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CN-122006304-A - Sedimentation washing device and method for acid leaching of aluminum silicon oxide

CN122006304ACN 122006304 ACN122006304 ACN 122006304ACN-122006304-A

Abstract

The invention relates to the technical field of sedimentation and washing, in particular to a sedimentation washing device and method for acid leaching of aluminum silicon oxides. Each module works cooperatively, acquires slurry flow, solid concentration and conductivity data in real time, optimizes sedimentation parameters through a sedimentation dynamics model, controls stirring intensity and material flow direction, implements countercurrent washing logic, and stabilizes underflow concentration through material balance closed-loop control. The invention adopts three or more than three settling washing tanks which are connected in series, and a mixer is arranged at the top of each tank to realize the premixing of the washing liquid and the materials. Through the cooperative operation of the device, the separation efficiency of the soluble mixed salt and the fine particles is effectively improved, so that the purity of the aluminum silicon oxide serving as an electrolysis raw material is improved, the subsequent aluminum silicon alloy production is facilitated, and the scab of a roasting furnace is inhibited.

Inventors

  • SHANG DONGJIE
  • WU ENMIN
  • MENG FANYANG
  • LI LINFENG

Assignees

  • 鄂尔多斯市蒙泰铝业有限责任公司

Dates

Publication Date
20260512
Application Date
20260115

Claims (10)

  1. 1. The sedimentation washing device for acid leaching of aluminum silicon oxide is characterized by comprising a physical equipment device and a control device which is in communication connection with the physical equipment device; The physical equipment device comprises three or more stages of sedimentation washing tanks, overflow weir systems, variable-frequency speed-regulating stirrers, blenders, a feed pump, an underflow pump, a washing liquid supply unit and a chelating agent adding unit, wherein the three or more stages of sedimentation washing tanks are arranged in series, the overflow weir systems are arranged at the tops of all tank bodies, the variable-frequency speed-regulating stirrers are arranged in all tank bodies, the blenders are arranged at the tops of all stages of sedimentation washing tanks, the feed pump is connected with an acid leaching slurry inlet and the first stage of sedimentation washing tank, the underflow pump is connected with a discharge port at the bottom of each stage of tank body, the washing liquid supply unit is connected with the washing tank through a metering pump, and the chelating agent adding unit is provided with an EDTA storage tank and is connected into a main washing liquid pipeline through an injection pump; the control device includes: the working condition data acquisition module is used for acquiring the slurry flow of the outlet of the feed pump, the solid concentration of the underflow pipeline of the secondary sedimentation tank and the conductivity of the overflow port of the washing tank in real time; the sedimentation parameter optimization module is used for receiving the slurry flow and the solid concentration data acquired by the working condition data acquisition module, calculating the optimal sedimentation time through a sedimentation dynamics model, generating a primary sedimentation tank liquid level adjustment instruction when the solid concentration is lower than a set threshold value, and generating a secondary sedimentation tank stirrer rotating speed correction instruction when the conductivity abnormally fluctuates; The grading sedimentation control module is used for receiving the liquid level adjusting instruction and the rotating speed correcting instruction from the sedimentation parameter optimizing module, converting the liquid level adjusting instruction into a frequency adjusting signal for the underflow pump of the primary sedimentation tank so as to control the stay time of slurry in the primary sedimentation tank and synchronously adjust the opening of a feed valve of the secondary sedimentation tank; The washing process regulating and controlling module is used for receiving the conductivity data from the working condition data acquisition module, increasing the adding amount of the chelating agent adding unit according to a preset proportion and instructing the washing liquid supply unit to increase the flow when the conductivity is continuously higher, and implementing countercurrent washing logic by controlling the start-stop sequence of each grade of underflow pumps to ensure that the flow direction of the washing liquid is opposite to the flow direction of the solid material; The system cooperative execution module is used for receiving equipment state signals of the grading sedimentation control module and the washing process regulation and control module, synchronously delaying the starting time of the washing liquid supply unit when the sedimentation time is required to be prolonged by an instruction generated by the sedimentation parameter optimization module, automatically improving the stirring intensity of the secondary sedimentation tank when the chelating agent is added by the washing process regulation and control module, and stabilizing the underflow concentration in a target interval by material balance closed-loop control.
  2. 2. The sedimentation washing device for acid leaching of aluminum silicon oxides according to claim 1, wherein the operating mode data acquisition module comprises: the electromagnetic flowmeter monitors the slurry flow of the outlet of the feed pump and outputs a first signal; the microwave concentration meter is arranged on the underflow pipeline of the secondary sedimentation tank and is used for collecting microwave signals and converting the microwave signals into solid concentration data through analyzing attenuation degree; The four-electrode conductivity electrode and the temperature sensor are arranged at the overflow port of the washing tank, the conductivity electrode measures a conductivity value, the temperature sensor collects temperature data and compensates the conductivity value, and the compensated conductivity data is output; the first signal, the solid concentration data and the compensated conductivity data are transmitted to a central processing unit through an industrial Ethernet, and are filtered by adopting a sliding average algorithm, so that stable working condition data for subsequent module processing are obtained.
  3. 3. The sedimentation washing device for acid leaching of aluminium silicon oxides according to claim 2, wherein the sedimentation parameter optimization module is configured to: Receiving stable working condition data transmitted by the working condition data acquisition module, wherein the stable working condition data comprises slurry flow, solid concentration and conductivity; the sedimentation dynamics model is based on Kynch theory, the received real-time slurry flow and historical concentration data are substituted into the model, and the optimal sedimentation time is obtained through iterative calculation; when the solid concentration data is continuously lower than a set threshold value, triggering a PID algorithm aiming at improving the underflow concentration, and dynamically calculating and generating a primary settling tank liquid level regulating instruction; When the conductivity data is subjected to step change, a frequency spectrum analysis program is started to identify abnormal frequency components, if the abnormal frequency components are judged to be caused by abnormal solid suspension, a preset expert database is called to match the optimal rotation speed correction value, and a rotation speed correction instruction of the secondary sedimentation tank stirrer is generated.
  4. 4. A sedimentation washing device for acid leaching of aluminum silicon oxides according to claim 3, wherein a liquid level adjustment instruction and a rotation speed correction instruction from the sedimentation parameter optimization module are received; The hierarchical sedimentation control module compares the liquid level adjusting instruction with a preset liquid level value to obtain liquid level deviation, and converts the liquid level deviation into a frequency adjusting signal of the primary sedimentation tank underflow pump by adopting a fuzzy control algorithm; meanwhile, the hierarchical sedimentation control module reversely pushes the opening correction coefficient of the feeding valve of the secondary sedimentation tank according to a material balance equation by the frequency adjusting signal, and synchronously adjusts the opening of the feeding valve; and based on the running state signal and the solid content data of the underflow pump, the rotating speed of the variable-frequency speed-regulating stirrer is properly increased when the running of the underflow pump is detected, and the variable-frequency speed-regulating stirrer is switched to a low-speed mode after the underflow pump is stopped.
  5. 5. The sedimentation washing device for acid leaching of aluminum silicon oxides of claim 4, wherein the washing process control module is configured to: continuously receiving conductivity data from the working condition data acquisition module; When the conductivity reading exceeds the threshold value, inquiring a prestored conductivity-impurity concentration mapping relation table, adopting a gradient lifting algorithm to predict impurity removal efficiency, dynamically calculating the increment proportion of the chelating agent based on a prediction result, then instructing the chelating agent adding unit to increase the adding amount proportionally, and instructing the washing liquid supply unit to increase the flow; for countercurrent washing, the washing process regulating and controlling module programs and sets the start-stop sequence of each stage of underflow pump through a built-in time sequence controller so as to enable the flow direction of washing liquid to be opposite to the flow direction of solid materials; Meanwhile, the washing process regulating and controlling module controls the washing liquid supply unit to carry out intermittent supply, monitors the liquid level of the washing tank, and triggers to stop single washing when the liquid level reaches a peak value.
  6. 6. The sedimentation washing device for acid leaching of aluminium silicon oxides according to claim 5, wherein the system co-execution module is configured to: receiving equipment state signals sent by the hierarchical sedimentation control module and the washing process regulation and control module; When the instruction generated by the sedimentation parameter optimization module requires to prolong the sedimentation time, the system collaborative execution module searches the current state of the washing liquid supply unit and generates a delayed starting instruction so as to synchronize the starting time of the washing liquid supply unit with a sedimentation completion signal; When the adding amount of the chelating agent is increased by the washing process regulating and controlling module, the system cooperative execution module calls a material diffusion model, calculates required stirring intensity according to the adding amount and sends a rotating speed lifting instruction to a variable-frequency speed-regulating stirrer of the secondary sedimentation tank; the system cooperative execution module also adopts a model predictive control algorithm, takes the underflow concentration as a target variable, calculates and outputs an optimization instruction for the material distribution proportion among all stages of tanks in real time.
  7. 7. The sedimentation washing device for acid leaching of aluminum silicon oxides according to claim 6, wherein the sedimentation parameter optimization module receives stable working condition data processed by the working condition data acquisition module; The sedimentation parameter optimization module calculates the optimal sedimentation time through a sedimentation dynamics model by utilizing the stable working condition data, and generates a liquid level adjustment instruction to be sent to the hierarchical sedimentation control module; The hierarchical sedimentation control module executes the liquid level adjustment instruction to adjust pump frequency and valve position, and the adjusted working condition is used as a feeding condition of the washing process adjustment module; The washing process regulation and control module washes under the feeding condition, the generated overflow liquid conductivity data is collected by the working condition data collection module and fed back to the sedimentation parameter optimization module, and the sedimentation parameter optimization module corrects the rotating speed parameter by utilizing the conductivity data to form closed loop optimization.
  8. 8. The sedimentation washing device for acid leaching of aluminum silicon oxides according to claim 7, wherein the staged sedimentation control module processes a liquid level adjustment instruction by a fuzzy control algorithm and controls the variable frequency speed regulating stirrer by a bimodal strategy; the hierarchical sedimentation control module outputs a regulating signal for pump frequency and valve position by executing the liquid level regulating instruction, and the regulating signal acts on an underflow state generated after the physical equipment device and is used as an input condition of the washing process regulating and controlling module; The washing process regulation and control module receives signals representing the underflow state and processes the signals by using a gradient lifting algorithm to calculate a chelating agent increment instruction; The system collaborative execution module receives the chelating agent increment instruction, generates a corresponding stirring intensity lifting instruction and sends the stirring intensity lifting instruction to the grading sedimentation control module, and the grading sedimentation control module adjusts the operation parameters of the variable-frequency speed-regulating stirrer according to the stirring intensity lifting instruction.
  9. 9. The sedimentation washing device for acid leaching of aluminum silicon oxide according to claim 8, wherein the time sequence controller in the washing process control module controls the sequential action of each stage of underflow pumps by outputting a countercurrent washing start-stop signal; The system cooperates with a model predictive control algorithm in an execution module, receives a countercurrent washing start-stop signal generated by the time sequence controller, and takes the signal as input of a periodic material flow fluctuation model; the model prediction control algorithm outputs a material distribution optimization instruction to the hierarchical sedimentation control module based on the fluctuation model; The hierarchical sedimentation control module executes the material distribution optimizing instruction, and the generated working condition change is fed back to the washing process regulating and controlling module; the system is used for cooperatively executing the module to receive the intermittent supply signal and generate a pre-adjusting instruction for a preceding sedimentation procedure according to the intermittent supply signal.
  10. 10. A sedimentation washing method for acid leaching of aluminum silicon oxide, applied to the sedimentation washing device for acid leaching of aluminum silicon oxide according to any one of claims 1 to 9, characterized by comprising: Step 1, collecting slurry flow at an outlet of a feed pump, solid concentration of an underflow pipeline of a secondary sedimentation tank and conductivity of an overflow port of a washing tank in real time; Step 2, receiving the slurry flow and the solid concentration data, and calculating the optimal sedimentation time through a sedimentation dynamics model, wherein when the solid concentration is lower than a set threshold value, a primary sedimentation tank liquid level regulating instruction is generated, and when the conductivity abnormally fluctuates, a secondary sedimentation tank stirrer rotating speed correcting instruction is generated; Step 3, receiving the liquid level regulating instruction and the rotating speed correcting instruction, converting the liquid level regulating instruction into a frequency regulating signal for an underflow pump of a primary sedimentation tank so as to control the residence time of slurry in the primary sedimentation tank and synchronously adjust the opening of a feed valve of a secondary sedimentation tank; Step 4, receiving the conductivity data, increasing the adding amount of the chelating agent adding unit according to a preset proportion when the conductivity is continuously higher, and instructing the washing liquid supply unit to increase the flow rate; and 5, receiving equipment state signals generated in the step 3 and the step 4, synchronously delaying the starting time of the washing liquid supply unit when the instructions generated in the step 2 require to prolong the sedimentation time, automatically improving the stirring strength of the secondary sedimentation tank when the chelating agent is added in the step 4, and stabilizing the concentration of the bottom flow in a target zone through material balance closed-loop control.

Description

Sedimentation washing device and method for acid leaching of aluminum silicon oxide Technical Field The invention relates to the technical field of sedimentation and washing, in particular to a sedimentation washing device and method for aluminum silicon oxide prepared by an acid leaching process. Background The aluminum silicon oxide is used as an important raw material for producing aluminum silicon alloy, and the impurity content of the aluminum silicon oxide can have a significant influence on the performance of the aluminum silicon alloy. The aluminum silicon oxide after acid leaching impurity removal treatment needs to be sufficiently washed to remove dissolved impurity salt, so that the quality standard of the aluminum silicon oxide is achieved. The slurry formed by mixing the acid leached aluminum silicon oxide and the washing water needs to be subjected to efficient liquid-solid separation and purification, and sedimentation washing is a key unit operation for achieving the aim. The basic principle of sedimentation washing is that the density difference between solid particles and solution is utilized, the solid particles are settled to form concentrated underflow under the action of gravity or centrifugal force, and clean washing water is fully contacted with the underflow and the impurity-containing mother liquor entrained in the underflow is replaced in a multistage countercurrent washing mode. Each stage of washing includes mixing, settling and overflow separation steps with the aim of gradually reducing the content of soluble impurities in the solid product while increasing the recovery of the useful components. The addition of the flocculant can promote the agglomeration of fine particles, accelerate the sedimentation process and improve the clarity of supernatant. Finally, the fully washed solid residue is discharged out of the system, and the recovered solution is returned to the process flow or treated according to the components, and the efficiency of the whole process directly influences the resource utilization rate and the stability of the subsequent process. The existing sedimentation washing for the aluminum silicon oxide after acid leaching has the technical pain points that the concentration of soluble hetero salts such as sodium salt and calcium salt in the acid leaching aluminum silicon oxide slurry is high, and the existing sedimentation washing process contains a large amount of fine particles, so that impurities can not be thoroughly separated due to insufficient washing stage number and insufficient solid-liquid mixing, the sedimentation separation unit is not designed, for example, the sedimentation time is too short or the stirring intensity is not proper, solid particles are re-suspended, the sedimentation of the impurities is insufficient, and meanwhile, the formula or the washing mode of the washing liquid are not optimized, for example, the chelating agent is lacked or the counter-current washing is performed, so that the impurity removal efficiency is reduced. For example, in the pretreatment of the raw material, sodium salts and calcium salts which are not completely separated enter a roasting process along with the material, low-melting-point compounds are formed at high temperature, and are deposited on the furnace wall to cause scab, so that the purity of the aluminum silicon oxide raw material is affected, the quality of the subsequent alloy is further affected, and the production continuity is interrupted. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a sedimentation washing device and a method for acid leaching aluminum silicon oxide, which solve the technical problems of low purity, high impurity content and serious scab of a roasting furnace of a final aluminum oxide product caused by incomplete separation of soluble impurity salts (such as sodium and calcium salts) and fine particles in acid leaching liquid. In order to solve the technical problems, the invention comprises the following specific contents: in a first aspect, the invention provides a sedimentation washing device for acid leaching of aluminum silicon oxides, comprising a physical equipment device and a control device in communication connection with the physical equipment device; The physical equipment device comprises three or more stages of sedimentation washing tanks, overflow weir systems, variable-frequency speed-regulating stirrers, mixers, a feed pump, an underflow pump, an overflow pump, a washing liquid supply unit and a chelating agent adding unit, wherein the three or more stages of sedimentation washing tanks are arranged in series, the overflow weir systems are arranged at the tops of all tank bodies, the variable-frequency speed-regulating stirrers are arranged in all tank bodies, the mixers are arranged at the tops of all stages of sedimentation washing tanks and are used for introducing washing liquid and flocculating agents and premixing