Zinc-lead combined smelting furnace and smelting method

Abstract

The invention relates to the technical field of smelting, in particular to a zinc-lead combined smelting furnace and a smelting method.According to the zinc-lead combined smelting furnace and the smelting method, lead-rich zinc calcine is used as a raw material, simultaneous reduction of zinc and lead is achieved in a closed electric furnace, and the situation that in a traditional zinc smelting electric furnace, all lead volatilizes and condenses along with zinc steam is effectively avoided; and therefore, the recovery rate and the utilization rate of the metal are improved. And energy consumption and equipment loss are reduced. By optimizing the smelting process, efficient separation of zinc and lead is achieved, and the smelting efficiency is improved. In the condenser, zinc-lead mixed steam is condensed into zinc liquid and lead liquid which are respectively discharged from the upper part and a siphon port, so that effective separation is ensured, and metal pollution and loss are reduced. And lead in the zinc liquid is further separated through the subsequent liquation furnace and the rectifying furnace, refined zinc and crude lead are obtained, the crude lead is refined into refined lead through an electrolytic method, the purity of zinc and lead is improved, valuable metal resources are recycled, and the problem that an existing smelting method is large in metal loss is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of smelting, and in particular to a zinc-lead combined smelting furnace and a smelting method. Background Art

[0002] The 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 ore-smelting electric furnace. It is a ore-smelting electric furnace that inserts graphite electrodes into liquid melt (slag). Under the action of the micro-arc formed on the interface between the electrode and the slag and the double layer of melt resistance, electrical energy is converted into thermal energy; the role of coke is used as a reducing agent. As described in the above chemical reaction formula, part of the carbon is used for direct reduction, and part of it reacts with carbon dioxide to generate carbon monoxide, which then reacts with metal oxides such as zinc oxide and lead oxide in the slag to generate metals such as zinc and lead. It is oxidized to carbon dioxide, and carbon dioxide reacts with the hot coke to generate carbon monoxide in a cyclic reduction reaction. The ore-smelting electric furnace mainly produces zinc ingots. The small amount of lead contained in the roasted sand is condensed and collected in the zinc liquid with the volatilization of zinc vapor in the closed furnace. It is generally required to control the lead content of the roasted sand to less than 2%.

[0003] The electric furnace for zinc smelting must control the superheat temperature of the melt, the zinc content in the slag and the reducing atmosphere. Basically, it controls only the reduction of zinc and lead. High-boiling-point metals such as copper, iron, and precious metals can only gather in the furnace after reduction and are discharged from the furnace with the slag, causing metal loss. Summary of the invention

[0004] The object of the present invention is to provide a zinc-lead combined smelting furnace and a smelting method, aiming to solve the problem of large metal loss in the existing smelting methods.

[0005] To achieve the above object, in a first aspect, the present invention provides a zinc-lead combined smelting method, comprising the following steps:

[0006] Adding lead-zinc-rich roasted sand and coke into a closed electric furnace;

[0007] When the closed electric furnace is working, zinc oxide reacts with coke and carbon monoxide to reduce the zinc oxide and lead oxide in the roasted sand into zinc-lead mixed vapor, metallic zinc and metallic lead.

[0008] The zinc-lead mixed vapor enters the condenser and condenses to obtain zinc liquid and lead liquid. The zinc liquid is discharged from the top and the lead liquid is discharged from the siphon port.

[0009] The lead contained in the zinc liquid is separated in the smelting furnace and the distillation furnace to obtain refined zinc and crude lead.

[0010] Among them, the step of "adding lead-zinc-rich roasted sand and coke into a closed electric furnace" includes the following steps:

[0011] Mixing lead, zinc and roasted sand according to a preset ratio to obtain lead-zinc-rich roasted sand;

[0012] adding coke to the lead-zinc-rich roasted sand for mixing;

[0013] The lead-zinc roasted sand rich with coke is put into a closed electric furnace.

[0014] Among them, in "the operation of a closed electric furnace, zinc oxide undergoes a reduction reaction with coke and carbon monoxide, and zinc oxide and lead oxide in the roasted sand are reduced to zinc-lead mixed vapor form, metallic zinc and metallic lead", the operating temperature of the closed electric furnace is 1100℃-1300℃.

[0015] Among them, in “separating the lead contained in the zinc liquid in a smelting furnace and a distillation furnace to obtain refined zinc and crude lead”, the crude lead is produced into refined lead by electrolysis.

[0016] In the second 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, a molten pool, a furnace wall, a furnace top, and two groups of 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 graphite electrodes are installed on the furnace top.

[0017] 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.

[0018] The invention discloses a zinc-lead combined smelting method, comprising the following steps: adding lead-rich zinc roasted sand and coke to a sealed electric furnace; the sealed electric furnace is operated, zinc oxide reacts with coke and carbon monoxide to reduce zinc oxide and lead oxide in the roasted sand to zinc-lead mixed steam, metal zinc and metal lead; the zinc-lead mixed steam enters a condenser to condense to obtain zinc liquid and lead liquid, the zinc liquid is discharged from the upper part, and the lead liquid is discharged from a siphon port; the lead contained in the zinc liquid is separated in a smelting furnace and a rectification furnace to obtain refined zinc and crude lead. The invention uses lead-rich zinc roasted sand as a raw material to realize simultaneous reduction of zinc and lead in a sealed electric furnace, effectively avoiding the loss of high-boiling-point metals discharged with slag caused by the volatilization and condensation of all lead with zinc steam in a traditional zinc smelting electric furnace, and lead is a good collector that can capture high-boiling-point valuable metals such as copper, silver, indium, germanium, etc. in lead and discharge them with crude lead from the siphon port, thereby improving the metal recovery rate and utilization rate. The smelting temperature is controlled at 1100℃-1300℃, which is conducive to the full reduction of zinc oxide and lead oxide, reducing energy consumption and equipment loss. By optimizing the smelting process, efficient separation of zinc and lead is achieved, and the smelting efficiency is improved. In the condenser, the zinc-lead mixed vapor is condensed into zinc liquid and lead liquid, which are discharged from the upper part and the siphon port respectively, ensuring effective separation and reducing metal pollution and loss. The subsequent smelting furnace and distillation furnace further separate the lead in the zinc liquid to obtain refined zinc and crude lead. The crude lead is refined into refined lead by electrolysis, which improves the purity of zinc and lead and recovers valuable metal resources, thereby solving the problem of large metal loss in existing smelting methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] 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 these drawings without paying creative work.

[0020] Figure 1 The present invention provides a flow chart of a zinc-lead combined smelting method.

[0021] Figure 2 It is a flow chart of adding lead-zinc-rich roasted sand and coke into a closed electric furnace.

[0022] Figure 3 and Figure 4 It is a schematic diagram of a zinc-lead combined smelting furnace provided by the present invention.

[0023] In the figure: 1-furnace bottom, 2-molten pool, 3-furnace wall, 4-furnace top, 5-graphite electrode, 6-lead outlet, 7-mixed furnace gas outlet. DETAILED DESCRIPTION

[0024] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0025] See also Figure 1 to Figure 2 In a first aspect, the present invention provides a zinc-lead combined smelting method, comprising the following steps:

[0026] S1 adds lead-zinc-rich roasted sand and coke into a closed electric furnace;

[0027] S11: mixing lead, zinc and roasted sand according to a preset ratio to obtain lead-zinc-rich roasted sand;

[0028] Specifically, first, accurately weigh the lead, zinc and roasted sand according to the ratio. The source of lead and zinc can be the ore or concentrate containing these two metals, and the corresponding metal oxides are obtained after pretreatment. Roasted sand is the product of zinc ore after roasting, mainly containing zinc oxide. These raw materials are fully mixed in the mixing equipment to ensure accurate ratio and uniform mixing, so as to obtain lead-zinc rich roasted sand.

[0029] S12 adds coke to the lead-zinc-rich roasted sand for mixing;

[0030] Specifically, coke is added to the lead-zinc-rich roasted sand in a certain proportion. The role of coke is to act as a reducing agent to reduce zinc oxide and lead oxide to metallic zinc and metallic lead. The amount of coke added should be determined according to the oxygen content of the raw materials and the requirements of the reduction reaction. The coke and the lead-zinc-rich roasted sand are fully mixed in the mixing equipment to ensure that the coke can be evenly distributed in the roasted sand to improve the reduction efficiency.

[0031] S13 adds the lead-zinc-rich roasted sand added with coke into a closed electric furnace.

[0032] Specifically, evenly mixed lead-zinc-rich roasted sand and coke are added into the closed 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 in the electric furnace.

[0033] When the S2 closed electric furnace is working, zinc oxide reacts with coke and carbon monoxide to reduce the zinc oxide and lead oxide in the roasted sand into zinc-lead mixed vapor, metallic zinc and metallic lead;

[0034] The working temperature of the closed electric furnace is 1100°C-1300°C.

[0035] Specifically, after the closed electric furnace starts working, the graphite electrode 5 is inserted into the liquid melt to form a double-layer effect of micro-arc and melt resistance, converting electrical energy into thermal energy. At high temperature, coke reacts with carbon dioxide to generate carbon monoxide, and carbon monoxide then undergoes a reduction reaction with zinc oxide and lead oxide to generate metallic zinc, metallic lead and carbon dioxide. At the same time, part of the coke directly reduces zinc oxide and lead oxide. The operating temperature of the electric furnace is controlled at 1100°C-1300°C to ensure that the reduction reaction can be fully carried out.

[0036] S3 zinc-lead mixed steam enters the condenser in the form of condensation to obtain zinc liquid and lead liquid. The zinc liquid is discharged from the upper part and the lead liquid is discharged from the siphon port;

[0037] Specifically, the zinc-lead mixed steam generated in the electric furnace enters the condenser through a pipe. A cooling device is provided inside the condenser to condense the zinc-lead mixed steam into liquid through cooling. Due to the different densities of zinc and lead, the zinc liquid will float on the upper layer, and the lead liquid will settle on the lower layer. The zinc liquid and the lead liquid are discharged from the upper part and the siphon port respectively through a separation device.

[0038] S4 separates the lead contained in the zinc liquid in the smelting furnace and the distillation furnace to obtain refined zinc and crude lead.

[0039] The crude lead is produced into refined lead by electrolysis.

[0040] Specifically, the discharged zinc liquid is sent to a smelting furnace, and the lead in the zinc liquid is precipitated in the form of compounds by controlling the temperature and adding an appropriate amount of flux. Then, the zinc liquid containing lead compounds is sent to a distillation furnace for further separation. In the distillation furnace, the lead compounds are decomposed and volatilized under high temperature and vacuum conditions, and crude lead is obtained by condensation and collection. The crude lead is then refined into refined lead by electrolysis. At the same time, the remaining zinc liquid in the distillation furnace can be further processed to obtain refined zinc.

[0041] Beneficial effects:

[0042] 1. 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 by the reaction of coke and carbon dioxide undergoes a reduction reaction with zinc oxide and lead oxide to generate metallic zinc, metallic lead, and carbon dioxide. Part of the lead vapor enters the condenser with the zinc vapor, condenses into zinc liquid and lead liquid, and then separates lead and zinc; most of the reduced metallic lead liquid passes through the slag layer to capture other reduced valuable metals (such as copper, silver, and indium) in the slag and is discharged from the siphon port at the lower lead recovery end, effectively improving the metal recovery rate.

[0043] Second, the use of a closed electric furnace for smelting reduces heat loss and exhaust gas emissions during the smelting process. At the same time, by accurately controlling the working temperature and feeding speed of the electric furnace, energy waste and environmental pollution are avoided. In addition, this method also utilizes the direct reduction effect of coke, reduces the amount of reducing agent, and further reduces production costs and environmental burdens.

[0044] 3. In the smelting furnace and the distillation furnace, by separating and refining the lead contained in the zinc liquid, high-purity refined zinc and refined lead can be obtained. This high-precision separation technology not only improves the quality of the product, but also meets the strict requirements of different fields for metal materials.

[0045] 4. 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 meet the needs of different raw materials and products, providing smelting enterprises with more choices and development space.

[0046] 5. It realizes efficient utilization of resources and energy conservation and emission reduction, reduces production costs and environmental burden, and thus has high economic benefits. At the same time, high-quality products also bring better market competitiveness and profitability to smelting enterprises.

[0047] See also Figure 3 to Figure 4 In the second aspect, a zinc-lead combined smelting furnace is provided, which is used in the zinc-lead combined smelting method described in the first aspect, and comprises a furnace bottom 1, a molten pool 2, a furnace wall 3, a furnace top 4, and two groups of 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.

[0048] 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.

[0049] 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.

[0050] The molten pool 2 is made of a plurality of chrome corundum sharp wedge-shaped bricks and a plurality of chrome corundum torn wedge-shaped bricks, and the plurality of chrome corundum torn wedge-shaped bricks and the plurality of chrome corundum sharp wedge-shaped bricks are laid crosswise;

[0051] The furnace wall 3 is made of a plurality of high-aluminum sharp wedge-shaped bricks and a plurality of high-aluminum torn wedge-shaped bricks, and the plurality of high-aluminum torn wedge-shaped bricks and the plurality of high-aluminum sharp wedge-shaped bricks are laid crosswise.

[0052] The mixed furnace gas outlet 7 is made of a plurality of high-aluminum vertical wedge-shaped bricks, and the plurality of high-aluminum vertical wedge-shaped bricks are laid on the furnace wall 3 in sequence.

[0053] The furnace roof 4 is made of a plurality of arch foot bricks, and the plurality of arch foot bricks are laid on the furnace wall 3 .

[0054] In this embodiment, the furnace bottom 1 is made of asbestos board, clay straight bricks, ramming material and high-aluminum straight bricks. The asbestos board serves as an insulating layer to prevent heat from being transferred to the furnace bottom; the clay straight bricks and high-aluminum straight bricks serve as load-bearing and refractory layers to ensure the strength and stability of the furnace bottom; the ramming material is filled in the brick joints to improve the sealing and refractory properties of the furnace bottom. The molten pool 2 is formed by cross-laying of multiple chrome corundum sharp wedge-shaped bricks and multiple chrome corundum wedge-shaped bricks. This laying method can increase the strength and stability of the molten pool while ensuring the smoothness and uniformity of the inside of the molten pool. The molten pool is used to hold liquid metal and slag, and is the main place for reduction reactions. The furnace wall 3 is also formed by cross-laying of multiple high-aluminum sharp wedge-shaped bricks and multiple high-aluminum wedge-shaped bricks. The function of the furnace wall is to protect the high temperature environment in the furnace, prevent heat from dissipating outward, and ensure the reducing atmosphere in the furnace. Mixed furnace gas outlet is formed by multiple high-aluminum vertical wedge-shaped bricks laid in sequence on the furnace wall. The mixed furnace gas outlet is used to discharge the waste gas generated in the furnace to ensure the stability of the reducing atmosphere in the furnace. Furnace roof 4: It is made of multiple arch foot bricks laid on the furnace wall. The shape of the furnace roof is arched, which can increase the strength and stability of the furnace roof and ensure that the heat in the furnace is not easily lost.

[0055] The zinc-lead combined smelting furnace significantly improves the efficiency, stability and environmental friendliness of the smelting process by adopting a multi-layer furnace bottom, cross-laid molten pool and furnace walls, arched furnace top design and the configuration of graphite electrodes. This design not only enhances the overall strength and heat resistance of the smelting furnace, ensures the effective use of heat and the stability of the reducing atmosphere, but also promotes the uniform distribution and effective separation of liquid metal, and improves the recovery rate and purity of zinc and lead. At the same time, by precisely controlling the current and voltage of the graphite electrode, precise control of the smelting process is achieved, energy consumption and production costs are reduced, and a positive role is played in environmental protection.

[0056] The above disclosure is only a preferred embodiment of a zinc-lead combined smelting furnace and a smelting method of the present invention. Of course, this cannot be used to limit the scope of rights of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiments and equivalent changes made according to the claims of the present invention still fall within the scope of the invention.

Claims

1. A zinc-lead combined smelting method, characterized in that: The following steps are involved: Adding lead-zinc-rich roasted sand and coke into a closed electric furnace; When the closed electric furnace is working, zinc oxide reacts with coke and carbon monoxide to reduce the zinc oxide and lead oxide in the roasted sand into zinc-lead mixed vapor, metallic zinc and metallic lead. The zinc-lead mixed vapor enters the condenser and condenses to obtain zinc liquid and lead liquid. The zinc liquid is discharged from the top and the lead liquid is discharged from the siphon port. The lead contained in the zinc liquid is separated in the smelting furnace and the distillation furnace to obtain refined zinc and crude lead.

2. The zinc-lead combined smelting method according to claim 1, characterized in that: In "adding lead-zinc-rich roasted sand and coke into a closed electric furnace", the following steps are included: Mixing lead, zinc and roasted sand according to a preset ratio to obtain lead-zinc-rich roasted sand; adding coke to the lead-zinc-rich roasted sand for mixing; The lead-zinc roasted sand rich with coke is put into a closed electric furnace.

3. The zinc-lead combined smelting method according to claim 1, characterized in that: In "the closed electric furnace operates, zinc oxide undergoes a reduction reaction with coke and carbon monoxide, and zinc oxide and lead oxide in the roasted sand are reduced to zinc-lead mixed vapor form, metallic zinc and metallic lead", the operating temperature of the closed electric furnace is 1100°C-1300°C.

4. The zinc-lead combined smelting method according to claim 3, characterized in that: In "separating the lead contained in the zinc liquid in a smelting furnace and a distillation furnace to obtain refined zinc and crude lead", the crude lead is produced into refined lead by electrolysis.

5. A zinc-lead combined smelting furnace, used in the zinc-lead combined smelting method according to any one of claims 1 to 4, characterized in that: It comprises a furnace bottom, a molten pool, a furnace wall, a furnace top and two groups of 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 graphite electrodes are installed on the furnace top.

6. The zinc-lead combined smelting furnace according to claim 5, 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.

Images