Method for directly smelting zinc by inhibiting zinc vapor oxidation and its application, and molten pool reduction furnace

Abstract

The present invention provides a method for direct zinc smelting by inhibiting zinc vapor oxidation, comprising the steps of: adding lead-zinc oxide material and a reducing agent to a molten pool reduction furnace, and obtaining a lead-zinc-copper melt after the mixed material is melted; adding coke to the molten pool reduction furnace, and the coke floats on the surface of the lead-zinc-copper melt to form a hot carbon layer; the amount of coke added is 0.8 to 1.5 times the amount of coke required to convert all gaseous CO2 in the molten pool reduction furnace into CO; the lead-zinc-copper melt is subjected to a reduction reaction to obtain a crude lead alloy, zinc vapor and slag; the zinc vapor passes through the hot carbon layer and enters a flue to recover metallic zinc, wherein the lower part of the flue is lined with a porous carbon material. The present invention can directly recover metallic zinc in a single substance form, which meets the requirements of short-process low-carbon development in the metallurgical industry.

Description

Technical Field

[0001] The invention belongs to the field of zinc smelting, and specifically relates to a method for direct zinc smelting by inhibiting zinc vapor oxidation and an application thereof, and a molten pool reduction furnace. Background Art

[0002] The low recycling level of metal-based materials such as copper, lead and zinc has caused serious resource loss. Therefore, some researchers are committed to co-processing metal-based solid waste in the primary smelting process to solve the above problems.

[0003] The characteristics of many types of metal bases and complex components determine that pyrometallurgy has great advantages in the treatment of metal-based solid waste. At present, the main technologies for treating zinc-based solid waste resources include volatilization kiln, Ausmelt top blowing method, fuming furnace method, side blowing molten pool smelting technology, etc. Among them, molten pool smelting is a representative of modern intensified metallurgical processes, with advantages such as energy saving and high efficiency. However, the existing molten pool smelting process for zinc-containing materials mainly recovers zinc in the form of zinc oxide smoke, which requires further leaching-electrolysis to obtain metallic zinc. The hydrometallurgical zinc smelting process such as leaching-electrolysis is complicated, and it is long awaited to develop a short-process technology for recovering metallic zinc. Summary of the invention

[0004] In order to solve the technical problem of recovering zinc in the form of zinc oxide dust in the above-mentioned conventional technology during zinc smelting in a molten pool, the present invention provides a method for directly smelting zinc by inhibiting oxidation of zinc vapor, comprising the steps of:

[0005] Adding lead-zinc oxide material and a reducing agent into a molten pool reduction furnace, and melting the mixed material to obtain a lead-zinc-copper melt;

[0006] Adding coke to the molten pool reduction furnace, the coke floats on the surface of the lead-zinc-copper melt to form a hot carbon layer; the amount of coke added is 0.8 to 1.5 times the amount of coke required to convert all gaseous CO2 in the molten pool reduction furnace into CO;

[0007] The lead-zinc-copper melt is subjected to a reduction reaction to obtain a crude lead alloy, zinc vapor and slag; the zinc vapor passes through the hot carbon layer and enters the flue to recover metallic zinc, wherein the lower part of the flue is lined with a porous carbon material.

[0008] Furthermore, the particle size of the coke is 10-80 mm, and the carbon content is 50%-80%.

[0009] Furthermore, the lead-zinc oxide material includes at least one of lead-zinc oxide ore, lead-zinc mixed carbonate ore, high-zinc slag from pyrometallurgical zinc smelting, and oxidative desulfurization melt of lead / zinc sulfide ore;

[0010] Calculated by mass fraction, the lead-zinc oxide material comprises: 8% to 25% lead oxide, 20% to 38% zinc oxide, 7% to 18% ferrous oxide, 12% to 25% silicon dioxide, 6% to 14% calcium oxide, and ≤2.5% sulfur element.

[0011] Furthermore, the adding of lead-zinc oxide material and reducing agent into the molten pool reduction furnace includes: the reducing agent includes pulverized coal, the reducing agent is added from the feeding port of the molten pool reduction furnace, and the amount of the reducing agent added is 0.8 to 1.5 times the mass of the reducing agent required to reduce all the metal oxides in the lead-zinc oxide material into metal elements.

[0012] Furthermore, the adding of lead-zinc oxide material and reducing agent into the molten pool reduction furnace also includes: the reducing agent also includes hot pulverized coal and coke powder, the reducing agent is blown into the molten pool reduction furnace with air and / or oxygen-rich gas as a carrier, and the amount of the reducing agent added is 0.8 to 1.5 times the mass of the reducing agent required to reduce all the metal oxides in the lead-zinc oxide material into metal elements.

[0013] Furthermore, the porous carbon material includes high-purity graphite, and the pore size of the porous carbon material is 20 to 100 mm and the height is 1 m to 5 m.

[0014] Furthermore, the reaction temperature of the reduction reaction is 1200° C. to 1350° C., and the reaction time of the reduction reaction is 40 to 90 minutes.

[0015] Furthermore, the zinc vapor passes through the hot carbon layer and enters the flue to recover the metallic zinc, which includes: the zinc vapor rises to the upper gas phase space of the molten pool, passes through the porous carbon material embedded in the flue, and enters the zinc condenser to recover the metallic zinc; wherein the atmosphere temperature in the gas phase space is 900-1100°C, and the temperature of the flue is 675-800°C.

[0016] The present invention also provides a molten pool reduction furnace, the molten pool reduction furnace comprising a furnace body and a molten pool, wherein;

[0017] The furnace body is in a hollow column shape, a charging port is provided on the top of the furnace body, a vertical flue is provided on the upper part of the furnace body, and the flue is lined with a porous carbon material, wherein the porous carbon material has a pore diameter of 20 to 100 mm and a height of 1 m to 5 m;

[0018] One side of 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.

[0019] The present invention also provides an application of any of the above methods for direct zinc smelting by inhibiting zinc vapor oxidation in molten pool reduction zinc smelting.

[0020] Compared with the prior art, the present invention has at least the following advantages:

[0021] In the present invention, a relatively closed gas phase space is formed by using a hot carbon layer formed by coke and a flue lined with a porous carbon material, and the amount of coke is controlled to be 0.8 to 1.5 times the amount of coke required to convert all the gas phase CO2 in the molten pool reduction furnace into CO, so that an atmosphere dominated by carbon monoxide is formed in the gas phase space. In this atmosphere, the Boudol reaction proceeds forward, effectively inhibiting the formation of carbon dioxide, and further avoiding the secondary oxidation of zinc vapor in the gas phase.

[0022] Specifically, zinc vapor passes through the hot carbon layer on the surface of the molten pool and enters the gas phase space above the reaction pool, and then is captured and recovered through a vertical flue lined with high-purity graphite to obtain elemental metallic zinc.

[0023] In contrast, in the commonly used technology, when zinc-containing materials undergo a molten pool reduction process, zinc vapor will be oxidized into zinc oxide when it escapes from the melt and rises to the flue. Zinc oxide is harmful to the condensation process, causing the zinc liquid to be covered by a layer of zinc oxide, which prevents the droplets from further coalescing into large particles. Therefore, blue powder is often generated 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 and deteriorates the condensation effect.

[0024] In addition, the generation of zinc oxide also poses challenges to the subsequent recovery of zinc, which often requires further leaching and electrolysis to obtain metallic zinc, making the entire zinc smelting process complicated. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] 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.

[0026] Figure 1 From right to left is a schematic diagram of the structure of a molten pool oxidation furnace and a molten pool reduction furnace which are connected to each other in one embodiment of the present invention.

[0027] Description of the drawings: 1. Feeding port of oxidation furnace; 2. Immersed spray gun of oxidation furnace; 3. Flue of oxidation furnace; 4. Slag outlet of oxidation furnace; 5. Partition wall with copper water jacket; 6. Feeding port of molten pool reduction furnace; 7. Immersed spray gun of molten pool reduction furnace; 8. Flue of molten pool reduction furnace; 9. Zinc vapor condensing device; 10. Siphon port; 11. Alloy separation device; 12. Slag outlet of molten pool reduction furnace; 13. Porous carbon material. DETAILED DESCRIPTION

[0028] 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.

[0029] 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.

[0030] 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.

[0031] The present invention provides a method for smelting zinc by smelting reduction, comprising the steps of:

[0032] S1. Adding lead-zinc oxide material and a reducing agent into a molten pool reduction furnace, and melting the mixed material to obtain a lead-zinc-copper melt.

[0033] Lead-zinc oxide materials include lead-zinc oxide ore, lead-zinc mixed carbonate ore, high-zinc slag from pyrometallurgical zinc smelting, oxidative desulfurization melt of lead / zinc sulfide ore, zinc oxide dust, lead soot, waste zinc-silver batteries, and zinc-air batteries.

[0034] 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 lead-zinc materials, thereby realizing the large-volume resource recovery of secondary resources such as urban minerals in the pyrometallurgical smelting process.

[0035] In some embodiments, the lead-zinc oxide material comprises, by mass fraction, 8% to 25% lead oxide, 20% to 38% zinc oxide, 7% to 15% ferrous oxide, 12% to 25% silicon dioxide, 6% to 14% calcium oxide, and ≤2.5% sulfur.

[0036] In some specific embodiments, the lead-zinc oxide material can be determined using XRF, ICP elemental analysis, and chemical titration methods.

[0037] In some embodiments, the lead-zinc oxide material may include an adjuster to adjust the slag properties such as viscosity, melting point, pH, and surface tension.

[0038] Exemplarily, the conditioning agent may be quartz and / or limestone.

[0039] In some specific embodiments, solid lead-zinc oxide material can be added from the charging port of the molten pool reduction furnace; or the molten lead-zinc oxide material can be introduced into the molten pool from the melt inlet, thereby improving the compatibility of molten pool material processing and making it not limited to the state of the oxide material.

[0040] It should be noted that the melted lead-zinc oxide material is the lead-zinc-copper melt.

[0041] In some embodiments, adding lead-zinc oxide material and a reducing agent into the molten pool reduction furnace includes: the reducing agent includes pulverized coal, and the reducing agent is added from a charging port of the molten pool reduction furnace.

[0042] Exemplarily, the amount of reducing agent added is 0.8 to 1.5 of the mass of reducing agent required to reduce all metal oxides in the lead-zinc oxide material to metal elements, and the amount of reducing agent added can be 6% to 30% of the total mass of the lead-zinc oxide material.

[0043] The reducing agent can be mixed with the lead-zinc oxide material to melt, bond and solidify, and then put into the molten pool reduction furnace in the form of lumps to melt to obtain a lead-zinc-copper melt.

[0044] In the laboratory, the reducing agent can be melted with the lead-zinc oxide material in a crucible and then placed in a medium frequency melting pool fume recovery integrated furnace for reduction.

[0045] In some embodiments, the adding of lead-zinc oxide material and reducing agent into the molten pool reduction furnace also includes: the reducing agent also includes hot pulverized coal and coke powder, and the reducing agent is blown into the molten pool reduction furnace with air and / or oxygen-rich gas as carriers to fully stir the lead-zinc-copper melt and accelerate heat and mass transfer during the reduction process.

[0046] Exemplarily, the amount of reducing agent added is 0.8 to 1.5 of the mass of reducing agent required to reduce all metal oxides in the lead-zinc oxide material to metal elements; that is, when the fixed carbon content in the reducing agent is 40% to 90%, the amount of reducing agent added is 6% to 20%.

[0047] As another example, when the carbon content of the reducing agent is 40% to 90%, the amount of the reducing agent added may be 6% to 12% of the mass of the lead-zinc oxide material (ie, the mass of the furnace charge).

[0048] In some specific embodiments, the reducing agent may be injected into the molten pool melt from a lance suspended from the top, side, or bottom of the molten pool reduction furnace using air and / or oxygen-rich gas as carriers.

[0049] S2. Adding coke into the molten pool reduction furnace, the coke floats on the surface of the lead-zinc-copper melt to form a hot carbon layer.

[0050] In some embodiments, the composition of the gas space in the molten pool reduction furnace (i.e., a relatively closed space formed between the hot carbon layer and the flue embedded with porous carbon material) includes: CO content 18% to 35%; CO2 content 5% to 20%, Zn(g) content 15% to 35%, N2 content 20% to 35%, and Pb(g) content 2% to 9%.

[0051] Among them, the content of gas phase CO2 can be measured using industrial gas online detection equipment.

[0052] In some embodiments, the amount of coke added is 0.8 to 1.5 times the amount of coke required to convert all gaseous CO2 in the molten pool reduction furnace into CO, that is, 3% to 25% of the mass of the lead-zinc oxide material.

[0053] Exemplarily, the amount of coke added may be 1 to 1.2 times the amount of coke required to convert all gaseous CO2 in the molten pool reduction furnace into CO, i.e., 3% to 10% times the mass of the lead-zinc oxide material.

[0054] As another example, the amount of coke added may be 0.08 to 0.2 times the mass of the charge (ie, lead-zinc oxide material).

[0055] In some embodiments, the coke has a particle size of 10 to 80 mm and a carbon content of 50% to 80%.

[0056] It should be noted that the particle size of coke is larger than that of coke powder, and its density is much lower than that of lead-zinc-copper melt. After large pieces of coke are put into the lead-zinc-copper melt, they float on the surface to form a hot coke layer, so that the gas phase space above the connected flue is relatively closed, forming a reducing environment dominated by CO.

[0057] In one embodiment of the present invention, the reducing agent and the lead-zinc oxide material are put into the furnace together. After melting into a lead-zinc-copper melt, the reducing agent is dispersed in the lead-zinc-copper melt in a fine solid phase and reacts preferentially with the metal oxide. In comparison, due to the smaller contact area, the degree of reaction between the coke floating on the surface of the lead-zinc-copper melt and the metal oxide is lower.

[0058] In another embodiment of the present invention, the reducing agent is blown into the molten pool reduction furnace with air and / or oxygen-rich gas as a carrier to stir the lead-zinc-copper melt. With the gas phase as the medium, the reducing agent fully stirs the lead-zinc-copper and metal oxides to react preferentially and fully. In comparison, due to the smaller contact area, the degree of reaction between the coke floating on the surface of the lead-zinc-copper melt and the metal oxides is lower.

[0059] In some embodiments, when the reducing gas is blown into the low-zinc melt with the gas phase as the carrier, the treatment effect is not as good as the treatment effect of the high-zinc melt in the present application: on the one hand, the viscosity of the low-zinc melt is relatively low, because the main reaction is a gas-solid phase reaction, and the zinc-containing melt rolls rapidly under the stirring of the airflow. On the one hand, the metallic zinc and zinc oxide powder are easy to volatilize and diffuse with the airflow under the action of high temperature and airflow, which is not conducive to the centralized separation and impurity removal on the path of the upper gas phase space → porous carbon material → new steam condensation device; on the other hand, the violently stirred lead-zinc-copper melt is easy to cause the coke layer on the surface of the lead-zinc-copper melt to break, thereby reducing the sealing effect of the gas phase space and affecting the reduction performance;

[0060] On the other hand, the treatment of low-zinc melt will increase the proportion of water vapor in the gas phase space, and gases such as water vapor and carbon dioxide will mix with zinc vapor, while oxidizing zinc vapor and affecting the subsequent separation effect. It should be noted that during the treatment of low-zinc melt, the proportion of water vapor in the gas phase space is 3% to 12% higher than that of high-zinc melt.

[0061] S3. The lead-zinc-copper melt is subjected to a reduction reaction to obtain a crude lead alloy, zinc vapor and slag; the zinc vapor passes through the hot carbon layer and enters a flue to recover metallic zinc, wherein the flue is lined with a porous carbon material.

[0062] In some embodiments, since the zinc-containing material processed by the present invention is a high-zinc material with a zinc content of up to 20% to 38%, the reduction ability requirements in this scenario are relatively high. Therefore, the reaction temperature of the reduction reaction in the present invention is 1200°C to 1350°C, and the reaction time of the reduction reaction is 40 to 90 minutes. Crude lead alloy, zinc vapor and slag can be obtained through the reduction reaction.

[0063] The zinc vapor rises to the upper gas phase space of the molten pool, passes through the porous carbon material embedded in the flue, and enters the zinc condenser to recover the metal zinc. The residual heat of the flue gas is used for heat preservation, and the atmosphere temperature is 900-1100°C; the temperature in the flue is 675-800°C.

[0064] The present invention adjusts the ratio of lead-zinc oxide materials to 8%-25% of lead oxide, 20%-38% of zinc oxide, 7%-18% of ferrous oxide, 12%-25% of silicon dioxide, 6%-14% of calcium oxide, and ≤2.5% of sulfur element, so that the atmosphere temperature in the gas phase space is controlled at 900-1100° C. and the temperature of the flue is controlled at 675-800° C. The relatively high temperature environment inhibits the oxidation and sublimation of zinc vapor, and optimizes the subsequent collection effect of zinc vapor.

[0065] The temperature of the zinc vapor is not less than 800°C. For example, the temperature of the zinc vapor may be 900-1150°C.

[0066] On the one hand, by controlling the temperature of zinc vapor in the furnace, the forward oxidation reaction is suppressed; on the other hand, when high-temperature zinc vapor enters the flue, it passes through the porous carbon material, providing a strong reducing environment for the zinc vapor, further balancing the oxidation trend caused by the sudden drop in ambient temperature, and achieving the best zinc vapor oxidation inhibition effect.

[0067] In some embodiments, the porous carbon material is provided to facilitate the fall of zinc oxide smoke and the reduction of zinc vapor. At the same time, zinc vapor enters the zinc vapor treatment device through the porous carbon material. Due to the reducibility and high specific surface area of ​​the porous carbon material, the zinc vapor is not easily oxidized by carbon dioxide, oxygen and other gases in the outside world or in the furnace itself.

[0068] Exemplarily, the porous carbon material includes high-purity graphite and / or high-purity carbon material, and the porous carbon material has a pore size of 20 to 100 mm and a height of 1 m to 5 m.

[0069] The porous carbon material can be a mesh-shaped or honeycomb-shaped porous material. The porous carbon material is mostly made of high-purity carbon material, which refers to a carbon material with a purity of more than 99%.

[0070] High purity graphite refers to graphite with a carbon content of >99.99%.

[0071] The porous carbon material is arranged on the inner wall of the flue, starting from the lower part of the flue, and its length runs through the middle and lower part of the flue.

[0072] In some embodiments, a replaceable porous carbon material may be provided to facilitate equipment maintenance.

[0073] The crude lead alloy obtained after reduction settles to the bottom of the molten pool and is released through the siphon port, and is recycled through the refining system; the reduced slag is discharged through the slag discharge port for further processing.

[0074] Compared with the prior art, the present invention has at least the following advantages:

[0075] 1. In the present invention, a relatively closed gas phase space is formed by using a hot carbon layer formed by coke and a flue lined with porous carbon material, and the amount of coke is controlled to be 0.8 to 1.5 times the amount of coke required to convert all the gas phase CO2 in the molten pool reduction furnace into CO, so that an atmosphere dominated by carbon monoxide is formed in the gas phase space. In this atmosphere, the Boudor reaction proceeds forward, effectively inhibiting the formation of carbon dioxide, and further avoiding zinc vapor oxidation.

[0076] Specifically, zinc vapor passes through the hot carbon layer on the surface of the molten pool and enters the gas phase space above the reaction pool, and then is captured and recovered through a vertical flue lined with high-purity graphite to obtain elemental metallic zinc.

[0077] In contrast, in the commonly used technology, when zinc-containing materials undergo a molten pool reduction process, zinc vapor will be oxidized into zinc oxide when it escapes from the melt and rises to the flue. Zinc oxide is harmful to the condensation process, causing the zinc liquid to be covered by a layer of zinc oxide, which prevents the droplets from further coalescing into large particles. Therefore, blue powder is often generated 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 and deteriorates the condensation effect.

[0078] In addition, the generation of zinc oxide also poses challenges to the subsequent recovery of zinc, which often requires further leaching and electrolysis to obtain metallic zinc, making the entire zinc smelting process complicated.

[0079] 2. The present invention provides a short-process technology, which realizes the coordinated extraction of multiple valuable metals mainly from high-zinc materials, and does not require zinc oxide reprocessing steps, thereby having excellent environmental and economic benefits.

[0080] The present invention provides a molten pool reduction furnace, which comprises a furnace body and a molten pool, wherein;

[0081] The furnace body is in a hollow column shape, a charging port is provided on the top of the furnace body, a vertical flue is provided on the upper part of the furnace body, and the flue is lined with a porous carbon material, wherein the porous carbon material has a pore diameter of 20 to 100 mm and a height of 1 m to 5 m;

[0082] 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.

[0083] In some embodiments, Figure 1 As shown, the molten pool reduction furnace can be connected with the oxidation furnace, and the desulfurized melt produced in the oxidation desulfurization section directly flows into the molten pool reduction furnace, thereby realizing the oxidation desulfurization and reduction recovery of the lead-zinc materials in one piece.

[0084] For example, Figure 1 As shown, the lead-zinc material enters the oxidation furnace through the oxidation furnace charging port 1, and is oxidized and desulfurized to obtain a desulfurized melt. The oxidized slag is discharged from the oxidation furnace slag outlet 4, and the oxidized flue gas is discharged from the oxidation furnace flue 3; after the desulfurized melt flows into the molten pool reduction furnace, it is reduced under the cover of coke together with the lead-zinc oxide material added through the molten pool reduction furnace charging port 6 to obtain zinc vapor, crude lead alloy and reduced slag. Among them, the zinc vapor enters the zinc vapor condensation device 9 through the molten pool reduction furnace flue 8 embedded with porous carbon material 13 for centralized recovery, the crude lead alloy enters the alloy separation device 11 through the siphon port 10, and the reduced slag is discharged from the reduction furnace slag outlet 12.

[0085] It should be noted that during the oxidative desulfurization process, the oxidant can be sprayed into the oxidation furnace melt by the oxidation furnace spray gun 2, and the oxidized melt can be stirred at the same time to promote mass transfer and heat transfer; during the reduction process, the reductant can be blown into the melt in the molten pool reduction furnace by the molten pool reduction furnace spray gun 7 to improve the reduction efficiency.

[0086] It should also be noted that there is a copper-jacketed partition wall 5 between the oxidation furnace and the molten pool reduction furnace to provide insulation for the materials.

[0087] The present invention also provides an application of the above-mentioned molten reduction zinc smelting method in molten pool reduction zinc smelting.

[0088] In order to facilitate those skilled in the art to further understand the present invention, examples are given below:

[0089] Example 1

[0090] S1. Firstly, a domestic lead-zinc oxide ore, high-zinc block material from pyrometallurgical zinc smelting, and lead fly ash are mixed in proportion to obtain 1000g of a mixed material, the composition of which includes: PbO 20%, ZnO 34%, FeO 12%, SiO220%, CaO 9%, and the rest are impurities such as aluminum and magnesium. The mixed material is added into a reduction molten pool through a closed feeding port, and coke powder with a fixed carbon content of 84.7% is blown into the molten pool through an upper spray gun using a 35% oxygen-enriched N2-O2 mixed gas as a carrier, and the total amount of coke powder sprayed is 8% of the charge.

[0091] S2. Then add 3% of the total charge with an average particle size of 10mm coke blocks to the surface of the molten pool from the closed charging port; control the melt reduction temperature to 1250±50℃ and reduce for 50min. Control the gas phase space temperature above the molten pool to 900±50℃, and control the flue (lined with 1.5m mesh high-purity graphite) temperature to 690±25℃. After measurement, the gas phase composition in the furnace is CO:CO2:Zn(g):N2:Pb(g)(%) is 28.4:8.3:31.7:23.5:8.1.

[0092] S3. The zinc vapor in the gas phase is condensed in a closed manner. The captured product is analyzed to be mainly metallic zinc. The zinc vapor oxidation inhibition rate is calculated to be 98.5%.

[0093] Example 2

[0094] S1. First, sintered block of a certain domestic lead-zinc mine, lead-zinc slag, lead paste of waste lead-acid batteries and zinc oxide dust are mixed in proportion to obtain 1500g of a mixed material, the composition of which includes: PbO 17%, ZnO 38%, FeO9%, SiO2 23%, CaO9%, and the rest are impurities such as antimony aluminum oxide. The mixed material is added into the reduction molten pool through a closed feeding port, and pulverized coal with a fixed carbon content of 56.8% is blown into the molten pool through a side spray gun using a 50% oxygen-enriched N2-O2 mixed gas as a carrier, and the total amount of coke powder sprayed is 12% of the charge.

[0095] S2. Then add 2% of the total charge and 15mm coke blocks with an average particle size to the surface of the molten pool from the closed charging port; control the melt reduction temperature to 1200±25℃ and reduce for 40min. Control the gas phase space temperature above the molten pool to 1000±50℃, and control the flue (lined with 1.2m honeycomb high-purity graphite) temperature to 750±10℃. After measurement, the gas phase composition in the furnace is CO:CO2:Zn(g):N2:Pb(g)(%) is 27.3:15.4:35.6:15.3:8.9.

[0096] S3. The zinc vapor in the gas phase is condensed in a closed manner. The captured product is analyzed to be mainly metallic zinc. The zinc vapor oxidation inhibition rate is calculated to be 95.4%.

[0097] Example 3

[0098] S1. First, oxidative desulfurization melts of a certain domestic lead-zinc oxide ore and lead / zinc sulfide ore are mixed in proportion to obtain 800g of a mixed material, the composition of which includes: PbO 12%, ZnO 28%, FeO 18%, SiO223%, CaO 12%, and the rest are other oxide impurities. The mixed material is added into a reduction molten pool through a closed feeding port, and anthracite with a fixed carbon content of 45.8% is blown into the molten pool through a bottom spray gun using a 25% oxygen-enriched N2-O2 mixed gas as a carrier, and the total amount of anthracite sprayed is 15% of the charge.

[0099] S2. Then add 4% of the total charge with an average particle size of 12mm coke blocks to the surface of the molten pool from the closed charging port; control the melt reduction temperature to 1300±50℃ and reduce for 30min. Control the gas phase space temperature above the molten pool to 1050±50℃, and control the flue (lined with 1m mesh high-purity graphite) temperature to 770±10℃. After measurement, the gas phase composition in the furnace is CO:CO2:Zn(g):N2:Pb(g)(%) is 21.4:8.16:23.7:34.2:12.6.

[0100] S3. The zinc vapor in the gas phase is condensed in a closed manner. The captured product is analyzed to be mainly metallic zinc. The zinc vapor oxidation inhibition rate is calculated to be 97.8%.

[0101] Comparative Example 1

[0102] S1. Firstly, a domestic lead-zinc oxide ore, high-zinc block material from pyrometallurgical zinc smelting, and lead fly ash are mixed in proportion to obtain 1000g of a mixed material, the composition of which includes: PbO 20%, ZnO 34%, FeO 12%, SiO220%, CaO 9%, and the rest are impurities such as aluminum and magnesium. The mixed material is added into a reduction molten pool through a closed feeding port, and coke powder with a fixed carbon content of 84.7% is blown into the molten pool through an upper spray gun using a 35% oxygen-enriched N2-O2 mixed gas as a carrier, and the total amount of coke powder sprayed is 8% of the charge.

[0103] S2. No coke is added, the melt reduction temperature is controlled at 1250±50℃, and the reduction is carried out for 50min. The gas phase space temperature above the molten pool is controlled at 900±50℃, and the flue (without adding mesh high-purity graphite lining) temperature is controlled at 690±25℃. After measurement, the gas phase composition in the furnace is CO2:CO:Zn(g):N2:Pb(g)(%) is 15.0:0.002:0.002:84.9:0.006.

[0104] S3. The zinc vapor in the gas phase is condensed in a closed manner. The captured product is analyzed to be mainly zinc oxide. The zinc vapor oxidation inhibition rate is 0.011%, which is not a good effect.

[0105] Comparative Example 2

[0106] S1. Firstly, a domestic lead-zinc oxide ore, high-zinc block material from pyrometallurgical zinc smelting, and lead fly ash are mixed in proportion to obtain 1000g of a mixed material, the composition of which includes: PbO 20%, ZnO 34%, FeO 12%, SiO220%, CaO 9%, and the rest are impurities such as aluminum and magnesium. The mixed material is added into a reduction molten pool through a closed feeding port, and coke powder with a fixed carbon content of 84.7% is blown into the molten pool through an upper spray gun using a 35% oxygen-enriched N2-O2 mixed gas as a carrier, and the total amount of coke powder sprayed is 8% of the charge.

[0107] S2. Then add 3% of the total charge with an average particle size of 10mm coke blocks to the surface of the molten pool from the closed charging port, control the melt reduction temperature to 1250±50℃, and reduce for 50min. Control the gas phase space temperature above the molten pool to 900±50℃, and control the flue (without adding mesh high-purity graphite lining) temperature to 690±25℃. After measurement, the gas phase composition in the furnace is CO:CO2:Zn(g):N2:Pb(g)(%) is 8:35:4:47:6.

[0108] S3. The zinc vapor in the gas phase is condensed in a closed manner. The captured product is analyzed to be mainly metallic zinc, and the zinc vapor oxidation inhibition rate is 61%.

[0109] Comparative Example 3

[0110] S1. First, a domestic lead-zinc oxide ore, high-zinc block material from pyrometallurgical zinc smelting, and lead ash are mixed in proportion to obtain 1000g of a mixed material, the composition of which includes: PbO 20%, ZnO 34%, FeO 12%, SiO220%, CaO 9%, and the rest are impurities such as aluminum and magnesium. The mixed material is added into the reduction molten pool through a closed feed port, and coke powder with a fixed carbon content of 84.7% is blown into the molten pool through an upper spray gun using a 35% oxygen-enriched N2-O2 mixed gas as a carrier. The total amount of coke powder sprayed is 8% of the charge.

[0111] S2. No coke is added, the melt reduction temperature is controlled at 1250±50℃, and the reduction is carried out for 50min. The temperature of the gas phase space above the molten pool is controlled at 900±50℃, and the temperature of the flue (with 1.5m mesh high-purity graphite lining) is controlled at 690±25℃. After measurement, the gas phase composition in the furnace is CO:CO2:Zn(g):N2:Pb(g)(%) is 15:30:5:42:8.

[0112] S3. The zinc vapor in the gas phase is condensed in a closed manner, and the captured product is analyzed to be a mixture of metallic zinc and zinc oxide. The zinc vapor oxidation inhibition rate is calculated to be 56.9%.

[0113] Comparative Example 4

[0114] S1. Firstly, a domestic lead-zinc oxide ore, high-zinc block material from pyrometallurgical zinc smelting, and lead fly ash are mixed in proportion to obtain 1000g of a mixed material, the composition of which includes: PbO 20%, ZnO 34%, FeO 12%, SiO220%, CaO 9%, and the rest are impurities such as aluminum and magnesium. The mixed material is added into a reduction molten pool through a closed feeding port, and coke powder with a fixed carbon content of 84.7% is blown into the molten pool through an upper spray gun using a 35% oxygen-enriched N2-O2 mixed gas as a carrier, and the total amount of coke powder sprayed is 8% of the charge.

[0115] S2. Then add 30% of the total charge with an average particle size of 10mm coke blocks to the surface of the molten pool from the closed charging port, control the melt reduction temperature to 1250±50℃, and reduce for 50min. Control the temperature of the gas phase space above the molten pool to 900±50℃, and control the temperature of the flue (with 1.5m mesh high-purity graphite lining) to 690±25℃. After measurement, the gas phase composition in the furnace is CO:CO2:Zn(g):N2:Pb(g)(%) is 48:0.02:7.4:39.58:5.

[0116] S3. Zinc vapor in the gas phase is condensed in a closed manner. The captured product is analyzed to be mainly metallic zinc. The zinc vapor oxidation inhibition rate is calculated to be 75.3%. 15% of carbon remains, which increases the cost.

[0117] Comparative Example 5

[0118] First, a domestic lead-zinc oxide ore and hydrometallurgical zinc acid leaching slag were mixed in proportion to obtain 800g of mixed material, which included: PbO 10%, ZnO 28%, FeO 26%, S11%, SiO2 7%, CaO18%, and the rest were other oxide impurities. The mixed material was added into the reduction molten pool through a closed feed port, and anthracite with a fixed carbon content of 45.8% was injected into the molten pool through a bottom spray gun using a 50% oxygen-enriched N2-O2 mixed gas as a carrier. The total amount of anthracite injected was 11% of the charge.

[0119] The slag flows into the fuming furnace through the chute, where it is reduced and volatilized to further recover lead and zinc. A secondary air outlet is set above the fuming furnace, and there is no zinc vapor oxidation inhibition method. According to the measurement, the volatilization rate of metal zinc is 92.5%, and the ZnO content of the obtained lead-zinc volatilization smoke is 89%, and the PbO content is 11%. The zinc vapor oxidation rate is above 95%.

[0120] 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 direct zinc smelting by inhibiting zinc vapor oxidation, characterized in that: Includes steps: Adding lead-zinc oxide material and a reducing agent into a molten pool reduction furnace, and after the mixed material is melted, a lead-zinc-copper melt is obtained; the lead-zinc oxide material comprises at least one of lead-zinc oxide ore, lead-zinc mixed carbonate ore, high-zinc slag from pyrometallurgical zinc smelting, and oxidative desulfurization melt of lead / zinc sulfide ore; in terms of mass fraction, the lead-zinc oxide material comprises: 8% to 25% lead oxide, 20% to 38% zinc oxide, 7% to 18% ferrous oxide, 12% to 25% silicon dioxide, 6% to 14% calcium oxide, and ≤2.5% sulfur element; The reducing agent includes pulverized coal, and the reducing agent is added from the charging port of the molten pool reduction furnace; or, the reducing agent includes hot pulverized coal and coke powder, and the reducing agent is blown into the molten pool reduction furnace with air and / or oxygen-rich gas as a carrier; the amount of the reducing agent added is 0.8 to 1.5 times the mass of the reducing agent required to reduce all the metal oxides in the lead-zinc oxide material to metal elements; Adding coke to the molten pool reduction furnace, the coke floats on the surface of the lead-zinc-copper melt to form a hot carbon layer; the amount of coke added is 0.8 to 1.5 times the amount of coke required to convert all gaseous CO2 in the molten pool reduction furnace into CO; The lead-zinc-copper melt undergoes a reduction reaction to obtain a crude lead alloy, zinc vapor and slag; the zinc vapor passes through the hot carbon layer and enters the flue to recover metallic zinc, wherein the lower part of the flue is lined with a porous carbon material; the zinc vapor passes through the hot carbon layer and enters the flue to recover metallic zinc, comprising: the zinc vapor rises to the upper gas phase space of the molten pool, passes through the porous carbon material embedded in the flue, and enters the zinc condenser to recover metallic zinc; wherein the atmosphere temperature in the gas phase space is 900-1100°C, and the temperature of the flue is 675-800°C; The molten pool reduction furnace comprises a furnace body and a molten pool, wherein; The furnace body is in a hollow column shape, a charging port is provided on the top of the furnace body, a vertical flue is provided on the upper part of the furnace body, and the flue is lined with a porous carbon material, wherein the porous carbon material has a pore diameter of 20 to 100 mm and a height of 1 m to 5 m; One side of 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.

2. The method for direct zinc smelting by inhibiting zinc vapor oxidation according to claim 1, characterized in that: The coke particle size is 10-80 mm and the carbon content is 50%-80%.

3. The method for direct zinc smelting by suppressing zinc vapor oxidation according to claim 1, characterized in that: The reaction temperature of the reduction reaction is 1200° C. to 1350° C., and the reaction time of the reduction reaction is 40 to 90 minutes.

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