Zinc-lead combined smelting furnace

Abstract

The utility model relates to the technical field of smelting, in particular to a zinc-lead combined smelting furnace which comprises a furnace bottom, a molten pool, a furnace wall, a furnace top and two groups of graphite electrodes, according to the zinc-lead combined smelting furnace, the efficiency, the stability and the environmental protection property of the smelting process are remarkably improved through the design of the furnace bottom of a multi-layer structure, the molten pools and the furnace walls which are laid in a crossed mode, the arch-shaped furnace top and the configuration of the graphite electrodes. By means of the design, the overall strength and heat resistance of the smelting furnace are enhanced, effective utilization of heat and stability of reducing atmosphere are guaranteed, even distribution and effective separation of liquid metal are promoted, and the recovery rate and purity of zinc and lead are improved. Meanwhile, by accurately controlling the current and the voltage of the graphite electrode, the smelting process is accurately controlled, the energy consumption and the production cost are reduced, and a positive role is played in environmental protection. The problem that an existing smelting method is large in metal loss is solved.

Description

Technical Field

[0001] This utility model relates to the field of metallurgical technology, and in particular to a zinc-lead combined smelting furnace. Background Technology

[0002] A zinc smelting electric furnace is a single-smelting furnace using zinc roasted ore (commonly known as roasted sand) as raw material. It is a type of submerged arc furnace, in which graphite electrodes are inserted into the liquid melt (slag). Under the dual action of the micro-arc formed at the electrode-slag interface and the resistance of the melt, electrical energy is converted into heat energy. The role of coke is as a reducing agent. As explained in the above chemical reaction formula, part of the carbon is used for direct reduction, and part reacts with carbon dioxide to produce carbon monoxide, which then reacts with zinc oxide, lead oxide, and other metal oxides in the slag to produce zinc, lead, and other metals. The carbon dioxide itself is oxidized to carbon dioxide, which then reacts with the hot coke in a cycle to produce carbon monoxide. Submerged arc furnaces mainly produce zinc ingots. The small amount of lead contained in the roasted sand is collected in the zinc liquid as zinc vapor volatilizes and condenses in the closed furnace. Generally, it is required to control the lead content of the roasted sand to be less than 2%.

[0003] In electric arc furnaces for zinc smelting, it is essential to control the superheat temperature of the melt, the zinc content in the slag, and the reducing atmosphere. Essentially, the furnace should only reduce zinc and lead. High-boiling-point metals such as copper, iron, and precious metals, after being reduced, can only accumulate in the furnace and be discharged outside the furnace with the slag, resulting in metal loss. Utility Model Content

[0004] The purpose of this invention is to provide a zinc-lead combined smelting furnace, which aims to solve the problem of large metal loss in existing smelting methods.

[0005] To achieve the above objectives, a zinc-lead combined smelting furnace includes a furnace bottom, a molten pool, a furnace wall, a furnace top, and two graphite electrodes; the molten pool is laid on the furnace bottom, the furnace wall is laid on the molten pool, the furnace top is laid on the furnace wall, and the two sets of graphite electrodes are installed on the furnace top.

[0006] The furnace bottom is made of asbestos board, clay straight bricks, ramming material and high alumina straight bricks. The clay straight bricks are laid on the asbestos board, the ramming material is laid on the clay straight bricks, and the high alumina straight bricks are laid on the ramming material.

[0007] The molten pool is made of multiple chromium corundum sharp wedge bricks and multiple chromium corundum blunt wedge bricks, with the multiple chromium corundum blunt wedge bricks and the multiple chromium corundum sharp wedge bricks laid in a cross pattern.

[0008] The furnace top is made of multiple arched bricks, which are laid on the furnace wall.

[0009] The furnace wall is made of multiple high-alumina sharp wedge bricks and multiple high-alumina blunt wedge bricks, with the high-alumina blunt wedge bricks and the high-alumina sharp wedge bricks laid in an alternating pattern.

[0010] The mixed furnace gas outlet is made of multiple high-alumina vertical wedge bricks, which are laid sequentially on the furnace wall.

[0011] The molten pool has a lead outlet, the furnace wall has a mixed furnace gas outlet, the mixed furnace gas outlet is located on one side of the furnace wall, and the lead outlet is located on one side of the molten pool.

[0012] Secondly, this utility model provides a zinc-lead co-smelting method for use in the zinc-lead co-smelting furnace described in the first aspect, comprising the following steps:

[0013] Add lead-zinc rich calcined sand and coke into a closed electric furnace;

[0014] When the closed electric furnace is working, zinc oxide undergoes a reduction reaction with coke and carbon monoxide, and the zinc oxide and lead oxide in the calcined sand are reduced to a zinc-lead mixed vapor form, metallic zinc and metallic lead.

[0015] The zinc-lead mixed vapor enters the condenser and is condensed to obtain zinc liquid and lead liquid. The zinc liquid is discharged from the top, and the lead liquid is discharged from the siphon.

[0016] The melting furnace and distillation furnace separate the lead contained in the zinc liquid to obtain refined zinc and crude lead.

[0017] The step of "adding lead-zinc rich roasted sand and coke to a closed electric furnace" includes the following steps:

[0018] Lead, zinc and calcined sand are mixed in a preset ratio to obtain lead-zinc rich calcined sand;

[0019] Add coke to lead-zinc calcined sand and mix.

[0020] Lead-zinc calcined sand with added coke is added to a closed electric furnace.

[0021] In the section "mixing lead, zinc and calcined sand according to a preset ratio to obtain lead-zinc-rich calcined sand", the lead and zinc are mentioned in the calcined sand section. In the section "operating in a closed electric furnace, zinc oxide undergoes a reduction reaction with coke and carbon monoxide, and zinc oxide and lead oxide in the calcined sand are reduced to zinc-lead mixed vapor, metallic zinc and metallic lead", the operating temperature of the closed electric furnace is 1100℃-1300℃.

[0022] In the section "separating lead contained in zinc liquid in a melting furnace and a distillation furnace to obtain refined zinc and crude lead", the crude lead is used to produce refined lead by electrolysis.

[0023] This utility model discloses a zinc-lead combined smelting furnace, comprising a furnace bottom, a molten pool, furnace walls, a furnace roof, and two graphite electrodes. The molten pool is laid on the furnace bottom, the furnace walls are laid on the molten pool, the furnace roof is laid on the furnace walls, and the two graphite electrodes are installed on the furnace roof. The furnace bottom is made of asbestos board, clay straight bricks, ramming material, and high-alumina straight bricks. The clay straight bricks are laid on the asbestos board, the ramming material is laid on the clay straight bricks, and the high-alumina straight bricks are laid on the ramming material. The zinc-lead combined smelting furnace, through its multi-layered furnace bottom structure, cross-laid molten pool and furnace walls, arched furnace roof design, and graphite electrode configuration, significantly improves the efficiency, stability, and environmental friendliness of the smelting process. This design not only enhances the overall strength and heat resistance of the smelting furnace, ensuring effective heat utilization and a stable reducing atmosphere, but also promotes the uniform distribution and effective separation of liquid metal, improving the recovery rate and purity of zinc and lead. Meanwhile, by precisely controlling the current and voltage of the graphite electrodes, precise control of the smelting process was achieved, reducing energy consumption and production costs, and playing a positive role in environmental protection. This also solved the problem of significant metal loss in existing smelting methods. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a flowchart of a zinc-lead co-smelting method provided by this utility model.

[0026] Figure 2 This is a flowchart of adding lead-zinc rich calcined sand and coke into a closed electric furnace.

[0027] Figure 3 and Figure 4 This is a schematic diagram of a zinc-lead combined smelting furnace provided by this utility model.

[0028] In the diagram: 1-furnace bottom, 2-molten pool, 3-furnace wall, 4-furnace top, 5-graphite electrode, 6-lead outlet, 7-mixed furnace gas outlet. Detailed Implementation

[0029] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0030] Please see Figures 3 to 4 In a first aspect, a zinc-lead combined smelting furnace is used in the zinc-lead combined smelting method described in the first aspect, comprising a furnace bottom 1, a molten pool 2, a furnace wall 3, a furnace top 4, and two graphite electrodes 5; the molten pool 2 is laid on the furnace bottom 1, the furnace wall 3 is laid on the molten pool 2, the furnace top 4 is laid on the furnace wall 3, and the two graphite electrodes 5 are installed on the furnace top 4.

[0031] The molten pool 2 has a lead outlet 6, and the furnace wall 3 has a mixed furnace gas outlet 7. The mixed furnace gas outlet 7 is located on one side of the furnace wall 3, and the lead outlet 6 is located on one side of the molten pool.

[0032] The furnace bottom 1 is made of asbestos board, clay straight bricks, ramming material and high alumina straight bricks. The clay straight bricks are laid on the asbestos board, the ramming material is laid on the clay straight bricks, and the high alumina straight bricks are laid on the ramming material.

[0033] The molten pool 2 is made of multiple chromium corundum sharp wedge bricks and multiple high-alumina blunt wedge bricks, with the multiple chromium corundum blunt wedge bricks and the multiple chromium corundum sharp wedge bricks laid in a cross pattern.

[0034] The furnace wall 3 is made of multiple high-alumina sharp wedge bricks and multiple high-alumina blunt wedge bricks, with the multiple high-alumina blunt wedge bricks and the multiple high-alumina sharp wedge bricks laid in an alternating pattern.

[0035] The mixed furnace gas outlet 7 is made of multiple high-alumina vertical wedge bricks, which are laid sequentially on the furnace wall 3.

[0036] The furnace top 4 is made of multiple arched bricks, which are laid on the furnace wall 3.

[0037] In this embodiment, the furnace bottom 1 is made of asbestos board, clay straight bricks, ramming mix, and high-alumina straight bricks. The asbestos board serves as an insulation layer to prevent heat transfer to the furnace bottom; the clay and high-alumina straight bricks act as load-bearing and refractory layers, ensuring the strength and stability of the furnace bottom; the ramming mix fills the brick joints, improving the sealing and refractory properties of the furnace bottom. The molten pool 2 is formed by interlacing multiple chrome corundum sharp wedge bricks and multiple chrome corundum blunt wedge bricks. This arrangement increases the strength and stability of the molten pool while ensuring its smoothness and uniformity. The molten pool contains liquid metal and slag and is the main site of the reduction reaction. The furnace wall 3 is also formed by interlacing multiple chrome corundum sharp wedge bricks and multiple chrome corundum blunt wedge bricks. The furnace wall protects the high-temperature environment inside the furnace, preventing heat loss and ensuring a reducing atmosphere. The mixed gas outlet is formed by sequentially laying multiple high-alumina vertical wedge bricks on the furnace wall. The mixed furnace gas outlet is used to discharge the waste gas generated inside the furnace, ensuring a stable reducing atmosphere within the furnace. Furnace roof 4: Composed of multiple arched bricks laid on the furnace wall. The arched shape of the furnace roof increases its strength and stability, while also ensuring that heat inside the furnace is not easily lost.

[0038] The zinc-lead combined smelting furnace significantly improves the efficiency, stability, and environmental friendliness of the smelting process through its multi-layered furnace bottom, cross-laid molten pool and furnace walls, arched furnace roof design, and graphite electrode configuration. This design not only enhances the overall strength and heat resistance of the furnace, ensuring effective heat utilization and a stable reducing atmosphere, but also promotes the uniform distribution and effective separation of molten metal, improving the recovery rate and purity of zinc and lead. Simultaneously, precise control of the current and voltage of the graphite electrodes enables precise control of the smelting process, reducing energy consumption and production costs, and playing a positive role in environmental protection.

[0039] Please see Figures 1 to 2 Secondly, this utility model provides a zinc-lead co-smelting method for use in the zinc-lead co-smelting furnace described in the first aspect, comprising the following steps:

[0040] S1 adds lead-zinc rich calcined sand and coke into a closed electric furnace;

[0041] S11 mixes lead, zinc and calcined sand according to a preset ratio to obtain lead-zinc rich calcined sand;

[0042] Specifically, first, lead, zinc, and roasted ore are precisely weighed according to a predetermined ratio. Lead and zinc can be obtained from ores or concentrates containing these two metals, which are then pretreated to obtain the corresponding metal oxides. Roasted ore is the product of roasting zinc ore and mainly contains zinc oxide. These raw materials are then thoroughly mixed in a mixing device to ensure accurate proportions and uniform mixing, thus obtaining lead-zinc enriched roasted ore.

[0043] S12 involves adding coke to lead-zinc rich calcined sand and mixing it.

[0044] Specifically, coke is added to lead-zinc rich calcined sand in a certain proportion. The coke acts as a reducing agent, reducing zinc oxide and lead oxide to metallic zinc and metallic lead. The amount of coke added should be determined based on the oxygen content of the raw materials and the requirements of the reduction reaction. The coke and lead-zinc rich calcined sand are thoroughly and evenly mixed in a mixing device to ensure that the coke is evenly distributed in the calcined sand, thereby improving the reduction efficiency.

[0045] S13 adds lead-zinc calcined sand with coke into a closed electric furnace.

[0046] Specifically, the well-mixed lead-zinc calcined sand and coke are added to the sealed electric furnace through the charging port. During the charging process, care should be taken to control the charging speed and amount to avoid excessive fluctuations in the temperature and reducing atmosphere inside the furnace.

[0047] When the S2 closed electric furnace is working, zinc oxide, lead oxide and other metal oxides react with coke and carbon monoxide to reduce zinc oxide and lead oxide in the calcined sand to zinc-lead mixed vapor form, metallic zinc and metallic lead.

[0048] The operating temperature of the sealed electric furnace is 1100℃-1300℃.

[0049] Specifically, after the sealed electric furnace starts operating, graphite electrode 5 is inserted into the molten metal, forming a dual effect of micro-arc and melt resistance, converting electrical energy into heat energy. At high temperatures, coke reacts with oxygen to produce carbon monoxide, which then reacts with zinc oxide and lead oxide to produce metallic zinc and metallic lead. Simultaneously, some coke directly reduces zinc oxide and lead oxide. This maintains the zinc content in the slag and prevents iron from being reduced. The operating temperature of the electric furnace is controlled between 1100℃ and 1300℃ to ensure the reduction reaction proceeds fully.

[0050] S3 zinc-lead mixed vapor enters the condenser and is condensed to obtain zinc liquid and lead liquid. The zinc liquid is discharged from the top and the lead liquid is discharged from the siphon.

[0051] Specifically, the zinc-lead mixed vapor generated in the electric furnace enters the condenser through pipes. The condenser is equipped with a cooling device that condenses the zinc-lead mixed vapor into a liquid state. Due to the different densities of zinc and lead, the zinc liquid floats on top, while the lead liquid settles at the bottom. A separation device then discharges the zinc and lead liquids separately from the top and through a siphon outlet.

[0052] S4 separates the lead contained in the zinc liquid in the melting furnace and distillation furnace to obtain refined zinc and crude lead.

[0053] When the lead content in the calcined ore is greater than 3-5%, the lead vapor cannot completely escape with the zinc vapor to form molten lead. The molten lead passes through the slag layer and collects at the bottom of the furnace. As the molten lead continues to accumulate, the liquid level rises and is discharged from the furnace through the siphon, resulting in crude lead.

[0054] The crude lead is processed into refined lead by electrolysis.

[0055] Specifically, the discharged molten zinc is fed into a melting furnace, where, by controlling the temperature and adding an appropriate amount of flux, lead in the molten zinc precipitates out as a compound. Then, the zinc molten zinc containing lead compounds is fed into a distillation furnace for further separation. In the distillation furnace, under high temperature and vacuum conditions, the lead compounds decompose and volatilize, and are collected by condensation to obtain crude lead. The crude lead is then refined into refined lead through electrolysis. Meanwhile, the remaining molten zinc in the distillation furnace undergoes further processing to obtain refined zinc.

[0056] Beneficial effects:

[0057] I. By precisely controlling the mixing ratio of lead, zinc, and roasted sand, and adding an appropriate amount of coke as a reducing agent, efficient utilization of zinc and lead ore resources is achieved. In a high-temperature closed electric furnace, carbon monoxide generated from the reaction of coke and carbon dioxide undergoes a reduction reaction with zinc oxide and lead oxide to produce metallic zinc and metallic lead. By controlling the temperature of the molten pool, the reduced metallic zinc and some metallic lead can be vaporized and entered into the condenser for recovery. Simultaneously, controlling the temperature of the molten pool at the lead outlet allows the remaining metallic lead and its captured high-boiling-point metals such as copper, silver, and indium to enter the crude lead and be continuously or intermittently discharged from the siphon. This effectively improves the metal recovery rate.

[0058] Second, the use of a closed electric furnace for smelting reduces heat loss and waste gas emissions during the smelting process. Simultaneously, precise control of the furnace's operating temperature and feeding rate avoids energy waste and environmental pollution. Furthermore, this method utilizes the direct reduction of coke, reducing the amount of reducing agent needed and further lowering production costs and environmental burden.

[0059] Third, by separating and refining the lead contained in molten zinc in melting furnaces and distillation furnaces, high-purity refined zinc and refined lead can be obtained. This high-precision separation technology not only improves product quality but also meets the stringent requirements of various fields for metallic materials.

[0060] Fourth, it is suitable for processing zinc and lead ores of different grades and types, and has strong process flexibility. By adjusting parameters such as mixing ratio, reducing agent dosage, and smelting conditions, it can adapt to the needs of different raw materials and products, providing smelting enterprises with more choices and development space.

[0061] Fifth, it achieves efficient resource utilization and energy conservation and emission reduction, reducing production costs and environmental burden, thus resulting in high economic benefits. At the same time, high-quality products also bring better market competitiveness and profitability to smelting enterprises.

[0062] The above-disclosed embodiments are merely preferred embodiments of the zinc-lead combined smelting furnace of this utility model, and should not be construed as limiting the scope of the utility model. Those skilled in the art can understand that implementing all or part of the above-described embodiments and making equivalent changes in accordance with the claims of this utility model are still within the scope of the utility model.

Claims

1. A zinc-lead combined smelting furnace, characterized in that: It includes a furnace bottom, a molten pool, furnace walls, a furnace top, and two sets of graphite electrodes; the molten pool is laid on the furnace bottom, the furnace walls are laid on the molten pool, the furnace top is laid on the furnace walls, and the two graphite electrodes are installed on the furnace top; The furnace bottom is made of asbestos board, clay straight bricks, ramming material and high alumina straight bricks. The clay straight bricks are laid on the asbestos board, the ramming material is laid on the clay straight bricks, and the high alumina straight bricks are laid on the ramming material. The molten pool is made of multiple chromium corundum sharp wedge bricks and multiple high-alumina blunt wedge bricks, with the multiple chromium corundum sharp wedge bricks being laid in a cross pattern. The furnace roof is made of multiple arched bricks, and the multiple arched bricks are laid on the furnace wall; The furnace wall is made of multiple high-alumina sharp wedge bricks and multiple high-alumina blunt wedge bricks, with the high-alumina blunt wedge bricks and the high-alumina sharp wedge bricks laid in an alternating pattern.

2. The zinc-lead combined smelting furnace as described in claim 1, characterized in that, The molten pool has a lead outlet, the furnace wall has a mixed furnace gas outlet, the mixed furnace gas outlet is located on one side of the furnace wall, and the lead outlet is located on one side of the molten pool.

3. The zinc-lead combined smelting furnace as described in claim 2, characterized in that, The mixed furnace gas outlet is made of multiple high-alumina vertical wedge bricks, which are laid sequentially on the furnace wall.

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