Zinc smelting method and its application

Abstract

The present invention provides a zinc smelting method, comprising the following steps: mixing zinc-lead materials, urban minerals and a regulator to obtain a mixed material; the elements and element mass fractions in the mixed material include: 10-50% lead, 10-40% zinc, and 2-15% copper; adding the mixed material to a molten pool reduction furnace, and after the mixed material is melted, a zinc-lead-copper melt entering the molten pool of the molten pool reduction furnace and a bed material maintained in situ are obtained; a first reaction gas, a zinc-lead-copper melt and a bed material are introduced into the molten pool, and a crude lead alloy, zinc vapor and slag are obtained through a reduction reaction; wherein the reduction reaction is carried out under non-oxygen-enriched conditions, the oxygen content in the atmosphere in which the reduction reaction is carried out is 0-20%, and at least one of the first reaction gas and the regulator includes a reducing agent. The present invention can selectively reduce the mixed material under non-oxygen-enriched and low reducing power conditions by controlling the ratio of the mixed material and the slag, thereby effectively improving the direct recovery rate of valuable metals and zinc.

Description

Technical Field

[0001] The invention belongs to the field of lead and zinc smelting, and specifically relates to a zinc smelting method and application thereof. Background Art

[0002] Zinc smelting technologies at home and abroad include pyrometallurgy and hydrometallurgy. The pyrometallurgy is mainly based on ISP technology, where the lead-zinc mixture is first sintered / roasted, and then reduced by blast reduction to recover metallic lead and zinc. However, at present, the ISP process blast furnace slag contains relatively high levels of valuable metals such as zinc, and the direct metal recovery rate per unit energy consumption and carbon consumption is low, and the sintering and other processes are seriously polluting. The ISP technology is subject to the dual impact of resource recycling and environmental protection, and is in need of a technological breakthrough. Zinc smelting at home and abroad is mainly based on the hydrometallurgy. Compared with the pyrometallurgy, the hydrometallurgy has significant advantages in technical indicators and environmental benefits, but it also has problems such as long process flow and large output of wastewater and hazardous waste leaching slag.

[0003] At the same time, various non-ferrous metal industries such as lead, zinc and copper are facing the challenge of coordinating the processing of secondary resources such as urban minerals. The traditional advantages of pyrometallurgy, such as large smelting processing volume and strong raw material adaptability, are highlighted in the coordinated disposal of secondary resources. Major resource recycling countries such as Europe, the United States and Japan have achieved large-scale resource recovery of secondary resources such as urban minerals in the pyrometallurgical smelting process.

[0004] Oxygen-enriched molten pool smelting technology has the above advantages of large smelting processing capacity and strong raw material adaptability. By increasing the oxygen content in the blast, the smelting intensity is improved and the output is increased. It has been widely used in lead and copper smelting, and has formed my country's independent intellectual property rights. It also has extremely broad development prospects in zinc and secondary resource pyrometallurgical smelting technology.

[0005] The oxygen content in the blast of oxygen-enriched molten pool smelting increases, the nitrogen content decreases, the air volume required to burn carbon decreases, and the amount of gas produced by the corresponding tuyere will also decrease. And because the effect of the reduction in the amount of gas on the reduction of the water equivalent ratio of gas and charge exceeds the effect of the increase in wind temperature, the gas temperature decreases more seriously when oxygen is enriched. Combined with the above-mentioned reduction in the amount of gas produced and the reduction in the furnace body temperature, the heat brought into the furnace body by the gas decreases, which may cause a tense thermal balance in this area.

[0006] Oxygen-enriched molten pool smelting technology will also affect the direct recovery rate of zinc and valuable metals. On the one hand, the reducing agent in the furnace will react with the oxygen blown in from the outside, thereby slowing down the reduction efficiency of zinc; on the other hand, since zinc has a higher affinity for oxygen than iron, the reduction of iron oxides takes precedence over that of zinc oxides, resulting in a large amount of high-melting-point metallic iron being produced while zinc is reduced and volatilized during the pyrometallurgical zinc smelting process, affecting the normal production of the zinc reduction smelting process, further sacrificing part of the direct recovery rate of metallic zinc, thereby reducing the reduction efficiency and direct recovery rate of zinc and valuable metal oxides.

[0007] The above-mentioned oxygen-enriched molten pool smelting process will also greatly increase the consumption of reducing agents, carbon emissions and slag output, which is likely to cause secondary pollution.

[0008] Based on the above analysis, the prior art still has technical problems such as tight heat balance in the reduction zone and low direct recovery rate of zinc and valuable metals. Summary of the invention

[0009] In order to solve the technical problems of tight heat balance in the reduction zone and low reduction efficiency of zinc and valuable metals in the above-mentioned prior art, the present invention provides a zinc smelting method, comprising the following steps:

[0010] The zinc-lead material, the urban mineral and the adjusting agent are mixed to obtain a mixed material; wherein the elements and the mass fractions of the elements in the mixed material include: 10-50% lead, 10-40% zinc, and 2-15% copper;

[0011] The mixed material is added into a molten pool reduction furnace, and after the mixed material is melted, a zinc-lead-copper melt is obtained which enters into a molten pool of the molten pool reduction furnace;

[0012] A first reaction gas is introduced into the molten pool, and the zinc-lead-copper melt undergoes a reduction reaction to obtain a crude lead alloy, zinc vapor and slag; wherein the reduction reaction is carried out under non-oxygen-rich conditions, the oxygen content in the atmosphere of the reduction reaction is 0-20%, and at least one of the first reaction gas and the adjusting agent includes a reducing agent.

[0013] Furthermore, the elements and their mass fractions in the slag include 25-50% iron, 10-25% calcium, 10-20% silicon, and 0-20% sodium.

[0014] Furthermore, the adjusting agent includes sodium carbonate and / or sodium hydroxide, and the elements and element mass fractions in the slag include 25-40% iron, 10-25% calcium, 15-20% silicon, and 5-20% sodium.

[0015] Further, the adjusting agent further comprises a reducing agent, and one or more of quartz and limestone; the reducing agent comprises one or more of pulverized coal, coke powder and coke, and the first reaction gas comprises nitrogen;

[0016] The amount of the reducing agent added is 0.9 to 1.5 of the mass of the reducing agent required to reduce all the metal oxides in the mixed material into metal elements.

[0017] Furthermore, the adjusting agent also includes one or more of quartz and limestone;

[0018] The first reaction gas includes a carrier gas and a solid substance, and at least one of the carrier gas and the solid substance includes a reducing agent;

[0019] The first reaction gas includes one or more of nitrogen, carbon monoxide, carbon dioxide, methane, hydrogen, natural gas and hot coal gas;

[0020] The fixed substance includes one or more of pulverized coal, coke powder and coke, and the amount of the reducing agent added is 0.9 to 1.5 of the mass of the reducing agent required to reduce all the metal oxides in the mixed material into metal elements.

[0021] Furthermore, the zinc-lead materials include one or more of lead oxide ore, zinc oxide ore, lead-silver slag from a hydrometallurgical zinc smelting system, zinc leaching slag, lead-containing smoke, zinc oxide soot, lead-zinc smelting dust removal sludge, copper-containing electroplating sludge, galvanizing sludge, zinc-containing soot from a steel plant, hot-dip galvanizing process dust, zinc powder replacement of precious metal sludge, and waste zinc-manganese batteries; the urban minerals include one or more of waste circuit boards, electronic components, lead-containing glass, and lead paste for lead-acid batteries.

[0022] Furthermore, the reaction temperature of the reduction reaction is 1000-1300° C., and the reduction time is 1-4 h.

[0023] Furthermore, the crude lead alloy is refined to recover valuable metals, and the zinc vapor is captured by a condensation device to recover metallic zinc.

[0024] Further, the molten pool reduction furnace comprises a furnace body and the molten pool, wherein;

[0025] The furnace body is in a hollow column shape, a sealed material cup is provided on the top of the furnace body, and a smoke exhaust port is provided on the upper part of the furnace body;

[0026] The molten pool is fixedly installed at the lower part of the furnace body and is connected to the furnace body. A spray gun is arranged at the bottom of the molten pool. A slag discharge port and a siphon port are arranged in sequence from top to bottom on the outer wall of the molten pool away from the furnace body.

[0027] The present invention also provides an application of any one of the above smelting methods in zinc smelting.

[0028] The specific reaction principle of the present invention is as follows:

[0029] MeO(s)+C=Me(l) / Me(g)+CO(g)

[0030] MeO(s)+CO(g)=Me(l) / Me(g)+CO2(g)

[0031] (ZnFe2O4)+C / CO(g)=Zn(g)+FeO+CO(g) / CO2(g)

[0032] (Zn2SiO4)+Na2CO3+C / CO(g)=Zn(g)+Na2SiO3+CO(g) / CO2(g)

[0033] (PbSiO3)+Na2CO3+C / CO(g)=Pb(l)+Na2SiO3+CO(g) / CO2(g)

[0034] (Pb2SiO4)+Na2CO3+C / CO(g)=2Pb(l)+Na2SiO3+CO(g) / CO2(g)

[0035] Among them, MeO is lead, zinc, and copper oxides such as ZnO, PbO, CuO, and Cu2O.

[0036] Compared with the prior art, the present invention has at least the following advantages:

[0037] The present invention maintains the heat balance of the reduction reaction system by rationally adjusting the ratio of the mixed materials and utilizing the heat released by the oxide reduction reaction. On the one hand, compared with the smelting atmosphere and smelting temperature with high reducing power under oxygen-rich conditions, the metal oxides in the present invention can selectively reduce lead, zinc, copper and other valuable metals under conditions close to self-reduction under lower furnace reducing power, thereby reducing the initial reduction temperature of the target metal oxide and reducing metal entrainment.

[0038] On the other hand, by adjusting the material ratio, a multi-component (≥quaternary) slag system different from the traditional lead, zinc and copper pyrometallurgical slag is pre-constructed, and a multi-component low-melting-point, low-viscosity and high-fluidity slag is formed in the form of lattice substitution, which is convenient for the enrichment and sedimentation of the reduced valuable metals, and the escape and volatilization of zinc vapor, thereby achieving the purpose of reducing the zinc and valuable metal content in the slag after reduction, and improving the reduction effect of zinc and valuable metals and the direct recovery rate.

[0039] The present invention also carries out reduction smelting reaction under non-oxygen-rich conditions. Under the premise of thermal balance of the above-mentioned reduction reaction system, the heat energy stored in the oxide and the heat of reduction reaction are fully utilized. The reducing components in the atmosphere combine with the oxygen in the oxide to be reduced, and no other side reactions occur with external oxygen, thereby effectively improving the reduction efficiency of the reducing agent, achieving the smelting effect of reducing the reducing agent, low industrial oxygen consumption and low CO2 emission reduction, reducing secondary pollution and cost loss, and effectively improving the direct recovery rate of valuable metals. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] 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.

[0041] Figure 1 This is a physical picture of the crude lead alloy and slag after cooling in Example 1 of the present invention.

[0042] Figure 2 This is a SEM line scan image of the slag in Example 2 of the present invention. DETAILED DESCRIPTION

[0043] 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.

[0044] 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.

[0045] 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 methods, equipment and materials of the prior art similar or equivalent to the methods, equipment and materials described in the embodiments of the present invention can also be used to implement the present invention.

[0046] The present invention provides a zinc smelting method, comprising the following steps:

[0047] S1. Mix zinc-lead materials, urban minerals and a regulator to obtain a mixed material.

[0048] In some embodiments, the zinc-lead material may include one or more of lead oxide ore, zinc oxide ore, lead-silver slag from a hydrometallurgical zinc smelting system (which may include materials such as jarosite slag and goethite slag), zinc leaching slag, lead-containing smoke, zinc oxide smoke, lead-zinc smelting dust removal sludge, copper-containing electroplating sludge, galvanizing sludge, zinc-containing smoke from a steel plant, hot-dip galvanizing process dust, zinc powder replacement of precious metal sludge, and waste zinc-manganese batteries.

[0049] Urban minerals may include one or more of waste circuit boards, electronic components, leaded glass (which may be CRT leaded glass), and lead paste for lead-acid batteries.

[0050] Exemplarily, the regulator includes one or more of sodium carbonate, sodium hydroxide, quartz and limestone. The presence of regulators such as sodium salts can significantly reduce the melting temperature of the slag. Due to the presence of the regulators, the slag is easier to flow at a relatively low temperature in the furnace, so that the various components of the slag and the various components of the liquid metal phase can be better separated, so that a more concentrated valuable metal phase and slag phase can be obtained at the same time in terms of the components required for the two phases.

[0051] As another example, the adjusting agent may include reducing agents such as coke and pulverized coal, and the reducing agent is fed together with other adjusting agents and the mixed material to provide sufficient reducing atmosphere for the mixed material.

[0052] The present invention makes full use of the traditional advantages of large processing capacity and strong raw material adaptability of pyrometallurgical molten pool smelting, and coordinates the large-scale processing of urban minerals and zinc-lead materials, thereby realizing the large-scale resource recovery of secondary resources such as urban minerals in the pyrometallurgical smelting process.

[0053] In some embodiments, the elements and their mass fractions in the controlled mixed material include: 10-50% lead, 10-40% zinc, and 2-15% copper.

[0054] By limiting the ratio of lead, zinc and copper content (wt.%) in the mixed material, the reduction reaction of the oxide in the mixed material maintains the thermal balance in the system. At the same time, by controlling the lead, zinc and copper content in the material, a multi-element (≥quaternary) slag system different from the traditional lead, zinc and copper pyrometallurgical slag type is constructed, and a multi-element low melting point, low viscosity and high fluidity slag is formed in the form of lattice substitution, which effectively reduces the reduction temperature of zinc and valuable metal oxidation, so that the oxides of zinc and valuable metals can be fully reduced under low reduction power (i.e., lower reduction temperature and reducing atmosphere conditions), avoiding the entrainment reduction of metals under high reduction power. While facilitating the enrichment and sedimentation of the reduced liquid valuable metals, it is conducive to the escape and volatilization of gaseous zinc, thereby achieving the purpose of reducing the valuable metal content in the slag after reduction and increasing the direct recovery rate of zinc and valuable metals.

[0055] In some embodiments, the elements and their mass fractions in the slag include 25-50% iron, 10-25% calcium, 10-20% silicon, and 0-20% sodium.

[0056] S2. adding the mixed material into a molten pool reduction furnace, and after the mixed material is melted, obtaining a zinc-lead-copper melt entering into a molten pool of the molten pool reduction furnace.

[0057] In some embodiments, the molten bath reduction furnace may include a furnace body and a molten bath, wherein;

[0058] The furnace body is in a hollow columnar shape, a closed material cup is provided on the top of the furnace body, and a smoke exhaust port is provided on the upper part of the furnace body; an air supply port and a secondary air port may also be provided in the middle part of the furnace body and in the upper part of the furnace body respectively to blow in hot inert gas or hot reducing agent to ensure the furnace temperature and promote mass transfer and heat transfer.

[0059] The molten pool is fixedly installed at the lower part of the furnace body and is connected to the furnace body. A spray gun is provided at the bottom of the molten pool. A slag discharge port and a siphon port are provided on the outer wall of the molten pool away from the furnace body from top to bottom. The outer wall of the molten pool can be connected to an external melt inlet to collect external melt into the molten pool, thereby improving the compatibility of material processing of the molten pool reduction furnace.

[0060] The external melt can gather the molten mixed materials, and the two are processed synergistically.

[0061] For example, the mixed material can be put into a closed column blast furnace to form a bed material and then melt and drip to form a melt; the mixed material can also be directly put into a molten pool smelting furnace.

[0062] By way of example, the mixed material can be pressed into pellets and then put into a molten pool reduction furnace.

[0063] In small-scale processes, such as laboratory smelting, the mixture can be first placed in a crucible for high-temperature melting, and then the crucible can be placed in a molten pool reduction furnace for treatment. The main functions are: on the one hand, the crucible material is resistant to high temperatures and has stable mechanical properties, which can protect the furnace body during high-temperature smelting and increase the service life of the furnace body; on the other hand, the use of a crucible is conducive to the removal and placement of samples in the furnace, which is convenient for real-time detection.

[0064] Specifically, after the mixed material is added from the closed material cup into the molten pool reduction furnace, part of the mixed material is softened, melted and reduced to form metal oxides to be reduced, liquid lead metal, zinc vapor and gangue, wherein zinc vapor overflows from the exhaust port, and liquid lead metal, gangue and metal oxides to be reduced drip into the molten pool to form zinc-lead-copper melt. The other part of the mixed material that has not yet melted forms a bed material maintained in place.

[0065] S3. A first reaction gas is introduced into the molten pool, and the zinc-lead-copper melt and the bed material are subjected to a reduction reaction to obtain a crude lead alloy, zinc vapor and slag; wherein the reduction reaction is carried out under non-oxygen-rich conditions, the oxygen content in the atmosphere of the reduction reaction is 0-20%, and at least one of the first reaction gas and the adjusting agent includes a reducing agent.

[0066] At least one of the first reaction gas and the adjusting agent includes a reducing agent. In some embodiments, the source of the reducing reaction atmosphere in step S3 may include three situations: 1) The source of the reducing agent is the adjusting agent, and the first reaction gas includes an inert gas such as hot nitrogen. The reducing agent can be introduced into the furnace from a closed material cup, and the first reaction gas can be blown into the zinc-lead-copper melt from a bottom spray gun or the above-mentioned air supply port to stir the bottom molten pool, quickly transfer heat, and promote efficient reduction of the first reducing agent and metal oxides.

[0067] 2) The source of the reducing agent is the first reaction gas, which may include one or more of hot hydrogen, hot coal gas and natural gas. The first reaction gas may be blown into the furnace from a spray gun at the bottom of the molten pool or the above-mentioned air inlet to stir the bottom molten pool, quickly transfer heat, and rise to fill the entire molten pool reduction furnace to fully reduce the metal oxides.

[0068] 3) The source of the reducing agent is the first reaction gas. The first reaction gas may include a carrier gas and a solid substance. The solid substance is blown into the molten pool reduction furnace with the carrier gas as a carrier. The solid substance includes one or more of pulverized coal, coke powder and coke, and the carrier gas may include one or more of nitrogen, carbon monoxide, carbon dioxide, methane, hydrogen, natural gas and hot coal gas. The bottom of the molten pool is stirred, mass and heat are transferred quickly, and the metal oxides in the mixed material are efficiently reduced.

[0069] It can be seen that no external oxygen is introduced into the first reaction gas, so that the smelting reduction reaction is carried out under non-oxygen-rich conditions. Under the premise of thermal balance of the above reduction reaction system, the heat energy stored in the oxide and the heat of reduction reaction are fully utilized, and the reducing components in the atmosphere are combined with the oxygen in the oxide to be reduced, and no other side reactions occur with the external oxygen, which effectively improves the reduction efficiency of the reducing agent, achieves the smelting effect of reducing the reducing agent, low industrial oxygen consumption and low CO2 emission, reduces secondary pollution and cost loss, and effectively improves the direct recovery rate of valuable metals.

[0070] In some embodiments, the amount of the reducing agent added may account for 0.9 to 1.5 of the mass of the reducing agent required to reduce all the metal oxides in the mixed material to metal elements.

[0071] Combined with the structural description of the above-mentioned molten pool reduction furnace, in specific applications: the first reaction gas can be blown into the zinc-lead-copper melt through the spray gun at the bottom of the molten pool, and the molten pool can be fully stirred to make the oxides in the melt fully react with the first reducing agent and / or the second reducing agent, promote the full reduction of difficult-to-reduce zinc-containing oxides, and enhance the escape of zinc vapor. Under the conditions of 1000-1300°C, after a reduction time of 1-4h, crude lead alloy, zinc vapor and slag are obtained. Among them, the crude lead alloy can be discharged from the siphon port and enter the refining system to further recover valuable metals, and the slag can be discharged from the slag discharge port for further resource utilization. Zinc vapor can be captured and recovered by the lead / zinc rain condensation device.

[0072] In some embodiments, the elements and element mass fractions in the slag include 25-50% iron, 10-25% calcium, 10-20% silicon, and 0-20% sodium. Due to the high direct recovery rate of zinc in the present invention, the slag does not need to be further reduced in a deep reduction device, which effectively simplifies the process and reduces costs.

[0073] In other embodiments, the adjusting agent includes sodium carbonate and / or sodium hydroxide, and the elements and element mass fractions in the slag include 25-40% iron, 10-25% calcium, 15-20% silicon, and 5-20% sodium. By controlling the lead, zinc, and copper content in the material, a multi-element (≥quaternary) slag system different from the traditional lead, zinc, and copper pyrometallurgical slag type is constructed, and a multi-element low melting point, low viscosity, and high fluidity slag is formed in the form of lattice substitution.

[0074] In some embodiments, the adjusting agent includes one or more of sodium carbonate, sodium hydroxide, quartz and limestone. Further adjusting the slag type is conducive to the efficient reduction smelting reaction.

[0075] The source of the reducing reaction atmosphere in case 1) may be as follows: the adjusting agent further includes a reducing agent, and one or more of quartz and limestone; the reducing agent includes one or more of pulverized coal, coke powder and coke, and the first reaction gas includes nitrogen;

[0076] The amount of the reducing agent added is 0.9 to 1.5 of the mass of the reducing agent required to reduce all the metal oxides in the mixed material into metal elements.

[0077] The source of the reducing reaction atmosphere in situation 3) can be as follows: the adjusting agent also includes one or more of quartz and limestone; the first reaction gas includes a carrier gas and a solid substance, and at least one of the carrier gas and the solid substance includes a reducing agent; the first reaction gas includes one or more of nitrogen, carbon monoxide, carbon dioxide, methane, hydrogen, natural gas and hot coal gas; the fixed substance includes one or more of pulverized coal, coke powder and coke, and the amount of the reducing agent added is 0.9 to 1.5 of the mass of the reducing agent required to reduce all the metal oxides in the mixed material into metal elements.

[0078] Exemplarily, the zinc-lead materials include one or more of lead oxide ore, zinc oxide ore, lead-silver slag from a hydrometallurgical zinc smelting system, zinc leaching slag, lead-containing smoke, zinc oxide soot, lead-zinc smelting dust removal sludge, copper-containing electroplating sludge, galvanizing sludge, zinc-containing soot from a steel plant, hot-dip galvanizing process dust, zinc powder replacement of precious metal sludge, and waste zinc-manganese batteries; the urban minerals include one or more of waste circuit boards, electronic components, CRT lead-containing glass, and lead paste for lead-acid batteries.

[0079] In some embodiments, the reactivity of the reduction reaction temperature can be 1000-1300°C, and the reduction time can be 1-4h. Among them, the reduction reaction area is mainly concentrated at 1200-1250°C. Since the invention innovates the oxide material batching system, slag system and reduction system that are different from the traditional zinc reduction process, the starting reduction point of the target metal oxide is reduced, so that more reducing agents can directly and selectively reduce the oxide to be reduced, and achieve atomic economic reduction, thereby reducing carbon consumption or other reducing agents and adjusting agents, and greatly reducing carbon emissions and slag output.

[0080] In some embodiments, the smelting reduction in the present invention can be carried out in a molten pool reduction furnace.

[0081] In some other embodiments, the molten pool reduction furnace comprises a furnace body and the molten pool, wherein;

[0082] The furnace body is in a hollow column shape, and a sealed material cup is provided on the upper part of the furnace body;

[0083] The molten pool is fixedly installed at the lower part of the furnace body and is connected to the furnace body. A spray gun is arranged at the bottom of the molten pool. A slag discharge port and a siphon port are arranged in sequence from top to bottom on the outer wall of the molten pool away from the furnace body.

[0084] The present invention also provides an application of any one of the above smelting methods in zinc smelting.

[0085] Example 1

[0086] Zinc oxide ore, lead-silver slag, zinc oxide soot, copper-zinc electroplating sludge and quartz from a domestic factory are mixed to obtain a mixed material, wherein the elements and element mass fractions in the mixed material include: lead 16%, zinc 28%, copper 3%. The elements and element mass fractions in the pre-mixed slag include iron 25%, calcium 15%, silicon 17%, and sodium 5%. The mixed material is then added into a crucible and melted at a high temperature of 1250°C.

[0087] The melted mixture is added to the molten pool reduction furnace, the reduction temperature is controlled at 1250℃, and the first reaction gas is sprayed into the molten pool reduction furnace through the nozzle at the bottom of the molten pool for 45 minutes to fully stir the molten pool. The first reaction gas is coke powder with hot N2 as the carrier, and the coke powder accounts for 8% of the volume of the first reaction gas. It is then left to stand for 30 minutes to clarify the crude lead alloy and slag, and then cool after stratification. The product after cooling is as follows Figure 1 As shown in the figure, it can be seen that the crude lead alloy is well separated from the slag after reduction, and the slag is dense.

[0088] After cooling, the products were separated, sampled and analyzed, and the mass fractions of zinc, lead and copper in the slag dropped to 0.8, 0.2 and 0.05 respectively; after calculation, the direct recovery rates of lead, zinc and copper in the crude lead alloy phase were 92%, 87% and 94% respectively.

[0089] Example 2

[0090] The jarosite slag, goethite slag, lead soot, waste circuit board powder and quartz are mixed to obtain a mixed material, wherein the elements and element mass fractions in the mixed material include: 20% lead, 32% zinc, and 6% copper. The elements and element mass fractions in the pre-mixed slag include 30% iron, 18% calcium, 20% silicon, and 8% sodium. The mixed material is then added into a crucible and melted at a high temperature of 1200°C.

[0091] The melted mixture is added to the molten pool reduction furnace, the reduction temperature is controlled at 1200℃, and the first reaction gas is sprayed into the molten pool reduction furnace through the nozzle at the bottom of the molten pool for 60 minutes to fully stir the molten pool. The first reaction gas is pulverized coal with CO-CO2 mixed gas as a carrier, wherein the volume ratio of CO in the CO-CO2 mixed gas is 35%, and the volume ratio of pulverized coal in the first reaction gas is 4%. Then stand for 30 minutes to clarify the crude lead alloy and slag, separate them and cool them.

[0092] After cooling, the products were separated, sampled and analyzed, and the mass fractions of zinc, lead and copper in the slag dropped to 0.6, 0.15 and 0.08 respectively. Figure 2The SEM micrograph of the slag and the line scan results of the elemental composition. The results show that the zinc, lead and copper in the slag have all dropped to a very low level after reduction, and there are no metal particles in the slag, indicating that the viscosity is low and the metal sedimentation effect is good. According to calculations, the direct recovery rates of lead, zinc and copper in the crude lead alloy phase are 91.2%, 90.4% and 92.8% respectively.

[0093] Example 3

[0094] The jarosite slag, goethite slag, lead soot, waste circuit board powder and quartz are mixed to obtain a mixed material, wherein the elements and element mass fractions in the mixed material include: 16% lead, 22% zinc, and 4% copper. The elements and element mass fractions in the pre-mixed slag slag include 40% iron, 25% calcium, 20% silicon, and 11% sodium. The mixed material is then added into a crucible and melted at a high temperature of 1300°C.

[0095] The melted mixture is added to the molten pool reduction furnace, the reduction temperature is controlled at 1300℃, and the first reaction gas is sprayed into the molten pool reduction furnace through the nozzle at the bottom of the molten pool for 30 minutes to fully stir the molten pool. The first reaction gas is coke with methane gas as a carrier, and the volume proportion of coke in the first reaction gas is 6%. It is then left to stand for 40 minutes to clarify the crude lead alloy and slag, and then cool after stratification.

[0096] After cooling, the products were separated, sampled and analyzed, and the mass fractions of zinc, lead and copper in the slag dropped to 0.98, 0.24 and 0.11 respectively; after calculation, the direct recovery rates of lead, zinc and copper in the crude lead alloy phase were 90.2%, 85.9% and 91.4% respectively.

[0097] Comparative Example 1

[0098] The jarosite slag, goethite slag, lead soot, waste circuit board powder and quartz are mixed to obtain a mixed material, wherein the elements and element mass fractions in the mixed material include: 16% lead, 22% zinc, and 4% copper. The elements and element mass fractions in the pre-mixed slag slag include 40% iron, 25% calcium, 20% silicon, and 11% sodium. The mixed material is then added into a crucible and melted at a high temperature of 1300°C.

[0099] The melted mixture will be added into the molten pool reduction furnace, the reduction temperature will be controlled at 1300℃, 70% N2-30% O2 mixed gas will be sprayed into the molten pool reduction furnace through the nozzle at the bottom of the molten pool, 6% coke will be added into the molten pool with the mixed gas as the carrier, and the spraying will be carried out for 30 minutes. The molten pool will be fully stirred and then left to stand for 40 minutes to clarify the crude lead alloy and slag, and then cool them after stratification.

[0100] After cooling, the products were separated, sampled and analyzed, and the mass fractions of zinc, lead and copper in the slag dropped to 4.48, 0.79 and 0.25 respectively; after calculation, the direct recovery rates of lead, zinc and copper in the crude lead alloy phase were 87.4%, 79.7% and 88.5% respectively.

[0101] The remaining variables in Example 3 are controlled, and only 30% of oxygen is added to the first reaction gas composition, so that the reaction gas fills the entire furnace body after entering the molten pool reduction furnace, and the reduction reaction is carried out under oxygen-rich conditions. Compared with the direct recovery rate of lead, zinc and copper in Example 3, it can be seen that the direct recovery rates of lead, zinc and copper in the present invention are all improved, breaking the bottleneck of improving the direct recovery rate of zinc, lead and copper in traditional oxygen-enriched molten pool smelting. Compared with the oxygen-enriched combustion heat energy provided in Comparative Example 1, the present invention can utilize the heat energy stored in the oxide and the heat of the reduction reaction to perform reduction in a non-oxygen-enriched environment with low consumption and high efficiency.

[0102] 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 zinc smelting method, characterized in that: The following steps are involved: Mixing zinc-lead materials, urban minerals and a regulator to obtain a mixed material; wherein the elements and element mass fractions in the mixed material include: 10-50% lead, 10-40% zinc, and 2-15% copper; the regulator can reduce the melting temperature of the slag; The mixed material is added into a molten pool reduction furnace, and after the mixed material is melted, a zinc-lead-copper melt is obtained which enters into a molten pool of the molten pool reduction furnace; A first reaction gas is introduced into the molten pool, and the zinc-lead-copper melt undergoes a reduction reaction to obtain a crude lead alloy, zinc vapor and slag; wherein the reduction reaction is carried out under non-oxygen-rich conditions, the oxygen content in the atmosphere of the reduction reaction is 0-20%, and at least one of the first reaction gas and the adjusting agent includes a reducing agent.

2. The smelting method according to claim 1, characterized in that: The elements and their mass fractions in the slag include 25-50% iron, 10-25% calcium, 10-20% silicon, and 0-20% sodium.

3. The smelting method according to claim 2, characterized in that: The adjusting agent includes sodium carbonate and / or sodium hydroxide, and the elements and their mass fractions in the slag include 25-40% iron, 10-25% calcium, 15-20% silicon, and 5-20% sodium.

4. The smelting method according to claim 1, characterized in that: The adjusting agent further includes a reducing agent, and quartz and / or limestone; the reducing agent includes one or more of pulverized coal, coke powder and coke, and the first reaction gas includes nitrogen; The amount of the reducing agent added is 0.9 to 1.5 of the mass of the reducing agent required to reduce all the metal oxides in the mixed material into metal elements.

5. The smelting method according to claim 1, characterized in that: The conditioning agent also includes quartz and / or limestone; The first reaction gas includes a carrier gas and a solid substance, and at least one of the carrier gas and the solid substance includes a reducing agent; The first reaction gas includes one or more of nitrogen, carbon monoxide, carbon dioxide, methane, hydrogen, natural gas and hot coal gas; The fixed substance includes one or more of pulverized coal, coke powder and coke, and the amount of the reducing agent added is 0.9 to 1.5 of the mass of the reducing agent required to reduce all the metal oxides in the mixed material into metal elements.

6. The smelting method according to claim 1, characterized in that: The zinc-lead materials include one or more of lead oxide ore, zinc oxide ore, lead-silver slag from a hydrometallurgical zinc smelting system, zinc leaching slag, lead-containing smoke, zinc oxide soot, lead-zinc smelting dust removal sludge, copper-containing electroplating sludge, galvanizing sludge, zinc-containing soot from steel mills, hot-dip galvanizing process dust, zinc powder replacement of precious metal sludge, and waste zinc-manganese batteries; the urban minerals include one or more of waste circuit boards, electronic components, lead-containing glass, and lead paste for lead-acid batteries.

7. The smelting method according to claim 1, characterized in that: The reaction temperature of the reduction reaction is 1000-1300° C., and the reduction time is 1-4 hours.

8. The smelting method according to claim 1, characterized in that: The crude lead alloy is refined to recover valuable metals, and the zinc vapor is captured by a condensation device to recover metallic zinc.

9. The smelting method according to claim 1, characterized in that: The molten pool reduction furnace comprises a furnace body and the molten pool, wherein; The furnace body is in a hollow column shape, a sealed material cup is provided on the top of the furnace body, and a smoke exhaust port is provided on the upper part of the furnace body; The molten pool is fixedly installed at the lower part of the furnace body and is connected to the furnace body. A spray gun is arranged at the bottom of the molten pool. A slag discharge port and a siphon port are arranged in sequence from top to bottom on the outer wall of the molten pool away from the furnace body.

10. Use of the smelting method according to any one of claims 1 to 9 in zinc smelting.

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