Method for recovering valuable metal through short-process zinc pyrometallurgy

Abstract

The invention provides a method for recovering valuable metals through short-process zinc pyrometallurgy, which comprises the following steps: carrying out primary oxidative desulfurization reaction on a mixed material formed by a zinc sulfide material and a flux and oxygen-enriched gas in an oxidative smelting area of a furnace chamber to obtain a primary oxide material and a copper matte material; the primary oxide material is subjected to a second oxidation desulfurization reaction in an oxidation smelting area to form a high-zinc material and high-cadmium smoke dust; the high-zinc material is reduced in a reduction smelting area, and the volume ratio of CO to CO2 is controlled to be (20-35): 1; an iron-containing metal material and zinc-containing steam are obtained; and condensing the zinc-containing steam to produce crude zinc, and rectifying the crude zinc to obtain zinc metal. According to the method, recovery of zinc metal in the zinc sulfide material and recovery of other valuable metal are achieved through reasonable oxidation and reduction methods, and good social benefits and production economic benefits are achieved.

Description

Technical Field

[0001] The present application relates to the field of metal reduction and recovery, and in particular to a method for recovering valuable metals by short-process pyrometallurgical zinc smelting. Background Art

[0002] Pyrometallurgical zinc smelting has the characteristics of processing complex raw materials and simple processes, and has been widely used in lead and zinc metal smelting. Among them, the pyrometallurgical process mainly includes blast furnace, vertical tank and electric furnace processes. Blast furnace zinc smelting can only process lead-zinc mixed ore with a certain lead-zinc ratio. The raw materials must be sintered before entering the furnace. The final slag of the blast furnace contains 5%-7% zinc, and the recovery rate of valuable metals such as zinc is low; in vertical tank zinc smelting, the zinc sulfide material must be roasted, pelletized and other desulfurization molding treatments before entering the furnace. The raw material composition requirements are high and the material preparation process is complicated. The final slag contains 5%-10% zinc, and the recovery rates of valuable metals such as zinc, copper, gold and silver are all low; in electric furnace zinc smelting, the zinc sulfide material needs to be roasted and desulfurized before entering the furnace. The atmosphere and temperature in the furnace need to be controlled during the smelting process after entering the furnace. The final slag contains 3%-6% zinc, and the recovery rate of valuable metals is low. Summary of the invention

[0003] The present application aims to solve at least one of the technical problems in the related art to a certain extent. The present application proposes a method for recovering valuable metals by short-process pyrometallurgical zinc smelting, which 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 high-zinc materials and high-cadmium smoke; the high-zinc materials are then reduced at a high temperature in a reduction process with a volume ratio of CO to CO2 of 20-35:1, and iron-containing metal materials and zinc-containing vapor are produced. 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 utilizes reasonable oxidation and reduction methods to achieve the recovery of zinc metal and other valuable metals in zinc sulfide materials, and has good social benefits and production economic benefits.

[0004] According to an embodiment of the present application, a method for recovering valuable metals by short-process pyrometallurgical zinc smelting is proposed, comprising the following steps: The mixed material formed by the zinc sulfide material and the flux undergoes a first oxidation desulfurization reaction with the oxygen-rich gas in the oxidation smelting zone of the furnace chamber to obtain a preliminary oxide material and a copper matte material; The preliminary oxide material is subjected to a second oxidation desulfurization reaction in the oxidation smelting zone to form high-zinc material and high-cadmium smoke; 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; 50Nm 3 / t≤OM2-OM1≤400Nm 3 / t; The high-zinc material is reduced in a reduction smelting zone and the volume ratio of CO to CO2 is controlled to be 20-35:1; iron-containing metal material and zinc-containing vapor are obtained; 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.

[0005] In some embodiments, the particle size of the mixed material is D, wherein 0.05 mm ≤ D ≤ 5 mm; 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 comprises at least one of quartz sand, quicklime and limestone; And / or, wherein the temperature of the first oxidation desulfurization reaction is 1100-1300°C, and the oxygen-to-material ratio is 100-250Nm 3 / t; And / or, the temperature of the second oxidation desulfurization reaction is 1350-1550°C, and the oxygen-to-material ratio is 300-500Nm 3 / t; And / or, the mass percentage of cadmium element in the high-cadmium smoke is greater than 12%.

[0006] In some embodiments, the reduction smelting zone includes a first reduction zone and a second reduction zone; The high-zinc material and the first reducing agent are initially reduced in the first reduction zone to obtain the initially reduced material; the initially reduced material is subjected to a deep reduction reaction in the second reduction zone with the oxygen-rich gas and the carbonaceous reducing agent introduced by jet blowing.

[0007] In some embodiments, based on the high-zinc material, the sulfur content in the high-zinc material is less than 1%, and the Zn content is 40%-60% in terms of mass percentage; And / or, the first reduction zone is an electric heating reduction zone, which uses electrode heating, and the reduction smelting temperature is 1200-1300°C; And / or, the first reducing agent includes at least one of coke block, crushed coke, and anthracite block; and is added from the feed port of the first reduction zone; And / or, the ratio of the molar amount of carbon element in the first reducing agent to the molar amount of zinc element in the high-zinc material is 0.8-1.2:1.

[0008] In some embodiments, the second reduction zone is a jet blowing combustion reduction, and the reduction smelting temperature is 1350-1500°C; And / or, the carbonaceous reducing agent comprises coke powder and / or coal powder; the ratio of the molar amount of carbon element in the carbonaceous reducing agent to the molar amount of 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.

[0009] In some embodiments, the time for the initial reduction and deep reduction reaction of the high-zinc material is 2-6 hours / heat; And / or, the time for the initial reduction of the high-zinc material is 1-3h / heat; And / or, the time for the deep reduction reaction of the preliminary reduced material is 1-3 h / heat.

[0010] In some embodiments, the ratio of supplementary heat between the first reduction zone and the second reduction zone is 2-5:1.

[0011] In some embodiments, the oxygen-rich gas has an oxygen concentration of 23-99.8% and a pressure of 0.20.5 MPa; And / or, the oxygen-rich gas and the carbonaceous reducing agent are sprayed into the second reduction zone, and the amount of the oxygen-rich gas sprayed is 0.1-0.5 of the total volume of oxygen required for complete combustion of the carbonaceous reducing agent.

[0012] In some embodiments, during the crude zinc distillation process: first, the steam temperature is controlled to be 900-950° C. to separate and recover lead metal; then, the steam temperature is controlled to be 500-600° C. to obtain refined zinc, and at the same time, cadmium metal, indium metal, and germanium metal are enriched 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 is >99.995%.

[0013] In some embodiments, the blowing modes of the oxidation smelting zone and the second reduction zone include side blowing alone, bottom blowing alone, or a mixture of side blowing and bottom blowing.

[0014] 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.

[0015] 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.

[0016] 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

[0017] 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: 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

[0018] 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.

[0019] The existing hydrometallurgical zinc smelting technology has a long process, complex process, huge investment and high energy consumption. Most importantly, the hydrometallurgical process produces a large amount of leaching slag, iron slag, etc., with an output rate of more than 50%, which are all hazardous wastes and need to be harmlessly treated, which in turn causes a large amount of energy consumption and brings new pollution. The existing pyrometallurgical zinc smelting technology generally has high energy consumption, complex material preparation process, low zinc direct recovery rate and recovery rate, and small single series production capacity, which cannot meet the requirements of modern large-scale industrial production.

[0020] At present, the relevant technology mentions the lead-zinc ore smelting method of melting the lead-zinc ore in an oxidation smelting furnace, sending the melt to an industrial frequency electric reduction furnace for reduction, and using the traditional lead rain condensation or zinc rain condensation to obtain crude zinc for zinc vapor; or using an oxygen bottom blowing smelting furnace to melt the zinc sulfide material, sending the melt to a side blowing reduction furnace for reduction, and using the traditional lead rain condensation or zinc rain condensation to obtain crude zinc for zinc vapor; using an oxygen bottom blowing smelting furnace to melt the zinc sulfide material, and then sending the ingot to a blast furnace for reduction, and using the traditional lead rain condensation or zinc rain condensation to obtain crude zinc for zinc vapor. The above methods all solve many problems existing in hydrometallurgical zinc smelting, but compared with the existing pyrometallurgical zinc smelting method, they only mainly solve the problem of complex material preparation system, and the smelting process and the recovery of valuable metals have not been significantly improved.

[0021] In order 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 cooled by the ingot, the material preparation process is complicated, the energy consumption is high, and the zinc recovery rate has not been improved compared with the traditional pyrometallurgical zinc smelting technology. There is room for further improvement in the recovery rate of valuable metals. Some other related technologies mention the use of two metallurgical furnaces. The molten slag flows from the bottom-blown furnace to the side-blown furnace, which inevitably causes heat loss and increases the fume escape point. The side-blown furnace reduction belongs to the molten pool smelting, and a large amount of oxygen-rich air needs to be blown in, resulting in a low zinc vapor concentration, which is more likely to cause secondary oxidation of zinc vapor and reduce the direct recovery rate of zinc. The smelting temperature of the side-blown furnace is 1200-1250℃, the slag contains a high zinc content, the direct recovery rate and recovery rate of zinc are low, iron cannot be recovered, and the subsequent flue gas treatment cost is high. There is room for further improvement in the recovery rate of valuable metals. In addition, the related art mentions the use of two metallurgical furnaces. The molten slag flows from the oxidation smelting furnace into the power frequency electric thermal reduction furnace, which inevitably causes heat loss and increases the fume escape point. The smelting temperature of the power frequency electric thermal reduction furnace is limited, which will cause the slag to contain high zinc, low zinc recovery rate, and inability to recover iron. The single series production capacity of the power frequency electric thermal reduction furnace is limited, and it is difficult to adapt to large-scale industrial production. There is room for further improvement in the recovery rate of valuable metals.

[0022] Based on this, the technical solution of the embodiment of the present application provides a method for recovering valuable metals by short-process pyrometallurgical zinc smelting. The zinc sulfide material does not require complicated preparation and processing, 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 high-zinc material and high-cadmium smoke; the high-zinc material is then reduced at high temperature during the reduction process to produce iron-containing metal material and 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.

[0023] "Scope" disclosed in the present application is limited in the form of lower limit and upper limit, and a given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a special range. The scope limited in this way can be including end values ​​or not including end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a scope. For example, if the scope of 60-120 and 80-110 is listed for a specific parameter, it is understood that the scope of 60-110 and 80-120 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3, 4 and 5 are listed, the following scope can be all expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In the present application, unless otherwise specified, the numerical range "ab" represents the abbreviation of any real number combination between a and b, wherein a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0024] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0025] To achieve the above-mentioned purpose, according to the embodiment of the present application, a method for recovering valuable metals by pyrometallurgical zinc smelting with a short process is proposed. Figure 1 , including the following steps: S1: The mixture formed by the zinc sulfide material and the flux undergoes the first oxidation desulfurization reaction with the oxygen-rich gas in the oxidation smelting zone of the furnace chamber to obtain the preliminary oxide material and the copper matte material; S2: The preliminary oxide material is subjected to a second oxidation desulfurization reaction in the oxidation smelting zone to form high-zinc material and high-cadmium smoke; 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℃≤t2-t1≤450℃; 50Nm 3 / t≤OM2-OM1≤400Nm 3 / t; S3: reducing the high-zinc material in a reduction smelting zone and controlling the volume ratio of CO to CO2 to be 20-35:1; obtaining iron-containing metal material and zinc-containing vapor; S4: Zinc-containing vapor is condensed to produce crude zinc, and the crude zinc is distilled to obtain zinc metal, cadmium metal and lead metal.

[0026] Among them, in S1, the mixed material formed by the zinc sulfide material and the flux, wherein the zinc sulfide material includes zinc, lead, 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 content of zinc, lead, iron, sulfur, calcium, and silicon elements is relatively high. Exemplarily, the lead-zinc sulfide material includes Zn 10-40wt.%; Pb 5-30 wt.%; S 10-30 wt.%; Fe 3-15 wt.%; Ca 1-10 wt.%; SiO22-10 wt.%. For example, Zn 20-40 wt.%, Pb 10-30 wt.%, S15-30 wt.%, Fe 4-15 wt.%, Ca 1-5 wt.%, SiO22-6wt.%. Lead-zinc sulfide materials can be natural lead-zinc sulfide minerals, or they can be smelted raw materials with relatively high sulfur, lead and zinc elements. Among them, according to the highest content of the elements, lead-zinc sulfide materials can be divided into lead concentrate (highest lead content) and zinc concentrate (highest lead content).

[0027] Exemplarily, the main elements or component contents of the lead concentrate are Pb 36.82 wt.%, Zn 16.25 wt.%, S1 3.86 wt.%, Fe 3.84 wt.%, Cu 0.40 wt.%, CaO 3.08 wt.%, and SiO2 5.16 wt.%.

[0028] Illustratively, the main elements or component contents of the zinc concentrate are Zn 43.49 wt.%, Pb 3.09 wt.%, S2 8.61 wt.%, Fe 11.10 wt.%, Cu 0.74 wt.%, Cd 0.39 wt.%, CaO 0.82 wt.%, and SiO2 6.12 wt.%.

[0029] In the present application, the mixture formed by the zinc sulfide material and the flux in a mass ratio of 5-20:1 is fine particles, wherein the flux includes at least one of quartz sand, quicklime and limestone, and the particle size does not need to be precisely controlled, and only needs to be less than or equal to 5mm and greater than or equal to 0.05mm; that is, the particle size of the mixture is D, wherein 0.05mm≤D≤5mm. The particle size of the mixture is D, wherein 0.05mm≤D≤5mm; for example, D is 0.05mm, 0.1mm, 0.5mm, 1mm, 2mm, 3mm, 4mm, 5mm, etc., wherein the particle size of the mixture is reasonable. When the particle size of the mixture is too large, such as greater than 5mm, the specific surface area of ​​the mixture is reduced, and the contact area with the oxygen-rich gas is reduced, resulting in a reduced reaction rate.

[0030] For example, the mass ratio of zinc sulfide material to flux is (5, 6, 7, 8, 10, 12, 14, 15, 17, 18, 19, 20): 1. When the mass ratio of zinc sulfide material to flux is large, such as greater than 20, the final high-zinc material generated has a high melting point and a large slag viscosity, which is not conducive to smelting; when the mass ratio of zinc sulfide material to flux is small, such as less than 5, the dosage is too high, resulting in increased smelting energy consumption and increased production costs.

[0031] The oxygen concentration in the oxygen-rich gas is 23-99.8%, and the pressure in the furnace chamber is 0.2MPa-0.5MPa; that is, the oxygen-rich gas can be pure oxygen or a mixture of oxygen and other gases (such as nitrogen). In this embodiment, the oxygen concentration in the oxygen-rich gas is 23-99.8%, and the oxygen concentration in the oxygen-rich gas is relatively high, which can provide sufficient oxygen to allow the mixed materials to fully react.

[0032] The mixed material and the oxygen-rich gas enter the oxidation smelting zone through the oxidation smelting zone spraying method for mixing and reaction, wherein the oxidation smelting zone spraying method includes single side blowing, single bottom blowing or side blowing and bottom blowing mixed. The mixed material undergoes the first oxidation desulfurization reaction in the oxidation smelting zone to obtain preliminary oxide material and copper matte material, wherein the mass percentage of sulfur element in the preliminary oxide material is 2%-5%; based on the zinc sulfide material, according to the mass percentage content, 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%.

[0033] The preliminary oxide material in S2 undergoes a second oxidation desulfurization reaction in the oxidation smelting zone to form high-zinc material and high-cadmium smoke. The sulfur content in the high-zinc material is less than 1%; the zinc content in the high-zinc material is 40%-60%; the cadmium content in the high-cadmium smoke is greater than 12%. 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℃≤t2-t1≤450℃; 50Nm 3 / t≤OM2-OM1≤400Nm 3 / t.

[0034] For example, the difference between t2 and t1 is 50°C, 100°C, 150°C, 200°C, 250°C, 300°C, 350°C, 400°C, 450°C, etc.; the difference between OM2 and OM1 is 50Nm 3 / t、100Nm 3 / t、150Nm 3 / t、200Nm 3 / t, 250Nm3 / t、300Nm 3 / t、350Nm 3 / t、400Nm 3 / t, etc.

[0035] In some embodiments, the temperature of the first oxidation desulfurization reaction is 1100°C, 1200°C, 1300°C, etc.; and the oxygen-to-material ratio is 100Nm 3 / t、150Nm 3 / t、200Nm 3 / t, 250Nm 3 / t, etc.; when the temperature of the first oxidation desulfurization reaction is lower than 1100℃, the slag is sticky, which is not conducive to the oxidation desulfurization reaction; when the temperature of the first oxidation desulfurization reaction is higher than 1300℃, the oxidation desulfurization reaction proceeds too fast, which is not conducive to the formation of copper matte materials; when the oxygen-to-material ratio of the first oxidation desulfurization reaction is lower than 100Nm 3 / t, the oxygen content is too low, which will cause the initial oxidation material to contain too much sulfur, which is not conducive to the second desulfurization reaction; when the oxygen-to-material ratio of the first oxidation desulfurization reaction is higher than 250Nm 3 / t, the first oxidation desulfurization reaction is too fast, which is not conducive to the formation of copper matte materials.

[0036] In some embodiments, the temperature of the second oxidation desulfurization reaction is 1350-1550°C, and the oxygen-to-material ratio is 300-500 Nm 3 / t, the temperature of the second oxidation desulfurization reaction in the example is 1350℃, 1400℃, 1450℃, 1550℃, etc.; at the same time, its oxygen-to-material ratio is 300Nm 3 / t、350Nm 3 / t、400Nm 3 / t、500Nm 3 / t, etc.; when the temperature of the second oxidation desulfurization reaction is lower than 1350℃, the slag is sticky, which is not conducive to the second deep oxidation desulfurization reaction; when the temperature of the second oxidation desulfurization reaction is higher than 1550℃, the molten pool temperature is too high, affecting the furnace body of the zinc smelting furnace and the life of the spray gun for the oxidation smelting zone; when the oxygen-to-material ratio of the second oxidation desulfurization reaction is lower than 300Nm 3 / t, there is insufficient oxygen, which is not conducive to the second deep oxidation desulfurization reaction; when the oxygen-to-material ratio of the second oxidation desulfurization reaction is higher than 500Nm 3 / t, the amount of oxygen required for desulfurization exceeds that required, resulting in waste.

[0037] The zinc sulfide material of the present application does not require complicated preparation and processing. The mixed material formed by the zinc sulfide material and the flux has a suitable particle size. The mixed material 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. By controlling the oxygen-to-material ratio to create a low temperature and low oxygen potential atmosphere, the limited oxygen preferentially reacts with the zinc-containing sulfide with high content and high activity to remove a portion of the sulfur, and the copper-containing sulfide in the mixed material generates copper matte, and finally a preliminary zinc-containing oxide material, i.e., a preliminary oxide material (a portion of the sulfur is still not removed) and a copper matte material are obtained. The copper matte material is discharged from a siphon port set in the oxidation smelting zone, that is, during the first oxidation desulfurization reaction, under the oxygen-to-material ratio conditions, it is ensured that the oxygen-rich gas can provide an oxygen-rich environment for the mixed gas to promote the oxidation desulfurization reaction, and at the same time, at the reaction temperature, the mixed material can reach a better reaction state in the first oxidation desulfurization reaction.

[0038] 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 high-zinc materials and high-cadmium smoke. During the second oxidation desulfurization reaction, 50°C ≤ t2-t1 ≤ 450°C, where the temperature of the first oxidation desulfurization reaction is t1, and the temperature of the second oxidation desulfurization reaction is t2. At this reaction temperature, the sulfide concentrate can be well subjected to deep oxidation desulfurization to form high-zinc materials and high-cadmium smoke. The above-mentioned oxidation desulfurization method of the zinc sulfide material provided in the present application does not require complex preparation and processing of the zinc sulfide material, and can effectively improve the recovery rate of valuable metals of the zinc sulfide material.

[0039] In the S3 process, it can be seen from the above that the sulfur content in the high-zinc material is less than 1%; the zinc content in the high-zinc material is 40%-60%; it also contains a variety of metals with recyclable value such as cadmium, lead, indium, germanium, iron, copper, gold, silver, etc. The high-zinc material is added to the first reduction zone, and the first reducing agent includes at least one of coke block, crushed coke, and anthracite block, and is added from the feeding port of the first reduction zone. The high-zinc material and the first reducing agent are initially reduced in the first reduction zone to obtain a preliminary reduced material.

[0040] For example, the ratio of the molar amount of carbon in the first reducing agent to the molar amount of zinc in the high-zinc material is 0.8-1.2:1, and the ratio of the molar amount of carbon in the first reducing agent to the molar amount of zinc in the high-zinc material is (0.8, 0.9, 1.0, 1.1, 1.2): 1. When the ratio of the molar amount of carbon in the first reducing agent to the molar amount of zinc in the high-zinc material is small, such as less than 0.8, the zinc content in the slag is too high, the zinc content in the slag is greater than 5%, and the direct recovery rate of zinc is reduced; when the ratio of the molar amount of carbon in the first reducing agent to the molar amount of zinc in the high-zinc material is large, such as greater than 1.2, the surplus amount of the first reducing agent is too large, which increases the production cost.

[0041] The first reduction zone is an electric heating reduction, which adopts the electrode heating method, and the reduction smelting temperature is 1200-1300℃; the reduction smelting temperature of the first reduction zone is 1200℃, 1230℃, 1250℃ and 1300℃, etc., and the time for the initial reduction of the high-zinc material is 1-3h / furnace; the time for the initial reduction of the high-zinc material is 1h / furnace, 2h / furnace or 3h / furnace, etc. When the reduction smelting temperature of the high-zinc material in the first reduction zone is low, such as lower than 1200℃ and the time is short, the zinc content in the slag is too high, the zinc content in the slag is greater than 5%, and the direct recovery rate of zinc is reduced; when the reduction smelting temperature of the high-zinc material in the first reduction zone is high, such as higher than 1300℃ and the time is long, it will increase the energy consumption of zinc smelting and increase production costs.

[0042] In addition, the volume ratio of CO to CO2 in the first reduction zone is controlled to be 20-35:1 during this process. 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, the CO2 in the flue gas will oxidize a large amount of metallic zinc vapor into zinc oxide, 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 excess amount of reducing agent is too large, increasing production costs.

[0043] In S2, the preliminary reduced material obtained in S1 is subjected to deep reduction reaction in the second reduction zone with oxygen-rich gas and carbonaceous reducing agent, wherein the oxygen concentration of the oxygen-rich gas is 23-99.8%, the pressure is 0.2-0.5MPa, 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 injection, 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. The injection amount of the oxygen-rich gas in the example is 0.1, 0.2, 0.3, 0.4, 0.5, etc. of the total volume of oxygen required for complete combustion of the carbonaceous reducing agent.

[0044] The injection amount of the carbonaceous reducing agent is 0.2-0.5:1, and the ratio of the molar amount of carbon in the carbonaceous reducing agent to the molar amount of zinc in the high-zinc material is (0.2, 0.3, 0.4, 0.5): 1. When the ratio of the molar amount of carbon in the carbonaceous reducing agent to the molar amount of zinc in the high-zinc material is small, such as less than 0.2, the reducing agent is insufficient. The second reduction zone is mainly to reduce the iron in the slag to generate pig iron. The reducing agent is insufficient, resulting in the pig iron being unable to be reduced or being reduced very little, and being mixed in the slag and unable to be separated from the slag, and the precious metals such as gold and silver cannot be further recovered; when the ratio of the molar amount of carbon in the carbonaceous reducing agent to the molar amount of zinc in the high-zinc material is large, such as greater than 0.5, the excess amount of reducing agent is too large, which increases the production cost.

[0045] In this embodiment, oxygen-rich gas and carbonaceous reducing agent are injected into the second reduction zone by jet blowing. The injection method of the second reduction zone includes side blowing alone, bottom blowing alone or a mixture of side blowing and bottom blowing. On the one hand, heat is provided for deep reduction, and on the other hand, carbonaceous reducing agent is provided for the reduction process. The continuous injection of carbonaceous reducing agent ensures that the volume ratio of CO to CO2 in the second reduction zone is 20-35:1, so that the high-zinc material undergoes a deep reduction reaction to obtain iron-containing metal material and zinc-containing vapor, which greatly improves the overflow rate of zinc metal.

[0046] The reduction smelting temperature of the second reduction zone is 1350-1500°C; the reduction smelting temperature of the second reduction zone in the example is 1350°C, 1400°C, 1450°C and 1500°C, etc., and the time for the initial reduction material to undergo a deep reduction reaction is 1-3h / heat; the time for the initial reduction material to undergo a deep reduction reaction in the example is 1h / heat, 2h / heat or 3h / heat, etc., wherein when the reduction smelting temperature of the initial reduction material in the second reduction zone is low, such as lower than 1350°C and the time is short, the power is insufficient during the reduction process, resulting in difficulty in reducing the pig iron or very little reduced iron 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 initial reduction material in the second reduction zone is high, such as higher than 1500°C and the time is long, the smelting energy consumption will increase, and the production cost will increase.

[0047] In 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, the reduction degree is insufficient, making it difficult to reduce pig iron or very little reduced iron is mixed in the slag, and it is impossible to separate from the slag, and it is impossible 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, the excess amount of reducing agent is too large, increasing production costs.

[0048] In some embodiments, the ratio of supplementary heat between the first reduction zone and the second reduction zone is 2-5:1.

[0049] The heat supplement ratio between the first reduction zone and the second reduction zone is (2, 3, 4, 5): 1, etc., wherein the heat supplement ratio can ensure that the 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 ensuring that the iron element in the slag is 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 used by the second reduction zone, which can effectively reduce smelting energy consumption and production costs. The time for the initial reduction and deep reduction reaction of high-zinc materials is 2-6h / furnace.

[0050] The high-zinc material is subjected to high-temperature reduction in the first reduction zone and the second reduction zone to obtain an iron-containing metal material and a zinc-containing vapor, wherein the iron-containing metal material includes pig iron and copper metal, gold metal and silver metal, wherein valuable metals such as copper metal, gold metal and silver metal are recovered from the pig iron; the zinc-containing vapor includes zinc vapor and lead and cadmium as well as indium and germanium reduced to form vapor, which enter the zinc vapor condensation device for capture and condensation to form a crude zinc liquid; the crude zinc liquid passes through a crude zinc distillation system, firstly controlling the vapor temperature to 900-950°C to separate and recover the lead metal; and then controlling the vapor temperature to 500-600°C to obtain refined zinc while enriching cadmium metal, indium metal and germanium metal into hard zinc, so as to achieve the purpose of recovering valuable metals such as cadmium metal, indium metal and germanium metal, and at the same time produce refined zinc with a purity of more than 99.995%.

[0051] 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%.

[0052] To facilitate further understanding of the present application, the scheme of the present application is further described below in conjunction with the embodiments. Those skilled in the art will understand that the description in the present application is only part of the examples, and any other suitable specific examples are within the scope of the present application.

[0053] Example 1 This embodiment provides a method for recovering valuable metals by short-process pyrometallurgical zinc smelting, wherein zinc concentrate is used as zinc sulfide material, and the specific operating parameters are as follows: the zinc concentrate is mixed with quartz sand at a mass ratio of 20:1 without complicated material 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 is heated in the oxidation smelting zone at 1100°C and the oxygen-to-material ratio is 100Nm 3 / t conditions for the first oxidation desulfurization reaction, this process forms copper matte material and preliminary oxide material, the mass percentage of S element in the preliminary oxide material is 5%, the mass percentage of Cu element in the copper matte material is 10%, the copper matte material is deposited on the bottom of the molten pool and discharged from the siphon port set in the oxidation smelting zone; increase the temperature of the oxidation smelting zone to 1350℃ and increase the oxygen-to-material ratio to 300Nm 3 / t, so that the slag is further desulfurized to form high-zinc material and high-cadmium smoke. The high-zinc material contains 0.9% S and 40% Zn, and the high-cadmium smoke contains 13% Cd.

[0054] The high-zinc material containing 0.9% S element and 40% Zn element and the coke block are initially reduced in the first reduction zone, the volume ratio of CO and CO2 is controlled to be 20:1, the temperature of the first reduction zone is 1200℃ for reduction for 1h, the ratio of the molar amount of carbon element in the reducing agent to the molar amount of zinc element in the low-sulfur high-zinc oxide is 0.8:1, and the initial reduction material and a large amount of zinc-containing vapor are obtained.

[0055] The preliminary reduced material is subjected to deep reduction reaction in the second reduction zone with the oxygen-rich gas and coal powder injected by jet injection, the volume ratio of CO to CO2 is controlled to be 20:1, the temperature of the second reduction zone is 1350℃ for 1h, the ratio of the molar amount of carbon element in the reducing agent to the molar amount of zinc element in the low-sulfur high-zinc oxide is 0.2:1, and iron-containing metal material and zinc-containing vapor are obtained; the zinc-containing vapor contains valuable metals such as cadmium, lead, indium, and germanium, and the zinc-containing vapor is condensed to produce crude zinc product. The iron-containing metal material is pig iron, and the iron element in the low-sulfur high-zinc oxide is reduced to generate pig iron, and copper, gold, and silver are enriched in the pig iron and recovered.

[0056] The crude zinc is refined by a crude zinc distillation system. In the distillation system, the temperature of the distillation metal vapor is first controlled at 900°C to separate and recover lead; then, the temperature of the distillation metal vapor is controlled at 500°C to separate and recover cadmium. The resulting refined zinc contains 99.996% Zn.

[0057] Example 2 This embodiment provides a method for recovering valuable metals by short-process pyrometallurgical zinc smelting, wherein zinc concentrate is used as the zinc sulfide material, and the specific operating parameters are as follows: the zinc concentrate does not need to be prepared in a complicated manner, 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 smelting furnace; the mixed material is heated in the oxidation smelting zone at 1200°C and an oxygen-to-material ratio of 200Nm 3 / t conditions for the first oxidation desulfurization reaction, this process forms copper matte material and preliminary oxide material, the mass percentage of S element in the preliminary oxide material is 3%, the mass percentage of Cu element in the copper matte material is 20%, the copper matte material is deposited on the furnace at the bottom of the molten pool and discharged from the siphon port set in the oxidation smelting zone; increase the temperature of the oxidation smelting zone to 1450℃ and increase the oxygen-to-material ratio to 400Nm 3 / t, so that the slag is further desulfurized to form high-zinc material and high-cadmium dust. The high-zinc material contains S 0.5%, Zn 50%, and the high-cadmium dust contains Cd 15%.

[0058] The high-zinc material containing 50% Zn and the crushed coke are initially reduced in the first reduction zone, the volume ratio of CO to CO2 is controlled to be 30:1, the temperature of the first reduction zone is 1250℃ for reduction for 2h, the ratio of the molar amount of carbon element in the reducing agent to the molar amount of zinc element in the low-sulfur high-zinc oxide is 1.0:1, and the initial reduced material and a large amount of zinc-containing vapor are obtained.

[0059] The preliminary reduced material is subjected to deep reduction reaction in the second reduction zone with the oxygen-rich gas and coke powder injected by jet injection, and the volume ratio of CO to CO2 is controlled to be 30:1. The temperature of the second reduction zone is 1400℃ for 2h. The ratio of the molar amount of carbon in the reducing agent to the molar amount of zinc in the low-sulfur high-zinc oxide is 0.3:1, and iron-containing metal materials and zinc-containing vapor are obtained; the zinc-containing vapor contains valuable metals such as cadmium, lead, indium, and germanium, and the zinc-containing vapor is condensed to produce crude zinc products. The iron-containing metal material is pig iron, and the iron element in the low-sulfur high-zinc oxide is reduced to generate pig iron, and copper, gold, and silver are enriched in the pig iron and recovered.

[0060] The crude zinc is refined by the crude zinc distillation system. In the distillation system, the temperature of the distillation metal vapor is first controlled at 925°C to separate and recover lead; then, the temperature of the distillation metal vapor is controlled at 550°C to separate and recover cadmium. The obtained refined zinc contains 99.997% Zn.

[0061] Example 3 This embodiment provides a method for recovering valuable metals by short-process pyrometallurgical zinc smelting, wherein zinc concentrate is used as zinc sulfide material, and the specific operating parameters are as follows: the zinc concentrate is mixed with quartz sand at a mass ratio of 5:1 to obtain a mixed material without complicated material preparation, and the mixed material is added to the oxidation smelting zone of the short-process pyrometallurgical zinc smelting furnace; the mixed material is smelted in the oxidation smelting zone at 1300°C and an oxygen-to-material ratio of 250Nm 3 / t conditions for the first oxidation desulfurization reaction, this process forms copper matte material and preliminary oxide material, the mass percentage of S element in the preliminary oxide material is 2%, the mass percentage of Cu element in the copper matte material is 30%, the copper matte material is deposited on the bottom of the molten pool furnace, and is discharged from the siphon port set in the oxidation smelting zone; the temperature of the oxidation smelting zone is increased to 1550℃ and the oxygen-to-material ratio is increased to 500Nm 3 / t, so that the slag is further desulfurized to form high-zinc material and high-cadmium smoke. In terms of mass percentage, the high-zinc material contains 0.3% S and 60% Zn, and the high-cadmium smoke contains 20% Cd.

[0062] The high-zinc material containing 0.3% S and 60% Zn and the coke block were initially reduced in the first reduction zone. The volume ratio of CO and CO2 was controlled to be 35:1. The temperature of the first reduction zone was 1300℃ for reduction for 3h. The ratio of the molar amount of carbon element in the reducing agent to the molar amount of zinc element in the low-sulfur and high-zinc oxide was 1.2:1, and the initial reduced material and a large amount of zinc-containing vapor were obtained.

[0063] The preliminary reduced material is subjected to deep reduction reaction in the second reduction zone with the oxygen-rich gas and coke powder injected by jet injection, and the volume ratio of CO to CO2 is controlled to be 35:1. The temperature of the second reduction zone is 1500℃ for 3h. The ratio of the molar amount of carbon in the reducing agent to the molar amount of zinc in the low-sulfur high-zinc oxide is 0.5:1, and iron-containing metal materials and zinc-containing vapor are obtained; the zinc-containing vapor contains valuable metals such as cadmium, lead, indium, and germanium, and the zinc-containing vapor is condensed to produce crude zinc products. The iron-containing metal material is pig iron, and the iron element in the low-sulfur high-zinc oxide is reduced to generate pig iron, and copper, gold, and silver are enriched in the pig iron and recovered.

[0064] The crude zinc is refined by the crude zinc distillation system. In the distillation system, the temperature of the distillation metal vapor is first controlled at 950°C to separate and recover lead; then, the temperature of the distillation metal vapor is controlled at 600°C to separate and recover cadmium. The obtained refined zinc contains Zn99.998%.

[0065] Among them, the zinc concentrate was treated by the traditional blast furnace process after batching as comparative example 1, the zinc concentrate was treated by the hydrometallurgical zinc smelting, i.e., the conventional leaching process as comparative example 2; the zinc concentrate was treated by the hydrometallurgical zinc smelting, i.e., the jarosite process as comparative example 3; the zinc concentrate was treated by the hydrometallurgical zinc smelting, i.e., the goethite process as comparative example 4. The valuable metal recovery rates obtained in each embodiment are exemplified and the results are shown in Table 1 below.

[0066] Table 1 Valuable metal recovery rates obtained in various examples and comparative examples

[0067] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction 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 may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0068] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify 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: The following steps are involved: The mixed material formed by the zinc sulfide material and the flux undergoes a first oxidation desulfurization reaction with the oxygen-rich gas in the oxidation smelting zone of the furnace chamber to obtain a preliminary oxide material and a copper matte material; The preliminary oxide material is subjected to a second oxidation desulfurization reaction in the oxidation smelting zone to form high-zinc material and high-cadmium smoke; 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; 50Nm 3 / t≤OM2-OM1≤400Nm 3 / t; The high-zinc material is reduced in a reduction smelting zone and the volume ratio of CO to CO2 is controlled to be 20-35:1; iron-containing metal material and zinc-containing vapor are obtained; 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.

2. The method according to claim 1, characterized in that The particle size of the mixed material is D, wherein 0.05 mm ≤ D ≤ 5 mm; 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 comprises at least one of quartz sand, quicklime and limestone; And / or, wherein the temperature of the first oxidation desulfurization reaction is 1100-1300°C, and the oxygen-to-material ratio is 100-250Nm 3 / t; And / or, the temperature of the second oxidation desulfurization reaction is 1350-1550°C, and the oxygen-to-material ratio is 300-500Nm 3 / t; And / or, the mass percentage of cadmium element in the high-cadmium smoke 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 and the first reducing agent are initially reduced in the first reduction zone to obtain the initially reduced material; the initially reduced material is subjected to a deep reduction reaction in the second reduction zone with the oxygen-rich gas and the carbonaceous reducing agent introduced by jet blowing.

4. The method according to claim 3, characterized in that Taking the high-zinc material as a reference, the sulfur content in the high-zinc material is less than 1%, and the Zn content is 40%-60% in terms of mass percentage; And / or, the first reduction zone is an electric heating reduction zone, which uses electrode heating, and the reduction smelting temperature is 1200-1300°C; And / or, the first reducing agent includes at least one of coke block, crushed coke, and anthracite block; and is added from the feed port of the first reduction zone; And / or, the ratio of the molar amount of carbon element in the first reducing agent to the molar amount of zinc element in the high-zinc material is 0.8-1.2:

1.

5. The method according to claim 3, characterized in that: The second reduction zone is a jet blowing combustion reduction, and the reduction smelting temperature is 1350-1500°C; And / or, the carbonaceous reducing agent comprises coke powder and / or coal powder; the ratio of the molar amount of carbon element in the carbonaceous reducing agent to the molar amount of 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 initial reduction and deep reduction reaction of the high-zinc material is 2-6h / heat; And / or, the time for the initial reduction of the high-zinc material is 1-3h / heat; And / or, the time for the deep reduction reaction of the preliminary reduced material is 1-3 h / heat.

7. The method according to claim 3, characterized in that The heat supplement ratio between the first reduction zone and the second reduction zone is 2-5:

1.

8. The method according to claim 3, characterized in that The oxygen concentration of the oxygen-rich gas is 23-99.8%, and the pressure is 0.20.5MPa; And / or, the oxygen-rich gas and the carbonaceous reducing agent are sprayed into the second reduction zone, and the amount of the oxygen-rich gas sprayed 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 distillation process: firstly, the steam temperature is controlled to be 900-950°C to separate and recover lead metal; then the steam temperature is controlled to be 500-600°C to obtain refined zinc, and at the same time, cadmium metal, indium metal and germanium metal are enriched to form 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 is >99.995%.

10. The method according to claim 3, characterized in that The blowing modes of the oxidation smelting zone and the second reduction zone include side blowing alone, bottom blowing alone or a mixture of side blowing and bottom blowing.

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