Electrolytic aluminum carbon residue low-temperature sintering and slag gas synchronous separation integrated combustion device and regulation method

Abstract

This invention belongs to the field of pretreatment technology for the recycling of electrolytic aluminum slag, and discloses an integrated combustion device and control method for low-temperature sintering and simultaneous separation of slag and gas in electrolytic aluminum slag. The device is based on a fully automatic cyclone furnace and includes a feeder, a primary air tangential feed channel, a secondary air tangential oxygen supply channel, a gas auxiliary channel, a cyclone separator, a bottom collector, a top rising exhaust channel, a waste heat recovery fan, a tail gas treatment system, and a centralized control box. After pre-combustion detection and preheating, the slag is carried tangentially into the cyclone separator by the primary air. Under controlled low temperature, limited oxygen, and reheating conditions, the carbonaceous components are oxidized, while the solid electrolyte is separated and collected downwards along the cyclone. The flue gas enters the heat recovery tail gas treatment system through the rising channel. The centralized control box adjusts the feed, air supply, gas supply, and reheating heat based on the feed rate, furnace temperature, oxygen content, flue gas composition, and post-combustion residue feedback, forming a coordinated closed loop.

Description

Technical Field

[0001] This invention belongs to the field of resource utilization treatment of electrolytic aluminum carbon slag and low-temperature thermal treatment of carbon and fluorine-containing solid waste. Specifically, it relates to an integrated combustion device and control method for low-temperature sintering and simultaneous separation of slag and gas of electrolytic aluminum carbon slag, which uses a fully automatic cyclone furnace as the physical carrier, performs low-temperature sintering and combustion of carbonaceous components, solid-phase separation of fluorine-containing salt phase and aluminum-containing phase, waste heat recovery of tail gas and dry purification treatment. Background Technology

[0002] The carbon slag produced during the electrolytic aluminum production process typically contains carbonaceous components, cryolite, sodium fluoride, aluminum fluoride, alumina, aluminum-containing electrolyte salts, and small amounts of water and metal inclusions. The carbonaceous components need to be removed or significantly reduced before recycling, while the fluorine-containing salt phase and aluminum-containing phase have reuse value. If a wet flotation route is used, fluorine-containing wastewater is easily formed. If a high-temperature pyrometallurgical route is used, problems such as increased fluorine volatiles, corrosion of refractory materials, high energy consumption, and changes in electrolyte phase may occur. Therefore, the core of carbon slag resource utilization is not simply burning off the carbon, but achieving full oxidation of the carbonaceous components under relatively low thermal intensity conditions, while maintaining the solid phase form of the recyclable salt phase and aluminum-containing phase as much as possible.

[0003] Existing carbon slag treatment solutions, mainly based on rotary kilns, fluidized beds, ordinary roasting furnaces, or experimental cyclone separators, typically treat combustion, separation, and tail gas treatment as sequential processes. The equipment structure lacks an industrial furnace body capable of simultaneously completing tangential feeding, segmented oxygen supply, low-temperature controlled combustion, centrifugal solid-phase separation, and tail gas reheating. Especially when using simplified experimental devices, materials are mostly added manually or transported by a single airflow, which fails to demonstrate the synergistic relationship between continuous feeding detection, primary air carrying material, secondary air oxygen supplementation, gas-assisted combustion, waste heat recovery fan, tail gas treatment system, and centralized control box. This can easily lead to the misconception that the cyclone separator is only used for separation and does not participate in combustion.

[0004] In practical engineering, the carbon content, moisture, particle size, fluoride-containing salt phase, and aluminum-containing phase content of electrolytic aluminum slag fluctuate significantly from batch to batch. If the furnace structure still uses general heat treatment equipment, or the control logic is limited to fixed temperature, fixed air volume, and fixed residence time, it is difficult to explain the causal relationship between low-temperature sintering, simultaneous slag-gas separation, and heat recovery tail gas treatment. The treated material may exhibit problems such as insufficient carbon removal, volatilization of fluoride-containing salt phase, insufficient retention of aluminum-containing phase, residue agglomeration, or increased flue gas treatment load. Therefore, it is necessary to provide a device and method with a fully automatic cyclone furnace as the core structure, so that the tangential combustion, centrifugal separation, reheating preheating, and tail gas purification of the slag can be completed in the same control chain. Summary of the Invention

[0005] The purpose of this invention is to provide an integrated combustion device and control method for low-temperature sintering and simultaneous separation of slag and gas in electrolytic aluminum slag, in order to solve the problems of insufficient integration between furnace structure and cyclone combustion separation process in the existing pyrometallurgical treatment of electrolytic aluminum slag, difficulty in simultaneously balancing the oxidation of carbonaceous components in slag with the retention of fluoride-containing salt phase and aluminum-containing solid phase, lack of coordination between waste heat from tail gas and slag preheating and air supply preheating, and difficulty in correspondingly controlling the fluctuation of slag composition in different material sections under continuous feeding conditions.

[0006] The low-temperature sintering described in this invention refers to a heat treatment process in which carbonaceous components in electrolytic aluminum slag are oxidized in a controlled manner at a temperature below the upper limit of the fluorine-containing salt phase to avoid significant volatilization and destruction of the aluminum-containing phase, and the post-combustion solid phase is maintained in the phase state required for subsequent recycling processes. This limitation is used to distinguish it from simple high-temperature incineration treatment and to avoid volatilization of the fluorine-containing salt phase, insufficient retention of the aluminum-containing phase, or agglomeration of the post-combustion solid phase caused by increasing the combustion temperature.

[0007] To achieve the above objectives, the present invention provides an integrated combustion device for low-temperature sintering of electrolytic aluminum carbon slag and simultaneous separation of slag and gas, comprising a feeding and metering unit, a segmented preheating unit, a cyclone furnace body, a solid phase collection unit, a waste heat recovery tail gas treatment unit, and a centralized control unit; the tangential feed pipes of the feeding and metering unit, the segmented preheating unit, and the cyclone furnace body are connected in sequence to form a feeding path from carbon slag metering and carbon slag preheating to tangential entry into the furnace.

[0008] The cyclone furnace body includes a cylindrical combustion separation cylinder, a tangential feed pipe, a primary air inlet, a secondary air inlet, a gas auxiliary inlet, a top rising exhaust channel, a bottom conical separation section, and a bottom discharge port. The outlet of the tangential feed pipe is tangentially arranged along the inner wall of the cylindrical combustion separation cylinder. The primary air inlet is connected to the tangential feed pipe or the cylindrical combustion separation cylinder. The secondary air inlet is located below the outlet of the tangential feed pipe and is tangentially arranged along the cylindrical combustion separation cylinder. The gas auxiliary inlet is connected to the primary air duct or the tangential feed pipe. The top rising exhaust channel is connected to the waste heat recovery tail gas treatment unit. The bottom conical separation section connects the cylindrical combustion separation cylinder and the bottom discharge port. The bottom discharge port is connected to the solid phase collection unit. The centralized control unit is electrically connected to the feeding and metering unit, the segmented preheating unit, the primary air duct, the secondary air duct, the gas duct, the waste heat recovery tail gas treatment unit, and the detection components.

[0009] When the above-mentioned device is used, the electrolytic aluminum carbon slag, after being metered and preheated, enters the cylindrical combustion separation cylinder through the tangential feed pipe. The primary air carries the carbon slag and forms an external swirling flow along the inner wall of the cylindrical combustion separation cylinder. The secondary air is added tangentially in the same swirling direction and participates in the low-temperature sintering combustion process. The gas auxiliary interface supplements gas to the primary air pipeline or the tangential feed pipe during the start-up stage or when the calorific value of the carbon slag is insufficient. The carbonaceous components in the carbon slag are oxidized during the swirling motion. The fluorine-containing salt phase and the aluminum-containing phase move downward along the inner wall of the cylindrical combustion separation cylinder and the bottom conical separation section with the solid phase material. The flue gas enters the top rising exhaust channel along the central area of ​​the cylindrical combustion separation cylinder. Thus, a solid phase external swirling downward path and a flue gas internal swirling upward path are formed in the cyclone furnace body, so that the combustion reaction, solid phase separation and flue gas discharge are continuously completed in the same furnace body.

[0010] The feeding and metering unit includes a feeder, a weighing bin, and a mass flow meter. The weighing bin is located upstream of or inside the feeder, and the mass flow meter is located on the discharge channel of the feeder. The discharge end of the feeder is connected to the carbon and slag preheating channel of the segmented preheating unit, and the discharge end of the carbon and slag preheating channel is connected to the tangential feed pipe. The amount of carbon and slag fed into the cyclone furnace body is obtained through the weighing bin and the mass flow meter, so that the amount of carbon and slag fed can be adjusted in accordance with the primary air volume, secondary air volume, gas auxiliary volume, and heat return, thereby reducing the fluctuations in furnace temperature and gas phase oxygen content caused by changes in material load during continuous feeding.

[0011] The cylindrical combustion separator comprises, from top to bottom, a swirl ignition section, a low-temperature sintering section, and a solid-phase centrifugal separation section; the top rising exhaust channel includes a central exhaust pipe arranged along the axis of the cylindrical combustion separator, with the lower end of the central exhaust pipe located within the swirl ignition section and above the centerline of the secondary air interface; the lower end of the solid-phase centrifugal separation section is connected to the large end of the bottom conical separation section, and the inner diameter of the bottom conical separation section gradually decreases from top to bottom.

[0012] The swirl ignition section is used to receive the tangentially entering carbon slag material flow and primary air; the low-temperature sintering section is used to complete the controlled oxidation of carbonaceous components; the solid phase centrifugal separation section and the bottom conical separation section are used to collect the post-combustion solid material; the central exhaust pipe is set at the axis of the cylindrical combustion separation cylinder, so that the flue gas is discharged along the direction of the internal swirling airflow, reducing the proportion of post-combustion solid material entering the tail gas pipeline with the flue gas.

[0013] The primary air inlet consists of two or more tangential inlets spaced apart circumferentially along the cylindrical combustion separator. The outlet centerline of each primary air inlet is arranged along the same tangential direction of the cylindrical combustion separator. The secondary air inlet consists of two or more tangential inlets spaced apart circumferentially along the cylindrical combustion separator. The outlet centerline of each secondary air inlet has the same tangential direction as the outlet centerline of the primary air inlet. The gas auxiliary inlet is located in the mixing pipe section upstream of the primary air inlet or in the mixing pipe section upstream of the tangential feed pipe. The gas pipeline where the gas auxiliary inlet is located is equipped with a gas flow meter, a gas regulating valve, and a check valve. The primary air inlet and the secondary air inlet are arranged tangentially in the same direction to ensure that the secondary air supply does not weaken the vortex formed by the primary air. The gas flow meter, gas regulating valve, and check valve are used for gas auxiliary quantity measurement, gas auxiliary quantity regulation, and gas pipeline backflow prevention, respectively, to match the gas auxiliary process with the primary air delivery process.

[0014] The segmented preheating unit includes a slag preheating channel, a primary air preheating channel, a secondary air preheating channel, a tail gas heat exchanger, a tail gas bypass pipe, and a reheat regulating valve. The tail gas heat exchanger serves as a shared heat exchange component between the segmented preheating unit and the waste heat recovery tail gas treatment unit. Its hot-side inlet is connected to the top rising exhaust channel, and its hot-side outlet is connected to the dust-laden gas separator. The cold side of the tail gas heat exchanger is connected to the slag preheating channel, the primary air preheating channel, and the secondary air preheating channel for heat exchange. The tail gas bypass pipe is connected in parallel between the hot-side inlet and the hot-side outlet of the tail gas heat exchanger, and the reheat regulating valve is located at either the tail gas bypass pipe or the hot-side inlet of the tail gas heat exchanger.

[0015] The heat from the flue gas discharged from the top rising exhaust channel is recovered by the tail gas heat exchanger and used for preheating of the carbon slag, primary air and secondary air respectively; the proportion of flue gas entering the tail gas heat exchanger is changed by the tail gas bypass pipe and the reheat regulating valve, so that the preheating intensity can be adjusted according to the changes in carbon slag composition, moisture content and feed rate.

[0016] The testing components include a pre-combustion testing assembly, a furnace body temperature testing assembly, a flue gas testing assembly, and a post-combustion residue testing assembly. The pre-combustion testing assembly is located upstream of the feeder or on the feeder's bypass sampling channel, and includes moisture content, particle size, and composition testing components. The composition testing components are used to detect the content of carbonaceous components, fluoride-containing salt phases, and aluminum-containing phases. The furnace body temperature testing assembly is located in the swirl ignition section, the low-temperature sintering section, and the solid-phase centrifugal separation section. The flue gas testing assembly is located in the top rising exhaust channel or on the hot-side inlet pipe of the tail gas heat exchanger, and includes the gas phase oxygen content. The system includes detection components for carbon monoxide, carbon dioxide, and volatile fluoride. A post-combustion residue detection assembly is installed at the outlet sampling channel of the solid phase collection unit to detect the content of residual carbonaceous components, the retention amount of fluoride-containing salt phase, the retention amount of aluminum-containing phase, and the agglomeration ratio. The retention amounts of fluoride-containing salt phase and aluminum-containing phase are obtained by conversion based on the dry basis mass or material balance of the same material section before and after combustion. Through these detection components, the state of charcoal slag before entering the furnace, the segmented temperature inside the furnace, the flue gas state, and the post-combustion solid phase state can be mapped to the same material section, providing a data basis for subsequent control parameter correction.

[0017] The centralized control unit includes a control box, a data storage module, an input / output module, and an interlocking control module. The data storage module stores a material segment identification table, a composition grading table, and a control parameter table. The material segment identification table includes the feeding start time, feeding end time, feeding quality, expected discharge time, and actual discharge time. The composition grading table includes grading of carbonaceous components, fluoride salt phase content, aluminum phase content, moisture content, and particle size distribution. The control parameter table includes the upper limit of low-temperature sintering temperature, the upper limit of gas phase oxygen content, primary air volume, secondary air volume, gas auxiliary volume, reheat valve opening, waste heat recovery fan frequency, and feeding rate.

[0018] The input / output module receives data from the pre-combustion detection component, furnace body temperature detection component, flue gas detection component, and post-combustion residue detection component, and outputs control signals to the feeder, primary air regulating valve, secondary air regulating valve, gas regulating valve, reheat regulating valve, and waste heat recovery fan. When the furnace body temperature, gas phase oxygen content, gas pressure, or tail gas treatment status exceeds the corresponding interlock limit, the interlock control module performs at least one of the following actions: reducing the feed rate, closing the gas regulating valve, reducing the secondary air volume, or stopping the feeder.

[0019] Therefore, the detection data, control data and post-combustion residue data of different material sections during continuous feeding can be saved accordingly, avoiding the mixing of data from different material sections.

[0020] The solid phase collection unit includes a cooling collection chamber, an airlock feed valve, an airlock discharge valve, an afterburning residue sampling port, a qualified material outlet, and a reburning return branch. The airlock feed valve is located between the bottom outlet and the cooling collection chamber, the airlock discharge valve is located at the lower end of the cooling collection chamber, the afterburning residue sampling port is located downstream of the airlock discharge valve, and the reburning return branch is connected to the distribution valve and feeder downstream of the afterburning residue sampling port.

[0021] The waste heat recovery tail gas treatment unit includes a tail gas heat exchanger, a dust-laden gas separator, a dry adsorption purifier, and an exhaust pipe connected in sequence. The solid phase outlet of the dust-laden gas separator is connected to the cooling collection bin or the reburning return material branch. The airlock feed valve and airlock discharge valve are used to isolate the bottom discharge port from the external environment and reduce the disturbance of the swirling flow and pressure state inside the cyclone furnace during the discharge process. The reburning return material branch is used to return solid phase materials that do not meet the feeding requirements of subsequent recovery processes to the feeder. The dust-laden gas separator is used to separate solid phase dust carried by the flue gas, and the dry adsorption purifier is used to adsorb fluorine-containing components in the flue gas.

[0022] This invention also provides a method for controlling the simultaneous separation of slag and gas during low-temperature sintering of electrolytic aluminum carbon slag, comprising the following steps: First, the electrolytic aluminum slag is crushed, screened, iron removed, and homogenized in sequence to obtain the slag material flow that enters the feeder. Crushing and screening are used to ensure that the particle size of the slag meets the requirements of tangential feed pipe conveying and cyclone furnace body cyclone treatment. Iron removal is used to reduce the interference of metallic iron impurities on post-combustion solid phase recovery. Homogenization is used to reduce local fluctuations in the composition and particle size of slag within the same production batch.

[0023] Secondly, the carbonaceous composition, fluoride salt phase content, aluminum phase content, moisture content, and particle size distribution of the char slag material are detected by the pre-combustion detection component. The centralized control unit establishes material segment identifiers according to the feeding start time, feeding end time, and feeding quality. The material segment identifiers are used to correspond and save the char slag entering the cyclone furnace body within the same time window with the pre-combustion detection data, furnace body temperature data, flue gas detection data, and post-combustion residue detection data.

[0024] Furthermore, the centralized control unit determines the upper limit of low-temperature sintering temperature, the upper limit of gas phase oxygen content, primary air volume, secondary air volume, gas auxiliary volume, reheat valve opening, waste heat recovery fan frequency, and feed volume based on the carbonaceous component content, fluorine salt phase content, aluminum phase content, moisture content, particle size distribution, and subsequent recovery process feed requirements of the same material section.

[0025] The upper limit of low-temperature sintering temperature is used to limit the highest temperature of low-temperature sintering combustion treatment in the cyclone furnace body. The upper limit of gas phase oxygen content is used to limit the oxidation intensity of carbonaceous components. The primary air volume is used to adjust the tangential conveying of carbon slag and the initial cyclone intensity. The secondary air volume is used to adjust the oxygen supply in the low-temperature sintering section and the cyclone maintenance intensity. The gas auxiliary amount is used to adjust the supplementary heat during the start-up stage or when the calorific value of carbon slag is insufficient. The opening degree of the reheat valve and the frequency of the waste heat recovery fan are used to adjust the heat of the exhaust gas waste heat entering the segmented preheating unit. The feed rate is used to adjust the material load entering the cyclone furnace body per unit time.

[0026] Then, the flue gas discharged from the top rising exhaust channel enters the tail gas heat exchanger, and the carbon slag material flow, primary air and secondary air exchange heat through the carbon slag preheating channel, primary air preheating channel and secondary air preheating channel respectively.

[0027] The carbon slag material, primary air, and secondary air are preheated before entering the cyclone furnace body after heat exchange, which can reduce the temperature fluctuation of the low-temperature sintering section caused by cold material and cold air entering the cyclone furnace body.

[0028] Subsequently, the feeder outputs the carbon slag flow to the tangential feed pipe according to the feed rate. The primary air carries the carbon slag flow tangentially into the cyclone furnace body along the cylindrical combustion separator. The secondary air enters the cylindrical combustion separator in the same cyclone direction as the primary air. The gas enters the front end of the primary air interface or the front end of the tangential feed pipe through the gas auxiliary interface.

[0029] The carbonaceous components in the slag material undergo controlled oxidation in the swirl ignition section and the low-temperature sintering section. The fluorine-containing salt phase and aluminum-containing phase, along with the solid material, enter the bottom discharge port through the solid centrifugal separation section and the bottom conical separation section. The flue gas enters the top rising exhaust channel through the central exhaust pipe. This step establishes a continuous correspondence between tangential feeding, primary air swirl, secondary air unidirectional oxygen supply, central exhaust, and bottom material collection, ensuring that post-combustion solid materials and flue gas are discharged separately from the structural path.

[0030] Next, the solid material output from the bottom outlet enters the cooling collection chamber through the airlock feed valve, and the flue gas discharged from the top rising exhaust channel enters the tail gas heat exchanger, dust-laden gas separator, dry adsorption purifier and exhaust pipe in sequence; the cooled solid material is sampled and tested through the afterburning residue sampling port, and the solid dust separated by the dust-laden gas separator enters the cooling collection chamber or the reburning return branch.

[0031] Finally, the centralized control unit writes the furnace temperature data, flue gas detection data, and afterburner residue detection data of the same material section into the material section identification table, and adjusts the feed rate, primary air volume, secondary air volume, gas auxiliary volume, reheat valve opening, and waste heat recovery fan frequency of subsequent material sections based on the afterburner residue detection results. This adjustment process transforms the combustion and separation results of the previous material section into control parameters for the next material section, adapting to changes in char composition, moisture content, and particle size distribution in different material sections.

[0032] The upper limit of low-temperature sintering temperature and the upper limit of gas phase oxygen content are determined as follows: a pre-combustion small-sample heating test is conducted on the same batch of char slag to obtain the residual carbonaceous component content, fluorine volatile concentration, fluorine salt phase retention amount, aluminum phase retention amount, and agglomeration ratio corresponding to each preset temperature point; the feed requirements of the subsequent recycling process are converted into the upper limit of residual carbonaceous component, the upper limit of fluorine volatile concentration, the lower limit of fluorine salt phase retention amount, the lower limit of aluminum phase retention amount, and the upper limit of agglomeration ratio; at each preset temperature point, the lower limit of residual carbonaceous component, the lower limit of aluminum phase retention amount, and the upper limit of agglomeration ratio are simultaneously satisfied.

[0033] Among the preset temperature points, the highest temperature that simultaneously satisfies the following conditions is defined as the upper limit of low-temperature sintering temperature: the content of residual carbonaceous components is not higher than the upper limit of residual carbonaceous components, the concentration of fluorine-containing volatiles is not higher than the upper limit of fluorine-containing volatiles, the retention amount of fluorine-containing salt phase is not lower than the lower limit of fluorine-containing salt phase retention, the retention amount of aluminum-containing phase is not lower than the lower limit of aluminum-containing phase retention, and the agglomeration ratio is not higher than the upper limit of agglomeration ratio.

[0034] Under the upper limit of low-temperature sintering temperature, the highest gaseous oxygen content that simultaneously meets the above conditions is determined as the upper limit of gaseous oxygen content; the above determination method is based on the test data of the same batch of carbon slag and the feeding requirements of the subsequent recycling process, so that the upper limit of low-temperature sintering temperature and the upper limit of gaseous oxygen content have clear sources.

[0035] When the content of residual carbonaceous components is higher than the upper limit of residual carbonaceous components, and the concentration of fluorine-containing volatiles is not higher than the upper limit of fluorine-containing volatiles concentration, the retention amount of fluorine-containing salt phase is not lower than the lower limit of fluorine-containing salt phase retention amount, the retention amount of aluminum-containing phase is not lower than the lower limit of aluminum-containing phase retention amount, and the agglomeration ratio is not higher than the upper limit of agglomeration ratio, the centralized control unit shall, under the condition that it does not exceed the upper limit of low-temperature sintering temperature and the upper limit of gas phase oxygen content, increase the secondary air volume, reduce the feed volume, or increase the frequency of waste heat recovery fan.

[0036] This adjustment method is used to increase the degree of oxidation of carbonaceous components or reduce the material load per unit time without breaking the boundary between the fluorine-containing salt phase and the aluminum-containing phase.

[0037] When the concentration of fluorinated volatiles is higher than the upper limit of fluorinated volatiles concentration, the retention amount of fluorinated salt phase is lower than the lower limit of fluorinated salt phase retention amount, the retention amount of aluminum phase is lower than the lower limit of aluminum phase retention amount, or the agglomeration ratio is higher than the upper limit of agglomeration ratio, the centralized control unit reduces the secondary air volume, reduces the gas auxiliary volume, reduces the flue gas flow rate entering the tail gas heat exchanger, or reduces the frequency of the waste heat recovery fan. This adjustment method is used to reduce the oxidation intensity or reheat intensity, reduce the volatilization of fluorinated salt phase, reduce the retention of aluminum phase, and reduce post-combustion solid phase agglomeration.

[0038] When the solid material output from the solid collection unit does not meet the feeding requirements of the subsequent recovery process, the distribution valve switches to the reburning return branch. The solid material returns to the feeder via the reburning return branch and re-enters the cyclone furnace body according to the new material segment identification. After the reburning material re-establishes the material segment identification, its pre-combustion detection data, process detection data, and post-combustion residue detection data are stored separately from the initial processing data to avoid confusion between the reburning data and the initial processing data of the raw materials.

[0039] Compared with existing technologies, this invention connects the feeding and metering unit, the segmented preheating unit, the cyclone furnace body, the solid phase collection unit, the waste heat recovery and tail gas treatment unit, and the centralized control unit in sequence. This allows the electrolytic aluminum carbon slag to be processed according to the path of continuous metering, segmented preheating, tangential feeding, cyclone combustion, solid-gas separation, waste heat recovery, and tail gas purification. This forms a continuous processing flow that matches the structure of the fully automatic cyclone furnace, avoiding the disconnect between the furnace structure and process control.

[0040] This invention, through the positional coordination between the tangential feed pipe, primary air interface, secondary air interface, central exhaust pipe, and bottom conical separation section, causes the carbon slag particles to rotate downward along the inner wall of the cylindrical combustion separation cylinder, while the flue gas rises and is discharged along the central area of ​​the cylindrical combustion separation cylinder. The oxidation of carbonaceous components, the retention of fluorine-containing salt phase and aluminum-containing phase solid phase, and the discharge of flue gas have corresponding structural paths, thus making the cyclone furnace body not only a tail-end separation device, but also the main device undertaking low-temperature sintering combustion and simultaneous slag-gas separation.

[0041] This invention establishes material segment identification through a pre-combustion detection component, a furnace body temperature detection component, a flue gas detection component, a post-combustion residue detection component, and a centralized control unit. It stores the corresponding information on charcoal and slag composition, feed rate, air supply parameters, gas auxiliary quantity, reheat parameters, flue gas composition, and post-combustion residue status for the same material segment. Furthermore, it determines the upper limit of low-temperature sintering temperature and the upper limit of gas phase oxygen content based on the heating test of small samples of the same production batch and the feeding requirements of subsequent recycling processes. This ensures that the control parameters have a clear data source and reduces the problem of insufficient adaptability of fixed empirical parameters to different batches of charcoal and slag.

[0042] The beneficial effects of this invention are as follows: 1. This invention uses the furnace structure of a fully automatic cyclone furnace as the physical carrier of the technical solution. Through the continuous connection of the feeding and metering unit, the segmented preheating unit, the cyclone furnace body, the solid phase collection unit, the waste heat recovery tail gas treatment unit, and the centralized control unit, the electrolytic aluminum carbon slag is processed according to the path of metered feeding, preheating into the furnace, tangential cyclone, low-temperature sintering and combustion, downward solid phase separation, upward discharge of flue gas from the center, and waste heat recovery of the tail gas. This structure does not use the cyclone separator as a separate terminal gas-solid separation component, but rather integrates it through a cylindrical combustion separation cylinder, a tangential feeding pipe, a primary air interface, a secondary air interface, and a top-rising exhaust channel. The positioning of the bottom conical separation section and the bottom discharge port allows the carbon slag particles to move along the outer swirling path inside the furnace, while the flue gas is discharged along the central exhaust path. The post-combustion solid material is collected by the bottom conical separation section and enters the solid collection unit. As a result, the three processes of carbonaceous component oxidation, fluorine-containing salt phase and aluminum-containing phase solid phase retention, and slag-gas separation can occur continuously within the same cyclone furnace body. This avoids the problem of the combustion space, separation space and discharge path being disconnected in the diagrams of traditional furnace types or experimental cyclone separators. It achieves the effect of improving the furnace structure's relevance, enhancing the adaptability to continuous industrial processing, and supporting the cyclone furnace's participation in the combustion and separation technology logic.

[0043] 2. This invention constructs a segmented preheating path through a carbon slag preheating channel, a primary air preheating channel, a secondary air preheating channel, and a tail gas heat exchanger. The hot side of the tail gas heat exchanger is positioned between the top rising exhaust channel and the tail gas treatment path, while the cold side of the tail gas heat exchanger is connected to the preheating paths of carbon slag, primary air, and secondary air respectively. This allows the waste heat from the tail gas to be used for preheating the carbon slag and combustion-supporting gas before entering the dust-laden gas separator and dry adsorption purifier. The proportion of flue gas entering the tail gas heat exchanger is adjusted by the tail gas bypass pipe and the reheat regulating valve, which can be adjusted according to changes in carbon slag moisture content, feed rate, low-temperature sintering section temperature, and fluorine volatile concentration. Adjusting the preheating intensity reduces temperature fluctuations caused by direct entry of cold materials and cold air into the furnace. Furthermore, by using a moving bed cooling collection bin, airlock feed valve, airlock discharge valve, afterburning residue sampling port, qualified material outlet, and reburning return branch, the afterburning solid material is discharged, cooled, detected, and diverted without significantly disturbing the furnace pressure and swirling state. This allows for the establishment of a closed-loop processing path within the fully automatic cyclone furnace structure, encompassing flue gas waste heat recovery, segmented preheating, solid phase collection, and reburning return, thereby reducing temperature fluctuations during low-temperature sintering combustion, decreasing reliance on wet treatment of fluorine-containing components, and improving the controllable output of afterburning solid materials.

[0044] 3. This invention establishes material segment identification through pre-combustion detection components, furnace body temperature detection components, flue gas detection components, post-combustion residue detection components, and a centralized control unit. It records the carbonaceous composition content, fluoride salt phase content, aluminum phase content, moisture content, particle size distribution, feed rate, primary air volume, secondary air volume, gas auxiliary volume, reheat valve opening, furnace body temperature, gas phase oxygen content, flue gas composition, and post-combustion residue status of the same material segment. The upper limits of low-temperature sintering temperature and gas phase oxygen content are not based on fixed empirical values, but rather on pre-combustion sample heating tests, fluoride volatile concentration, fluoride salt phase retention, aluminum phase retention, agglomeration ratio, and subsequent recovery process feed data from the same production batch of charcoal slag. The requirements are to be determined and written into the control parameter table; when the residual carbon content in the current material section is high and the recyclable phase retention state does not exceed the control boundary, the centralized control unit increases the secondary air volume, reduces the feed rate, or increases the frequency of the waste heat recovery fan, provided that the temperature and gas phase oxygen content do not exceed the upper limit; when the fluorine-containing volatiles, fluorine-containing salt phase retention, aluminum-containing phase retention, or agglomeration ratio exceed the control boundary, the oxygen supplementation intensity, gas auxiliary amount, or reheat intensity is reduced; thus, the batch differences of carbon slag, the reaction state in the furnace, and the post-combustion quality results can be mapped to the same control object, thereby improving the clarity of the source of the low-temperature sintering control boundary, reducing the mismatch of fixed operating conditions, and stabilizing the feed quality of subsequent recovery processes. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the overall structure of a fully automatic cyclone furnace; Figure 2 This is a flowchart illustrating the low-temperature sintering of carbon slag and the simultaneous separation of slag and gas in this invention. Figure 3 This is a logic diagram of segmented heating and feedback control in this invention; Figure 4 This is a schematic diagram of the integrated combustion device and control process for low-temperature sintering of electrolytic aluminum carbon slag and synchronous separation of slag and gas, as well as the control process of the present invention.

[0046] Explanation of reference numerals in the attached diagram: 1. Air compressor; 2. Central control box; 3. Gas storage tank; 4. Feeder; 5. Cyclone separator; 6. Gas flow meter; 7. Mass flow meter; 8. Collector; 9. Waste heat recovery fan; 10. Exhaust gas treatment system. Detailed Implementation

[0047] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0048] like Figures 1 to 4As shown in the figure, this embodiment provides an integrated combustion device for low-temperature sintering of electrolytic aluminum carbon slag and simultaneous separation of slag and gas; the device is used to treat electrolytic aluminum carbon slag generated during the electrolytic aluminum production process, the electrolytic aluminum carbon slag includes carbonaceous components, fluorine-containing salt phase, aluminum-containing phase, moisture, and solid particles of different particle sizes.

[0049] The low-temperature sintering described in this embodiment refers to a heat treatment process in which the carbonaceous components in the electrolytic aluminum slag undergo controlled oxidation under the constraints of the upper limit of the low-temperature sintering temperature and the upper limit of the gas phase oxygen content, and the fluorine-containing salt phase and aluminum-containing phase are mainly introduced into the bottom discharge port along with the post-combustion solid phase material.

[0050] The upper limit of the low-temperature sintering temperature is not a fixed empirical temperature, but is determined based on the results of the pre-combustion sample heating test of the same batch of char slag, the concentration of fluorine volatiles, the retention amount of fluorine salt phase, the retention amount of aluminum phase, the agglomeration ratio, and the feeding requirements of the subsequent recycling process, and is written into the control parameter table of the centralized control unit.

[0051] The integrated combustion device includes a feeding and metering unit, a segmented preheating unit, a cyclone furnace body, a solid phase collection unit, a waste heat recovery tail gas treatment unit, and a centralized control unit; the feeding and metering unit, the segmented preheating unit, and the cyclone furnace body are connected in sequence by tangential feed pipes to form a feeding path from carbon slag metering and carbon slag preheating to tangential entry into the furnace; the cyclone furnace body includes a cylindrical combustion separation cylinder, a tangential feed pipe, a primary air interface, a secondary air interface, a gas auxiliary interface, a top rising exhaust channel, a bottom conical separation section, and a bottom discharge port.

[0052] The outlet of the tangential feed pipe is arranged tangentially along the inner wall of the cylindrical combustion separator. The primary air interface is connected to the tangential feed pipe or the cylindrical combustion separator. The secondary air interface is located below the outlet of the tangential feed pipe and is arranged tangentially along the cylindrical combustion separator. The gas auxiliary interface is connected to the primary air pipeline or the tangential feed pipe.

[0053] The top rising exhaust channel is connected to the waste heat recovery tail gas treatment unit, the bottom conical separation section is connected to the cylindrical combustion separation cylinder and the bottom discharge port, and the bottom discharge port is connected to the solid phase collection unit; the centralized control unit is electrically connected to the feeding and metering unit, the segmented preheating unit, the primary air pipeline, the secondary air pipeline, the gas pipeline, the waste heat recovery tail gas treatment unit and the detection device respectively.

[0054] The feeding and metering unit includes a feeder, a weighing bin, and a mass flow meter. The feeder receives electrolytic aluminum slag after crushing, screening, iron removal, and homogenization. The weighing bin is located upstream of or inside the feeder to obtain the mass of the slag before or during its entry into the feeder. The mass flow meter is located on the discharge channel of the feeder to detect the mass flow rate of the slag output per unit time. In this embodiment, the feeder is a quantitative feeder with an airlock structure, the mass flow meter is a weighing-type mass flow meter, and a weighing sensor is installed inside the weighing bin. The weighing sensor is electrically connected to the centralized control unit.

[0055] The quantitative feeder with airlock structure can reduce the direct entry of external air into the cyclone furnace body while continuously feeding materials, thus avoiding significant disturbance to the furnace pressure and cyclone state during the feeding process.

[0056] The discharge end of the feeder is connected to the slag preheating channel of the segmented preheating unit, and the discharge end of the slag preheating channel is connected to the tangential feed pipe. The slag preheating channel is a closed conveying channel. The slag preheating channel is heat exchanged with the cold side heat exchange channel of the exhaust gas heat exchanger, so that the slag material flow can indirectly exchange heat with the heat provided by the exhaust gas heat exchanger before entering the tangential feed pipe. The slag material flow in the slag preheating channel does not directly mix with the exhaust gas. The exhaust gas and the slag material flow transfer heat through the heat exchange wall. The slag feed amount obtained by the weighing bin and mass flow meter is used by the centralized control unit to determine the correspondence between the primary air volume, secondary air volume, gas auxiliary volume, reheat valve opening, waste heat recovery fan frequency and feed amount.

[0057] The cylindrical combustion separator in the cyclone furnace body is a vertically arranged cylindrical furnace body used to form a swirling combustion space and a slag-gas separation space. The outlet end of the tangential feed pipe is connected to the side wall of the cylindrical combustion separator, and the center line of the outlet of the tangential feed pipe is arranged along the tangential direction of the inner wall of the cylindrical combustion separator. The primary air interface is connected to the tangential feed pipe, so that the primary air carries the carbon and slag material flow into the cylindrical combustion separator in the tangential feed pipe. In another embodiment, the primary air interface can also be connected to the cylindrical combustion separator and arranged in parallel with the tangential feed pipe, so that the carbon and slag material flow and the primary air converge in the inlet area of ​​the cylindrical combustion separator. Both of the above connection methods allow the primary air to enter tangentially along the inner wall of the cylindrical combustion separator and give the carbon and slag particles an initial rotational speed.

[0058] The secondary air inlet is located below the outlet of the tangential feed pipe and is arranged tangentially along the cylindrical combustion separator.

[0059] The outlet direction of the secondary air inlet is consistent with the rotation direction of the primary air after entering the cylindrical combustion separator; there are two or more secondary air inlets, and each secondary air inlet is arranged at intervals along the circumference of the cylindrical combustion separator, and the outlet center line of each secondary air inlet is arranged along the tangent direction of the same rotation direction of the cylindrical combustion separator.

[0060] The secondary air replenishes gaseous oxygen while maintaining the swirling motion path of the char residue particles in the cylindrical combustion separation cylinder, avoiding the formation of an impact airflow opposite to that of the primary air. By dispersing oxygen replenishment through a secondary air interface, it can reduce the increase in volatilization of fluorine-containing salt phase or local agglomeration of post-combustion solid materials caused by excessively high local gaseous oxygen content.

[0061] The gas auxiliary interface is connected to the primary air duct or the tangential feed pipe; the gas auxiliary interface is set in the mixing pipe section at the front end of the primary air interface, or in the mixing pipe section at the front end of the tangential feed pipe; during the start-up stage, the stage of insufficient calorific value of char and slag, or the stage of increased char and slag moisture content leading to a drop in furnace temperature, the gas enters the primary air duct or the tangential feed pipe through the gas auxiliary interface, and enters the columnar combustion separation cylinder with the primary air.

[0062] A gas flow meter, a gas regulating valve, and a check valve are installed on the gas pipeline where the gas auxiliary interface is located. The gas flow meter is used to obtain the amount of gas auxiliary, the gas regulating valve is used to regulate the gas supply, and the check valve is used to prevent gas or primary air from entering the gas pipeline in reverse. The gas supply of the gas auxiliary interface is limited by the gas regulating valve to the corresponding range in the control parameter table. The gas is used for start-up, stable combustion, or to compensate for fluctuations in the calorific value of charcoal and slag, and is not used as a salt-based combustion aid added to the charcoal and slag.

[0063] The cylindrical combustion separator comprises, from top to bottom, a swirl ignition section, a low-temperature sintering section, and a solid-phase centrifugal separation section. The swirl ignition section, the low-temperature sintering section, and the solid-phase centrifugal separation section are functional areas within the cylindrical combustion separator, divided according to their height. The division is based on the arrangement of the tangential feed pipe outlet, the secondary air interface, the lower port of the central exhaust pipe, the bottom conical separation section, and the furnace body temperature detection components.

[0064] The functional areas mentioned above do not require physical partitions, allowing the char slag flow and flue gas to flow continuously within the cylindrical combustion separation cylinder. The swirl ignition section receives the tangentially entering char slag flow and primary air, and establishes the rotational motion of the char slag particles. The low-temperature sintering section completes the oxidation of carbonaceous components under controlled temperature and controlled gas phase oxygen content. The solid-phase centrifugal separation section allows the post-combustion solid material to enter the bottom conical separation section along the inner wall of the cylindrical combustion separation cylinder.

[0065] The top-rising exhaust channel includes a central exhaust pipe arranged along the axis of the cylindrical combustion separation cylinder; the lower end of the central exhaust pipe is located within the swirl ignition section, and the lower end of the rising pipe is flush with or slightly lower than the lower end of the secondary air; the upper end of the central exhaust pipe is connected to the waste heat recovery tail gas treatment unit.

[0066] The central exhaust pipe is located in the axial region of the cylindrical combustion separator, corresponding to the upward spiral path of the flue gas; the bottom conical separation section corresponds to the downward spiral path of the solid phase; under centrifugal force, the carbon slag particles tend to move towards the inner wall of the cylindrical combustion separator and enter the bottom discharge port through the bottom conical separation section; the flue gas enters the central exhaust pipe along the central region of the cylindrical combustion separator, thus forming a separation path of downward spiral of the solid phase and upward spiral of the flue gas within the cyclone furnace body.

[0067] The large end of the bottom conical separation section is connected to the lower end of the cylindrical combustion separation cylinder, and the small end of the bottom conical separation section is connected to the bottom discharge port. The inner diameter of the bottom conical separation section gradually decreases from top to bottom, which is used to collect the afterburning solid material flowing down the inner wall of the cylindrical combustion separation cylinder. The bottom discharge port is connected to the solid phase collection unit. The bottom conical separation section is part of the cyclone furnace body and undertakes the transition function of afterburning solid material from the rotation path inside the furnace to the solid phase collection unit. Through the cooperation of the cylindrical combustion separation cylinder, the central exhaust pipe and the bottom conical separation section, the cyclone furnace body simultaneously provides a low-temperature sintering combustion space and a slag-gas synchronous separation space.

[0068] The segmented preheating unit includes a slag preheating channel, a primary air preheating channel, a secondary air preheating channel, a tail gas heat exchanger, a tail gas bypass pipe, and a reheat regulating valve. The tail gas heat exchanger is a shared heat exchange component between the segmented preheating unit and the waste heat recovery tail gas treatment unit. The hot side of the tail gas heat exchanger is located on the flue gas discharge path, and the cold side is located on the preheating paths of the slag, primary air, and secondary air. The hot side inlet of the tail gas heat exchanger is connected to the top rising exhaust channel, and the hot side outlet of the tail gas heat exchanger is connected to the dust-laden gas separator. The cold side of the tail gas heat exchanger is connected to the slag preheating channel, the primary air preheating channel, and the secondary air preheating channel for heat exchange. The tail gas does not directly mix with the slag material flow, primary air, or secondary air, but transfers heat through the heat exchange wall.

[0069] A bypass pipe is connected in parallel between the hot-side inlet and hot-side outlet of the exhaust gas heat exchanger, and a reheat regulating valve is installed at the bypass pipe or the hot-side inlet of the exhaust gas heat exchanger. When the moisture content of the slag is high or the feed rate increases, the centralized control unit increases the proportion of flue gas entering the hot side of the exhaust gas heat exchanger, so that the slag preheating channel, the primary air preheating channel, and the secondary air preheating channel can obtain more heat. When the temperature of the low-temperature sintering section is close to the upper limit of the low-temperature sintering temperature or the concentration of fluorine volatiles increases, the centralized control unit reduces the proportion of flue gas entering the hot side of the exhaust gas heat exchanger, so that the preheating intensity is reduced. The bypass pipe and the reheat regulating valve are used to adjust the proportion of exhaust gas waste heat participating in the slag flow, primary air, and secondary air segmented preheating.

[0070] The primary air preheating channel connects the primary air source and the primary air interface, and the secondary air preheating channel connects the secondary air source and the secondary air interface; a primary air gas flow meter and a primary air regulating valve are installed on the primary air duct, and a secondary air gas flow meter and a secondary air regulating valve are installed on the secondary air duct.

[0071] Primary air is used for tangential conveying of carbon slag and initial cyclone establishment, while secondary air is used for oxygen supplementation and cyclone maintenance in the low-temperature sintering section. After preheating, the primary and secondary air enter the cyclone furnace body, which can reduce the local temperature drop caused by the entry of cold air and reduce the fluctuation of auxiliary gas supply.

[0072] The waste heat recovery tail gas treatment unit includes a tail gas heat exchanger, a dust-laden gas separator, a dry adsorption purifier, and an exhaust pipe connected in sequence. The dust-laden gas separator is used to separate solid dust entrained in the flue gas, and the dry adsorption purifier is used to adsorb fluorine-containing components in the flue gas. The solid phase outlet of the dust-laden gas separator is connected to the moving bed cooling collection chamber of the solid phase collection unit, or to the reburning return material branch.

[0073] Solid dust entering the moving bed cooling collection chamber is collected together with the post-combustion solid material output from the bottom outlet; solid dust entering the reburning return branch returns to the feeder and re-enters the cyclone furnace body; through this setting, solid material carried by flue gas is included in the solid collection or reburning path.

[0074] The solid phase collection unit includes a moving bed cooling collection chamber, an airlock feed valve, an airlock discharge valve, a post-combustion residue sampling port, a qualified material outlet, and a reburning return branch; the airlock feed valve is located between the bottom discharge port and the moving bed cooling collection chamber, and the airlock discharge valve is located at the lower end of the moving bed cooling collection chamber.

[0075] The moving bed cooling collection chamber is used to receive the afterburning solid material output from the bottom outlet and to cool the solid material during its movement; the airlock feed valve and airlock discharge valve are used to isolate the bottom outlet from the external environment and reduce the disturbance to the internal pressure and swirling state of the cyclone furnace body during the discharge process.

[0076] The afterburning residue sampling port is located downstream of the airlock discharge valve, and the afterburning residue detection component is located at the afterburning residue sampling port or on a sampling channel connected to the afterburning residue sampling port. The qualified material outlet is used to output solid materials that meet the feed requirements of subsequent recycling processes. The reburning return branch connects to the distribution valve and feeder downstream of the afterburning residue sampling port, and is used to return solid materials that do not meet the feed requirements to the feeder.

[0077] The detection components include a pre-combustion detection module, a furnace body temperature detection module, a flue gas detection module, and a post-combustion residue detection module. The pre-combustion detection module is located upstream of the feeder or on the feeder's bypass sampling channel.

[0078] The pre-combustion testing components include a moisture content testing element, a particle size testing element, and a composition testing element. The moisture content testing element is used to detect the moisture content of the char slag flow, the particle size testing element is used to detect the particle size distribution of the char slag flow, and the composition testing element is used to detect the content of carbonaceous components, the content of fluorine-containing salt phases, and the content of aluminum-containing phases.

[0079] The pre-combustion component detection adopts a bypass sampling detection method, that is, a representative sample is obtained from the upstream of the feeder or the bypass sampling channel. The sample is tested for moisture content, particle size, carbonaceous components, fluorine-containing salt phase and aluminum-containing phase, and the detection results are written into the centralized control unit. The pre-combustion detection component can also be equipped with online detection devices. The online detection devices are used for process tracking, and the bypass sampling detection results are used to correct the online detection results.

[0080] The furnace body temperature detection components are respectively set in the swirl ignition section, the low-temperature sintering section, and the solid-phase centrifugal separation section; the furnace body temperature detection components adopt thermocouples, infrared thermometers, or high-temperature resistant thermometers; each temperature measuring point is arranged along the height direction of the cylindrical combustion separation cylinder, so that the centralized control unit can distinguish the temperature of the swirl ignition section, the low-temperature sintering section, and the solid-phase centrifugal separation section, avoiding the use of a single point furnace temperature to represent the thermal state of the entire cyclone furnace body; the upper limit of the low-temperature sintering temperature is mainly controlled by the detected temperature of the low-temperature sintering section, while also taking into account the temperature changes of the swirl ignition section and the solid-phase centrifugal separation section.

[0081] The flue gas detection assembly is installed in the top rising exhaust channel or on the hot-side inlet pipe of the tail gas heat exchanger. The flue gas detection assembly includes a gaseous oxygen content detector, a carbon monoxide detector, a carbon dioxide detector, and a fluorinated volatiles detector. The gaseous oxygen content detector detects the gaseous oxygen content in the top exhaust gas; the carbon monoxide and carbon dioxide detectors reflect the oxidation state of carbonaceous components; and the fluorinated volatiles detector reflects the volatilization state of fluorinated salt phases. The flue gas detection assembly is installed before the hot-side inlet of the tail gas heat exchanger or on the top rising exhaust channel, enabling the acquisition of furnace reaction state data before the flue gas enters the heat exchange and purification process.

[0082] The post-combustion residue detection component is located at the outlet sampling channel of the solid phase collection unit and is used to detect the content of residual carbonaceous components, the amount of fluorine-containing salt phase retained, the amount of aluminum-containing phase retained, and the agglomeration ratio. The content of residual carbonaceous components is obtained from the total carbon detection results of the post-combustion solid phase sample, or from the loss on ignition results after ash correction.

[0083] The retention amount of fluorine-containing salt phase is obtained by converting the dry basis mass of fluorine-containing salt phase before combustion and the dry basis mass of fluorine-containing salt phase after combustion in the same material section. The retention amount of aluminum-containing phase is obtained by converting the dry basis mass of aluminum-containing phase before combustion and the dry basis mass of aluminum-containing phase after combustion in the same material section. The agglomeration ratio is the proportion of the mass of agglomerates with a particle size larger than the upper limit of the allowable feed particle size in the post-combustion solid phase sample to the total mass of the post-combustion solid phase sample.

[0084] Specifically, the mass of the pre-combustion dry basis of the same material segment is multiplied by the pre-combustion fluorine-containing salt phase content to obtain the pre-combustion fluorine-containing salt phase mass; the mass of the post-combustion dry basis of the same material segment is multiplied by the post-combustion fluorine-containing salt phase content to obtain the post-combustion fluorine-containing salt phase mass; the ratio of the post-combustion fluorine-containing salt phase mass to the pre-combustion fluorine-containing salt phase mass is used as the fluorine-containing salt phase retention amount; the aluminum phase retention amount is obtained by converting the pre-combustion aluminum phase mass and the post-combustion aluminum phase mass in the same way; the screening limit of the agglomeration ratio is determined by the upper limit of the allowable feed particle size in the subsequent recycling process and written into the centralized control unit before processing the same production batch.

[0085] The centralized control unit includes a control box, a data storage module, an input / output module, and an interlocking control module. The data storage module stores a material segment identification table, a composition classification table, and a control parameter table. The material segment identification table includes the feeding start time, feeding end time, feeding quality, estimated discharge time, and actual discharge time. The estimated discharge time is determined based on the feeding start time, feeding end time, material residence time within the cyclone furnace, and discharge time from the solid phase collection unit. The actual discharge time is determined by the discharge detection signal at the afterburning residue sampling port or the airlock discharge valve. The composition classification table includes classifications of carbonaceous components, fluoride-containing salt phases, aluminum-containing phases, moisture content, and particle size distribution. The control parameter table includes the upper limit of low-temperature sintering temperature, the upper limit of gas phase oxygen content, primary air volume, secondary air volume, gas auxiliary volume, reheat valve opening, waste heat recovery fan frequency, and feeding rate.

[0086] The input / output module receives data from the weighing bin, mass flow meter, primary air gas flow meter, secondary air gas flow meter, gas flow meter, pre-combustion detection component, furnace body temperature detection component, flue gas detection component, and post-combustion residue detection component, and outputs control signals to the feeder, primary air regulating valve, secondary air regulating valve, gas regulating valve, reheat regulating valve, waste heat recovery fan, and distribution valve.

[0087] When the furnace temperature exceeds the interlock temperature limit, the gas phase oxygen content exceeds the interlock gas phase oxygen content limit, the gas pressure is abnormal, or the tail gas treatment system malfunctions, the interlock control module will perform at least one of the following actions: reduce the feed rate, close the gas regulating valve, reduce the secondary air volume, or stop the feeder. The interlock limits are jointly determined by the equipment safety operation requirements and the feeding requirements of the subsequent recycling process, and are written into the centralized control unit before the same production batch is processed.

[0088] This embodiment also provides a method for controlling the low-temperature sintering of electrolytic aluminum carbon slag and the synchronous separation of slag and gas, which is based on the above-mentioned integrated combustion device.

[0089] First, the electrolytic aluminum slag is crushed, screened, iron removed, and homogenized to obtain a slag feed stream that enters the feeder. Crushing and screening are used to give the slag feed stream a particle size distribution suitable for tangential feed pipe conveying and cyclone furnace body cyclone treatment. Iron removal is used to reduce the impact of metallic iron impurities on post-combustion solid phase recovery and downstream sorting. Homogenization is used to reduce local fluctuations in slag composition, moisture content, and particle size distribution within the same production batch. Before entering the feeder, the pretreated slag feed stream enters a buffer bin for short-term buffering, and the outlet of the buffer bin is connected to the feeder.

[0090] Secondly, the carbonaceous composition, fluoride-containing salt phase content, aluminum-containing phase content, moisture content, and particle size distribution of the char slag material are detected by the pre-combustion detection component. The centralized control unit establishes material segment identifiers according to the feeding start time, feeding end time, and feeding quality. During continuous feeding, the material entering the feeder within a fixed time window is considered as a material segment, or the material reaching the set feeding quality is considered as a material segment. Each material segment has a unique material segment identifier. Pre-combustion detection data, feeding amount data, primary air volume data, secondary air volume data, gas auxiliary volume data, reheat valve opening data, waste heat recovery fan frequency data, furnace temperature data, flue gas detection data, and post-combustion residue detection data are all stored according to the material segment identifier. Through the material segment identifier, the data of the same material segment in the four stages of pre-combustion, furnace, tail gas, and post-combustion correspond to each other.

[0091] Furthermore, the centralized control unit determines the upper limit of low-temperature sintering temperature, the upper limit of gas phase oxygen content, primary air volume, secondary air volume, gas auxiliary volume, reheat valve opening, waste heat recovery fan frequency, and feed volume based on the carbonaceous component content, fluorine salt phase content, aluminum phase content, moisture content, particle size distribution, and subsequent recovery process feed requirements of the same material section. The carbonaceous component content is used to determine the required decarburization intensity of the material section; the fluorine salt phase content is used to determine the fluorine salt phase volatilization control requirements; the aluminum phase content is used to determine the aluminum phase retention requirements; the moisture content is used to determine the preheating intensity and gas auxiliary volume; and the particle size distribution is used to determine the tangential conveying air volume, swirl residence time, and agglomeration control requirements.

[0092] The feed requirements for subsequent recycling processes include the upper limit of residual carbonaceous components, the lower limit of fluorine-containing salt phase retention, the lower limit of aluminum-containing phase retention, and the upper limit of agglomeration ratio. These feed requirements are determined by the production process documents for the same batch or the feed control conditions of subsequent recycling equipment.

[0093] The upper limit of low-temperature sintering temperature and the upper limit of gas phase oxygen content are determined according to the pre-combustion sample heating test of the same batch of slag. The pre-combustion sample is taken from the front, middle and rear sections of the same batch of slag feed, and the sample is mixed and reduced to form the test sample. The test sample is subjected to heating or holding tests at multiple temperature points set in the test record. At each temperature point, the residual carbonaceous component content, fluorine volatile concentration, fluorine salt phase retention, aluminum phase retention and agglomeration ratio are detected.

[0094] The feed requirements for subsequent recycling processes are converted into upper limits for residual carbonaceous components, upper limits for fluorine volatile concentration, lower limits for fluorine salt phase retention, lower limits for aluminum phase retention, and upper limits for agglomeration ratio. At each temperature point, the highest temperature that simultaneously satisfies the following conditions is recorded in the control parameter table: residual carbonaceous component content is not higher than the upper limit for residual carbonaceous components, fluorine volatile concentration is not higher than the upper limit for fluorine volatile concentration, fluorine salt phase retention is not lower than the lower limit for fluorine salt phase retention, aluminum phase retention is not lower than the lower limit for aluminum phase retention, and agglomeration ratio is not higher than the upper limit for agglomeration ratio. This temperature is used as the upper limit for low-temperature sintering temperature of this production batch.

[0095] Under the upper limit of the low-temperature sintering temperature, the gaseous oxygen content in the test atmosphere is changed, and the highest gaseous oxygen content that simultaneously meets the following requirements is written into the control parameter table: the residual carbonaceous component content is not higher than the upper limit of the residual carbonaceous component content, the concentration of fluorine-containing volatiles is not higher than the upper limit of the concentration of fluorine-containing volatiles, the retention amount of fluorine-containing salt phase is not lower than the lower limit of the retention amount of fluorine-containing salt phase, the retention amount of aluminum-containing phase is not lower than the lower limit of the retention amount of aluminum-containing phase, and the agglomeration ratio is not higher than the upper limit of the agglomeration ratio. This is used as the upper limit of the gaseous oxygen content for this production batch. In actual operation, the gaseous oxygen content is fed back by the gaseous oxygen content detection value in the top rising exhaust channel or the hot side inlet pipe of the tail gas heat exchanger. Thus, the upper limit of the low-temperature sintering temperature and the upper limit of the gaseous oxygen content have the same production batch sample test and subsequent recycling process feed requirements as the source.

[0096] Subsequently, the flue gas discharged from the top rising exhaust channel enters the exhaust gas heat exchanger; the hot side of the exhaust gas heat exchanger receives the flue gas from the top rising exhaust channel, and the cold side of the exhaust gas heat exchanger exchanges heat with the carbon slag preheating channel, the primary air preheating channel and the secondary air preheating channel respectively.

[0097] The charcoal slag flows through the charcoal slag preheating channel for heat exchange before entering the tangential feed pipe; the primary air flows through the primary air preheating channel for heat exchange before entering the primary air inlet; and the secondary air flows through the secondary air preheating channel for heat exchange before entering the secondary air inlet.

[0098] The centralized control unit adjusts the opening of the reheat valve and the frequency of the waste heat recovery fan based on the moisture content, feed rate, and furnace temperature data of the material section, so that the amount of flue gas entering the hot side of the tail gas heat exchanger corresponds to the preheating requirements of the material section. If the moisture content increases, the centralized control unit increases the opening of the reheat valve or increases the frequency of the waste heat recovery fan. If the temperature of the low-temperature sintering section approaches the upper limit of the low-temperature sintering temperature or the concentration of fluorine volatiles increases, the centralized control unit reduces the flow rate of flue gas entering the tail gas heat exchanger or reduces the frequency of the waste heat recovery fan.

[0099] Then, the feeder outputs the char and slag flow to the tangential feed pipe according to the feed rate. The primary air carries the char and slag flow tangentially into the cyclone furnace body along the cylindrical combustion separation cylinder. After the char and slag flow enters the cyclone ignition section, it forms an outer cyclone along the inner wall of the cylindrical combustion separation cylinder under the action of the primary air. The gas enters the front end of the primary air interface or the front end of the tangential feed pipe through the gas auxiliary interface, and enters the cyclone ignition section with the primary air to start the furnace or compensate for the insufficient heat caused by low calorific value char and slag.

[0100] The secondary air enters the low-temperature sintering section in the same swirling direction as the primary air, replenishing the carbon slag particles in the swirling flow with gaseous oxygen, so that the carbonaceous components are oxidized in a controlled manner within the upper limit of the low-temperature sintering temperature and the upper limit of the gaseous oxygen content.

[0101] Fluorine-containing salt phase and aluminum-containing phase enter the solid phase centrifugal separation section along the inner wall of the cylindrical combustion separation cylinder with the post-combustion solid phase material, and then enter the bottom discharge port through the bottom conical separation section.

[0102] The flue gas enters the central exhaust pipe along the central area of ​​the cylindrical combustion separation cylinder, and then enters the exhaust heat exchanger through the top rising exhaust channel.

[0103] In the above process, primary air is responsible for tangential conveying and initial swirl establishment, secondary air is responsible for oxygen replenishment and swirl maintenance in the low-temperature sintering section, and gas-fired auxiliary air is responsible for heat compensation when the furnace is started or the calorific value is insufficient.

[0104] The boundaries of the functions of the three are clearly defined. Gas-assisted combustion is not used as a way to add salts to charcoal slag for combustion, nor is secondary air set as a destructive airflow that is opposite to primary air.

[0105] Fluorine-containing salt phase and aluminum-containing phase are not targeted for gas phase discharge, but instead enter the solid phase collection unit through the bottom discharge port along with the post-combustion solid phase material; the flue gas is discharged through the central exhaust pipe and then enters the waste heat recovery tail gas treatment unit; this treatment path corresponds to the structure of the fully automatic cyclone furnace, which can explain the process of the cyclone furnace body participating in low-temperature sintering combustion and realizing the synchronous separation of slag and gas.

[0106] The afterburning solid material output from the bottom outlet enters the moving bed cooling and collection chamber through the airlock feed valve. The moving bed cooling and collection chamber cools the afterburning solid material, which is then discharged through the airlock discharge valve. The afterburning residue detection component obtains samples from the afterburning residue sampling port and detects the content of residual carbonaceous components, the retention amount of fluorine-containing salt phase, the retention amount of aluminum-containing phase, and the agglomeration ratio.

[0107] Afterburning solids that meet the requirements for subsequent recycling processes are output from the qualified material outlet; afterburning solids that do not meet the requirements for subsequent recycling processes are switched to the reburning return branch by the distribution valve and returned to the feeder; the reburning material returned to the feeder is re-identified into a material section, and the pre-combustion test data, furnace temperature data, flue gas test data, and afterburning residue test data of the reburning material are stored separately from the initial treatment data.

[0108] The flue gas discharged from the top rising exhaust channel enters the tail gas heat exchanger, and the released heat is used for preheating of carbon slag, primary air, and secondary air. The flue gas discharged from the hot side outlet of the tail gas heat exchanger enters the dust-laden gas separator, and the solid dust separated by the dust-laden gas separator enters the moving bed cooling collection bin or the reburning return branch.

[0109] The flue gas, after being treated by the dust-laden gas separator, enters the dry adsorption purifier, which adsorbs the fluorine-containing components in the flue gas. The flue gas is then discharged through the exhaust pipe. This exhaust gas treatment path does not produce wet fluorine-containing wastewater. The waste heat of the exhaust gas is used for staged preheating before discharge, thereby establishing a thermal coupling relationship between the exhaust gas treatment and the front-end preheating.

[0110] The centralized control unit writes the furnace temperature data, flue gas detection data, and post-combustion residue detection data of the same material section into the material section identification table, and corrects the feed rate, primary air volume, secondary air volume, gas auxiliary volume, reheat valve opening degree, and waste heat recovery fan frequency of the subsequent material sections based on the detection results.

[0111] When the residual carbonaceous component content measured by the afterburning residue detection component is higher than the upper limit of residual carbonaceous component, and the concentration of fluorinated volatiles measured by the flue gas detection component is not higher than the upper limit of fluorinated volatiles concentration, the retention amount of fluorinated salt phase is not lower than the lower limit of fluorinated salt phase retention amount, the retention amount of aluminum phase is not lower than the lower limit of aluminum phase retention amount, and the agglomeration ratio is not higher than the upper limit of agglomeration ratio, it indicates that the decarbonization of this section is insufficient, but the retention state of the fluorinated salt phase and the aluminum phase has not exceeded the control boundary.

[0112] At this time, under the condition that the low-temperature sintering temperature limit and the gas phase oxygen content limit are not exceeded, the centralized control unit increases the secondary air volume, reduces the feed volume, or increases the frequency of the waste heat recovery fan, so as to increase the degree of oxidation of carbonaceous components in the subsequent material section or reduce the material load per unit time.

[0113] When the concentration of fluorine-containing volatiles is higher than the upper limit of fluorine-containing volatiles concentration, the retention amount of fluorine-containing salt phase is lower than the lower limit of fluorine-containing salt phase retention amount, the retention amount of aluminum-containing phase is lower than the lower limit of aluminum-containing phase retention amount, or the agglomeration ratio is higher than the upper limit of agglomeration ratio, it indicates that the low-temperature sintering combustion intensity, oxygen supplementation intensity, or reheating intensity of this material section has affected the retention state of the recyclable phase.

[0114] At this time, the centralized control unit reduces the secondary air volume, reduces the gas auxiliary volume, reduces the flue gas flow entering the tail gas heat exchanger, or reduces the frequency of the waste heat recovery fan, so as to reduce the oxidation intensity and reheat intensity of the subsequent material section. If the post-combustion solid material in this section does not meet the feeding requirements of the subsequent recovery process, the distribution valve switches to the reburning return branch, and the post-combustion solid material returns to the feeder through the reburning return branch and re-enters the cyclone furnace body according to the new material section marking.

[0115] In this embodiment, the control parameter table is written into the centralized control unit before the same production batch is processed, or it can be corrected by the centralized control unit based on the afterburning residue detection results during continuous processing.

[0116] The classification of carbonaceous components, fluoride salt phases, aluminum phases, moisture content, and particle size distribution in the composition classification table are determined by pre-combustion test data of the same production batch, pre-combustion sample heating test data, and subsequent recycling process feed requirements.

[0117] This embodiment determines the control boundaries using test data from the same production batch, ensuring that the upper limit of the low-temperature sintering temperature and the upper limit of the gas phase oxygen content have traceable data sources.

[0118] The integrated combustion device in this embodiment uses a fully automatic cyclone furnace as its physical carrier. The cyclone furnace body includes a cylindrical combustion separation cylinder, a tangential feed pipe, a primary air interface, a secondary air interface, a gas auxiliary interface, a central exhaust pipe, a bottom conical separation section, and a bottom discharge port.

[0119] The charcoal slag undergoes tangential feeding, swirling ignition, low-temperature sintering and combustion, solid-phase centrifugal separation, and central exhaust within the cyclone furnace body. The post-combustion solid material output from the bottom outlet enters the moving bed cooling and collection chamber, while the flue gas output from the top rising exhaust channel enters the tail gas heat exchanger, dust-laden gas separator, and dry adsorption purifier.

[0120] This structure integrates the combustion space, solid-phase separation space, exhaust gas waste heat recovery path, and solid-phase return path into the same continuous processing system. Unlike experimental structures that only use venturi tubes for sample delivery, air compressors for gas supply, cyclone separators for combustion, and collection bottles for material reception, this structure can support continuous feeding, continuous exhaust, continuous solid-phase collection, and closed-loop control based on material segment identification.

[0121] Through the above-described implementation methods, the feeding and metering unit, segmented preheating unit, cyclone furnace body, solid phase collection unit, waste heat recovery tail gas treatment unit, centralized control unit, tangential feed pipe, primary air interface, secondary air interface, gas auxiliary interface, top rising exhaust channel, bottom conical separation section, bottom discharge port, feeder, weighing bin, mass flow meter, carbon slag preheating channel, primary air preheating channel, secondary air preheating channel, tail gas heat exchanger, tail gas bypass pipe, reheat regulating valve, pre-combustion detection component, furnace body temperature detection component, flue gas detection component, post-combustion residue detection component, material section identification table, composition classification table, control parameter table, moving bed cooling collection bin, airlock feed valve, airlock discharge valve, post-combustion residue sampling port, qualified material outlet, and reburning return branch all have clearly defined structural positions, connection relationships, and operating modes. Those skilled in the art, based on the above disclosure, can manufacture corresponding fully automatic cyclone furnace devices and complete the low-temperature sintering of electrolytic aluminum carbon slag and simultaneous separation of slag and gas according to the described control method.

[0122] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0123] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An integrated combustion device for low-temperature sintering of electrolytic aluminum slag and simultaneous separation of slag and gas, characterized in that, It includes a feeding and metering unit, a segmented preheating unit, a cyclone furnace body, a solid phase collection unit, a waste heat recovery and tail gas treatment unit, and a centralized control unit; The feeding and metering unit, the segmented preheating unit, and the tangential feed pipe of the cyclone furnace body are connected in sequence; The cyclone furnace body includes a cylindrical combustion separation cylinder, a tangential feed pipe, a primary air interface, a secondary air interface, a gas auxiliary interface, a top rising exhaust channel, a bottom conical separation section, and a bottom discharge port; The outlet of the tangential feed pipe is arranged tangentially along the inner wall of the cylindrical combustion separator. The primary air interface is connected to the tangential feed pipe or the cylindrical combustion separator. The secondary air interface is located below the outlet of the tangential feed pipe and is arranged tangentially along the cylindrical combustion separator. The gas auxiliary interface is connected to the primary air pipeline or the tangential feed pipe. The top rising exhaust channel is connected to the waste heat recovery tail gas treatment unit, the bottom conical separation section is connected to the cylindrical combustion separation cylinder and the bottom discharge port, and the bottom discharge port is connected to the solid phase collection unit. The centralized control unit is electrically connected to the feeding and metering unit, the segmented preheating unit, the primary air duct, the secondary air duct, the gas duct, the waste heat recovery exhaust gas treatment unit, and the detection device.

2. The integrated combustion device for low-temperature sintering of electrolytic aluminum slag and simultaneous separation of slag and gas as described in claim 1, characterized in that: The feeding and metering unit includes a feeder, a weighing bin, and a mass flow meter. The weighing bin is located upstream of or inside the feeder, and the mass flow meter is located on the discharge channel of the feeder. The discharge end of the feeder is connected to the carbon slag preheating channel of the segmented preheating unit, and the discharge end of the carbon slag preheating channel is connected to the tangential feed pipe.

3. The integrated combustion device for low-temperature sintering of electrolytic aluminum slag and simultaneous separation of slag and gas as described in claim 2, characterized in that: The cylindrical combustion separation cylinder comprises, from top to bottom, a swirl ignition section, a low-temperature sintering section, and a solid-phase centrifugal separation section; the top rising exhaust channel includes a central exhaust pipe arranged along the axis of the cylindrical combustion separation cylinder, the lower end of which is located within the swirl ignition section and is flush with or slightly downwards from the secondary air inlet; the lower end of the solid-phase centrifugal separation section is connected to the large end of the bottom conical separation section, and the inner diameter of the bottom conical separation section gradually decreases from top to bottom.

4. The integrated combustion device for low-temperature sintering of electrolytic aluminum slag and simultaneous separation of slag and gas as described in claim 3, characterized in that: The primary air inlet consists of two or more tangential inlets spaced apart circumferentially along the cylindrical combustion separator, with the outlet centerline of each primary air inlet arranged along the same tangential direction of the cylindrical combustion separator. The secondary air inlet consists of two or more tangential inlets spaced apart circumferentially along the cylindrical combustion separator, with the outlet centerline of each secondary air inlet having the same tangential direction as the outlet centerline of the primary air inlet. The gas auxiliary inlet is located in the mixing pipe section at the front end of the primary air inlet or in the mixing pipe section at the front end of the tangential feed pipe. A gas flow meter, a gas regulating valve, and a check valve are provided on the gas pipeline where the gas auxiliary inlet is located.

5. The integrated combustion device for low-temperature sintering of electrolytic aluminum slag and simultaneous separation of slag and gas as described in claim 4, characterized in that: The segmented preheating unit includes a slag preheating channel, a primary air preheating channel, a secondary air preheating channel, a tail gas heat exchanger, a tail gas bypass pipe, and a reheat regulating valve. The hot-side inlet of the tail gas heat exchanger is connected to the top rising exhaust channel, and the hot-side outlet is connected to the waste heat recovery tail gas treatment unit. The tail gas bypass pipe is connected in parallel between the hot-side inlet and the hot-side outlet of the tail gas heat exchanger, and the reheat regulating valve is located at the hot-side inlet of the tail gas bypass pipe or the tail gas heat exchanger. The slag preheating channel, the primary air preheating channel, and the secondary air preheating channel are respectively connected to the cold-side heat exchange channel of the tail gas heat exchanger.

6. The integrated combustion device for low-temperature sintering of electrolytic aluminum slag and simultaneous separation of slag and gas as described in claim 5, characterized in that: The detection components include a pre-combustion detection component, a furnace body temperature detection component, a flue gas detection component, and a post-combustion residue detection component. The pre-combustion detection component is located upstream of the feeder or on the bypass sampling channel of the feeder, and includes a moisture content detection component, a particle size detection component, and a composition detection component. The furnace body temperature detection component is located in the swirl ignition section, the low-temperature sintering section, and the solid-phase centrifugal separation section, respectively. The flue gas detection component is located in the top rising exhaust channel or on the hot side inlet pipe of the tail gas heat exchanger, and includes an oxygen content detection component, a carbon monoxide detection component, a carbon dioxide detection component, and a fluorine-containing volatile matter detection component. The post-combustion residue detection component is located on the outlet sampling channel of the solid phase collection unit.

7. The integrated combustion device for low-temperature sintering of electrolytic aluminum slag and simultaneous separation of slag and gas as described in claim 6, characterized in that: The centralized control unit includes a control box, a data storage module, an input / output module, and an interlocking control module. The data storage module stores a material segment identification table, a composition grading table, and a control parameter table. The material segment identification table includes the feeding start time, feeding end time, feeding quality, and corresponding discharge time. The composition grading table includes grading of carbonaceous components, fluoride-containing salt phase content, aluminum-containing phase content, moisture content, and particle size distribution. The control parameter table includes the upper limit of low-temperature sintering temperature, the upper limit of gas phase oxygen content, primary air volume, secondary air volume, gas auxiliary volume, reheat valve opening, waste heat recovery fan frequency, and feeding volume.

8. The integrated combustion device for low-temperature sintering of electrolytic aluminum slag and simultaneous separation of slag and gas as described in claim 1, characterized in that: The solid phase collection unit includes a moving bed cooling collection chamber, an airlock feed valve, an airlock discharge valve, a post-combustion residue sampling port, a qualified material outlet, and a reburning return branch. The airlock feed valve is located between the bottom outlet and the moving bed cooling collection chamber, and the airlock discharge valve is located at the lower end of the moving bed cooling collection chamber. The reburning return branch is connected to a distribution valve and a feeder downstream of the post-combustion residue sampling port. The waste heat recovery tail gas treatment unit includes a tail gas heat exchanger, a dust-laden gas separator, a dry adsorption purifier, and an exhaust pipe connected in sequence. The solid phase outlet of the dust-laden gas separator is connected to the moving bed cooling collection chamber or the reburning return branch.

9. A method for controlling the low-temperature sintering of electrolytic aluminum carbon slag and the simultaneous separation of slag and gas, applied to the integrated combustion device for the low-temperature sintering of electrolytic aluminum carbon slag and the simultaneous separation of slag and gas as described in any one of claims 1 to 8, characterized in that, Includes the following steps: S1. The electrolytic aluminum carbon slag is crushed, screened, iron removed and homogenized in sequence to obtain the carbon slag material flow that enters the feeder; S2. The carbonaceous components, fluoride-containing salt phase content, aluminum-containing phase content, moisture content and particle size distribution of the char slag material are detected by the pre-combustion detection component. The centralized control unit establishes material section identification according to the feeding start time, feeding end time and feeding quality. S3. The centralized control unit determines the upper limit of low-temperature sintering temperature, upper limit of gas phase oxygen content, primary air volume, secondary air volume, gas auxiliary volume, reheat valve opening, waste heat recovery fan frequency and feed volume based on the carbonaceous component content, fluorine salt phase content, aluminum phase content, moisture content, particle size distribution and subsequent recovery process feed requirements of the same material section. S4. The flue gas discharged from the top rising exhaust channel enters the tail gas heat exchanger. The carbon slag material flow, primary air and secondary air exchange heat through the carbon slag preheating channel, primary air preheating channel and secondary air preheating channel respectively. S5. The feeder outputs the carbon slag flow to the tangential feed pipe according to the feed rate. The primary air carries the carbon slag flow tangentially into the cyclone furnace body along the cylindrical combustion separation cylinder. The secondary air enters the cylindrical combustion separation cylinder in the same cyclone direction as the primary air. The gas enters the front end of the primary air interface or the front end of the tangential feed pipe through the gas auxiliary interface. The carbonaceous components in the carbon slag flow are oxidized in the cyclone furnace body. The fluoride-containing salt phase and aluminum-containing phase enter the bottom discharge port along with the solid material through the bottom conical separation section. The flue gas is discharged through the top rising exhaust channel. S6. The solid material output from the bottom outlet enters the solid collection unit, and the flue gas discharged from the top rising exhaust channel enters the waste heat recovery tail gas treatment unit. S7. The centralized control unit writes the flue gas detection data, furnace temperature data and post-combustion residue detection data of the same material section into the material section identification table, and corrects the feed rate, primary air volume, secondary air volume, gas auxiliary volume, reheat valve opening and waste heat recovery fan frequency of the subsequent material sections.

10. The method for simultaneous separation and control of low-temperature sintering and slag gas separation of electrolytic aluminum carbon slag according to claim 9, characterized in that: In step S3, the upper limit of the low-temperature sintering temperature and the upper limit of the gas phase oxygen content are determined as follows: Pre-combustion small-sample heating tests were conducted on the same batch of char residue to obtain the residual carbonaceous component content, fluorine volatile concentration, fluorine salt phase retention amount, aluminum phase retention amount, and agglomeration ratio at each temperature point. The feed requirements for subsequent recycling processes are converted into the upper limit of residual carbonaceous components, the upper limit of fluorine-containing volatile concentration, the lower limit of fluorine-containing salt phase retention, the lower limit of aluminum-containing phase retention, and the upper limit of agglomeration ratio. Among all temperature points, the highest temperature that simultaneously satisfies the upper limit of residual carbonaceous components, the upper limit of fluorine-containing volatile concentration, the lower limit of fluorine-containing salt phase retention, the lower limit of aluminum-containing phase retention, and the upper limit of agglomeration ratio is determined as the upper limit of low-temperature sintering temperature. Under the upper limit of low-temperature sintering temperature, the highest gas phase oxygen content that simultaneously meets the upper limit of residual carbonaceous components, the upper limit of fluorine volatile concentration, the lower limit of fluorine salt phase retention, the lower limit of aluminum phase retention, and the upper limit of agglomeration ratio is determined as the upper limit of gas phase oxygen content. In step S7, when the content of residual carbonaceous components is higher than the upper limit of residual carbonaceous components, and the concentration of fluorine-containing volatiles is not higher than the upper limit of fluorine-containing volatiles concentration, the retention amount of fluorine-containing salt phase is not lower than the lower limit of fluorine-containing salt phase retention amount, the retention amount of aluminum-containing phase is not lower than the lower limit of aluminum-containing phase retention amount, and the agglomeration ratio is not higher than the upper limit of agglomeration ratio, the centralized control unit increases the secondary air volume, reduces the feed volume, or increases the frequency of the waste heat recovery fan, provided that the temperature does not exceed the upper limit of low-temperature sintering temperature and the upper limit of gas phase oxygen content. When the concentration of fluorine-containing volatiles is higher than the upper limit of fluorine-containing volatiles concentration, the retention amount of fluorine-containing salt phase is lower than the lower limit of fluorine-containing salt phase retention amount, the retention amount of aluminum-containing phase is lower than the lower limit of aluminum-containing phase retention amount, or the agglomeration ratio is higher than the upper limit of agglomeration ratio, the centralized control unit reduces the secondary air volume, reduces the gas auxiliary volume, reduces the flue gas flow rate entering the tail gas heat exchanger, or reduces the frequency of the waste heat recovery fan. When the solid material output from the solid collection unit does not meet the feeding requirements of the subsequent recycling process, the distribution valve switches to the reburning return branch. The solid material returns to the feeder through the reburning return branch and re-enters the cyclone furnace body according to the new material section marking.

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