction during the reduction process to produce an iron-containing metal material and zinc vapor, and the zinc vapor is condensed to produce crude zinc, and the crude zinc is rectified to obtain zinc metal, cadmium metal and lead metal.

[0044] The "range" disclosed in the present application is defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a specific range. The ranges defined in this way can include or exclude the end values, and can be combined arbitrarily, that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, ranges of 60-110 and 80-120 are also contemplated. In addition, if the minimum range values 1 and 2 are listed, and if the maximum range values 3, 4 and 5 are listed, then the following ranges are all contemplated: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In the present application, unless otherwise specified, the numerical range "a-b" represents an abbreviated representation of any real number combination between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been fully listed herein, and "0-5" is only an abbreviated representation of these numerical combinations. In addition, when it is stated that a certain parameter is an integer ≥2, it is equivalent to disclosing that the parameter is, for example, the integers 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0045] In the description of the embodiments of the present application, the term "and / or" is merely a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this article generally represents an "or" relationship between the associated objects before and after.

[0046] To achieve the above object, according to an embodiment of the present application, a method for short-process pyrometallurgical zinc smelting to recover valuable metals is proposed as Figure 1 , including the following steps:

[0047] S1: A mixed material formed by a zinc sulfide material and a flux undergoes a first oxidation desulfurization reaction with oxygen-enriched gas in the oxidation smelting zone of the furnace cavity to obtain a preliminarily oxidized material and a matte material;

[0048] S2: The preliminarily oxidized material undergoes a second oxidative desulfurization reaction in the oxidative smelting zone to form a high-zinc material and high-cadmium fume. The temperature of the first oxidative desulfurization reaction is t1, and the oxygen-to-material ratio is OM1; the temperature of the second oxidative desulfurization reaction is t2, and the oxygen-to-material ratio is OM2; 50°C ≤ t2 - t1 ≤ 450°C; 50 Nm 3 / t ≤ OM2 - OM1 ≤ 400 Nm 3 / t;

[0049] S3: The high-zinc material is reduced in the reduction smelting zone, and the volume ratio of CO to CO2 is controlled to be 20 - 35:1; an iron-containing metal material and zinc vapor are obtained;

[0050] S4: The zinc vapor is condensed to produce crude zinc, and the crude zinc is rectified to obtain zinc metal, cadmium metal, and lead metal.

[0051] Among them, in S1, the mixed material formed by the zinc sulfide material and the flux. The zinc sulfide material includes zinc, lead, and sulfur elements, and usually also includes iron, sulfur, calcium, and silicon elements. In addition to the above elements, in some embodiments, the lead-zinc sulfide material may also include other elements, such as oxygen, magnesium, copper, aluminum, cadmium, arsenic, etc. Compared with other elements, the contents of zinc, lead, iron, sulfur, calcium, and silicon elements are relatively high. Exemplarily, the lead-zinc sulfide material includes Zn 10 - 40 wt.%; Pb 5 - 30 wt.%; S 10 - 30 wt.%; Fe 3 - 15 wt.%; Ca 1 - 10 wt.%; SiO2 2 - 10 wt.%. For example, Zn 20 - 40 wt.%, Pb 10 - 30 wt.%, S 15 - 30 wt.%, Fe 4 - 15 wt.%, Ca 1 - 5 wt.%, SiO2 2 - 6 wt.%. The lead-zinc sulfide material can be natural lead-zinc sulfide minerals or raw materials formed by smelting with relatively high contents of sulfur, lead, and zinc elements. Among them, according to the different elements with the highest content, the lead-zinc sulfide material can be divided into lead concentrate (highest lead content) and zinc concentrate (highest zinc content).

[0052] Exemplarily, the main element or component content of the lead concentrate is Pb 36.82 wt.%, Zn 16.25 wt.%, S 13.86 wt.%, Fe 3.84 wt.%, Cu 0.40 wt.%, CaO 3.08 wt.%, SiO2 5.16 wt.%.

[0053] Exemplarily, the main element or component content of zinc concentrate is Zn 43.49 wt.%, Pb 3.09 wt.%, S 28.61 wt.%, Fe 11.10 wt.%, Cu 0.74 wt.%, Cd 0.39 wt.%, CaO 0.82 wt.%, SiO2 6.12 wt.%.

[0054] In this application, the mixed material formed by the zinc sulfide material and the flux in a mass ratio of 5-20:1 is fine particles. The flux includes at least one of quartz sand, quicklime, and limestone. The particle size does not need to be precisely controlled, only less than or equal to 5 mm and greater than or equal to 0.05 mm; that is, the particle size of the mixed material is D, where 0.05 mm ≤ D ≤ 5 mm. For example, D is 0.05 mm, 0.1 mm, 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, etc. The particle size of the mixed material is reasonable. When the particle size of the mixed material is too large, such as greater than 5 mm, the specific surface area of the mixed material decreases, and its contact area with the oxygen-rich gas decreases, resulting in a decrease in the reaction rate.

[0055] Exemplarily, the mass ratio of the zinc sulfide material to the flux is (5, 6, 7, 8, 10, 12, 14, 15, 17, 18, 19, 20):1. When the mass ratio value of the zinc sulfide material to the flux is relatively large, such as greater than 20, the melting point of the final high-zinc material generated is high, and the viscosity of the slag is large, which is not conducive to smelting; when the mass ratio value of the zinc sulfide material to the flux is relatively small, such as less than 5, the dosage is too high, resulting in an increase in smelting energy consumption and production cost.

[0056] The oxygen concentration in the oxygen-rich gas is 23-99.8%, and the pressure in the furnace cavity is 0.2 MPa - 0.5 MPa; that is, the oxygen-rich gas can be pure oxygen or a mixed gas of oxygen and other gases (such as nitrogen). In this embodiment, the oxygen concentration in the oxygen-rich gas is 23-99.8%. The oxygen concentration in the oxygen-rich gas is relatively high, which can provide sufficient oxygen to enable the mixed material to react fully.

[0057] The mixed material and the oxygen-rich gas enter the oxidation smelting zone through the injection method in the oxidation smelting zone for mixing and reaction. The injection method in the oxidation smelting zone includes single side blowing, single bottom blowing, or a combination of side blowing and bottom blowing. The mixed material undergoes the first oxidation desulfurization reaction in the oxidation smelting zone to obtain the preliminary oxidized material and the copper matte material. The mass percentage of sulfur element in the preliminary oxidized material is 2%-5%; based on the zinc sulfide material, calculated by mass percentage, 70%-80% of the copper element, 80%-90% of the gold element, and 80%-90% of the silver element in the zinc sulfide material are enriched in the copper matte material for recovery; based on the copper matte material, the mass percentage of copper element in the copper matte material is 10%-30%.

[0058] In S2, the preliminarily oxidized material undergoes a second oxidative desulfurization reaction in the oxidative smelting zone to form a high-zinc material and high-cadmium fume. The sulfur element content in the high-zinc material is less than 1%; the zinc element content in the high-zinc material is 40%-60%; the cadmium element content in the high-cadmium fume is greater than 12%. The temperature of the first oxidative desulfurization reaction is t1, and the oxygen-to-material ratio is OM1; the temperature of the second oxidative desulfurization reaction is t2, and the oxygen-to-material ratio is OM2; 50°C ≤ t2 - t1 ≤ 450°C; 50 Nm 3 / t ≤ OM2 - OM1 ≤ 400 Nm 3 / t.

[0059] For example, the difference value of t2 - t1 is 50°C, 100°C, 150°C, 200°C, 250°C, 300°C, 350°C, 400°C, 450°C, etc.; the difference value of OM2 - OM1 is 50 Nm 3 / t, 100 Nm 3 / t, 150 Nm 3 / t, 200 Nm 3 / t, 250 Nm 3 / t, 300 Nm 3 / t, 350 Nm 3 / t, 400 Nm 3 / t, etc.

[0060] In some embodiments, the temperature of the first oxidative desulfurization reaction is 1100°C, 1200°C, 1300°C, etc.; meanwhile, its oxygen-to-material ratio is 100 Nm 3 / t, 150 Nm 3 / t, 200 Nm 3 / t, 250 Nm 3 / t, etc.; when the temperature of the first oxidative desulfurization reaction is lower than 1100°C, the slag is relatively viscous, which is not conducive to the oxidative desulfurization reaction; when the temperature of the first oxidative desulfurization reaction is higher than 1300°C, the oxidative desulfurization reaction proceeds too fast, which is not conducive to the formation of copper matte material; when the oxygen-to-material ratio of the first oxidative desulfurization reaction is lower than 100 Nm 3 / t, the oxygen content is too low, which will cause the sulfur content in the preliminarily oxidized material to be too high and is not conducive to the second desulfurization reaction; when the oxygen-to-material ratio of the first oxidative desulfurization reaction is higher than 250 Nm 3 / t, the first oxidative desulfurization reaction is too fast and is not conducive to the formation of copper matte material.

[0061] In some embodiments, the temperature of the second oxidative desulfurization reaction is 1350 - 1550°C, and the oxygen-to-material ratio is 300 - 500 Nm 3 / t. The example temperatures of the second oxidative desulfurization reaction are 1350°C, 1400°C, 1450°C, 1550°C, etc.; meanwhile, its oxygen-to-material ratio is 300 Nm3 / t, 350 Nm 3 / t, 400 Nm 3 / t, 500 Nm 3 / t, etc.; when the temperature of the second oxidative desulfurization reaction is lower than 1350 °C, the slag is relatively viscous, which is not conducive to the second deep oxidative desulfurization reaction; when the temperature of the second oxidative desulfurization reaction is higher than 1550 °C, the temperature of the molten bath is too high, affecting the service life of the furnace body of the zinc smelting furnace and the lance for injection in the oxidative smelting zone; when the oxygen-to-feed ratio of the second oxidative desulfurization reaction is lower than 300 Nm 3 / t, there is insufficient oxygen, which is not conducive to the second deep oxidative desulfurization reaction; when the oxygen-to-feed ratio of the second oxidative desulfurization reaction is higher than 500 Nm 3 / t, it exceeds the oxygen amount required for desulfurization, resulting in waste.

[0062] The zinc sulfide material of the present application does not require complex preparation and treatment. The mixed material formed by the zinc sulfide material and the flux has a suitable particle size. The mixed material and the oxygen-enriched gas are in full contact in the oxidative smelting zone of the furnace cavity and undergo the first oxidative desulfurization reaction under low-temperature and low-oxygen-potential conditions. By controlling the oxygen-to-feed ratio, a low-temperature and low-oxygen-potential atmosphere is created. The limited oxygen preferentially reacts with the zinc sulfide with high content and high activity to remove a part of sulfur. The copper sulfide in the mixed material forms copper matte. Finally, a preliminarily zinc-containing oxidized material, i.e., a preliminary oxidized material (there is still a part of sulfur not removed), and copper matte material are obtained. The copper matte material is discharged from the siphon port provided in the oxidative smelting zone. That is, during the first oxidative desulfurization reaction, under this oxygen-to-feed ratio condition, it is ensured that the oxygen-enriched gas can provide an oxygen-enriched environment for the mixed gas to promote the oxidative desulfurization reaction, and at the same time, at this reaction temperature, the mixed material can reach a better reaction state during the first oxidative desulfurization reaction.

[0063] And the preliminary oxidized material continues to undergo further deep oxidative desulfurization in the oxidative smelting zone under high-temperature and high-oxygen-potential conditions to form a high-zinc material and high-cadmium dust. When the second oxidative desulfurization reaction occurs, 50 °C ≤ t2 - t1 ≤ 450 °C, where the temperature of the first oxidative desulfurization reaction is t1 and the temperature of the second oxidative desulfurization reaction is t2. At this reaction temperature, the sulfide concentrate can better undergo deep oxidative desulfurization to form a high-zinc material and high-cadmium dust. The above oxidative desulfurization method for zinc sulfide material provided by the present application does not require complex preparation and treatment of the zinc sulfide material and can effectively improve the recovery rate of valuable metals in the zinc sulfide material.

[0064] In the S3 process, as described above, the sulfur element content in the high-zinc material is less than 1%; the zinc element content in the high-zinc material is 40%-60%; it also contains various metals with recyclable value such as cadmium, lead, indium, germanium, iron, copper, gold, and silver. The high-zinc material is added to the first reduction zone. The first reducing agent includes at least one of lump coke, crushed coke, and anthracite lump, and is added through the feeding port of the first reduction zone. The high-zinc material and the first reducing agent are preliminarily reduced in the first reduction zone to obtain preliminarily reduced material.

[0065] For example, the molar ratio of carbon element in the first reducing agent to zinc element in the high-zinc material is 0.8-1.2:1. For example, the molar ratio of carbon element in the first reducing agent to zinc element in the high-zinc material is (0.8, 0.9, 1.0, 1.1, 1.2):1. When the molar ratio of carbon element in the first reducing agent to zinc element in the high-zinc material is relatively small, such as less than 0.8, the zinc content in the slag is too high, the zinc content in the slag > 5%, and the direct recovery rate of zinc decreases; when the molar ratio of carbon element in the first reducing agent to zinc element in the high-zinc material is relatively large, such as greater than 1.2, the surplus of the first reducing agent is too large, increasing the production cost.

[0066] Among them, the first reduction zone is electrically heated for reduction, and it adopts the method of electrode heat compensation. The reduction smelting temperature is 1200-1300°C; for example, the reduction smelting temperatures of the first reduction zone are 1200°C, 1230°C, 1250°C, and 1300°C, etc. The time for the high-zinc material to be preliminarily reduced is 1-3 h per furnace; for example, the time for the high-zinc material to be preliminarily reduced is 1 h per furnace, 2 h per furnace, or 3 h per furnace, etc. When the reduction smelting temperature of the high-zinc material in the first reduction zone is relatively low, such as lower than 1200°C and the time is short, the zinc content in the slag is too high, the zinc content in the slag > 5%, and the direct recovery rate of zinc decreases; when the reduction smelting temperature of the high-zinc material in the first reduction zone is relatively high, such as higher than 1300°C and the time is long, the energy consumption for zinc smelting will increase, increasing the production cost.

[0067] In addition, during this process, the volume ratio of CO to CO2 in the first reduction zone is controlled to be 20-35:1. For example, the volume ratio of CO to CO2 in the first reduction zone is (20, 21, 24, 25, 26, 28, 29, 30, 31, 32, 23, 24, 35):1, etc. Among them, when the volume ratio of CO to CO2 in the first reduction zone is relatively small, such as less than 20, a large amount of metallic zinc vapor will be oxidized to zinc oxide by CO2 in the flue gas, reducing the direct recovery rate of zinc; when the volume ratio of CO to CO2 in the first reduction zone is relatively large, such as greater than 35, the surplus of the reducing agent is too large, increasing the production cost.

[0068] In S2, the preliminarily reduced material obtained in S1 undergoes a deep reduction reaction with an oxygen-rich gas and a carbonaceous reducing agent in the second reduction zone. The oxygen concentration of the oxygen-rich gas is 23-99.8%, the pressure is 0.2-0.5 MPa, and the carbonaceous reducing agent is coke powder and / or coal powder. The oxygen-rich gas and the carbonaceous reducing agent enter the second reduction zone by means of injection. The injection amount of the oxygen-rich gas is 0.1-0.5 of the total volume of oxygen required for the complete combustion of the carbonaceous reducing agent. Example injection amounts of the oxygen-rich gas are 0.1, 0.2, 0.3, 0.4, 0.5, etc. of the total volume of oxygen required for the complete combustion of the carbonaceous reducing agent.

[0069] The injection amount of the carbonaceous reducing agent is such that the molar ratio of carbon in the carbonaceous reducing agent to zinc in the high-zinc material is 0.2-0.5:1. Example molar ratios of carbon in the carbonaceous reducing agent to zinc in the high-zinc material are (0.2, 0.3, 0.4, 0.5):1. When the molar ratio of carbon in the carbonaceous reducing agent to zinc in the high-zinc material is relatively small, such as less than 0.2, the reducing agent is insufficient. The second reduction zone is mainly for reducing iron in the slag to produce pig iron. With insufficient reducing agent, the pig iron cannot be reduced or is reduced very little and is mixed in the slag and cannot be separated from the slag, making it impossible to further recover precious metals such as gold and silver. When the molar ratio of carbon in the carbonaceous reducing agent to zinc in the high-zinc material is relatively large, such as greater than 0.5, the surplus of the reducing agent is too large, increasing production costs.

[0070] In this embodiment, the oxygen-rich gas and the carbonaceous reducing agent enter the second reduction zone by means of jet injection. The injection method in the second reduction zone includes single side blowing, single bottom blowing, or a combination of side blowing and bottom blowing. On the one hand, it provides heat for deep reduction, and on the other hand, it provides a carbonaceous reducing agent for the reduction process. The continuous injection of the carbonaceous reducing agent ensures that the volume ratio of CO to CO2 in the second reduction zone is 20-35:1, enabling the high-zinc material to undergo a deep reduction reaction to obtain an iron-containing metal material and zinc vapor, significantly increasing the overflow rate of zinc metal.

[0071] Among them, the reduction smelting temperature in the second reduction zone is 1350 - 1500 °C; the reduction smelting temperatures in the second reduction zone in the examples are 1350 °C, 1400 °C, 1450 °C, 1500 °C, etc., and the time for the deep reduction reaction of the preliminarily reduced material is 1 - 3 h per furnace; the times for the deep reduction reaction of the preliminarily reduced material in the examples are 1 h per furnace, 2 h per furnace, 3 h per furnace, etc. Among them, when the reduction smelting temperature of the preliminarily reduced material in the second reduction zone is relatively low, such as lower than 1350 °C and the time is short, then the power during the reduction process is insufficient, resulting in difficult reduction of pig iron or little reduction and being mixed in the slag, unable to be separated from the slag, and unable to further recover precious metals such as gold and silver; when the reduction smelting temperature of the preliminarily reduced material in the second reduction zone is relatively high, such as higher than 1500 °C and the time is long, then the smelting energy consumption will increase and the production cost will increase.

[0072] During this process, the volume ratio of CO to CO2 in the second reduction zone is (20, 21, 24, 25, 26, 28, 29, 30, 31, 32, 23, 24, 35):1, etc. Among them, when the volume ratio of CO to CO2 in the second reduction zone is relatively small, such as less than 20, then the reduction degree is insufficient, resulting in difficult reduction of pig iron or little reduction and being mixed in the slag, unable to be separated from the slag, and unable to further recover precious metals such as gold and silver; when the volume ratio of CO to CO2 in the second reduction zone is relatively large, such as greater than 35, then the surplus amount of the reducing agent is too large, increasing the production cost.

[0073] In some embodiments, the heat supplement ratio between the first reduction zone and the second reduction zone is 2 - 5:1.

[0074] Among them, the heat supplement ratio between the first reduction zone and the second reduction zone is (2, 3, 4, 5):1, etc. Among them, using this heat supplement ratio can, on the one hand, ensure that a large amount of zinc in the slag is reduced in the form of zinc vapor, reducing the zinc content in the final slag, and at the same time ensure that iron elements in the slag are reduced to produce pig iron, enriching and recovering precious metals such as gold, silver, and copper. On the other hand, the sensible heat of the slag in the first reduction zone can be directly utilized by the second reduction zone, which can effectively reduce the smelting energy consumption and the production cost. Among them, the time for ensuring the preliminary reduction and deep reduction reactions of the high-zinc material is 2 - 6 h per furnace.

[0075] The high-zinc materials are subjected to high-temperature reduction in the first reduction zone and the second reduction zone to obtain iron-containing metal materials and zinc-containing vapors. The iron-containing metal materials include pig iron, as well as copper metal, gold metal, and silver metal. The valuable metals such as copper metal, gold metal, and silver metal are recovered from the pig iron. The zinc-containing vapors include zinc vapor, as well as lead, cadmium, and indium and germanium reduced to form vapors, which enter the zinc vapor condensation device together for capture and condensation to form crude zinc liquid. The crude zinc liquid passes through the crude zinc rectification system. First, the vapor temperature is controlled at 900-950 °C to separate and recover lead metal. Then, the vapor temperature is controlled at 500-600 °C to obtain refined zinc while enriching cadmium metal, indium metal, and germanium metal to hard zinc, achieving the purpose of recovering valuable metals such as cadmium metal, indium metal, and germanium metal, and at the same time producing refined zinc with a purity > 99.995%.

[0076] Using this method, the recovery rate of zinc can reach 97%-98%, the recovery rate of lead can reach 97%-98%, the recovery rate of copper can reach 90%-95%, the recovery rate of cadmium can reach 90%-95%, the recovery rate of gold can reach 90%-95%, the recovery rate of silver can reach 90%-95%, the recovery rate of indium can reach 90%-95%, and the recovery rate of germanium can reach 90%-95%.

[0077] To facilitate further understanding of this application, the following describes the solution of this application in combination with embodiments. Those skilled in the art will understand that only some examples are described in this application, and any other suitable specific examples are within the scope of this application.

[0078] Example 1

[0079] This example provides a method for short-process pyrometallurgical zinc smelting to recover valuable metals, in which zinc concentrate is used as the zinc sulfide material for development. The specific operating parameters are as follows: The zinc concentrate is mixed with quartz sand in a mass ratio of 20:1 without complex preparation to obtain a mixed material, and the mixed material is added to the oxidation smelting zone of the short-process pyrometallurgical zinc smelting furnace. The mixed material undergoes the first oxidation desulfurization reaction in the oxidation smelting zone at 1100 °C and an oxygen-to-feed ratio of 100 Nm 3 / t. In this process, copper matte materials and preliminary oxidized materials are formed. The mass percentage of sulfur element in the preliminary oxidized materials is 5%, and the mass percentage of copper element in the copper matte materials is 10%. The copper matte materials are deposited at the bottom of the molten pool in the hearth and discharged through the siphon port set in the oxidation smelting zone. The temperature of the oxidation smelting zone is increased to 1350 °C and the oxygen-to-feed ratio is increased to 300 Nm 3 / t to further desulfurize the molten slag, forming high-zinc materials and high-cadmium dust. The high-zinc materials contain 0.9% S and 40% Zn, and the high-cadmium dust contains 13% Cd.

[0080] Preliminarily reduce a high-zinc material containing 0.9% S element and 40% Zn element and coke lumps in the first reduction zone, control the volume ratio of CO to CO2 to be 20:1, the temperature in the first reduction zone is 1200 °C for 1 h, and the molar amount of carbon element in the reducing agent is 0.8:1 compared with the molar amount of zinc element in the low-sulfur high-zinc oxide to obtain a preliminarily reduced material and a large amount of zinc vapor.

[0081] Deeply reduce the preliminarily reduced material in the second reduction zone with oxygen-rich gas and pulverized coal entering through jet injection, control the volume ratio of CO to CO2 to be 20:1, the temperature in the second reduction zone is 1350 °C for 1 h, and the molar amount of carbon element in the reducing agent is 0.2:1 compared with the molar amount of zinc element in the low-sulfur high-zinc oxide to obtain an iron-containing metal material and zinc vapor; the zinc vapor contains valuable metals such as cadmium, lead, indium, and germanium, and a crude zinc product is produced after the zinc vapor condenses. The iron-containing metal material is pig iron, the iron element in the low-sulfur high-zinc oxide is reduced to form pig iron, and copper, gold, and silver are enriched and recovered in the pig iron.

[0082] The crude zinc is refined by a crude zinc rectification system. First, control the temperature of the rectified metal vapor in the rectification system to be 900 °C to separate and recover lead; then, control the temperature of the rectified metal vapor to be 500 °C to separate and recover cadmium, and the obtained refined zinc contains 99.996% Zn.

[0083] Example 2

[0084] This example provides a method for short-process pyrometallurgical zinc smelting to recover valuable metals, which uses zinc concentrate as a zinc sulfide material for development, and its specific operating parameters are as follows; the zinc concentrate does not require complex preparation, and is mixed with flux quartz sand at a mass ratio of 10:1 to obtain a mixed material, and the mixed material is added to the oxidation smelting zone of the short-process pyrometallurgical zinc furnace; the mixed material undergoes the first oxidation desulfurization reaction in the oxidation smelting zone at 1200 °C and an oxygen-to-material ratio of 200 Nm 3 / t to form copper matte material and a preliminarily oxidized material. The mass percentage of S element in the preliminarily oxidized material is 3%, and the mass percentage of Cu element in the copper matte material is 20%. The copper matte material deposits at the bottom of the molten pool hearth and is discharged through the siphon port set in the oxidation smelting zone; raise the temperature of the oxidation smelting zone to 1450 °C and raise the oxygen-to-material ratio to 400 Nm 3 / t to further desulfurize the slag to form a high-zinc material and high-cadmium dust. The high-zinc material contains 0.5% S and 50% Zn, and the high-cadmium dust contains 15% Cd.

[0085] A high-zinc material containing 50% Zn is preliminarily reduced with crushed coke in the first reduction zone, controlling the volume ratio of CO to CO2 to be 30:1. The temperature in the first reduction zone is 1250 °C for 2 hours. The molar ratio of carbon element in the reducing agent to zinc element in the low-sulfur high-zinc oxide is 1.0:1, obtaining preliminarily reduced material and a large amount of zinc vapor.

[0086] The preliminarily reduced material is deeply reduced in the second reduction zone with oxygen-rich gas and coke powder injected through jet injection, controlling the volume ratio of CO to CO2 to be 30:1. The temperature in the second reduction zone is 1400 °C for 2 hours. The molar ratio of carbon element in the reducing agent to zinc element in the low-sulfur high-zinc oxide is 0.3:1, obtaining iron-containing metal material and zinc vapor; the zinc vapor contains valuable metals such as cadmium, lead, indium, and germanium. After the zinc vapor is condensed, a crude zinc product is produced. The iron-containing metal material is pig iron, and the iron element in the low-sulfur high-zinc oxide is reduced to form pig iron, and copper, gold, and silver are enriched and recovered in the pig iron.

[0087] The crude zinc is refined through a crude zinc rectification system. First, the temperature of the rectified metal vapor is controlled at 925 °C in the rectification system to separate and recover lead; then, the temperature of the rectified metal vapor is controlled at 550 °C to separate and recover cadmium, and the obtained refined zinc contains 99.997% Zn.

[0088] Example 3

[0089] This example provides a method for short-process pyrometallurgical zinc smelting to recover valuable metals, which uses zinc concentrate as the zinc sulfide material for development. The specific operating parameters are as follows: The zinc concentrate is mixed with quartz sand in a mass ratio of 5:1 without complex preparation to obtain a mixed material, and the mixed material is added to the oxidation smelting zone of the short-process pyrometallurgical zinc furnace; the mixed material undergoes the first oxidation desulfurization reaction in the oxidation smelting zone at 1300 °C and an oxygen-to-material ratio of 250 Nm 3 / t, forming copper matte material and preliminarily oxidized material. The mass percentage of S element in the preliminarily oxidized material is 2%, and the mass percentage of Cu element in the copper matte material is 30%. The copper matte material deposits at the bottom of the molten pool in the hearth and is discharged through the siphon port set in the oxidation smelting zone; the temperature of the oxidation smelting zone is increased to 1550 °C and the oxygen-to-material ratio is increased to 500 Nm 3 / t to further desulfurize the molten slag, forming high-zinc material and high-cadmium dust. The high-zinc material contains 0.3% S and 60% Zn by mass percentage, and the high-cadmium dust contains 20% Cd.

[0090] High-zinc materials containing 0.3% S and 60% Zn are preliminarily reduced with coke lumps in the first reduction zone, controlling the volume ratio of CO to CO2 to be 35:1, the temperature in the first reduction zone to be 1300 °C for 3 hours, and the molar amount of carbon element in the reducing agent to the molar amount of zinc element in the low-sulfur high-zinc oxide to be 1.2:1, obtaining preliminarily reduced materials and a large amount of zinc vapor.

[0091] The preliminarily reduced materials are deeply reduced in the second reduction zone with oxygen-rich gas and coke powder injected through jet injection, controlling the volume ratio of CO to CO2 to be 35:1, the temperature in the second reduction zone to be 1500 °C for 3 hours, and the molar amount of carbon element in the reducing agent to the molar amount of zinc element in the low-sulfur high-zinc oxide to be 0.5:1, obtaining iron-containing metal materials and zinc vapor; the zinc vapor contains valuable metals such as cadmium, lead, indium, and germanium, and crude zinc products are produced after the zinc vapor is condensed. The iron-containing metal materials are pig iron, and the iron element in the low-sulfur high-zinc oxide is reduced to produce pig iron, and copper, gold, and silver are enriched and recovered in the pig iron.

[0092] The crude zinc is refined by a crude zinc rectification system. First, the temperature of the rectified metal vapor is controlled at 950 °C in the rectification system to separate and recover lead; then, the temperature of the rectified metal vapor is controlled at 600 °C to separate and recover cadmium, and the obtained refined zinc contains 99.998% Zn.

[0093] Among them, using zinc concentrate as the raw material and treating it by the traditional blast furnace process is taken as Comparative Example 1, treating zinc concentrate by hydrometallurgy, that is, the conventional leaching process, is taken as Comparative Example 2; treating zinc concentrate by hydrometallurgy, that is, the jarosite process, is taken as Comparative Example 3; treating zinc concentrate by hydrometallurgy, that is, the goethite process, is taken as Comparative Example 4. The recovery rates of valuable metals obtained in each example are shown in the following Table 1.

[0094] Table 1 Recovery rates of valuable metals obtained in each example and comparative example methods

[0095]

[0096] In the description of this specification, the description referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0097] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limitations on the present application. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present application.

Claims

1. A method for recovering valuable metals by short-process pyrometallurgical zinc smelting, characterized in that, It includes the following steps: The mixed material formed by zinc sulfide material and flux undergoes a first oxidative desulfurization reaction with oxygen-rich gas in the oxidation smelting zone of the furnace cavity to obtain a preliminarily oxidized material and a copper matte material; The preliminary oxidized material is subjected to a second oxidative desulfurization reaction in the oxidative smelting zone to form a high-zinc material and high-cadmium fume; wherein the temperature of the first oxidative desulfurization reaction is t1, and the oxygen-to-material ratio is OM1; the temperature of the second oxidative desulfurization reaction is t2, and the oxygen-to-material ratio is OM2; 50°C ≤ t2 - t1 ≤ 450°C; 50 Nm 3 / t ≤ OM2 - OM1 ≤ 400 Nm 3 / t; wherein the temperature t1 of the first oxidative desulfurization reaction is 1100 - 1300°C, and the oxygen-to-material ratio OM1 is 100 - 250 Nm 3 / t; The high-zinc material is reduced in the reduction smelting zone and the volume ratio of CO to CO2 is controlled to be 20 - 35:1; an iron-containing metal material and zinc vapor are obtained; The zinc vapor is condensed to produce crude zinc, and the crude zinc is rectified to obtain zinc metal, cadmium metal, and lead metal.

2. The method according to claim 1, wherein The particle size of the mixed material is D, where 0.05mm ≤ D ≤ 5mm; And / or, the mass ratio of the zinc sulfide material to the flux in the mixed material is 5 - 20:1; And / or, the flux includes at least one of quartz sand, quicklime, and limestone; And / or, the temperature t2 of the second oxidative desulfurization reaction is 1350 - 1550 °C, and the oxygen-to-feed ratio OM2 is 300 - 500 Nm 3 / t; And / or, the mass percentage content of cadmium element in the high-cadmium soot is greater than 12%; 3. The method according to claim 1 or 2, characterized in that, The reduction smelting zone includes a first reduction zone and a second reduction zone; The high-zinc material is preliminarily reduced with a first reducing agent in the first reduction zone to obtain a preliminarily reduced material; the preliminarily reduced material undergoes a deep reduction reaction with oxygen-rich gas and a carbonaceous reducing agent injected through jet injection in the second reduction zone.

4. The method according to claim 3, characterized in that Based on the high-zinc material, by mass percentage, the sulfur element content in the high-zinc material is less than 1%, and the Zn element content is 40% - 60%; And / or, the first reduction zone is electrically heated and reduced, with electrode heat supplement, and the reduction smelting temperature is 1200 - 1300°C; And / or, the first reducing agent includes at least one of coke lumps, crushed coke, and anthracite lumps; it is added through the charging port of the first reduction zone; And / or, the molar ratio of carbon element in the first reducing agent to zinc element in the high-zinc material is 0.8 - 1.2:

1.

5. The method according to claim 3, wherein The second reduction zone is jet injection combustion reduction, and the reduction smelting temperature is 1350 - 1500°C; And / or, the carbonaceous reducing agent includes coke powder and / or coal powder; the molar ratio of carbon element in the carbonaceous reducing agent to zinc element in the high-zinc material is 0.2 - 0.5:1; And / or, the injection amount of the oxygen-rich gas is 0.1 - 0.5 of the total volume of oxygen required for complete combustion of the carbonaceous reducing agent in the second reduction zone.

6. The method according to claim 3, characterized in that, The time for the high-zinc material to undergo preliminary reduction and deep reduction reaction is 2 - 6h per furnace charge; And / or, the time for the high-zinc material to undergo preliminary reduction is 1 - 3h per furnace charge; And / or, the time for the preliminarily reduced material to undergo deep reduction reaction is 1 - 3h per furnace charge.

7. The method according to claim 3, wherein The heat supplement ratio of the first reduction zone to the second reduction zone is 2 - 5:

1.

8. The method according to claim 3, wherein The oxygen concentration of the oxygen-rich gas is 23 - 99.8%, and the pressure is 0.2 - 0.5MPa; And / or, the oxygen-rich gas and the carbonaceous reducing agent are injected into the second reduction zone, and the injection amount of the oxygen-rich gas is 0.1 - 0.5 of the total volume of oxygen required for complete combustion of the carbonaceous reducing agent.

9. The method according to claim 3, characterized in that, In the crude zinc rectification process: First, control the vapor temperature at 900 - 950 °C to separate and recover lead metal; then control the vapor temperature at 500 - 600 °C to obtain refined zinc, while enriching cadmium metal, indium metal, and germanium metal into hard zinc; And / or, the recovery rate of zinc in the high-zinc material is 97% - 98%, the recovery rate of lead is 97% - 98%, the recovery rate of copper is 90% - 95%, the recovery rate of cadmium is 90% - 95%, the recovery rate of gold is 90% - 95%, the recovery rate of silver is 90% - 95%, the recovery rate of indium is 90% - 95%, and the recovery rate of germanium is 90% - 95%; And / or, the purity of the refined zinc > 99.995%.

10. The method according to claim 3, wherein The injection methods in the oxidation melting zone and the second reduction zone include single side injection, single bottom injection, or a combination of side injection and bottom injection.

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