Liquid slag electrically enhanced reduction mother-son furnace and method for reducing lead, zinc and iron

Abstract

The present application relates to the field of nonferrous metallurgy, and particularly relates to a liquid slag electrically enhanced reduction mother-son furnace and a method for reducing lead, zinc and iron, the mother-son furnace comprising a mother furnace and a son furnace, the son furnace being in communication with the bottom of the mother furnace to form a slag inlet channel; the mother furnace is divided into three furnace bodies, a first charging port for adding coke particles, a second charging port for adding lime and / or silicon dioxide and at least one group of electrodes A are arranged above each furnace body; a flue gas outlet and a slag outlet are arranged at the end of the mother furnace away from the son furnace; a protruding platform is arranged at the inner bottom of the mother furnace, and the platform divides the mother furnace into a lead collection area on the left and an iron collection area on the right. The present application adopts a liquid slag electrically enhanced direct reduction mother-son furnace for lead, zinc and iron polymetal, at least one group of electrodes A is arranged above each furnace body, the heating temperature of the electrodes A of different furnace bodies is different, energy saving and high efficiency are achieved, and metal zinc and metal iron can be obtained at the same time of outputting metal lead products, so that the iron in the liquid slag is realized as a high-value resource.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of non-ferrous metallurgy, in particular to a liquid slag electrically enhanced reduction mother-son furnace and a method for reducing lead, zinc and iron. BACKGROUND

[0002] The production of lead is mainly a pyrometallurgical process, and the pyrometallurgical lead smelting mainly adopts an oxidation smelting-liquid slag direct reduction-fuming zinc extraction three-in-one furnace device, and the byproduct zinc is mainly recovered and enriched in the form of zinc oxide in the fuming furnace; the smelting of zinc is mainly based on a wet process, and mainly adopts a series of devices of sulfuric acid leaching, purification and electrodeposition; the current lead-zinc smelting device does not involve the high-value recovery of iron.

[0003] These methods have problems of high energy consumption, long process, large amount of flue gas, etc., which are not compatible with the high-quality development of the current national double-carbon economy, green economy and circular economy. SUMMARY

[0004] In order to solve the technical problem that the current lead-zinc smelting device does not involve the high-value recovery of iron, the present application provides a liquid slag electrically enhanced reduction mother-son furnace and a method for reducing lead, zinc and iron, which can directly reduce lead, zinc and iron polymetallic.

[0005] The present application adopts the following technical solutions:

[0006] A liquid slag electrically enhanced reduction mother-son furnace, comprising a mother furnace and a son furnace, the son furnace is in communication with the bottom of the mother furnace to form a slag inlet channel; the son furnace is used to balance the liquid level in the son furnace and the mother furnace, so that the liquid slag submerges the slag inlet channel, and air is prevented from entering when the substances in the mother furnace react;

[0007] The mother furnace is divided into three furnace bodies from left to right, which are a left furnace body, a middle furnace body and a right furnace body, a first feeding port for adding coke particles, a second feeding port for adding lime and / or silicon dioxide and at least one group of electrodes A are arranged above each furnace body; each group of electrodes A extends downward into the mother furnace;

[0008] The end of the mother furnace away from the son furnace is provided with a flue gas outlet and a slag discharge port;

[0009] The inner bottom of the mother furnace is provided with a protruding platform, which divides the inner bottom of the mother furnace into a lead collection area on the left side and an iron collection area on the right side, the side wall of the mother furnace where the lead collection area is located is provided with a lead discharge port, and the side wall of the mother furnace where the iron collection area is located is provided with an iron discharge port.

[0010] Further, an electrode B extending downward into the son furnace is arranged above the son furnace, and a chute is connected to the upper feeding port of the son furnace. The chute is used to send the lead, zinc and iron-containing oxidized slag melt from the upstream process into the son furnace in the mother-son furnace; the electrode B is further arranged above the son furnace, which prevents the liquid slag in the son furnace and the slag inlet channel from solidifying after being heated by electricity.

[0011] Further, the lead discharging port is provided with a first siphon well, and the slag discharging port is provided with a second siphon well. The discharging of the lead liquid and the tail slag is through the siphon well mode, so as to balance the liquid level in the furnace and avoid the external air entering the mother furnace.

[0012] Further, the mother furnace is provided with a manhole and a plurality of detection holes.

[0013] Further, the top surface of the platform is higher than the upper surface of the iron liquid in the iron collecting area and the upper surface of the lead liquid in the lead collecting area, and the platform is located in the middle furnace body.

[0014] Further, the upper end of the first feeding port is connected to a coke particle material sealing bin, and a closed screw conveyor A is arranged on the pipeline between the first feeding port and the coke particle material sealing bin to realize closed feeding and avoid the external air entering the mother furnace. The second feeding port is connected to a lime material sealing bin and / or a silicon dioxide material sealing bin, and a closed screw conveyor A is arranged on the pipeline between the second feeding port and the lime material sealing bin and / or the silicon dioxide material sealing bin to realize closed feeding and avoid the external air entering the mother furnace.

[0015] Further, the bottom surface of the electrode A of the right furnace body is lower than the bottom surface of the electrode A of the left furnace body and the middle furnace body. The bottom surface of the electrode A of the right furnace body is higher than the top surface of the platform and close to the top surface of the platform.

[0016] Further, the liquid level of the liquid slag in the sub-furnace is higher than the highest position of the slag inlet channel.

[0017] Further, the mother furnace is a rectangular furnace with four corners and a top round transition. One side of the bottom of the connection between the mother furnace and the sub-furnace is provided with an inlet, and the sub-furnace is a rectangle with a feeding port at the top and an outlet at one side of the bottom. The outlet of the sub-furnace and the inlet of the mother furnace are in communication to form a slag inlet channel, and the height of the sub-furnace is lower than the height of the mother furnace.

[0018] Further, the group of electrodes A includes three electrodes arranged in a triangular shape or a straight line shape.

[0019] Further, the height of the platform is greater than 200 mm.

[0020] A method for directly reducing lead, zinc and iron by liquid slag electrically enhanced reduction mother and sub-furnace, comprising the following steps:

[0021] Step A, the lead, zinc, iron containing oxidized slag melt is sent into the sub-furnace of the mother and child furnace, and then enters the mother furnace through the slag channel, the content of lead, zinc and iron in the oxidized slag melt is detected, according to the detection result, coke particles, silicon dioxide and calcium oxide are added to the left section of the furnace body of the mother furnace, the addition amount of the coke particles is 72.5-94.3 kg of coke particles with a carbon purity of 80% per ton of lead, the addition amount of the silicon dioxide and the calcium oxide should satisfy the ratio of Fe:SiO2:CaO (1.2-2.4):1:(0.4-0.5) in the oxidized slag melt, coke particles and calcium oxide are added to the middle section of the furnace body, the addition amount of the coke particles is 230.7-350 kg of coke particles with a carbon purity of 80% per ton of zinc, the addition amount of the calcium oxide should satisfy the ratio of SiO2:CaO=1:(0.4-1) in the oxidized slag melt, coke particles and calcium oxide are added to the right section of the furnace body, the addition amount of the coke particles is 267.9-348.3 kg of coke particles with a carbon purity of 80% per ton of iron, and the addition amount of the calcium oxide should satisfy the ratio of SiO2:CaO=1:(0.6-1.5) in the oxidized slag melt;

[0022] The heating temperature of the electrode A arranged in the three-section furnace body is different, so that the temperature in the three-section furnace body is controlled differently, when there are multiple groups of the electrode A arranged in each section of the furnace body, the heating temperature of the multiple groups of the electrode A arranged in the same section of the furnace body is the same, the heating temperature of the electrode A arranged in the left section of the furnace body is 1000-1150 DEG C, which is used for preparing lead liquid, the heating temperature of the electrode A arranged in the middle section of the furnace body is 1200-1350 DEG C, which is used for preparing zinc vapor, and the heating temperature of the electrode A arranged in the right section of the furnace body is 1400-1600 DEG C, which is used for preparing iron liquid, so that the direct reduction reaction of the multi-metal oxide and carbon of lead, zinc and iron is realized, and metal lead liquid, metal iron liquid, tail slag and flue gas containing zinc vapor, lead vapor and CO are produced;

[0023] The lead liquid is converged to the lead collecting area, and then is discharged from the lead discharging port, the iron liquid is converged to the iron collecting area, and then is discharged from the iron discharging port, the tail slag is discharged from the slag discharging port, and the flue gas containing zinc vapor, lead vapor and CO is discharged from the flue gas outlet;

[0024] Step B, after the flue gas containing zinc vapor, lead vapor and CO produced in step A is discharged from the flue gas outlet, the flue gas enters the condenser, and lead, zinc and CO are condensed and separated, so that lead liquid, zinc liquid and CO fuel gas are produced.

[0025] Compared with the prior art, the present application has the following technical effects:

[0026] 1. The application adopts liquid slag electrically enhanced direct reduction of lead, zinc and iron multi-metal mother-son furnace, at least one group of electrodes A is arranged above each furnace body of left furnace body, middle furnace body and right furnace body, the heating temperature of electrodes A in three furnace bodies is different, the metal lead product is output at the same time, the metal zinc and the metal iron are obtained, the added value of the product is improved, the iron in the slag realizes high value resource, the lead content in the final tail slag is reduced to below 0.3%, the zinc content is reduced to below 0.4%, the loss of lead and zinc resources and energy consumption are reduced, and the recovery rate of iron reaches more than 50%.

[0027] 2. The liquid level in the mother-son furnace is higher than the highest part of the slag inlet channel, the liquid sealing effect is realized during the feeding and reduction smelting of the mother furnace; the first feeding port and the second feeding port adopt closed screw conveyors to realize closed feeding; the mother furnace realizes oxygen-free state closed direct reduction of liquid slag, realizes short process operation of synchronous reduction of lead, zinc and iron, realizes high value resource of iron in liquid slag, and solves the problem of long process flow in the prior art. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a structural schematic view of a liquid slag electrically enhanced reduction mother-son furnace of the application (omitting electrodes B on the son furnace);

[0029] Figure 2 is Figure 1 A-A sectional view in the middle (omitting the closed screw conveyor A of the chute, the middle furnace body and the right furnace body and the coke particle sealing warehouse;);

[0030] Figure 3 is Figure 1 B-B sectional view in the middle;

[0031] Figure 4 is Figure 1 C-C sectional view in the middle;

[0032] Reference numerals in the drawings are:

[0033] 1 is an oxidizing smelting furnace;

[0034] 20 is a mother furnace, 200 is a platform, 201 is a first feeding port, 201-2 is a coke particle sealing warehouse, 201-1 is a closed screw conveyor A, 202 is a second feeding port, 202-2 is a lime material sealing warehouse and / or a silicon dioxide material sealing warehouse, 202-1 is a closed screw conveyor B, 203-1 is an electrode A, 203-2 is an electrode B, 204 is a lead discharging port, 204-1 is a first siphon well, 205 is an iron discharging port, 206 is a slag discharging port, 206-1 is a second siphon well, 207 is a lead collecting area, 208 is an iron collecting area, 209 is a flue gas outlet, 2010 is a manhole, and 2011 is a detection hole;

[0035] 21 is a sub-furnace;

[0036] 23 is a slag inlet channel;

[0037] 3 is a condenser. DETAILED DESCRIPTION

[0038] The application is further described below in conjunction with the drawings and specific embodiments.

[0039] As shown in the drawings, Figures 1 to 4 A liquid slag electrically enhanced reduction mother and sub-furnace includes a mother furnace 20 and a sub-furnace 21, and the sub-furnace 21 is in communication with the bottom of the mother furnace 20 to form a slag inlet channel 23.

[0040] The mother furnace 20 is divided into three furnace bodies from left to right, namely a left furnace body, a middle furnace body and a right furnace body. Each furnace body is provided with a first charging port 201 for adding coke particles, a second charging port 202 for adding lime and / or silicon dioxide, and at least one group of electrodes A 203-1, each group of electrodes A 203-1 extending downward into the mother furnace 20. When there is only one group of electrodes A provided in each furnace body, the heating temperatures of each group of electrodes A provided in the three furnace bodies are different. When there are multiple groups of electrodes A provided in each furnace body, the heating temperatures of the multiple groups of electrodes A provided in the same furnace body are the same. The heating temperature of the electrodes A in the left furnace body is 1000-1150°C, mainly used for reducing lead in the liquid slag to prepare lead liquid. The heating temperature of the electrodes A in the middle furnace body is 1200-1350°C, mainly used for reducing zinc in the liquid slag to prepare zinc vapor. The heating temperature of the electrodes A in the right furnace body is 1400-1600°C, mainly used for reducing iron in the liquid slag to prepare iron liquid.

[0041] The end of the mother furnace 20 away from the sub-furnace 21 is provided with a flue gas outlet 209 and a slag discharge port 206;

[0042] The inner bottom of the mother furnace 20 is provided with a protruding platform 200, which divides the inner bottom of the mother furnace 20 into a lead collecting area 207 on the left side and an iron collecting area 208 on the right side. The side wall of the mother furnace 20 where the lead collecting area 207 is located is provided with a lead discharge port 204, and the side wall of the mother furnace 20 where the iron collecting area 208 is located is provided with an iron discharge port 205. The lead liquid prepared in the left furnace body is heavy and deposits on the inner bottom of the furnace, flows into the lead collecting area 207, and then is discharged through the first siphon well 204-1 from the lead discharge port 204. The iron liquid prepared in the right furnace body flows into the iron collecting area 208, and is discharged through the iron discharge port 205 when the thickness of the iron liquid reaches 50-200 mm. The protruding platform 200 is provided in the application, and the top surface of the platform 200 is higher than the upper surface of the lead liquid and the iron liquid, which can prevent the mixing of the iron liquid and the lead liquid. Because the liquid level of the lead liquid needs to be maintained within a certain height range, the lead collecting area 207 is provided in the application, which reduces the flat area of the lead liquid in the entire furnace body, thereby reducing the amount of lead liquid stored in the mother furnace and reducing the volatilization of the lead liquid.

[0043] As an implementable manner, the electrode B 203-2 is arranged above the sub-furnace 21 and extends downward into the sub-furnace 21, the heating temperature of the electrode B 203-2 is 850-1200℃, the electrode B 203-2 is installed and fixed by an externally arranged frame body, the bottom of the sub-furnace 21 is provided with a bottom anode to form a loop with the electrode B, and the electrode B 203-2 is used to maintain the liquid slag in the sub-furnace and the slag inlet channel in a molten state, so that the liquid slag flows according to the liquid level difference in the mother furnace and the sub-furnace, realizes the liquid sealing function and the liquid level balance, and the upper portion of the sub-furnace 21 is connected with a chute 24.

[0044] As an implementable manner, the lead discharging port 204 is externally provided with a first siphon well 204-1 for closed siphon balance discharge of the lead liquid and control of the thickness of the lead liquid in the mother furnace; and the slag discharging port 206 is externally provided with a second siphon well 206-1 for balanced discharge of tail slag.

[0045] As an implementable manner, the mother furnace is provided with a manhole 2010 and a plurality of detection holes 2011. The manhole 2010 can be used for manual access into the furnace for cleaning and furnace lining during shutdown.

[0046] As an implementable manner, the top surface of the platform 200 is higher than the upper surface of the iron liquid in the iron collecting area 208 and the upper surface of the lead liquid in the lead collecting area 207, and the platform 200 is located in the middle section of the furnace body.

[0047] As an implementable manner, the upper end of the first charging port 201 is connected to a coke particle storage bin 201-2, a closed screw conveyor A 201-1 is arranged on the pipeline between the first charging port 201 and the coke particle storage bin 201-2 to realize closed feeding; the second charging port 202 is connected to a lime material storage bin and / or a silicon dioxide material storage bin 202-2, and a closed screw conveyor B 202-1 is arranged on the pipeline between the second charging port 202 and the lime material storage bin and / or the silicon dioxide material storage bin 202-2 to realize closed feeding.

[0048] As an implementable manner, the bottom surface of the electrode A 203-1 of the right furnace body is lower than the bottom surface of the electrode A 203-1 of the left furnace body and the middle furnace body, and the bottom surface of the electrode A 203-1 of the right furnace body is higher than the top surface of the platform 200 and close to the top surface of the platform 200. That is, the insertion depth of the electrode A of the right furnace body is deeper than the insertion depth of the electrode A of the left furnace body and the middle furnace body. The electrode A of the left furnace body and the middle furnace body is inserted shallowly because the principle of electric conduction and heat generation is that the electrode (positive and negative electrode) and the liquid slag form an electric conduction system, mainly relying on the resistance heating of the liquid slag, and the cold slag material (referring to the added coke particles, silicon dioxide and calcium oxide) enters the furnace and floats or suspends in the melt, so that the place where the heat source is needed is mainly the upper layer of the melt, and therefore the electrode A of the left furnace body and the middle furnace body is inserted shallowly. The right furnace body of the present application relies on two heating methods of electric arc and resistance, and in order to form an electric arc, a good conductor is needed, and the electric conduction performance of metal iron is good, and the arc striking medium of the electrode is also the arc striking medium, that is, when the electrode approaches the metal iron, an arc light is generated, which is similar to the arc striking process phenomenon of electric welding. In this way, the electric conduction in the liquid slag forms a loop with the electrode, the arc light, the iron liquid and the liquid slag. The arc light has strong energy, mainly including kinetic energy and thermal energy. The melting point of iron is high, and only strong heat can make it become an iron liquid, otherwise it will solidify at the bottom of the furnace, causing the production to be unable to proceed normally.

[0049] As an implementable manner, the liquid level of the liquid slag in the sub-furnace 21 is higher than the highest point of the slag inlet channel 23. When the reduction smelting is carried out in the mother furnace 20, because the liquid level in the sub-furnace 21 is higher than the highest point of the slag inlet channel 23, air is prevented from entering the mother furnace 20. Because a large amount of CO is generated during reduction smelting, if air enters the furnace, there is a risk of explosion. The sub-furnace 21 of the present application realizes the liquid sealing effect of the mother furnace 20, and has good effect.

[0050] As an implementable manner, the mother furnace 20 is a rectangular furnace with four corners and a top round transition. An inlet is formed at one side of the bottom of the connection between the mother furnace 20 and the sub-furnace 21. The sub-furnace 21 is a rectangle with a feeding port at the top and an outlet at one side of the bottom. The outlet of the sub-furnace 21 and the inlet of the mother furnace 20 are connected to each other to form a slag inlet channel 23, and the height of the sub-furnace 21 is lower than the height of the mother furnace 20.

[0051] As an implementable manner, each group of electrode A 203-1 includes three electrodes arranged in a triangular shape or a straight line shape. The outer wall of the electrode A is clamped by an electrode holder connected with an electrode lifting device.

[0052] As an implementation manner, the height of the platform 200 is greater than 200 mm, that is, the distance between the top surface of the platform 200 and the inner bottom surface of the mother furnace 20 where the lead collection area 208 is located is greater than 200 mm, and the distance between the top surface of the platform 200 and the inner bottom surface of the mother furnace 20 where the lead collection area 207 is located is greater than 200 mm.

[0053] A system for electrically enhanced reduction of lead, zinc and iron from liquid slag, comprising an oxidizing smelting furnace 1, the above-mentioned electrically enhanced reduction mother-son furnace for liquid slag, and a condenser 3; the oxidizing smelting furnace 1 is connected to the son furnace 21, and the condenser 3 is connected to the flue gas outlet 209.

[0054] A method for electrically enhanced reduction of lead, zinc and iron from liquid slag in a mother-son furnace, characterized in that it comprises the following steps:

[0055] Step A: the oxidized slag melt containing lead, zinc and iron is fed into the son furnace 21 in the mother-son furnace, and then enters the mother furnace 20 through the slag inlet channel 23. The son furnace 21 and the mother furnace 20 are connected as a whole through the slag inlet channel 23. The height of the liquid slag in the son furnace 21 is higher than the highest point of the slag inlet channel 23, so that the liquid level balance of the mother furnace 20 is achieved.

[0056] The contents of lead, zinc and iron in the oxidized slag melt are detected, and according to the detection results, coke particles, silicon dioxide and calcium oxide are added to the left section of the mother furnace (20). The amount of coke particles added is 72.5-94.3 kg of coke particles with a carbon purity of 80% per ton of lead. The amounts of silicon dioxide and calcium oxide added should satisfy the ratio of Fe:SiO2:CaO being (1.2-2.4):1:(0.4-0.5) in the oxidized slag melt. Coke particles and calcium oxide are added to the middle section of the furnace. The amount of coke particles added is 230.7-350 kg of coke particles with a carbon purity of 80% per ton of zinc. The amount of calcium oxide added should satisfy the ratio of SiO2:CaO=1:(0.4-1) in the oxidized slag melt. Coke particles and calcium oxide are added to the right section of the furnace. The amount of coke particles added is 267.9-348.3 kg of coke particles with a carbon purity of 80% per ton of iron. The amount of calcium oxide added should satisfy the ratio of SiO2:CaO=1:(0.6-1.5) in the oxidized slag melt. Airtight screw conveyor A 201-1 is arranged on the pipeline between the first feeding port 201 and the coke particle storage bin 201-2 to realize airtight feeding. Airtight screw conveyor B 202-1 is arranged on the pipeline between the second feeding port 202 and the lime storage bin and / or the silicon dioxide storage bin 202-2 to realize airtight feeding.

[0057] The temperature in the three-section furnace is controlled by setting different heating temperatures for the electrodes A in the three-section furnace. When there are multiple groups of electrodes A in each section of the furnace, the heating temperatures of the multiple groups of electrodes A in the same section of the furnace are the same. The heating temperature of the electrodes A in the left section of the furnace is 1000-1150°C, which is used for preparing lead liquid. The heating temperature of the electrodes A in the middle section of the furnace is 1200-1350°C, which is used for preparing zinc vapor. The heating temperature of the electrodes A in the right section of the furnace is 1400-1600°C, which is used for preparing iron liquid. The direct reduction reaction of the multi-metal oxides of lead, zinc and iron and carbon is realized, and the metal lead liquid, metal iron liquid, tailing and flue gas containing zinc vapor, lead vapor and CO are produced.

[0058] The lead liquid flows into the lead collecting area 207 and is discharged from the lead discharging port 204. The iron liquid flows into the iron collecting area 208 and is discharged from the iron discharging port 205. The tailing is discharged from the slag discharging port 206. The flue gas containing zinc vapor, lead vapor and CO is discharged from the flue gas outlet 209.

[0059] The lead, zinc and iron-containing oxidized slag melt is prepared by the prior art. For the convenience of implementation, the lead, zinc and iron-containing raw materials are mixed with calcium oxide and silicon dioxide, granulated and then fed into the oxidizing smelting furnace 1. Oxygen is introduced into the furnace through an oxygen lance, and the temperature in the furnace is controlled at 1000-1300°C. After smelting, SO 2 The flue gas and the lead, zinc and iron-containing oxidized slag melt are sent to an acid making process after being discharged from the oxidizing smelting furnace 1.

[0060] The lead, zinc and iron-containing raw materials include lead ore, zinc ore, lead-zinc mixed ore, lead paste, pyrite, steel ash and lead-zinc-containing secondary materials. The composition of the granulated materials includes Pb 10-50%, Zn 5-35%, FeO 8-20%, SiO2 5-15%, CaO 2-10%, Cu 0.5-3% and S 10-20%.

[0061] The direct reduction reaction of the multi-metal oxides of lead, zinc and iron and carbon is completed in the process, and the reaction mechanism is as follows:

[0062] In step A, the obtained lead, zinc and iron-containing oxidized slag melt mainly exists in the forms of PbO, ZnO, FeO, Fe3O4, CaO and PbO•(SiO2) X , ZnO•(SiO2) X , FeO•(SiO2) X , CaO•(SiO2) X , ZnO•Fe2O3. C reacts with PbO, PbO•(SiO2) X , ZnO, ZnO•(SiO2) X , FeO and FeO•(SiO2).X , ZnO•Fe2O3 occurs reaction, when C and PbO•(SiO2) X After the reaction, the metal Pb and dissociated SiO2 will be obtained, the melting point of SiO2 is as high as 1750 DEG C, and it is necessary to find a combination to reduce the melting point to meet the smelting temperature below 1600 DEG C, ZnO, FeO, CaO becomes the combination object of SiO2; similarly, when the zinc in the oxidized state (including the complex oxidized state of zinc combined with SiO2) is reduced to metal zinc, the dissociated SiO2 in the reaction is combined into the low-melting FeO-SiO2-CaO ternary slag system by adding CaO. Similarly, when part of the oxidized iron (including the complex oxidized iron combined with SiO2) is reduced to metallic iron, the dissociated SiO2 in the reaction is combined into the low-melting FeO-SiO2-CaO ternary slag system by adding CaO. This is the principle of adding CaO to combine SiO2 to form a low-melting slag system.

[0063] The reaction equation is as follows:

[0064] PbO+C=Pb+CO

[0065] ZnO +C=Zn+CO

[0066] FeO+C=Fe+CO

[0067] Fe3O4+4C=3Fe+4CO

[0068] PbO•(SiO2) X +C+CaO=Pb+CaO•(SiO2) X +CO

[0069] ZnO•(SiO2) X +C+CaO=Zn+CaO•(SiO2) X +CO

[0070] FeO•(SiO2) X +C+CaO=Fe+CaO•(SiO2) X +CO

[0071] ZnO•Fe2O3+4C=Zn+2Fe+4CO

[0072] The present application completely changes the traditional indirect reduction reaction mechanism of lead, zinc, iron and carbon monoxide, and the combustion heat source required for the reaction, and the traditional reaction equation is as follows:

[0073] PbO+CO=Pb+CO2

[0074] FeO+CO=Fe+CO2

[0075] ZnO + CO = Zn + CO2

[0076] C + 0.5O2 = CO

[0077] C + O2 = CO2

[0078] CO + 0.5O2 = CO2

[0079] Step B, the flue gas containing zinc vapor, lead vapor and CO prepared in step A is discharged from the flue gas outlet 209 and enters the condenser 3, and the lead, zinc and CO are condensed and separated to produce lead liquid, zinc liquid and CO fuel gas.

[0080] As an implementable manner, the amount of coke added in the left furnace body is 82.5 kg of coke with a carbon purity of 80% per ton of lead, the amount of silica and calcium oxide added should meet the ratio of Fe:SiO2:CaO = 1.8:1:0.5 in the oxidized slag melt; the amount of coke added in the middle furnace body is 265.3 kg of coke with a carbon purity of 80% per ton of zinc, the amount of calcium oxide added should meet the ratio of SiO2:CaO = 1:0.7 in the oxidized slag melt; the amount of coke added in the right furnace body is 308.1 kg of coke with a carbon purity of 80% per ton of iron, the amount of calcium oxide added should meet the ratio of SiO2:CaO = 1:1.1 in the oxidized slag melt.

[0081] The above-mentioned embodiments are only preferred embodiments of the present application, and are only used to explain the present application, and are not intended to limit the scope of the present application. For those skilled in the art, other embodiments can be easily obtained by substitution or change based on the technical content disclosed in the present specification, and therefore, any changes and improvements made within the principles and process conditions of the present application should be included in the scope of the patent application.

Claims

1. A liquid slag electrically enhanced reduction mother-daughter furnace characterized by, The furnace comprises a mother furnace (20) and a sub-furnace (21), and the sub-furnace (21) is communicated with the bottom of the mother furnace (20) to form a slag inlet channel (23); The mother furnace (20) is divided into three sections, from left to right, into a left section, a middle section and a right section, and a first feeding port (201) for adding coke particles, a second feeding port (202) for adding lime and / or silicon dioxide and at least one group of electrodes A (203-1) are arranged above each section; each group of electrodes A (203-1) extends downward into the mother furnace (20); The mother furnace (20) is provided with a flue gas outlet (209) and a slag outlet (206) at one end away from the sub-furnace (21); The inner bottom of the mother furnace (20) is provided with a protruding platform (200), which divides the inner bottom of the mother furnace (20) into a lead collection area (207) on the left side and an iron collection area (208) on the right side; the side wall of the mother furnace (20) where the lead collection area (207) is located is provided with a lead outlet (204), and the side wall of the mother furnace (20) where the iron collection area (208) is located is provided with an iron outlet (205); The sub-furnace (21) is provided with electrodes B (203-2) extending downward into the sub-furnace (21) above the sub-furnace (21), and a chute (24) is connected to the upper feeding port of the sub-furnace (21); The top surface of the platform (200) is higher than the upper surface of the iron liquid in the iron collection area (208) and the upper surface of the lead liquid in the lead collection area (207), and the platform (200) is located in the middle section; The bottom surface of the electrodes A (203-1) of the right section is lower than the bottom surface of the electrodes A (203-1) of the left section and the middle section, and the bottom surface of the electrodes A (203-1) of the right section is higher than and close to the top surface of the platform (200); One side of the connection between the mother furnace (20) and the sub-furnace (21) is provided with an inlet, and the sub-furnace (21) is rectangular with a feeding port at the top and an outlet at one side; the outlet of the sub-furnace (21) and the inlet of the mother furnace (20) are communicated to form a slag inlet channel (23), and the height of the sub-furnace (21) is lower than the height of the mother furnace (20); one group of electrodes A comprises three electrodes arranged in a triangular or linear shape.

2. A liquid slag electrically enhanced reduction mother-daughter furnace as claimed in claim 1, wherein, A first siphon well (204-1) is arranged outside the lead outlet (204), and a second siphon well (206-1) is arranged outside the slag outlet (206).

3. The liquid slag electrically enhanced reduction mother-daughter furnace of claim 1, wherein, A manhole (2010) and a plurality of detection holes (2011) are arranged on the mother furnace; The upper end of the first feeding port (201) is connected to a coke particle sealing bin (201-2), and a closed screw conveyor A (201-1) is arranged on the pipeline between the first feeding port (201) and the coke particle sealing bin (201-2) to realize closed feeding; the second feeding port (202) is connected to a lime and / or silicon dioxide sealing bin (202-2), and a closed screw conveyor B (202-1) is arranged on the pipeline between the second feeding port (202) and the lime and / or silicon dioxide sealing bin (202-2) to realize closed feeding.

4. The liquid slag electrically enhanced reduction mother-daughter furnace of claim 1, wherein, The liquid level of the liquid slag in the sub-furnace (21) is higher than the highest point of the slag inlet channel (23).

5. The liquid slag electrically enhanced reduction mother-daughter furnace of claim 1, wherein, The mother furnace (20) is a rectangular furnace with four corners and a top round transition.

6. The method for reducing lead, zinc and iron in a liquid residue electrically enhanced reduction mother- daughter furnace according to any one of claims 1-5, characterized in that, The method comprises the following steps: Step A, the lead, zinc and iron containing oxidized slag melt is fed into the sub-furnace (21) in the mother and sub-furnace, and then is fed into the mother furnace (20) through the slag feeding channel (23). The content of lead, zinc and iron in the oxidized slag melt is detected. According to the detection result, coke particles, silicon dioxide and calcium oxide are added to the left section of the furnace body of the mother furnace (20). The addition amount of the coke particles is 72.5-94.3 kg of coke particles with a carbon purity of 80% per ton of lead. The addition amount of the silicon dioxide and the calcium oxide should satisfy the ratio of Fe:SiO2:CaO being (1.2-2.4):1:(0.4-0.5). Coke particles and calcium oxide are added to the middle section of the furnace body. The addition amount of the coke particles is 230.7-350 kg of coke particles with a carbon purity of 80% per ton of zinc. The addition amount of the calcium oxide should satisfy the ratio of SiO2:CaO being 1:(0.4-1) in the oxidized slag melt. Coke particles and calcium oxide are added to the right section of the furnace body. The addition amount of the coke particles is 267.9-348.3 kg of coke particles with a carbon purity of 80% per ton of iron. The addition amount of the calcium oxide should satisfy the ratio of SiO2:CaO being 1:(0.6-1.5) in the oxidized slag melt. The temperature control in the three sections of the furnace body is realized by the different heating temperatures of the electrodes A arranged in the three sections of the furnace body. When there are multiple groups of electrodes A arranged in each section of the furnace body, the heating temperatures of the multiple groups of electrodes A arranged in the same section of the furnace body are the same. The heating temperature of the electrodes A in the left section of the furnace body is 1000-1150 DEG C, which is used for preparing lead liquid. The heating temperature of the electrodes A in the middle section of the furnace body is 1200-1350 DEG C, which is used for preparing zinc vapor. The heating temperature of the electrodes A in the right section of the furnace body is 1400-1600 DEG C, which is used for preparing iron liquid. The direct reduction reaction of the multi-metal oxides of lead, zinc and iron and carbon is realized, and the metal lead liquid, metal iron liquid, tail slag and flue gas containing zinc vapor, lead vapor and CO are produced. The lead liquid flows into the lead collecting area (207), and then is discharged from the lead discharging port (204). The iron liquid flows into the iron collecting area (208), and then is discharged from the iron discharging port (205). The tail slag is discharged from the slag discharging port (206). The flue gas containing zinc vapor, lead vapor and CO is discharged from the flue gas outlet (209). Step B, after the flue gas containing zinc vapor, lead vapor and CO produced in step A is discharged from the flue gas outlet (209), the flue gas enters the condenser (3), and the lead, zinc and CO are condensed and separated, and the lead liquid, zinc liquid and CO fuel gas are produced.

7. The process for the reduction of lead, zinc and iron in a liquid slag by electro- enhanced reduction in a mother-daughter furnace according to claim 6, characterized in that, The left section furnace body coke particle addition amount is 82.5 kg of 80% pure carbon per ton of lead, the silica and calcium oxide addition amount meets the ratio of Fe:SiO2:CaO in the oxidized slag melt is 1.8:1:0.5; the middle section furnace body coke particle addition amount is 265.3 kg of 80% pure carbon per ton of zinc, the calcium oxide addition amount should meet the ratio of SiO2:CaO in the oxidized slag melt is 1:0.7; the right section furnace body coke particle addition amount is 308.1 kg of 80% pure carbon per ton of iron, the calcium oxide addition amount should meet the ratio of SiO2:CaO in the oxidized slag melt is 1:1.1.

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