System for harmlessly treating arsenic and recovering lead from copper smelting white smoke dust

Abstract

The utility model discloses a system for harmlessly treating arsenic and recovering lead from copper smelting white smoke dust, which comprises an oxygen-enriched reinforced reduction smelting furnace and a pressure leaching reaction kettle, a lead bullion discharge port of the oxygen-enriched reinforced reduction smelting furnace is communicated with a feed port of an electrolytic refining system, and the pressure leaching reaction kettle is communicated with the lead bullion discharge port of the electrolytic refining system. And a discharge port of the pressure leaching reaction kettle is communicated with a feed port of the oxygen-enriched reinforced reduction smelting furnace. According to the utility model, the pressure leaching reaction kettle is additionally arranged, heating and pressurizing are adopted, and ferrous sulfate is added, so that lead bismuth slag and other lead-containing materials are obtained, and more than 90% of arsenic in the copper smelting white smoke dust is converted into iron arsenate; and then the raw materials, flux, scrap iron, coke and return slag are fed into an oxygen-enriched reinforced reduction smelting furnace to be subjected to reduction smelting to obtain crude lead, lead matte, arsenic-iron alloy, reduction furnace slag and reduction furnace smoke dust, harmless treatment of arsenic is achieved, the crude lead is subjected to electrolytic refining through an electrolytic refining system, and lead ingots are prepared.

Description

Technical Field

[0001] This utility model relates to hazardous waste treatment in the field of copper smelting, and in particular to a system for harmlessly treating arsenic and recovering lead from copper smelting white smoke dust. Background Technology

[0002] Copper is an important metal in the non-ferrous metals industry, and copper smelting capacity has been gradually increasing in recent years. Copper smelting produces white fumes, which mainly contain elements such as copper, lead, zinc, and arsenic. Because these elements are harmful to the copper smelting process, they need to be periodically separated from the copper smelting system. The generated white fumes are classified as hazardous waste and require strict hazardous waste treatment requirements.

[0003] Currently, the main methods for treating white dust from copper smelting in my country are wet + pyrometallurgical and fully wet processes. The wet + pyrometallurgical process suffers from low copper-zinc leaching rates, and the arsenic trioxide produced after sulfur dioxide reduction for arsenic removal remains hazardous waste, posing a significant environmental risk when stored in the company's hazardous waste storage facility. The fully wet process for treating white dust has drawbacks, including a long production process, large wastewater treatment volumes, and the leaching residue remaining hazardous waste. Furthermore, this process has high production costs, which cannot meet the needs of healthy enterprise development.

[0004] Because the use of arsenic as a finished product is very limited, a small portion of arsenic trioxide is reduced to metallic arsenic, primarily used in the manufacture of alloys and semiconductor materials. The majority of arsenic remains stockpiled as an intermediate product, arsenic trioxide, placing a significant environmental burden on businesses. Therefore, achieving the harmless treatment of arsenic is crucial.

[0005] Chinese patent CN108707756B discloses a method for comprehensively treating copper flue dust using an oxygen-enriched side-blown reduction smelting furnace. The method involves batching the copper flue dust and acid leaching residue to create brick-like materials suitable for smelting in the oxygen-enriched side-blown reduction smelting furnace. These materials can be directly fed into the furnace for reduction smelting without desulfurization, yielding primary crude lead, primary lead matte, slag, and dust-laden flue gas. The primary lead matte obtained from reduction smelting is then enriched and smelted in the same furnace to yield secondary crude lead, secondary lead matte, slag, and dust-laden flue gas. In this method, most of the arsenic in the acid leaching residue is reduced and enters the flue gas and slag. Ultimately, the arsenic is mainly collected in the flue dust as arsenic trioxide, which remains hazardous waste. Utility Model Content

[0006] The technical problem to be solved by this utility model is to provide a system for harmlessly treating arsenic and recovering lead from copper smelting white smoke dust, thereby achieving comprehensive utilization of white smoke dust and harmless treatment of arsenic.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0008] A system for harmlessly treating arsenic and recovering lead from copper smelting white smoke dust includes an oxygen-enriched enhanced reduction smelting furnace, the crude lead outlet of which is connected to the inlet of an electrolytic refining system, and a pressure leaching reactor, the outlet of which is connected to the inlet of the oxygen-enriched enhanced reduction smelting furnace.

[0009] This application adds a pressure leaching reactor, uses heating and pressure, and adds ferrous sulfate to obtain lead-bismuth slag and other lead-containing materials. At the same time, more than 90% of the arsenic in the white smoke dust from copper smelting is converted into ferric arsenate. This arsenate is then sent to an oxygen-enriched enhanced reduction smelting furnace with flux, iron filings, coke, and return slag for reduction smelting to obtain crude lead, lead matte, ferroarsenic alloy, reduction slag, and reduction furnace dust, thus achieving the harmless treatment of arsenic. The crude lead is then electrolytically refined using an electrolytic refining system to produce lead ingots.

[0010] In a preferred embodiment of this utility model, the outlet of the oxygen-enriched enhanced reduction smelting furnace is connected to the electric heating front bed, and the crude lead outlet of the electric heating front bed is then connected to the inlet of the electrolytic refining system.

[0011] In a preferred embodiment of the present invention, the electrolytic refining system includes a detinning tower, the outlet of which is connected to the inlet of the disc casting device.

[0012] The crude lead produced is refined by fire, and qualified lead anode plates are made using the disc casting device. The lead anode plates are then subjected to electrolytic refining and oxidation to remove arsenic and antimony, producing electrolytic lead.

[0013] In a preferred embodiment of this invention, the slag outlet of the electrothermal forebed is connected to the inlet of the water quenching device. The reducing slag can be sold directly after water quenching.

[0014] In a preferred embodiment of this utility model, the copper slag outlet of the detinning tower is connected to the feed inlet of the oxygen-enriched enhanced reduction smelting furnace.

[0015] In a preferred embodiment of this utility model, the flue gas outlet of the oxygen-enriched enhanced reduction smelting furnace is connected to the air inlet of the surface cooler, the air outlet of the surface cooler is connected to the air inlet of the bag filter, and the air outlet of the bag filter is connected to the desulfurization and denitrification system.

[0016] After the flue gas from the reduction smelting furnace is cooled by a surface cooler and collected by a bag filter, it is sent to a desulfurization and denitrification system to ensure that the flue gas meets environmental protection requirements before being discharged.

[0017] In a preferred embodiment of this utility model, the discharge port of the surface cooler and the discharge port of the bag dust collector are both connected to the inlet of the dust leaching device.

[0018] In a preferred embodiment of this utility model, the outlet of the pressurized leaching reactor is connected to the inlet of the batching machine, the outlet of the batching machine is connected to the inlet of the briquetting machine, and the outlet of the briquetting machine is connected to the inlet of the oxygen-enriched enhanced reduction smelting furnace.

[0019] Preferably, the white dust from copper smelting is white dust from pyrometallurgical copper smelting.

[0020] According to Chinese patent CN108707756B, about 50% of the arsenic in the white smoke dust enters the leaching residue and enters the subsequent reduction smelting process. However, half of the arsenic still enters the flue gas. Ultimately, the arsenic is mainly collected in the smoke dust in the form of arsenic trioxide.

[0021] In this invention, approximately 90% or more of the arsenic in the white flue dust enters the leaching residue. Therefore, step two processes a mixture of lead sulfate and ferric arsenate, which has a much higher arsenic content than conventional flue dust leaching residue. It should be noted that in traditional reduction smelting processes, after arsenic is reduced, it volatilizes from the melt into the flue gas at around 600°C. During this process, it combines with oxygen in the furnace to generate arsenic trioxide, ultimately producing white arsenic. This invention, by adding a large amount of iron filings during reduction smelting, causes the elemental arsenic produced by reduction to combine with iron to form an arsenic-iron alloy that precipitates in the melt, preventing the vast majority of the arsenic from volatilizing into the flue gas.

[0022] Compared with the prior art, the beneficial effects of this utility model are as follows: This utility model uses a pressurized leaching reactor to convert most of the arsenic in the white smoke dust from copper smelting into ferric arsenate, and uses an oxygen-enriched enhanced reduction smelting furnace to reduce and recover lead, thereby achieving the harmless treatment of arsenic. Attached Figure Description

[0023] Figure 1 This is a structural schematic diagram of an embodiment of the present utility model.

[0024] Among them, 1 is an oxygen-enriched enhanced reduction smelting furnace, 2 is a pressure leaching reactor, 3 is an electric heating forebed, 4 is a detinning tower, 5 is a disc casting device, 6 is a water quenching device, 7 is a surface cooler, 8 is a bag dust collector, 9 is a desulfurization and denitrification system, 10 is a flue gas leaching device, 11 is a batching machine, and 12 is a briquetting machine. Detailed Implementation

[0025] like Figure 1 As shown, a system for harmlessly treating arsenic and recovering lead from copper smelting white smoke dust includes an oxygen-enriched enhanced reduction smelting furnace 1, the crude lead outlet of the oxygen-enriched enhanced reduction smelting furnace 1 being connected to the feed inlet of an electrolytic refining system, characterized in that it further includes a pressure leaching reactor 2, the outlet of the pressure leaching reactor 2 being connected to the feed inlet of the oxygen-enriched enhanced reduction smelting furnace 1.

[0026] The outlet of the oxygen-enriched enhanced reduction smelting furnace 1 is connected to the electric heating front bed 3, and the crude lead outlet of the electric heating front bed 3 is connected to the inlet of the electrolytic refining system.

[0027] The electrolytic refining system includes a tin removal tower 4, the outlet of which is connected to the inlet of a disc casting device 5. Lead anode plates are produced using the disc casting device, and these plates are then subjected to electrolysis and oxidation to remove arsenic and antimony, before being directly cast into lead ingots for external shipment.

[0028] The slag outlet of the electric heating front bed 3 is connected to the feed inlet of the water quenching device 6.

[0029] The copper slag outlet of the detinning tower 4 is connected to the feed inlet of the oxygen-enriched enhanced reduction smelting furnace 1.

[0030] The flue gas outlet of the oxygen-enriched enhanced reduction smelting furnace 1 is connected to the air inlet of the surface cooler 7, the air outlet of the surface cooler 7 is connected to the air inlet of the bag filter 8, and the air outlet of the bag filter 8 is connected to the desulfurization and denitrification system 9.

[0031] The discharge port of the surface cooler 7 and the discharge port of the bag filter 8 are both connected to the dust leaching device 9.

[0032] The outlet of the pressurized leaching reactor 2 is connected to the inlet of the batching machine 10, the outlet of the batching machine 10 is connected to the inlet of the briquetting machine 11, and the outlet of the briquetting machine 11 is connected to the inlet of the oxygen-enriched enhanced reduction smelting furnace 1.

[0033] The operation method of the system for harmlessly treating arsenic and recovering lead from copper smelting white dust in this utility model includes the following steps: 1) Acid leaching of white dust, controlling the working pressure in the pressure leaching reactor to be 1.0 MPa to 1.5 MPa, controlling the working temperature in the pressure leaching reactor to be 100 to 180°C, controlling the pressure leaching reaction time to be 2 to 5 hours, adding ferrous sulfate during the reaction, and leaching lead-bismuth slag and ferric arsenate produced; 2) Lead-bismuth slag produced by leaching white dust. 1) Ferric arsenate is mixed with lead mud and other lead-containing materials and dried naturally; 2) Lead bismuth slag, ferric arsenate and other lead-containing materials are mixed with flux, iron filings, coke and return slag, and then sent to an oxygen-enriched enhanced reduction smelting furnace for reduction smelting. After smelting, the melt enters the electric heating front bed for sedimentation and separation to obtain crude lead, lead matte, ferroarsenic alloy, reduction slag and reduction furnace dust; 3) The crude lead produced is pyrometallurgically refined to produce qualified lead anode plates, and then electrolytically refined to produce electrolytic lead.

[0034] The principle of this utility model:

[0035] The main reactions in the oxygen-enriched enhanced reduction smelting furnace are (1) to (10), including the thermal decomposition reaction of lead-bismuth slag and ferric arsenate, the reduction reaction of arsenic trioxide and the slag-forming reaction.

[0036] 2C + O2 = 2CO (1)

[0037] C + O₂ = CO₂ (2)

[0038] PbSO4 + 4CO = PbS + 4CO2 (3)

[0039] PbSO4 + 4C = PbS + 4CO (4)

[0040] PbSO4=PbO+SO2+1 / 2O2 (5)

[0041] PbO + PbS = Pb + SO2 (6)

[0042] 2FeAsO4+C=Fe2O3+As2O3+2CO2 (7)

[0043] As₂O₃ + 3CO = 2As + 3CO₂ (8)

[0044] 2Fe₂O₃ + 2CO = 4FeO + 2CO₂ (9)

[0045] FeO + SiO2 = FeO·SiO2 (10)

Claims

1. A system for detoxifying arsenic and recovering lead from copper smelter white dust, comprising an oxygen-enriched enhanced reduction smelting furnace (1), a crude lead discharge port of the oxygen-enriched enhanced reduction smelting furnace (1) being communicated with a feed inlet of an electrolytic refining system, characterized in that, The pressure leaching reactor (2) is also included, and the discharge port of the pressure leaching reactor (2) is communicated with the feeding port of the oxygen-enriched and strengthened reduction smelting furnace (1); The flue gas outlet of the oxygen-enriched and strengthened reduction smelting furnace (1) is communicated with the air inlet of the surface cooler (7), the air outlet of the surface cooler (7) is communicated with the air inlet of the bag-type dust collector (8), and the air outlet of the bag-type dust collector (8) is communicated with the desulfurization and denitrification system (9); The discharge port of the surface cooler (7) and the discharge port of the bag-type dust collector (8) are both communicated with the feeding port of the dust leaching device (10); The discharge port of the pressure leaching reactor (2) is communicated with the feeding port of the batching machine (11), the discharge port of the batching machine (11) is communicated with the feeding port of the briquetting machine (12), and the discharge port of the briquetting machine (12) is communicated with the feeding port of the oxygen-enriched and strengthened reduction smelting furnace (1).

2. The system for detoxification of arsenic and recovery of lead from copper smelter white dust according to claim 1, characterized in that, The discharge port of the oxygen-enriched and strengthened reduction smelting furnace (1) is communicated with the electric heating forehearth (3), and the coarse lead discharge port of the electric heating forehearth (3) is communicated with the feeding port of the electrolytic refining system.

3. The system for detoxification of arsenic and recovery of lead from copper smelter white dust according to claim 1, characterized in that, The electrolytic refining system includes a tin removal tower (4), and the discharge port of the tin removal tower (4) is communicated with the feeding port of the disc burning and casting device (5).

4. The system for detoxification of arsenic and recovery of lead from copper smelter white dust according to claim 2, characterized in that, The smelting slag discharge port of the electric heating forehearth (3) is communicated with the feeding port of the water quenching device (6).

5. The system for detoxification of arsenic and recovery of lead from copper smelter white dust according to claim 3, characterized in that, The copper floating slag discharge port of the tin removal tower (4) is communicated with the feeding port of the oxygen-enriched and strengthened reduction smelting furnace (1).

Images