Method and equipment for recovering valuable metals from lead-zinc smoke and urban minerals

Abstract

This invention provides a method and equipment for the synergistic reduction and recovery of valuable metals from lead-zinc dust and urban minerals. The method includes the following steps: Lead-zinc dust, zinc-lead oxide materials, and urban minerals are prepared into lumps and mixed with a first reducing agent, then added to a smelting apparatus to form a bed material; a first oxygen-enriched gas is then bubbled into the bed material, resulting in a first zinc-containing gas, liquid lead metal, and unreduced oxides and gangue; the latter three components drip into a bottom molten pool to form a melt to be reduced; a second reducing agent, a second oxygen-enriched gas, and a reactive flux are bubbled into the melt to react, yielding a reactive gas. The first and second zinc-containing gases are then collected and recovered to obtain zinc metal. This invention is simple to operate, highly effective, and worthy of promotion.

Description

Technical Field

[0001] The invention belongs to the field of metal production or refining, and specifically relates to a method and equipment for collaboratively recovering valuable metals from lead-zinc smoke and urban minerals. Background Art

[0002] Lead-zinc dust and urban minerals are often treated in combination with pyrometallurgy in common technologies. In order to comply with the country's call to vigorously develop the urban mineral resource recycling industry, domestic lead-zinc smelting enterprises are transforming towards the use of secondary resources. Lead-zinc dust and urban minerals, as a relatively large type of secondary resources, have huge potential for use and appreciation.

[0003] As a difficult point in overcoming the technical barriers to secondary resource utilization, secondary resource utilization technology for refining valuable metals means huge economic and environmental benefits, and has become a technical focus of research and development in many countries and regions.

[0004] In this regard, my country has introduced oxygen-enriched molten pool smelting technology, which has been widely recognized by many countries. For example, the patent with publication number CN103421955B discloses a method for treating zinc leaching slag, in which kiln slag is fed into a smelting furnace, furnace charge is added from the top of the smelting furnace, oxygen-enriched air is blown into the molten pool through an oxygen lance to complete slag smelting, wherein the lead and zinc vapor generated after reduction is enriched in the flue gas. However, the above oxygen-enriched molten pool smelting technology still has technical problems such as large furnace gas dust and zinc vapor mostly existing in the form of oxidation, which makes capture difficult and inefficient.

[0005] Based on this, in order to solve the technical problems existing in the commonly used technology, such as large amount of smoke and dust in oxygen-rich molten pool smelting, large fluctuations in furnace gas composition, and easy oxidation of zinc-containing vapor resulting in difficulty in recovering metallic zinc. Summary of the invention

[0006] The invention aims to solve the technical problems existing in the above-mentioned conventional technologies, such as large amount of dust in oxygen-enriched molten pool smelting furnace gas, large fluctuation of furnace gas composition, and difficulty in recovering metallic zinc due to easy oxidation of zinc-containing vapor. The present invention provides a method for recovering valuable metals by synergistic reduction of lead-zinc dust and urban minerals, comprising the following steps:

[0007] Agglomerates are made from lead-zinc dust, zinc-lead oxide materials and urban minerals to obtain agglomerates;

[0008] The agglomerates are mixed with a first reducing agent and added to a smelting device to form a bed material, wherein the mass proportion of the first reducing agent in the agglomerates is 6 to 15%;

[0009] Blowing a first oxygen-rich gas into the bed material, reducing the metal oxides in the bed material to obtain a reduction residue, which includes the first zinc-containing gas, liquid lead metal, and unreduced oxides and gangue;

[0010] Liquid lead metal, unreduced oxides and gangue drop into the bottom molten pool of the smelting equipment to form a melt to be reduced, and a second reducing agent, a second oxygen-rich gas and a reaction flux are blown into the melt to be reduced to react and obtain a reaction gas, which includes CO, CO2 and zinc-containing vapor;

[0011] The first zinc-containing gas and the second zinc-containing gas are captured and recovered to obtain zinc metal, and the second zinc-containing gas is formed by the reaction gas rising through the bed material.

[0012] Furthermore, the temperature of the bed tuyere zone is 1100-1400°C, and the temperature of the melt to be reduced is 1100-1350°C.

[0013] Furthermore, the melt to be reduced also includes a lead-zinc-copper oxide melt introduced from the outside, and the lead-zinc-copper oxide melt includes one or more of the elements lead, zinc and copper;

[0014] The lead-zinc-copper oxide melt includes the following components in mass percentage: 1-30% lead, 1-40% zinc, 0-15% copper, 5-40% iron, 0.1-6% sulfur, 10-35% SiO2, and 1-15% CaO.

[0015] Furthermore, the agglomerate includes the following components in percentage by mass: 5-40% lead, 10-70% zinc, 0-10% copper, 10-20% flux or 0-5% binder.

[0016] Furthermore, the first zinc-containing gas and the second zinc-containing gas are captured by a lead rain / zinc rain condenser to obtain zinc metal.

[0017] Furthermore, the reaction products of the reaction of blowing a second reducing agent, a second oxygen-rich gas and a reaction flux into the molten metal to be reduced also include a crude lead alloy and slag. The crude lead alloy and the slag are separated after standing for 1 to 4 hours, and the crude lead alloy is recovered to obtain valuable metals.

[0018] Furthermore, the oxygen blowing amount of the first oxygen-rich gas is 0.3-1.5 of the theoretical amount of oxygen required to completely oxidize the first reducing agent into carbon monoxide, wherein the oxygen content in the first oxygen-rich gas is 21%-100%.

[0019] Furthermore, the injection amount of the second reducing agent is 0.8 to 2.0 of the mass of the second reducing agent required to reduce all the metal oxides in the reducing melt into metal elements.

[0020] Furthermore, the first reducing agent includes one or more of coke, bituminous coal and lump coal; the second reducing agent includes one or more of coke powder, anthracite, pulverized coal, natural gas and waste carbonaceous electrode rods / powder.

[0021] The present invention also provides a device for recovering valuable metals by synergistic reduction of lead-zinc smoke and urban minerals, comprising:

[0022] The bed layer is provided with an inner lining made of refractory bricks, and the outer surface of the bed layer is provided with smoke exhaust ports and air supply ports from top to bottom;

[0023] Wherein, one end of the smoke exhaust port away from the bed layer is fixedly connected with a condensing device;

[0024] The molten pool part is connected to the bed part, and an inlet is provided on the upper part of the outer surface of the molten pool part close to the bed part, a spray gun is provided on the outer surface of the molten pool part close to the bed part along its own length extension direction, and a slag discharge port and a siphon port are provided on the outer surface of the molten pool part away from the bed part from top to bottom.

[0025] The sealed material cup is fixedly connected to the top of the bed layer.

[0026] Compared with the commonly used techniques, the present invention has at least the following advantages:

[0027] The present invention can be used in large quantities in the lead-zinc joint smelting process to process secondary resources such as lead-zinc dust, zinc-lead oxide materials, and urban minerals, thereby achieving clean and efficient recycling of the above resources, synergistically extracting multiple valuable metals, and maximizing environmental and economic benefits.

[0028] The present invention couples the bed layer and the molten pool vertically, and can process solid and liquid materials at the same time, greatly improving the material processing capacity and efficiency. On the one hand, the bed layer can filter the furnace gas and dust generated by the smelting in the molten pool, so that the rising first zinc-containing gas and the second zinc-containing gas are purer. On the other hand, the materials in the bed layer fully react under a closed reducing atmosphere, including: the first reductant is burned under the injection of the first oxygen-rich gas to provide a reducing atmosphere, the unreduced oxides in the bed layer drip into the molten pool and are reduced under the injection of the second reductant and the second oxidant, and the CO generated by the reduction in the molten pool rises into the bed layer to further reduce the bed layer materials. Under triple reduction conditions, the material enters the capture and recovery device in the form of pure zinc vapor to obtain metallic zinc, and the metallic zinc is efficiently recovered. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0030] Figure 1 It is a schematic structural diagram of equipment for collaborative reduction and recovery of valuable metals from lead-zinc smoke and urban minerals in one embodiment of the present invention.

[0031] Figure 2 The present invention is a schematic flow chart of a method for recovering valuable metals by synergistic reduction of lead-zinc smoke and urban minerals in one embodiment of the present invention.

[0032] Description of the drawings: 1. Bed layer; 11. Bed material; 12. Smoke exhaust port; 13. Air supply port; 2. Molten pool; 21. Confluence port; 22. Spray gun; 23. Slag discharge port; 24. Siphon port; 3. Sealed material cup. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] Furthermore, the technical solutions between the various embodiments of the present invention may be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in the field. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0035] When numerical ranges are given in the embodiments, it should be understood that unless otherwise specified in the present invention, both endpoints of each numerical range and any value between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used in the present invention are familiar to those skilled in the art and the description of the present invention, and any method, device and material of the prior art similar or equivalent to the method, device and material in the embodiments of the present invention can also be used to implement the present invention.

[0036] It should be noted in advance that at present, the zinc smelting technologies at home and abroad include pyrometallurgy and hydrometallurgy, with the hydrometallurgy being the main one. As the mainstream process of zinc smelting at present, hydrometallurgy follows the procedures of "sulfuric acid roasting" / direct "leaching" - "purification" - "removal of old iron impurities" - "electrolytic refining". The hydrometallurgy technology has advantages and disadvantages: the process is long, the wastewater output is large, and the leaching slag produced (including yellow potassium iron alum slag, hematite slag, goethite slag, etc.) is hazardous waste and needs to be further treated by pyrometallurgy.

[0037] In most cases, compared with the pyrometallurgical treatment, the wet treatment of urban minerals, difficult-to-treat lead-zinc oxide ores, steel zinc dust, heavy metal sludge, etc., is more limited both at home and abroad. Therefore, pyrometallurgy is the mainstream method of industrial practice for urban minerals in the future. my country's urban minerals containing lead, zinc, copper, etc. have accumulated 4 billion tons. The country encourages and vigorously develops the urban mineral resource recycling industry, with a market size of 100 billion.

[0038] Among the pyrometallurgical zinc smelting technologies, horizontal zinc smelting and vertical zinc distillation have been phased out, electric furnace zinc smelting is small-scale and has not seen new development, and ISP technology is unique in pyrometallurgical zinc smelting. Under the background of the "three highs" problem in the non-ferrous industry, the ISP technology sintering link has been questioned by the industry due to problems such as pollution load; the benefits of smelting and processing of primary lead and zinc ore have also caused troubles to enterprises due to market fluctuations, and at the same time, it has also been impacted by hydrometallurgical zinc smelting and direct lead smelting technology. Pyrometallurgical zinc smelting technology has reached a critical juncture of self-innovation.

[0039] To this end, my country has specially introduced oxygen-enriched molten pool smelting technology, attempting to generate recycled lead, zinc and copper through recycling renewable resources and pyrometallurgical smelting to create economic and environmental benefits. However, my country is constrained by the technical problems of oxygen-enriched molten pool smelting technology, such as large smoke and dust, large fluctuations in furnace gas composition, and easy oxidation of zinc-containing vapor, resulting in low zinc metal recovery efficiency.

[0040] It should be noted that zinc oxide plays a harmful role in the condensation process, covering the zinc liquid with a layer of zinc oxide, which prevents the droplets from further coalescing into large particles. Therefore, blue powder is often produced during the pyrometallurgical zinc smelting process. This blue powder is actually zinc droplets covered by zinc oxide, which reduces the condensation efficiency of zinc vapor condensing into liquid zinc, making the condensation efficiency lower.

[0041] It should also be noted that the bed-coupled molten pool smelting of the present invention is not a simple superposition of the molten pool and the bed. The separate molten pool smelting and column blast reduction in the commonly used technology usually have the following limitations: separate molten pool smelting is often subject to the technical defects of large furnace gas dust and zinc vapor in the form of oxidation, which leads to difficulty in capture and low efficiency during the smelting process; and column blast reduction still has technical defects such as complex expected pretreatment process (sintering is required), low thermal utilization rate, high energy and carbon consumption, and poor material compatibility. The present invention ingeniously couples the bed and the molten pool, and overcomes the technical shackles of the inability to efficiently reduce high-zinc melts in the molten pool and the inability to directly recover metallic zinc in the molten pool reduction by means of bed and molten pool linkage and atmosphere control.

[0042] like Figure 2 As shown, the present invention provides a method for recovering valuable metals by synergistic reduction of lead-zinc smoke and urban minerals, comprising the following steps:

[0043] S1. Agglomerate lead-zinc dust, zinc-lead oxide materials and urban minerals to obtain agglomerates.

[0044] In some embodiments, lead-zinc smoke may include one or more of zinc oxide ash, lead-zinc smelting dust removal sludge, copper-containing electroplating sludge, galvanizing sludge, steel plant zinc-containing ash, lead-containing smoke, hot-dip galvanizing process dust and zinc powder replacement precious metal sludge; zinc-lead oxide materials may include one or more of lead / zinc oxide ore, lead-silver slag from hydrometallurgical zinc smelting system, and zinc leaching slag; urban minerals may include one or more of waste circuit boards, electronic components, copper-containing sludge, CRT lead glass, lead paste for lead-acid batteries, and waste zinc-manganese batteries.

[0045] S2. Mixing the agglomerates with the first reducing agent and adding them into the smelting equipment to form a bed material, wherein the mass proportion of the first reducing agent in the agglomerates is 6-15%.

[0046] In some embodiments, the excess coefficient of the first reducing agent may be between 0.7 and 1.2, that is, the mass of the first reducing agent is 0.7 to 1.2 times the theoretical mass required to completely reduce the metal oxides in the agglomerates.

[0047] Exemplarily, the first reducing agent may be coke. After the agglomerates and the coke are mixed in proportion, they are added into the smelting equipment through the closed material pot 3 to form the bed material 11.

[0048] In other embodiments, the smelting equipment may be a vertically coupled bed and furnace, such as the equipment for collaborative reduction of lead-zinc smoke and urban minerals to recover valuable metals as provided below in the present invention (i.e., a bed-coupled molten pool furnace, the same below).

[0049] S3. Blowing the first oxygen-rich gas into the bed material, the metal oxides in the bed material 11 are reduced to obtain a reduction residue, which includes the first zinc-containing gas, liquid lead metal, and unreduced oxides and gangue.

[0050] S4. Liquid lead metal, unreduced oxides and gangue drop into the bottom molten pool to form a melt to be reduced, into which a second reducing agent, a second oxygen-rich gas and a reaction flux are blown to react to obtain a reaction gas, which includes CO, CO2 and zinc-containing vapor.

[0051] In some embodiments, dust formed by volatilization of the material at high temperature rises with the reaction gas, and the dust is filtered through the bed material 11 and filled into the pores between the bed materials 11; and the above-mentioned CO further participates in the reduction reaction of the bed material, providing a reducing atmosphere for the bed material 11 in the closed smelting equipment.

[0052] In other embodiments, the excess coefficient of the second reducing agent is controlled between 0.8 and 2.0, that is, the mass of the second reducing agent is 0.8 to 2.0 times the theoretical mass required to completely reduce the metal oxides in the melt to be reduced.

[0053] The second oxygen-rich gas can be used as a carrier to spray the second reducing agent and the reaction flux (which can also be a slag type regulator) into the melt to be reduced. The above three can fully stir the molten pool and efficiently complete the slag-making reaction.

[0054] Exemplarily, the second reductant may include one or more of coke powder, pulverized coal, natural gas, and waste carbonaceous electrode rods / powder.

[0055] S5. Capture and recover the first zinc-containing gas and the second zinc-containing gas to obtain zinc metal, wherein the second zinc-containing gas is formed by the reaction gas rising through the bed material.

[0056] The specific reactions in the smelting equipment are as follows:

[0057] Bed section 1 reaction;

[0058] ZnO(s)+C=Zn(g)+CO(g)

[0059] ZnO(s)+CO(g)=Zn(g)+CO2(g)

[0060] PbO(s)+C=Pb(l)+CO(g)

[0061] PbO(s)+CO(g)=Pb(l)+CO2(g)

[0062] Molten pool part 2 reaction:

[0063] (ZnO)+C / CO(g)=Zn(g)+CO(g) / CO2(g)

[0064] (ZnFe2O4)+C / CO(g)=Zn(g)+FeO+CO(g) / CO2(g)

[0065] (Zn2SiO4)+C / CO(g)=Zn(g)+SiO2+CO(g) / CO2(g)

[0066] PbO(l)+C / CO(g)=[Pb](l)+CO(g) / CO2(g)

[0067] PbSiO3(l)+C / CO(g)=[Pb](l)+SiO2+CO(g) / CO2(g)

[0068] Cu2O(l)+C / CO(g)=[Cu](l)+CO(g) / CO2(g)

[0069] The present invention can be used in large quantities in the lead-zinc joint smelting process to process secondary resources such as lead-zinc dust, zinc-lead oxide materials, and urban minerals, thereby achieving clean and efficient recycling of the above resources, synergistically extracting multiple valuable metals, and maximizing environmental and economic benefits.

[0070] The present invention couples the bed layer 1 and the molten pool 2 and sets them vertically, which can process solid and liquid materials at the same time, and the material processing capacity and efficiency are greatly improved. On the one hand, the bed material 11 can filter the furnace gas and dust generated by the molten pool smelting, so that the rising first zinc-containing gas and the second zinc-containing gas are purer; on the other hand, the bed material 11 fully reacts under the closed reducing atmosphere, including: the first reducing agent is burned under the injection of the first oxygen-rich gas to provide a reducing atmosphere, the unreduced oxides in the bed material 11 drip into the molten pool and are reduced under the injection of the second reducing agent and the second oxidant, and the CO generated by the reduction in the molten pool rises into the bed material 11 to further reduce the bed material. Under the triple reduction conditions, the material enters the capture and recovery device in the form of pure zinc vapor to obtain metallic zinc, and the metallic zinc is efficiently recovered.

[0071] In some embodiments, the temperature of the blast tuyere zone of the bed material 11 is 1100-1400°C, and the temperature of the melt to be reduced is 1100-1350°C.

[0072] The first oxygen-rich gas can be blown into the bed portion 1 from the lower air inlet 13, and the blowing volume can be adjusted so that the temperature of the air inlet area of ​​the bed material 11 is maintained at 1100-1400°C, so as to supplement heat for the combustion of the reducing agent and provide sufficient reducing atmosphere for the bed material 11, so that the bed material can be fully reduced under the cooperation of the first reducing agent and the reducing atmosphere.

[0073] The melt to be reduced can be sprayed with a suitable proportion of the second reducing agent and the reaction flux through the submerged spray guns 22 on both sides, using the second oxygen-rich gas as a carrier, to fully stir the molten pool. The air volume is adjusted to control the temperature of the melt to be reduced to be maintained at 1100-1350°C, providing sufficient heat for the reduction reaction of the unreduced oxides and gangue in the molten pool, and efficiently completing the slag-making reaction.

[0074] In some embodiments, the melt to be reduced may also include a lead-zinc-copper oxide melt introduced from outside, wherein the lead-zinc-copper oxide melt includes at least one of lead, zinc and copper, thereby effectively improving the waste slag treatment capacity of the molten pool.

[0075] The lead-zinc-copper oxide melt may include a lead-zinc sulfide desulfurization melt and a lead-zinc hot smelting slag introduced from the outside, and the lead-zinc sulfide desulfurization melt and the lead-zinc hot smelting slag may include the following components in mass percentage: 1-30% lead, 1-40% zinc, 0-15% copper, 5-40% iron, 0.1-6% sulfur, 10-35% SiO2, and 1-15% CaO.

[0076] The agglomerate may include the following components in percentage by mass: 5-40% lead, 10-70% zinc, 0-10% copper, 10-20% flux or 0-5% binder.

[0077] In some embodiments, the melt to be reduced may include the following components in mass percentage: 25-33% zinc, 5-20% lead, 0.3-5% copper, 5-12% iron, 12-20% silicon, and 4-8% calcium.

[0078] The composition of the agglomerate and the melt to be reduced is slightly different because the ratio of the components in the agglomerate is to ensure that the agglomerate has a certain compressive strength and a higher soft melting temperature, while the composition of the melt to be reduced needs to ensure that the high zinc (>25%) material is in a molten state at the conventional melting temperature.

[0079] In some embodiments, the first zinc-containing gas and the second zinc-containing gas are captured by a lead rain / zinc rain condenser to obtain zinc metal.

[0080] In some embodiments, the reaction products of the reaction of blowing a second reducing agent, a second oxygen-rich gas, and a reaction flux into the molten metal to be reduced also include a crude lead alloy and slag. The crude lead alloy and the slag are separated after standing for 1 to 4 hours, and the crude lead alloy is recovered to obtain valuable metals.

[0081] The reduced crude lead alloy in the molten pool settles at the bottom of the molten pool and is enriched with precious metals such as gold and silver. The crude lead alloy and the slag are separated after standing for 1 hour. Further, the crude lead alloy can be discharged from the siphon port 24 and sent to the refining workshop to obtain pure metal, while the slag can be discharged from the slag discharge port for water quenching or sent to a fuming furnace for treatment.

[0082] In some embodiments, the amount of oxygen blown into the first oxygen-rich gas can be 0.3 to 1.5 of the theoretical amount of oxygen required to completely reduce the first reducing agent into carbon monoxide, wherein the oxygen content in the first oxygen-rich gas is 21% to 100%; the amount of oxygen blown into the second reducing agent is 0.8 to 2.0 of the mass of the second reducing agent required to completely reduce the metal oxides in the reducing melt into elemental metals.

[0083] Exemplarily, the first reducing agent may include one or more of coke, bituminous coal and lump coal; the second reducing agent may include one or more of coke powder, anthracite, pulverized coal, natural gas and waste carbonaceous electrode rod powder.

[0084] As another example, the composition of coke powder, anthracite, pulverized coal, natural gas and waste carbonaceous electrode rods / powder may include: 40-90% fixed carbon, 1-30% volatile matter, and 10-25% ash.

[0085] When the second reducing agent is coke powder, its composition may be 75-90% fixed carbon, 1-5% volatile matter, 10-20% ash, 20-30% total iron in the ash, 40-50% SiO2, 20-30% CaO, and 1-10% Al2O3.

[0086] Specifically, the above-mentioned smelting equipment may be a bed-coupled molten pool furnace, as described below:

[0087] The present invention also provides an equipment (bed-coupled molten pool furnace) for recovering valuable metals by synergistic reduction of lead-zinc smoke and urban minerals, comprising a bed portion 1, a molten pool portion 2 and a closed charging cup 3.

[0088] In some embodiments, the bed portion 1 may be columnar, with a diameter of 2-6 meters and a height of 2-10 meters, and a steel plate spray water jacket or a copper water jacket may be provided in the high temperature zone of the bed 11. The molten pool portion 2 may be provided with a rectangular space surrounded by a copper water jacket, with a height of 1-8 meters, a width of 2-8 meters, and a length of 4-10 meters.

[0089] The interior of the bed portion 1 may be provided with an inner lining made of refractory bricks, and the outer surface of the bed portion 1 may be provided with a smoke exhaust port 12 and an air supply port 13 in sequence from top to bottom. The end of the smoke exhaust port 12 away from the bed portion 1 is fixedly connected to a condensing device.

[0090] Exemplarily, the condensing device may be a lead rain / zinc rain condensing device.

[0091] In some embodiments, the number of the air supply ports 13 may be 8-24, and the cross-sectional area of ​​each air supply port 13 may be 3-120 cm 2 .

[0092] The molten pool portion 2 is connected to the bed portion 1, and an inlet 21 is provided on the upper portion of the outer surface of the molten pool portion 2 close to the bed portion 1, a spray gun 22 is provided on the outer surface of the molten pool portion 2 on one side close to the bed portion 1 along its own length extension direction, and a slag discharge port 23 and a siphon port 24 are provided from top to bottom on the outer surface of the molten pool portion 2 away from the bed portion 1.

[0093] The molten pool 2 may be provided with a reduction zone and a clarification zone in sequence along the length extension direction, wherein the reduction zone is located directly below the connection between the molten pool 2 and the bed layer 1. The above-mentioned spray gun 22 is located in the reduction zone, the number of the spray gun 22 may be 2 to 24, and the cross-sectional area of ​​the nozzle of the spray gun 22 may be 2 to 120 cm 2 The angle between the center axis of the nozzle and the horizontal plane can be -15° to 15°.

[0094] The sealed material cup 3 is fixedly connected to the top of the bed layer part 1.

[0095] In practical applications, the agglomerates mixed in proportion and the first reducing agent can be added to the bed material 11 through the closed material cup 3, and the first oxygen-rich gas is blown into the bed material 11 through the air supply port 13, and the blowing amount is adjusted so that the temperature of the bed tuyere area is maintained at 1100-1400°C. Sufficient oxygen and heat allow the first reducing agent to react with the bed material, and the carbon monoxide generated by the combustion of the first reducing agent further provides a reducing atmosphere for the bed material. After the reaction is completed, the first zinc-containing gas generated rises and enters the lead rain / zinc rain condensation device through the exhaust port 12 to recover valuable metals; the remaining reduction residues, including liquid lead metal and unreduced oxides and gangue, drip from the bed material 11 to the bottom of the molten pool, and form a melt to be reduced with the lead-zinc-copper oxide melt (which may include lead-zinc sulfide desulfurization melt and lead-zinc hot smelting slag) introduced from the inlet 21.

[0096] The spray gun 22 is located below the liquid surface of the melt to be reduced, and uses the second oxygen-rich gas as a carrier to spray a sufficient amount of the second reducing agent and the reaction flux into the melt to be reduced, while maintaining the temperature of the melt to be reduced at 1100-1350°C and fully stirring the melt to be reduced. The melt to be reduced reacts to generate reaction gas, crude lead alloy and slag, and the reaction gas rises to the bed material 11, the smoke is filtered by the bed material 11, CO and the bed material 11 further undergo a reduction reaction, and the second zinc-containing gas is discharged from the exhaust port 12 together with the first zinc-containing gas and captured by the condensation device; the crude lead alloy and the slag are separated after standing for 1-4 hours, the crude lead alloy is enriched with precious metals such as gold and silver and settles, the crude lead alloy is discharged from the siphon port 24 and enters the refining system for further recovery, and the slag is collected from the slag discharge port 23 and enters the fuming furnace for treatment.

[0097] In order to facilitate those skilled in the art to further understand the present invention, examples are given below:

[0098] Some nouns or names in the embodiments may be explained here.

[0099] Example 1

[0100] See attached Figure 1 The present invention provides a device for the synergistic reduction of lead-zinc smoke and urban minerals to recover valuable metals. The bed-coupled molten pool furnace consists of an upper bed portion 1 and a lower molten pool portion 2. The interior of the bed portion 1 is lined with refractory bricks, and the molten pool portion is built into a rectangular space, which is divided into a reduction zone and a clarification zone. The reduction zone is provided with horizontal but laterally inclined nozzles, the number of nozzles can be 24, and the cross-sectional area of ​​each nozzle is 120 cm 2The angle between the axis of the nozzle 00 and the horizontal plane is 15°; the bed portion 1 is provided with an air supply port 13 and a smoke exhaust port 12, the smoke exhaust port 12 is connected to the condensation facility, a liquid melt inlet 21 is provided on one side of the molten pool reduction zone near the bed portion 1, and a slag discharge port 23 and a siphon port 24 are provided in the molten pool clarification zone at the other end from top to bottom in vertical height.

[0101] In this embodiment, the diameter of the bed portion 1 is 6 meters and the height is 10 meters. The number of air supply ports 13 at the lower part of the bed portion 1 is 24, and the cross-sectional area of ​​each air supply port 13 is 120 cm 2 The high temperature area of ​​the bed is provided with a steel plate spraying water jacket or a copper water jacket. In this embodiment, the molten pool part 2 is provided with a rectangular space surrounded by a copper water jacket, which is 8 meters in height, 8 meters in width and 10 meters in length.

[0102] Example 2

[0103] According to the present invention, a method for recovering valuable metals by synergistic reduction of zinc-lead oxide materials and urban minerals is as follows:

[0104] (1) Zinc-containing fly ash, zinc-lead oxide material, zinc-containing sludge and lead-silver slag from a hydrometallurgical zinc smelting system are mixed and pressed into agglomerates to prepare a composition containing 29.6 wt.% of lead, 43.9 wt.% of zinc, 1.6 wt.% of copper, 4.5 wt.% of iron, 5.4 wt.% of SiO2 and 2.7 wt.% of CaO. The agglomerates are then mixed with 15% of coke and added to the bed layer of a bed-coupled molten pool furnace from an upper closed charging bowl 3.

[0105] (2) Hot air at 900°C is blown into the air inlet 13 below the bed layer, and the temperature of the air inlet area is controlled to be 1300°C (error ±50°C). The lead, zinc and copper oxides in the bed agglomerates are reduced to obtain the first zinc-containing gas, liquid lead metal and unreduced oxides and gangue under the synergistic reduction effect of the hot CO-CO2 mixed gas overflowing and rising from the coke and the molten pool.

[0106] (3) Liquid lead metal and unreduced oxides and gangue drop into the molten pool and together with the lead-zinc-copper oxide melt (composition: 11.7wt.% lead, 26.7wt.% zinc, 7.1wt.% copper, 15.4wt.% iron, 0.8wt.% sulfur, 13.2wt.% SiO2, 12.4wt.% CaO) added into the molten pool from the molten pool inlet at the lower end of the bed-coupled molten pool furnace form a melt to be reduced. Through the spray guns on both sides, the reaction flux and coke powder are blown into the melt to be reduced with the second oxygen-rich gas as the carrier (the coke powder consists of: 81.3% fixed carbon, 3.3% volatile matter, 15.4% ash, 25.2% total iron, 41.2% SiO2, 25.2% CaO, 6.6% Al2O3 in the ash, and the oxygen content in the second oxygen-rich gas is 35%), the molten pool is strongly stirred, the temperature of the melt to be reduced is controlled to be maintained at 1250°C, the unreduced metal oxides such as lead, zinc, and copper in the molten pool are continuously reduced, and the slag-making reaction is completed at the same time.

[0107] (4) The reduced lead, copper and other alloys in the molten pool are clarified in the clarification zone for 3 hours and enriched with precious metals such as gold and silver, separated from the slag, and the reaction gas enters the gas phase, which is then filtered through the bed material to reduce the dust particle content in the gas phase to obtain the second zinc-containing gas. The first zinc-containing gas and the second zinc-containing gas are captured by the condensation facility to obtain zinc metal.

[0108] After reduction, the alloy product contains 81.1% lead, 13.2% copper and 3.6% zinc. The gold and silver capture rate is greater than 93%. The copper, lead and zinc contents in the slag are reduced to below 0.2%, 1% and 5% respectively.

[0109] Example 3

[0110] According to the present invention, a method for recovering valuable metals by synergistic reduction of zinc-lead oxide materials and urban minerals is as follows:

[0111] (1) Lead-containing smoke dust, lead-silver slag, zinc leaching slag, galvanizing sludge, zinc-containing smoke ash from a steel plant, and copper-containing electroplating sludge are mixed and pressed into agglomerates to prepare a composition of 16.7 wt.% lead, 37.7 wt.% zinc, 4.1 wt.% copper, 3.7 wt.% iron, 7.1 wt.% SiO2, and 7.5 wt.% CaO; the agglomerates are then mixed with 12% bituminous coal and added to the bed layer of a bed-coupled molten pool furnace from an upper closed material cup 3.

[0112] (2) hot air at 700°C is blown into the air inlet 13 below the bed layer, and the temperature of the air inlet area is controlled to be 1350°C (error ±50°C). The lead, zinc and copper oxides in the bed agglomerates are reduced to obtain the first zinc-containing gas, liquid lead metal and unreduced oxides and gangue under the synergistic reduction effect of the hot CO-CO2 mixed gas overflowing and rising from the molten pool;

[0113] (3) Liquid lead metal and unreduced oxides and gangue drop into the molten pool and together with the lead-zinc-copper oxide melt (composition: 25.1wt.% lead, 32.5wt.% zinc, 4.4wt.% copper, 13.9wt.% iron, 0.4wt.% sulfur, 10.2wt.% SiO2, 2.5wt.% CaO) added into the molten pool from the molten pool inlet at the lower end of the bed-coupled molten pool furnace, form a melt to be reduced. Through the spray guns on both sides, the reaction flux and anthracite (the anthracite composition is: 48.5% fixed carbon, 0.75% total sulfur, 33.8% volatile matter, 16.1% ash, and the oxygen content in the second oxygen-enriched gas is 50%) are blown into the melt to be reduced with the second oxygen-enriched gas as a carrier, the molten pool is strongly stirred, the temperature of the melt to be reduced is controlled to be maintained at 1350°C, the unreduced metal oxides such as lead, zinc, and copper in the molten pool are continuously reduced, and the slag-making reaction is completed at the same time;

[0114] (4) The reduced lead, copper and other alloys in the molten pool are clarified in the clarification zone for 3 hours and enriched with precious metals such as gold and silver, and separated from the slag. The reaction gas is filtered through the bed material to reduce the dust particle content in the gas phase to obtain the second zinc-containing gas. The first zinc-containing gas and the second zinc-containing gas are captured by the condensation facility to obtain zinc metal.

[0115] After reduction, the alloy product contains 82.5% lead, 13.6% copper, 2.3% zinc, and the gold and silver capture rate is greater than 95%; the copper, lead and zinc contents in the slag are reduced to below 0.3%, 1.5% and 7% respectively.

[0116] Example 4

[0117] According to the present invention, a method for recovering valuable metals by synergistic reduction of zinc-lead oxide materials and urban minerals is as follows:

[0118] (1) Lead and zinc smelting dust removal sludge, galvanizing sludge, hot-dip galvanizing process dust, steel mill zinc-containing fly ash, zinc powder replacement precious metal sludge and electronic component powder after organic matter removal are mixed and pressed into agglomerates to prepare a composition containing 37.2wt.% of lead, 24.1wt.% of zinc, 2.4wt.% of copper, 8.6wt.% of ferrous oxide (equivalent), 9.5wt.% of SiO2 and 8.2wt.% of CaO. The agglomerates are then mixed with 10% of lump coal and added to the bed layer of the bed-coupled molten pool furnace from the upper closed charging cup 3.

[0119] (2) Hot air of 800°C is blown into the air inlet 13 below the bed layer, and the temperature of the air inlet area is controlled to be 1250°C (error ±50°C). The lead, zinc and copper oxides in the bed agglomerates are reduced to obtain the first zinc-containing gas, liquid lead metal and unreduced oxides and gangue under the synergistic reduction action of the hot CO-CO2 mixed gas overflowing and rising from the molten pool;

[0120] (3) Liquid lead metal and unreduced oxides and gangue drop into the molten pool and together with the lead-zinc-copper oxide melt (composition: 15.8wt.% lead, 34.6wt.% zinc, 6.5wt.% copper, 8.56wt.% iron, 1.2wt.% sulfur, 18.5wt.% SiO2, 7.2wt.% CaO) added into the molten pool from the molten pool inlet at the lower end of the bed-coupled molten pool furnace form a melt to be reduced. Through the nozzles on both sides, the reaction flux and bituminous pulverized coal (wherein the bituminous coal composition is: 48.72% fixed carbon, 0.64% total sulfur, 26.52% volatile matter, 24.12% ash, and the oxygen content in the second oxygen-enriched gas is 70%) are blown into the melt to be reduced with the second oxygen-enriched gas as a carrier, the molten pool is strongly stirred, the temperature of the melt to be reduced is controlled to be maintained at 1300°C, the unreduced metal oxides such as lead, zinc, and copper in the molten pool are continuously reduced, and the slag-making reaction is completed at the same time;

[0121] (4) The reduced lead, copper and other alloys in the molten pool are clarified in the clarification area for 2.5 hours and enriched with precious metals such as gold and silver, and separated from the slag. The reaction gas enters the gas phase, and the gas phase is filtered through the bed material to reduce the dust particle content in the gas phase to obtain the second zinc-containing gas. The first zinc-containing gas and the second zinc-containing gas are captured by the condensation facility to obtain zinc metal.

[0122] After reduction, the alloy product contains 86.4% lead, 10.6% copper, 2.5% zinc, and the gold and silver capture rate is greater than 96%; the copper, lead and zinc contents in the slag are reduced to below 0.1%, 1.2% and 4% respectively.

[0123] The above technical solutions of the present invention are only preferred embodiments of the present invention, and the patent scope of the present invention is not limited thereto. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A method for recovering valuable metals by synergistic reduction of lead-zinc smoke and urban minerals, characterized in that: The following steps are involved: Lead-zinc smoke, zinc-lead oxide materials and urban minerals are pelletized to obtain briquettes, wherein the briquettes include the following components in percentage by mass: 5-40% lead, 10-70% zinc, 0-10% copper, 10-20% flux or 0-5% binder; The agglomerates are mixed with a first reducing agent and added into a smelting device to form a bed material, wherein the mass proportion of the first reducing agent in the agglomerates is 6 to 15%; The smelting equipment comprises: The bed layer is provided with an inner lining made of refractory bricks, and the outer surface of the bed layer is provided with smoke exhaust ports and air supply ports in sequence from top to bottom; Wherein, one end of the smoke exhaust port away from the bed portion is fixedly connected with a condensing device; The molten pool part is connected with the bed part, the upper part of the outer surface of the molten pool part close to the bed part is provided with a confluence port, the outer surface of the molten pool part close to the bed part along the length extension direction thereof is provided with a spray gun, and the outer surface of the molten pool part away from the bed part is provided with a slag discharge port and a siphon port from top to bottom respectively; the molten pool part is provided with a reduction zone and a clarification zone in sequence along the length extension direction, wherein the reduction zone is located directly below the place where the molten pool part and the bed part are connected; A sealed material cup is fixedly connected to the top of the bed layer; Blowing a first oxygen-rich gas into the bed material, reducing the metal oxides in the bed material to obtain a reduction residue, wherein the reduction residue includes a first zinc-containing gas, liquid lead metal, and unreduced oxides and gangue; The liquid lead metal, the unreduced oxide and the gangue drop into the bottom molten pool of the smelting equipment to form a melt to be reduced, and a second reducing agent, a second oxygen-rich gas and a reaction flux are blown into the melt to be reduced to react and obtain a reaction gas, wherein the reaction gas includes CO, CO2 and zinc-containing vapor; The first zinc-containing gas and the second zinc-containing gas are captured and recovered to obtain zinc metal, and the second zinc-containing gas is formed when the reaction gas rises and passes through the bed material.

2. The method for recovering valuable metals by synergistic reduction of lead-zinc smoke and urban minerals according to claim 1, characterized in that: The temperature of the bed tuyere zone is 1100-1400°C, and the temperature of the melt to be reduced is 1100-1350°C.

3. The method for recovering valuable metals by synergistic reduction of lead-zinc smoke and urban minerals according to claim 1, characterized in that: The melt to be reduced also includes a lead-zinc-copper oxide melt introduced from outside; The lead-zinc-copper oxide melt includes the following components in mass percentage: 1-30% lead, 1-40% zinc, 0-15% copper, 5-40% iron, 0.1-6% sulfur, 10-35% SiO2, and 1-15% CaO.

4. The method for recovering valuable metals by synergistic reduction of lead-zinc smoke and urban minerals according to claim 1, characterized in that: The first zinc-containing gas and the second zinc-containing gas are captured by a lead rain / zinc rain condenser to obtain zinc metal.

5. The method for recovering valuable metals by synergistic reduction of lead-zinc smoke and urban minerals according to claim 1, characterized in that: The reaction products of the reaction of blowing the second reducing agent, the second oxygen-rich gas and the reaction flux into the molten metal to be reduced also include crude lead alloy and slag. The crude lead alloy and the slag are separated after standing for 1 to 4 hours, and the crude lead alloy is recovered to obtain valuable metals.

6. The method for recovering valuable metals by synergistic reduction of lead-zinc smoke and urban minerals according to claim 1, characterized in that: The amount of oxygen injected into the first oxygen-rich gas is 0.3-1.5 of the theoretical amount of oxygen required to completely oxidize the first reducing agent into carbon monoxide, wherein the oxygen content in the first oxygen-rich gas and the second oxygen-rich gas is 21%-100%.

7. The method for recovering valuable metals by synergistic reduction of lead-zinc smoke and urban minerals according to claim 1, characterized in that: The injection amount of the second reducing agent is 0.8 to 2.0 of the mass of the second reducing agent required to reduce all the metal oxides in the melt to be reduced into metal elements.

8. The method for recovering valuable metals by synergistic reduction of lead-zinc smoke and urban minerals according to any one of claims 1 to 7, characterized in that: The first reducing agent includes one or more of coke, bituminous coal and lump coal; the second reducing agent includes one or more of coke powder, anthracite, pulverized coal, natural gas and waste carbonaceous electrode rods / powder.

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