Waste battery treatment process and waste battery treatment process flue gas purification system

Abstract

The application discloses a flue gas purification system and a waste battery treatment process. The flue gas purification system comprises a heat exchange system, an air distribution system, a flue gas dust removal and denitration system and a flue gas desulfurization system. The heat exchange system comprises a first heat exchanger, a second heat exchanger and a third heat exchanger. The first heat exchanger is used for heat exchange between first high-temperature flue gas discharged from a pre-reduction furnace and air, and first cooled flue gas and first heated air are output respectively. The second heat exchanger is used for heat exchange between second high-temperature flue gas discharged from a sulfidic reduction smelting furnace and air, and second cooled flue gas and second heated air are output respectively. The third heat exchanger is used for heat exchange between third high-temperature flue gas discharged from a lean furnace and air, and third cooled flue gas and third heated air are output respectively. The air distribution system is used for preparing the first heated air, the second heated air and the third heated air into heating gas and providing the heating gas to the dryer. The flue gas dust removal and denitration system is used for obtaining flue gas after dust removal and denitration treatment. The flue gas desulfurization system is used for obtaining flue gas after desulfurization treatment.

Description

Technical Field

[0001] This invention relates to a flue gas purification system for waste battery processing. Background Technology

[0002] Ternary lithium-ion batteries are widely used in mobile phones, computers, and electric vehicles due to their high energy density, high operating voltage, and long cycle life. With the popularization of electronic communication devices and the rapid development of the electric vehicle industry, the consumption of ternary lithium-ion batteries has surged. However, the average lifespan of ternary lithium-ion batteries is only 5-8 years, resulting in a large amount of waste batteries. Waste ternary lithium-ion batteries contain large amounts of metals such as lithium, cobalt, nickel, and manganese. Improper disposal not only wastes resources but also causes serious environmental pollution. Therefore, effective technologies for recycling and reusing lithium batteries are essential. Currently, the main process for processing waste ternary lithium-ion batteries involves sulfuric acid leaching, adjusting the pH value for impurity removal, and extraction and purification to obtain solutions of cobalt sulfate, nickel sulfate, and manganese sulfate. This method suffers from problems such as large waste residue, difficult waste residue treatment, high acid and alkali consumption, and a long process. Summary of the Invention

[0003] The purpose of this invention is to provide a flue gas purification system for a waste battery processing technology, addressing the technical problem of more rational and effective waste heat utilization and thorough purification of the large amount of flue gas generated by a novel waste battery processing technology (shorter process flow, smaller waste residue). The invention also aims to provide a waste battery processing technology that utilizes the aforementioned flue gas purification system.

[0004] Firstly, a flue gas purification system for a waste battery processing technology is provided. This process employs a sulfide reduction smelting technique to smelt the solid slag after lithium extraction from waste battery black powder, thereby extracting valuable metals. The sulfide reduction smelting technique utilizes a dryer, a pre-reduction furnace, a sulfide reduction smelting furnace, and a depletion furnace arranged sequentially. The dryer dries the solid slag to obtain dried material. The pre-reduction furnace pre-reduces the dried material to obtain pre-reduced material. The sulfide reduction smelting furnace performs sulfide reduction smelting on the pre-reduced material to obtain valuable metal products and slag. The depletion furnace further refines the slag to obtain valuable metal products. The system includes a heat exchange system comprising a first heat exchanger, a second heat exchanger, and a third heat exchanger. The first heat exchanger exchanges heat with air using the first high-temperature flue gas emitted from the pre-reduction furnace and outputs a first cooled flue gas and a first heated air, respectively. The system comprises: a second heat exchanger for exchanging heat between the second high-temperature flue gas emitted from the sulfurization reduction smelting furnace and air, and outputting the second cooled flue gas and the second heated air respectively; a third heat exchanger for exchanging heat between the third high-temperature flue gas emitted from the lean furnace and air, and outputting the third cooled flue gas and the third heated air respectively; a gas distribution system for preparing the first heated air, the first heated air, and the third heated air into a heating gas and supplying it to the dryer; a flue gas dust removal and denitrification system for treating the first cooled flue gas, the second cooled flue gas, and the third cooled flue gas with dust removal before SCR denitrification, and for treating the flue gas discharged from the dryer with dust removal, thereby obtaining flue gas after dust removal and denitrification; and a flue gas desulfurization system for treating the flue gas after dust removal and denitrification with flue gas desulfurization, thereby obtaining flue gas after desulfurization.

[0005] Optionally, the gas distribution system includes: a first gas mixing device for mixing a first heated air, a third heated air, and a second heated air mixture for outputting a heated air mixture gas; and a second gas mixing device for mixing at least a portion of the heated air mixture gas with at least a portion of the denitrified flue gas after the SCR denitrification treatment and outputting a mixed gas, wherein the mixed gas is used to provide the heating gas.

[0006] Optionally, the gas distribution system further includes a gas heating device for heating the mixed gas to make it a heating gas.

[0007] Optionally, the gas heating device employs a combustion supplementer, which mixes and combusts at least a portion of the heated air mixture, at least a portion of the denitrified flue gas after the SCR denitrification treatment, and natural gas to produce the heating gas.

[0008] Optionally, the first gas mixing device has a split gas supply line, which is used to supply a portion of the heated air-mixed gas as heating gas to a portion of the dryer, and to supply another portion of the heated air-mixed gas to a second gas mixing device, thereby supplying heating gas to another portion of the dryer through the second gas mixing device.

[0009] Optionally, the flue gas dust removal and denitrification system includes multiple first coarse dust collectors respectively arranged after the first heat exchanger, the second heat exchanger, and the third heat exchanger; a first fine dust collector located after these first coarse dust collectors; a second coarse dust collector arranged after the dryer; and a second fine dust collector arranged after the second coarse dust collector. The first fine dust collector is followed by an SCR denitrification processor that performs the SCR denitrification treatment. The exhaust end of the SCR denitrification processor is connected in parallel with the exhaust end of the second coarse dust collector and the inlet end of the second fine dust collector.

[0010] Optionally, the exhaust end of the SCR denitrification processor is connected to a first exhaust pipe and a second exhaust pipe. The first exhaust pipe is connected to a second gas mixing device, and the second exhaust pipe is connected in parallel with the exhaust end of the second coarse dust collector and the inlet end of the second fine dust collector. A flow regulating valve is provided on the second exhaust pipe.

[0011] Optionally, both the first and second coarse dust collectors are cyclone dust collectors; the first fine dust collector is an electrostatic precipitator; and the second fine dust collector is a spray dust collection tower.

[0012] Optionally, it also includes a flue gas emission device, which is used to discharge the flue gas after desulfurization treatment into the atmosphere.

[0013] Secondly, a waste battery treatment process is provided. This process employs a sulfide reduction smelting technique to smelt the solid slag after lithium extraction from waste battery black powder, thereby extracting valuable metals. The sulfide reduction smelting technique utilizes a dryer, a pre-reduction furnace, a sulfide reduction smelting furnace, and a depletion furnace arranged sequentially. The dryer dries the solid slag to obtain dried material. The pre-reduction furnace pre-reduces the dried material to obtain pre-reduced material. The sulfide reduction smelting furnace performs sulfide reduction smelting on the pre-reduced material to obtain valuable metal products and slag. The depletion furnace further refines the slag to obtain valuable metal products. The process also incorporates the flue gas purification system of the waste battery treatment process described in the first aspect.

[0014] The aforementioned flue gas purification system is based on a novel waste battery treatment process. This process utilizes a sulfide reduction smelting technique to smelt the solid slag after lithium extraction from waste battery black powder (using a wet lithium extraction method) to extract valuable metals (taking ternary lithium-ion secondary batteries as an example, the main valuable metals are cobalt, nickel, and manganese). The sulfide reduction smelting technique employs a dryer, a pre-reduction furnace, a sulfide reduction smelting furnace, and a depletion furnace arranged sequentially. The dryer dries the solid slag to obtain dried material. The pre-reduction furnace pre-reduces the dried material to obtain pre-reduced material. The sulfide reduction smelting furnace performs sulfide reduction smelting on the pre-reduced material to obtain valuable metal products and slag. The depletion furnace further refines the slag to obtain valuable metal products. This waste battery treatment process can significantly shorten the recycling process for other major valuable metals besides lithium, and the depletion furnace generates less waste slag.

[0015] The aforementioned flue gas purification system utilizes the high-temperature flue gas generated by the pre-reduction furnace, sulfide reduction smelting furnace, and lean furnace to heat air. This air is then formulated into heating gas and supplied to the dryer, thus rationally and effectively utilizing the waste heat of the high-temperature flue gas. The first, second, and third cooled flue gas undergo dust removal treatment before SCR denitrification, effectively preventing dust contamination and poisoning of the SCR denitrification catalyst during the process. The flue gas discharged from the dryer also undergoes dust removal treatment. This results in flue gas with low dust and low nitrogen oxide content after dust removal and denitrification. Following dust removal and denitrification, the flue gas undergoes further desulfurization treatment, ultimately ensuring that the flue gas generated by the aforementioned waste battery processing process is fully purified.

[0016] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Additional aspects and advantages provided by the present invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice. Attached Figure Description

[0017] The accompanying drawings, which form part of this specification, are used to aid in understanding this application. The content provided in the drawings and the related descriptions in this specification can be used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0018] Figure 1 This is a schematic diagram of the flue gas purification system for a waste battery treatment process according to an embodiment of the present invention. Detailed Implementation

[0019] The present invention will now be clearly and completely described in conjunction with the accompanying drawings. Those skilled in the art will be able to implement the present invention based on these descriptions. Before describing the present invention in conjunction with the accompanying drawings, it should be particularly noted that:

[0020] The technical solutions and features provided in the various sections, including the following description, can be combined with each other without conflict. Furthermore, where possible, these technical solutions, features, and related combinations can be given specific technical subject matter and protected by relevant patents.

[0021] The embodiments of the present invention described below are generally only some embodiments and not all embodiments. Based on these embodiments, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of patent protection.

[0022] The terms "comprising," "including," and any variations thereof in this specification, the corresponding claims, and related sections are intended to cover non-exclusive inclusion. Other related terms and units can be reasonably interpreted based on the relevant content provided in this specification.

[0023] Figure 1 This is a schematic diagram of the flue gas purification system for a waste battery treatment process according to an embodiment of the present invention. Figure 1As shown, a flue gas purification system for a waste battery treatment process is disclosed. The waste battery treatment process employs a sulfide reduction smelting technology to smelt the solid slag after lithium extraction from waste battery black powder (using a wet lithium extraction method) to extract valuable metals (taking ternary lithium-ion secondary batteries as an example, the valuable metals are mainly cobalt, nickel, and manganese). The sulfide reduction smelting technology utilizes a dryer 11, a pre-reduction furnace 12, a sulfide reduction smelting furnace 13, and a depletion furnace 14 arranged sequentially. The dryer 11 is used to dry the solid slag to obtain dried material, and the pre-reduction furnace 12 is used to dry the dried material... The material undergoes pre-reduction treatment to obtain pre-reduced material. The sulfide reduction smelting furnace 13 is used to sulfide reduce smelt the pre-reduced material to obtain valuable metal products and slag. The leaning furnace 14 is used to further refine the slag to obtain valuable metal products. It includes a heat exchange system 21, which comprises a first heat exchanger 211, a second heat exchanger 212, and a third heat exchanger 213. The first heat exchanger 211 is used to exchange heat between the first high-temperature flue gas discharged from the pre-reduction furnace 12 and air, and respectively outputs a first cooled flue gas and a first heated air. The second heat exchanger 212 is used to exchange heat between the second high-temperature flue gas emitted from the sulfidation reduction smelting furnace 13 and air, and output the second cooled flue gas and the second heated air respectively. The third heat exchanger 213 is used to exchange heat between the third high-temperature flue gas emitted from the lean furnace 14 and air, and output the third cooled flue gas and the third heated air respectively. A gas distribution system 22 is used to prepare the first heated air, the first heated air, and the third heated air into a heating gas and supply it to the dryer 11. A flue gas dust removal and denitrification system 23 is used to... The flue gas dust removal and denitrification system 23 is used to remove dust from the first, second, and third cooled flue gas before performing SCR denitrification treatment, and to remove dust from the flue gas discharged from the dryer 11, thereby obtaining flue gas after dust removal and denitrification treatment; and a flue gas desulfurization system (not shown in the figure), which is used to desulfurize the flue gas after dust removal and denitrification treatment, thereby obtaining flue gas after desulfurization treatment; and a flue gas emission device (not shown in the figure), which is used to discharge the flue gas after desulfurization treatment into the atmosphere.

[0024] The pre-reduction furnace 12 typically employs a rotary kiln. The temperature of the first high-temperature flue gas output from the pre-reduction furnace 12 is typically 750℃-1100℃, and the flow rate is typically 8000 Nm³. 3 -11000Nm 3 Therefore, the temperature of the first cooled flue gas output from the first heat exchanger 211 is typically 350℃-500℃, and the flow rate is typically 8000 Nm³. 3 -11000Nm 3 The temperature of the first air to be heated is typically 350℃-500℃, and the flow rate is typically 8000 Nm³.3 -11000Nm 3 .

[0025] The sulfur reduction smelting furnace 13 is typically an electric furnace. The temperature of the second high-temperature flue gas output from the sulfur reduction smelting furnace 13 is typically 800℃-1100℃, and the flow rate is typically 7000 Nm³. 3 -10000Nm 3 Therefore, the temperature of the second cooled flue gas output from the second heat exchanger 212 is typically 350℃-500℃, and the flow rate is typically 7000 Nm³. 3 -10000Nm 3 The temperature of the second type of heated air is typically 350℃-500℃, and the flow rate is typically 7000 Nm. 3 -10000Nm 3 .

[0026] The lean-firing furnace 14 is typically an electric furnace. The temperature of the third high-temperature flue gas output from the lean-firing furnace 14 is typically 800℃-1100℃, and the flow rate is typically 7000 Nm³. 3 -10000Nm 3 Therefore, the temperature of the third cooled flue gas output from the third heat exchanger 213 is typically 350℃-500℃, and the flow rate is typically 7000 Nm³. 3 -10000Nm 3 The temperature of the third type of heated air is typically 350℃-500℃, and the flow rate is typically 7000 Nm. 3 -10000Nm 3 .

[0027] In other words, the first heat exchanger 211, the second heat exchanger 212, and the third heat exchanger 213 can generate heated air at a flow rate approximately one time (typically 0.8 to 1.2 times) the total flow rate of the first, second, and third high-temperature flue gas. This heated air is then formulated into a heating gas and supplied to the dryer 11, thereby significantly reducing the energy consumption of the dryer 11.

[0028] In a typical implementation, the gas distribution system 22 may include: a first gas mixing device 221, which is used to mix a first heated air, a third heated air, and output a heated air mixed gas; and a second gas mixing device 222, which is used to mix at least a portion of the heated air mixed gas with at least a portion of the denitrified flue gas after the SCR denitrification treatment and output a mixed gas, wherein the mixed gas is used to provide the heating gas.

[0029] This not only greatly increases the flow rate of the heating gas (ensuring the drying effect of the dryer 11), but also allows the heating gas to be sourced almost entirely from the gas output from the first heat exchanger 211, the second heat exchanger 212, and the third heat exchanger 213, minimizing the introduction of airflow from the outside. Furthermore, the second gas mixing device 222 mixes at least a portion of the heated air mixture with at least a portion of the denitrified flue gas after the SCR denitrification treatment, making full use of the original heat of the denitrified flue gas after the SCR denitrification treatment.

[0030] Furthermore, the gas distribution system 22 may also include a gas heating device for heating the mixed gas, thereby making the mixed gas a heating gas. Specifically, the gas heating device is a combustion supplement 223, which mixes and combusts at least a portion of the heated air-gas mixture, at least a portion of the denitrified flue gas after the SCR denitrification treatment, and natural gas to produce the heating gas. The combustion supplement 223 can be the same device as the second gas mixing device 222. Thus, by supplementing the heat of the heating gas through the gas heating device, the drying effect of the dryer 11 is further guaranteed.

[0031] In one optional embodiment, the first gas mixing device 221 has a split gas supply line, which supplies a portion of the heated air-mixed gas as heating gas to a portion of the dryers, and supplies another portion of the heated air-mixed gas to a second gas mixing device 222, which then supplies heating gas to another portion of the dryers. In this method, the split gas supply line first ensures a sufficient supply of heating gas (heated air-mixed gas) to a portion of the dryers, while the remaining heated air-mixed gas enters the second gas mixing device 222 and is then supplied to another portion of the dryers. Thus, even if the second gas mixing device 222 malfunctions, it will not affect the operation of all the dryers.

[0032] Specifically, the flue gas dust removal and denitrification system 23 includes multiple first coarse dust collectors 231 respectively arranged after the first heat exchanger 211, the second heat exchanger 212 and the third heat exchanger 213, a first fine dust collector 232 located after these first coarse dust collectors 231, a second coarse dust collector 233 arranged after the dryer 11 and a second fine dust collector 234 arranged after the second coarse dust collector 233. The first fine dust collector 231 is followed by an SCR denitrification processor 235 that performs the SCR denitrification treatment. The exhaust end of the SCR denitrification processor 235 is connected in parallel with the exhaust end of the second coarse dust collector 233 and the inlet end of the second fine dust collector 234.

[0033] Specifically, both the first coarse dust collector 231 and the second coarse dust collector 233 are cyclone dust collectors; the first fine dust collector is an electrostatic precipitator 232; and the second fine dust collector 235 is a spray dust collection tower. Cyclone dust collectors, electrostatic precipitators, and spray dust collection towers are all commonly used dust removal equipment. Among them, the spray dust collection tower belongs to wet dust removal.

[0034] The SCR denitrification processor 235 has a first exhaust pipe and a second exhaust pipe at its exhaust end. The first exhaust pipe is connected to the second gas mixing device 222, and the second exhaust pipe is connected in parallel with the exhaust end of the second coarse dust collector 233 and the inlet end of the second fine dust collector 234. A flow regulating valve is installed on the second exhaust pipe. Clearly, by adjusting the flow regulating valve, the flow rate of the denitrified flue gas after SCR denitrification treatment entering the second gas mixing device 222 can be adjusted.

[0035] The flue gas desulfurization system can employ a variety of existing desulfurization technologies. The flue gas emission device can be a chimney.

[0036] The foregoing has described the relevant content of the present invention. Those skilled in the art will be able to implement the present invention based on these descriptions. All other embodiments obtained by those skilled in the art based on the foregoing content of this specification without inventive effort should fall within the scope of the present invention.

Claims

1. A flue gas purification system for waste battery processing, characterized in that: The waste battery treatment process employs a sulfide reduction smelting technology to smelt the solid slag after lithium extraction from waste battery black powder, thereby extracting valuable metals. The sulfide reduction smelting technology utilizes a dryer, a pre-reduction furnace, a sulfide reduction smelting furnace, and a depletion furnace arranged sequentially. The dryer is used to dry the solid slag to obtain dried material. The pre-reduction furnace is used to pre-reduce the dried material to obtain pre-reduced material. The sulfide reduction smelting furnace is used to perform sulfide reduction smelting on the pre-reduced material to obtain valuable metal products and slag. The depletion furnace is used to further refine the slag to obtain valuable metal products. It includes: A heat exchange system comprising a first heat exchanger, a second heat exchanger, and a third heat exchanger, wherein the first heat exchanger is used to exchange heat between the first high-temperature flue gas discharged from the pre-reduction furnace and air, and respectively outputs a first cooled flue gas and a first heated air; the second heat exchanger is used to exchange heat between the second high-temperature flue gas discharged from the sulfidation reduction smelting furnace and air, and respectively outputs a second cooled flue gas and a second heated air; and the third heat exchanger is used to exchange heat between the third high-temperature flue gas discharged from the lean furnace and air, and respectively outputs a third cooled flue gas and a third heated air. A gas distribution system is used to prepare a heating gas from the first heated air and the third heated air and supply it to the dryer; A flue gas dust removal and denitrification system is used to treat the first, second, and third cooled flue gases by dust removal before subjecting them to SCR denitrification treatment, and to treat the flue gas discharged from the dryer by dust removal, thereby obtaining flue gas after dust removal and denitrification treatment; and A flue gas desulfurization system is used to desulfurize flue gas after dust removal and denitrification treatment to obtain flue gas after desulfurization. The gas distribution system includes: A first gas mixing device is used to mix a first heated air, a third heated air, and output a heated air-gas mixture. The second gas mixing device is used to mix at least a portion of the heated air mixture with at least a portion of the denitrified flue gas after the SCR denitrification treatment and output the mixed gas, the mixed gas being used to provide the heating gas; The first gas mixing device has a split gas supply line, which is used to supply a portion of the heated air-mixed gas as heating gas to a portion of the dryer, and to supply another portion of the heated air-mixed gas to a second gas mixing device, which then supplies the heating gas to another portion of the dryer.

2. The flue gas purification system for the waste battery treatment process as described in claim 1, characterized in that: The gas distribution system also includes: A gas heating device is used to heat the mixed gas so that the mixed gas becomes a heating gas.

3. The flue gas purification system for the waste battery treatment process as described in claim 2, characterized in that: The gas heating device employs a combustion supplementer, which mixes and combusts at least a portion of the heated air mixture, at least a portion of the denitrified flue gas after the SCR denitrification treatment, and natural gas to produce the heating gas.

4. The flue gas purification system for the waste battery treatment process as described in any one of claims 1-3, characterized in that: The flue gas dust removal and denitrification system includes multiple first coarse dust collectors respectively located after the first heat exchanger, the second heat exchanger, and the third heat exchanger; a first fine dust collector located after these first coarse dust collectors; a second coarse dust collector located after the dryer; and a second fine dust collector located after the second coarse dust collector. The first fine dust collector is followed by an SCR denitrification processor that performs the SCR denitrification process. The exhaust end of the SCR denitrification processor is connected in parallel with the exhaust end of the second coarse dust collector and the inlet end of the second fine dust collector.

5. The flue gas purification system for the waste battery treatment process as described in claim 4, characterized in that: The SCR denitrification processor has a first exhaust pipe and a second exhaust pipe at its exhaust end. The first exhaust pipe is connected to a second gas mixing device, and the second exhaust pipe is connected in parallel with the exhaust end of the second coarse dust collector and the inlet end of the second fine dust collector. A flow regulating valve is provided on the second exhaust pipe.

6. The flue gas purification system for the waste battery treatment process as described in claim 4, characterized in that: Both the first and second coarse dust collectors are cyclone dust collectors; the first fine dust collector is an electrostatic precipitator; and the second fine dust collector is a spray dust collection tower.

7. The flue gas purification system for the waste battery treatment process as described in claim 1, characterized in that: It also includes a flue gas emission device, which is used to discharge the flue gas into the atmosphere after desulfurization treatment.

8. A waste battery processing technology, characterized in that: The waste battery treatment process employs a sulfide reduction smelting technology to smelt the solid slag after lithium extraction from waste battery black powder, thereby extracting valuable metals. The sulfide reduction smelting technology utilizes a dryer, a pre-reduction furnace, a sulfide reduction smelting furnace, and a depletion furnace arranged sequentially. The dryer dries the solid slag to obtain dried material. The pre-reduction furnace pre-reduces the dried material to obtain pre-reduced material. The sulfide reduction smelting furnace performs sulfide reduction smelting on the pre-reduced material to obtain valuable metal products and slag. The depletion furnace further refines the slag to obtain valuable metal products. The process also incorporates a flue gas purification system as described in any one of claims 1-7.

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