Iron phosphate synthesis automatic control program production method

Abstract

The invention discloses an iron phosphate synthesis automatic control program production method which comprises the following steps: S1, automatically acquiring a formula list used by a synthesis kettle by a program, and calculating a preset value (SV) of an addition amount according to the concentration of raw materials; s2, automatically judging initial conditions by a program, and completing feeding of the ferrous sulfate solution; s3, automatically judging initial conditions by a program, and completing charging of the'mixed solution 'MAP solution; s4, the temperature of the synthesis kettle is obtained in real time through a program, whether the mixed liquid meets the hydrogen peroxide adding condition or not is judged, and hydrogen peroxide adding is completed after the condition is met; s5, automatically adding a'mixed solution 'to finish a synthetic reaction; s6, after detection is qualified, automatic synthesis is completed, and discharging is completed; s7, S8, automatically judging initial conditions by a program, and completing material re-pulping; and step S9, automatically judging initial conditions by a program, and completing heating aging and discharging of the materials. Through a sequential control program, misoperation is effectively avoided, and the production efficiency and the product quality stability are improved.

Description

Technical Field

[0001] The present application relates to the technical field of iron phosphate synthesis, and in particular to a method for producing an automated control program for iron phosphate synthesis. Background Art

[0002] Domestic fine chemicals, pharmaceuticals, lithium iron phosphate, petroleum refining ABS / rubber and other industries often use batch control formulas from well-known domestic and foreign system manufacturers for intermittent or continuous production control. Domestic iron phosphate and lithium iron phosphate often use Zhejiang SUPCON ECS700, VxBatch batch control, and Siemens PCS7 batch control for production control. In addition to the originally purchased DCS control systems from the system manufacturers, it is necessary to purchase the Batch control systems of the corresponding system manufacturers.

[0003] Taking the Zheda Zhongkong ECS700 system as an example, based on control points, the cost of purchasing a batch control system from the corresponding system manufacturer is approximately RMB 500,000 to 1 million, which increases production investment.

[0004] In the production process of some domestic iron phosphate and lithium iron phosphate, traditional manual operation is adopted, and DCS and Batch control are used. The synthesis, re-slurry and aging processes of the existing first-phase 100,000-ton iron phosphate unit are all intermittent production. The original design was single-loop control. There are 816 operation control points in the synthesis and aging chemical sections of the four production lines. Single-pot and single-batch operations are frequent, and the manual operation intensity is high. During the synthesis operation, the addition of raw materials such as ferrous sulfate, monoammonium phosphate, hydrogen peroxide, pure water, and phosphoric acid requires manual operation. There are many manual operation control points in the synthesis, and the process is prone to accidents such as excessive addition of materials, excessive temperature control, unstable aging time, and incorrect input of formula. Once an incorrect operation occurs, it will affect the quality and pass rate of the batch of products.

[0005] At the same time, the existing control methods cannot achieve full-load operation of multiple lines at the same time, which affects the improvement of production output value and energy conservation and consumption reduction rate.

[0006] The existing control methods result in high manual operation intensity, many and frequent operation steps, high error rate and low automatic control rate. For example, replacing the batch control equipment of Zhejiang Zhongkong Batch requires increasing the equipment procurement cost, which leads to increased production costs.

[0007] The information disclosed in the background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0008] In view of the above technical problems, the present application provides a method for producing an automated control program for the synthesis of iron phosphate. The method can be implemented on the basis of the DCS ECS700 system platform of Zhejiang University Central Control without the need to purchase the batch control function of Zhejiang University Central Control, and can achieve the effect of replacing the existing multi-point manual feeding, discharging and process condition control with sequential control production.

[0009] The present application provides a method for producing an automated control program for ferric phosphate synthesis, comprising the following steps:

[0010] Step S1: Obtain the formula, formula sheet, and formula number used in each production kettle in the two-step ferric phosphate production, and calculate the preset value (SV) of each raw material addition amount of the synthesis kettle, aging kettle, and reaction kettle through the formula calculation module according to the raw material concentration required for production;

[0011] Step S2: before adding materials, the program automatically determines the initial conditions and operation buttons. When the conditions are met, the formula calculation module is run to obtain the addition SV value of each raw material of the "ferrous sulfate solution" according to the input raw material concentration and single-pot target output, and then the addition of materials is started. During the addition process, the addition SV of each raw material is set to have the function of climbing and precise addition. After the addition is completed, stirring is started to obtain the "ferrous sulfate solution";

[0012] Step S3: Before MAP is added, the program automatically determines the initial conditions and operation buttons. When the conditions are met, the formula calculation module is run to obtain the SV value of the addition amount of the monoammonium phosphate solution in each mixed liquid tank according to the input MAP concentration and density, and then the monoammonium phosphate solution is added to the mixed liquid tank, and the agitator is turned on to obtain the "monoammonium phosphate finished product". During the addition of each raw material, the addition SV is set to have the function of climbing and precise feeding;

[0013] Before adding MAP, obtain and store the residual liquid in the mixed liquid tank of each raw material. During the adding process, make real-time judgments, automatically deduct, assign values ​​and calculate to ensure that the accumulated weight of MAP is consistent with the program-controlled set value.

[0014] Step S4: Determine whether the "mixed liquid" meets the initial conditions for adding hydrogen peroxide. If it meets the requirements of the process step, the hydrogen peroxide addition is performed in sequence, and the hydrogen peroxide addition SV is set to the ramp and precise addition functions until the addition is completed;

[0015] The “initial condition for adding hydrogen peroxide” is that all manual valves on site are in the open state, the instrument and automatic valve are debugged to be qualified, and the temperature of the synthesis kettle reaches 25-40℃;

[0016] Before adding hydrogen peroxide, obtain and store the residual liquid in the mixed liquid tank. During the adding process, automatically deduct, assign and calculate in real time to ensure that the cumulative weight of hydrogen peroxide added is consistent with the program control setting value.

[0017] Step S5: After the "mixed liquid" is prepared and before it is sent into the synthesis kettle, the temperature of the synthesis kettle is obtained in real time. After confirming that the synthesis kettle is heated to 25-40°C, the agitator is started in sequence, the "mixed liquid" feed valve is opened, and the "mixed liquid" delivery pump is started. The weight of the mixed liquid tank is obtained. When the weight is less than 355 kg, the "mixed liquid" delivery pump is stopped, the valve is closed to stop adding the "mixed liquid", and the ferrous ion content of the material in the kettle is sampled and analyzed. The reaction is normal or abnormal according to the presence or absence of ferrous ions. If the judgment result is that there are ferrous ions, hydrogen peroxide is added, and the reaction is recirculated to determine whether it is normal; if the judgment result is that there are no ferrous ions, the discharge conditions are met, and the discharge is sent to the next process;

[0018] Step S6: After confirming that the reaction liquid meets the discharge conditions, the reaction liquid is pumped until the liquid level in the synthesis reactor is less than 12%, then the external delivery is stopped, the water replenishment pump is started, and the residual solution in the pipeline is replaced. When the water replenishment reaches the liquid level of 15%, the water replenishment is stopped, and the discharge pump is started until the liquid level in the synthesis reactor is less than 11% again, and then the replacement is stopped and the discharge is ended;

[0019] Step S7: When the liquid level in the re-slurry tank is less than 13%, water is automatically added. When the liquid level meets the process requirements, water addition is stopped and stirring is started. After the re-slurry treatment conditions are met, the filter cake obtained by the primary plate and frame filtration is transported to the re-slurry tank through a belt unloader. After the re-slurry stirring timing is at least 30 minutes, water is added again. When the liquid level meets the process requirements again, the water inlet valve is closed, and after another 30 minutes of timing, the next step is entered;

[0020] Step S8: Obtaining a preset value of phosphoric acid addition according to the formula calculation module, adding phosphoric acid to the reslurry tank, and then entering the next process section;

[0021] Step S9: Perform temperature rise aging and crystal transformation. First, obtain and determine in real time whether the material level in the aging kettle is less than 10%. If so, add water to the aging kettle for the first time. When the accumulated water flow reaches the aging kettle water addition SV setting value, close the water inlet valve.

[0022] Determine whether the circulation conditions are met. If yes, start the circulation pump to circulate the materials in the kettle, and gradually increase the frequency conversion of the circulation pump to the set value;

[0023] The slurry in the re-slurry tank is introduced into the aging kettle. After the addition is completed and the timing reaches the process setting value, the program automatically heats up to the set temperature at the preset heating rate. After 30 minutes of timing, the heating steam valve is automatically closed at the preset frequency. The slurry is kept warm and then the process sampling is taken to confirm whether it meets the discharge conditions. If it meets the conditions, the material is discharged to the secondary plate and frame filtration for washing;

[0024] This method is used in the production of iron phosphate by Zhejiang SUPCON ECS700 DCS system.

[0025] Preferably, step S2 also includes the following steps:

[0026] Step S21: During the feeding process, the opening of the control valve on each material feeding pipeline is adjusted according to the cumulative amount of the feeding: when the cumulative amount of the feeding is 80-90% of the preset amount of the feeding, the opening of the control valve is reduced;

[0027] Step S22: After the addition is completed, the difference between the SV set addition amount and the actual addition cumulative amount is obtained as the addition difference. If the addition difference is within the allowable process error range, the batch of "ferrous sulfate finished product" is marked as qualified and the subsequent operation is continued;

[0028] Step S23: If the addition difference exceeds the allowable error range of the process, it is judged as abnormal. The system issues an abnormal addition amount prompt and alarm for the batch of "ferrous sulfate finished products", prompting the operator to check the actual addition amount of the batch of "ferrous sulfate finished products", make adjustments and then proceed to the next step.

[0029] Preferably, the feeding process of step S3 also includes the following operations:

[0030] Step S31: During the feeding process of each raw material, the opening of the control valve on each material feeding pipeline is adjusted according to the cumulative amount of the feeding. When the cumulative amount of the feeding is 80-90% of the preset amount of the feeding, the opening of the control valve is reduced;

[0031] Step S32: After the addition is completed, the difference between the SV set addition amount of each raw material and the actual addition cumulative amount is obtained. If the difference is within the allowable process error range, the batch of "monoammonium phosphate finished product" is marked as qualified and the subsequent operation is continued;

[0032] Step S33: If the difference exceeds the allowable error range of the process, it is determined to be abnormal, and the system issues an abnormal addition amount prompt and alarm to the batch of "monoammonium phosphate finished products", prompting the operator to manually discharge or add MAP solution.

[0033] Preferably, the feeding process of step S4 includes:

[0034] Step S41: During the feeding process, when the cumulative amount of hydrogen peroxide added reaches 90% of the preset value

[0035] When the valve is opened, gradually reduce the valve opening;

[0036] Step S42: After the addition is completed, the difference between the set amount of hydrogen peroxide SV added and the actual cumulative amount of added is obtained. If the difference is within the allowable error range of the process, it is marked as normal material for subsequent operations;

[0037] Step S43: If the difference exceeds the range, it is determined to be abnormal, and the system gives an abnormal addition amount prompt and an alarm, prompting the operator to manually add hydrogen peroxide.

[0038] Preferably, the repulping process in step S7 includes:

[0039] Step S71: when the liquid level in the re-slurry tank is less than 13% during the feeding process, water is automatically added. When the liquid level meets the process requirements, water addition is stopped and stirring is started until the re-slurry processing conditions are met;

[0040] Step S72: The filter cake obtained by the primary plate and frame filtration is conveyed to the re-slurry tank through a belt unloader. After the re-slurry stirring is automatically timed for at least 30 minutes, water is automatically replenished again. When the liquid level meets the process requirements again, the water inlet valve is closed. After another 30 minutes of timing, the next step is entered.

[0041] Preferably, the phosphoric acid addition process in step S8 includes: obtaining the difference between the phosphoric acid SV setting value and the cumulative amount of added material in real time, and if the difference is within the process allowable error range, performing subsequent operations;

[0042] If the addition difference exceeds the allowable error range, it is judged as abnormal, and an abnormal addition amount prompt and alarm are issued to prompt the operator to manually add phosphoric acid.

[0043] Preferably, the method further includes: during the heating process of step S10: obtaining the material temperature in the aging kettle in real time, and after the material addition is completed and the timing reaches the process setting value, the program automatically heats up to the set temperature at a preset heating rate, and automatically closes the heating steam valve at a preset frequency after timing for 30 minutes.

[0044] The beneficial effects of this application include:

[0045] 1) The automated control program production method for ferrous phosphate synthesis provided in the present application shortens the raw material preparation time to 40 minutes relative to the manual operation process of the two-step ferrous phosphate process through a two-step sequential control program, effectively improving production efficiency, and adding a new section program control program for the re-slurry tank to achieve automatic control and curing operation, and uniform dispersion of the process raw materials in the re-slurry, thereby improving the consistency and stability of process product indicators.

[0046] 2) The automated control program production method for the synthesis of iron phosphate provided in this application can reduce the labor intensity of process operations, reduce the rate of misoperation, and avoid situations such as bubbling and inconsistent water replenishment. A new program control program for the standby kettle section is added to solidify the standby kettle operating parameters, accurately add materials, unify the cycle time, heating rate, and aging time, improve the stability of process product indicators, optimize the phosphoric acid addition program for the standby kettle and re-slurry tank, change the phosphoric acid addition point, and improve the slurry dispersion effect to stabilize the process. The qualified rate of Fe and P indicators in the synthesis kettle slurry increased from 80.63% to 99.64%, which improved the stability of product indicators.

[0047] 3) The automated control program production method for ferric phosphate synthesis provided in the present application greatly improves production efficiency and output without increasing equipment investment. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 A diagram of a synthetic sequential control operation interface in at least one embodiment provided in this application;

[0049] Figure 2 A diagram of the repulping control operation interface in at least one embodiment provided in the present application;

[0050] Figure 3 A diagram of the sequential control operation interface of a standby kettle in at least one embodiment provided in the present application;

[0051] Figure 4 A two-step iron phosphate production flow chart applicable to the iron phosphate synthesis automation control program production method in at least one embodiment provided in the present application;

[0052] Figure 5 A flow chart of a control operation process in at least one embodiment provided in the present application; DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0054] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0055] The technical means that are not described in detail in this application and are not used to solve the technical problems of this application are all set according to the common knowledge in the field, and can be implemented in a variety of common knowledge settings.

[0056] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments, but the present invention is not limited in any way. Any changes or improvements made based on the teachings of the present invention fall within the protection scope of the present invention.

[0057] Example

[0058] Unless otherwise specified, the materials and instruments used in the following examples were obtained from commercial channels; the detection methods used were all existing methods unless otherwise specified.

[0059] In the following examples, SV refers to the preset target value of each process parameter; MAP refers to monoammonium phosphate or diammonium phosphate.

[0060] Example 1

[0061] See also Figures 1 to 5 , S1: Recipe system programming: The following functions are realized through the program:

[0062] 1. Recipe recording function, through the data acquisition module and data storage module, records the recipes, recipe sheets and recipe numbers used by each kettle at different times, and realizes the data entry, storage and assignment of the previous kettle recipe and the current kettle recipe; see the specific operation interface Figure 1 .

[0063] 2. Formula calculation function: According to the raw material concentration required for the batch production entered in the data storage module by the data acquisition module, the formula program formula calculates the amount of each raw material added to the synthesis kettle, aging kettle, and reaction kettle to achieve accurate feeding. The specific calculation formula used is calculated according to the commonly used method in this field, specifically based on the output and reaction equation.

[0064] 3. System prompt and error correction function, program writing and upper-level monitoring operation screen, intelligent selection of operation buttons, color change, conditional logic judgment, realization of operation process condition judgment, abnormal reminder and error correction function.

[0065] S2: "Ferrous Sulfate Solution" Batch Feed:

[0066] Before adding materials, the program automatically determines the initial conditions and operation buttons. When the conditions are met, press Figure 1 The process shown is to add materials for preparing "ferrous sulfate finished product". First, according to the concentration of the input raw materials and the target output of a single kettle, the formula program is run to obtain the SV value of ferrous sulfate addition. Then, the SV value of the addition of each raw material is executed in sequence, and the functions of ramping and precise addition are set. After the addition starts, the cumulative amount of ferrous sulfate solution added is obtained in real time. Specifically, the instantaneous flow rate and cumulative flow rate of each material addition are recorded. When the cumulative flow rate of addition is less than 85% of the SV value, the program automatically increases the valve opening to increase the instantaneous flow rate. When the cumulative flow rate of addition is greater than 85% of the SV value, the program automatically reduces the valve opening to reduce the instantaneous flow rate. When the flow rate reaches the SV set value, the addition is closed.

[0067] The conditions here refer to: all manual valves on site are in the open state, and the instruments and automatic valves are debugged and qualified.

[0068] During the feeding process, adjust the opening of the control valve on each material adding pipeline according to the cumulative amount of feeding. When the cumulative amount of feeding is 85% of the preset amount of feeding, reduce the opening of the control valve to achieve accurate feeding. After the feeding is completed, obtain the feeding difference between the SV set addition amount and the actual cumulative amount of feeding. If the feeding difference is within the allowable error range of the process, mark the batch of "ferrous sulfate finished product" as qualified and continue with subsequent operations;

[0069] If the difference in the amount of added materials exceeds the allowable error range of the process, it is judged as abnormal. The system will issue an abnormal addition reminder and alarm for the batch of "ferrous sulfate finished products", prompting the operator to actually measure the ferrous sulfate concentration of the batch of "ferrous sulfate finished products". If the amount of ferrous sulfate added is too high or too low, manual addition or reduction of the mixed liquid preparation amount is performed to avoid material waste and achieve the requirements of accurate feeding and stable control in the process. At the same time, the program has timing functions for each stage and abnormal pause functions to ensure the safe and continuous operation of the program under abnormal conditions of process equipment.

[0070] S3: Preparation of “mixed solution”:

[0071] Before MAP is added, the program automatically determines the initial conditions and operation buttons. When the conditions are met, press Figure 1 The requirements for the feeding steps of the process shown in the figure, the conditions here refer to: all manual valves on site are in the open state, and the instruments and automatic valves are debugged and qualified.

[0072] Sequential feeding:

[0073] Preparation of "mixed liquid": first, according to the input MAP concentration and density, run the formula program to obtain the SV value of the addition amount of monoammonium phosphate solution in each mixed liquid tank, then add monoammonium phosphate solution to the mixed liquid tank and turn on the agitator.

[0074] During the addition of each raw material, the feeding SV is set with the function of ramping and precise feeding. After the feeding starts, the cumulative amount of MAP solution added is obtained in real time. Specifically, it can be done by recording the instantaneous flow rate and cumulative flow rate of each material. When the cumulative flow rate of feeding is less than 85% of the SV value, the program automatically increases the valve opening to increase the instantaneous flow rate. When the cumulative flow rate of feeding is greater than 85% of the SV value, the program automatically reduces the valve opening to reduce the instantaneous flow rate. When the flow rate reaches the SV setting value, the feeding is closed.

[0075] The conditions here refer to: all manual valves on site are in the open state, and the instruments and automatic valves are debugged and qualified.

[0076] During the feeding process, adjust the opening of the control valve on each material adding pipeline according to the cumulative amount of feeding. When the cumulative amount of feeding is 85% of the preset amount of feeding, reduce the opening of the control valve to achieve accurate feeding. After the feeding is completed, obtain the feeding difference between the SV set amount of feeding and the actual cumulative amount of feeding. If the feeding difference is within the allowable error range of the process, mark the batch of "monoammonium phosphate finished product" as qualified and continue with subsequent operations;

[0077] If the difference exceeds the allowable error range of the process, it is judged as abnormal. The system will issue an abnormal addition amount prompt and alarm for the batch of "monoammonium phosphate finished products", prompting the operator to manually discharge or add MAP solution.

[0078] This method can timely detect abnormal addition amounts, avoid the production of unqualified synthetic slurry, and achieve the requirement of accurate feeding in the process. At the same time, the program has timing functions for each stage and abnormal pause functions to ensure the safe and continuous operation of the program under abnormal conditions of process equipment.

[0079] Difficulties in controlling the addition of MAP solution during the preparation of the "mixed solution":

[0080] 1. For the initial weight of the mixing tank and its deduction, before each addition, the program automatically obtains and stores the residual liquid base of the mixing tank (the weight of the material in the tank before any material is added). During the addition process, the program automatically deducts, assigns values ​​and calculates in real time to ensure that the MAP added cumulative weight is consistent with the program-controlled set value.

[0081] 2. In order to save batching time, the program structure was optimized and a new CASE program was added so that the batch feeding program control of ferrous sulfate solution and the MAP preparation program control program could run simultaneously.

[0082] S4: Programming of “mixed liquid” preparation:

[0083] The program automatically determines whether the "mixed liquid" meets the initial conditions for adding hydrogen peroxide (all manual valves on site are in the open state, the instrument and automatic valve are debugged to be qualified, and the temperature of the synthesis kettle reaches 25-40℃). When the conditions are met, the hydrogen peroxide addition is performed in sequence according to the requirements of the process addition steps. The hydrogen peroxide addition SV is set to climb and accurately add functions. During the process, when the cumulative amount of hydrogen peroxide added reaches 90% of the preset value, the valve opening is gradually reduced, and accurate addition is performed. After the addition is completed, the addition difference between the hydrogen peroxide SV set addition amount and the actual addition cumulative amount is obtained. If the addition difference is within the allowable error range of the process, it is marked as normal material for subsequent operations; if the addition difference exceeds the range, it is judged as abnormal, and the system gives an abnormal addition amount prompt and alarm;

[0084] The requirement of accurate feeding in the process is achieved. At the same time, the program has timing functions for each stage and abnormal pause functions to ensure safe and continuous operation of the program under abnormal conditions of process equipment.

[0085] Difficulties in the preparation of the “mixed solution”:

[0086] 1. For the initial weight of the mixing tank and its deduction, before each addition, the program automatically obtains and stores the residual liquid base in the mixing tank. During the addition process, the system automatically deducts, assigns values ​​and calculates in real time to ensure that the cumulative weight of hydrogen peroxide added is consistent with the program-controlled set value.

[0087] S5: Add the "mixed liquid" into the synthesis reactor:

[0088] After the "mixed liquid" is prepared and before it is sent into the synthesis kettle, the temperature of the synthesis kettle is obtained in real time. When the temperature of the synthesis kettle is <25°C, steam is introduced to preheat the synthesis kettle to 25-40°C; the agitator, the "ferrous sulfate finished product" feed valve, the "mixed liquid" feed valve, the "ferrous sulfate finished product" delivery pump, and the "mixed liquid" delivery pump are started in sequence. The weight of the "mixed liquid" delivered by the pump is obtained. When its weight is less than 355Kg, the valve is closed to stop adding the "mixed liquid", and the ferrous ion content of the material in the kettle is sampled and analyzed. The reaction of the "mixed liquid" is judged to be normal or abnormal based on the presence or absence of ferrous ions. If the judgment result is that there are ferrous ions, hydrogen peroxide is added and recycled to determine whether the reaction is normal. If the judgment result is that there are no ferrous ions, it is judged that the conditions for discharging are met and the material is discharged to the next process.

[0089] S6: Reaction solution delivery:

[0090] After confirming that the reaction liquid meets the discharge conditions, the program automatically starts the discharge pump to discharge the reaction liquid in the synthesis kettle until the liquid level in the synthesis kettle is less than 12%, then stops sending out, the program automatically starts the water replenishment pump to replace the residual solution in the pipeline, stops replenishing water when the liquid level reaches 15%, starts the discharge pump until the liquid level in the synthesis kettle is less than 11% again, stops replacing, and ends the discharge program.

[0091] The reaction liquid discharged from the synthesis reactor enters the primary plate and frame filtration, and the filtrate after washing enters the primary washing tank and is reused for the washing process many times, and then enters the mother liquor for unified water treatment; the filtered filter cake enters the re-slurry tank.

[0092] S7: Reslurry tank control:

[0093] Click on the re-slurry tank sequence control program to start, the system automatically determines that when the re-slurry tank liquid level is less than 13%, the program automatically replenishes water for the first time. When the liquid level meets the process requirements, close the water inlet valve, start the agitator, and after the re-slurry treatment conditions are met, the system automatically starts the belt conveyor to transport the filter cake obtained from the primary plate and frame filtration to the re-slurry tank through the belt unloader. Re-slurry stirring is timed for at least 30 minutes before replenishing water again. When the liquid level meets the process requirements again, close the water inlet valve, and time it for 30 minutes. When the conditions for external delivery are met, confirm that the reaction liquid is sent externally, the program automatically starts the delivery pump. When the liquid level is less than 15%, the external delivery is stopped, and the program automatically replenishes water and replaces the pipeline (start the pump again to pump out the water). When the liquid level is less than 13% again, the replacement is stopped and the program ends.

[0094] S8: Batch adding of phosphoric acid in the re-slurry tank: The SV setting value of phosphoric acid is calculated by the formula of the formulation program, and phosphoric acid is added according to the SV setting value. During the adding process, the difference between the SV setting value of phosphoric acid and the cumulative amount of added material is obtained in real time. If the difference is within the allowable error range of the process, subsequent operations are performed; if the addition difference exceeds the allowable error range, it is judged as abnormal, and the system gives a prompt and alarm for abnormal addition amount to prevent unqualified materials from entering the next process stage.

[0095] This method can achieve the requirement of accurate feeding in the process. At the same time, the program has timing function and abnormal pause function to ensure the safe and continuous operation of the program under abnormal conditions of process equipment.

[0096] S9: Temperature rise aging and crystal transformation process control:

[0097] Click on the temperature rise aging and crystal transfer program to start. The system will automatically determine that when the liquid level in the aging kettle is less than 10%, the program will automatically add water to the aging kettle for the first time. When the accumulated water flow reaches the aging kettle water addition SV setting value, the water inlet valve will be closed.

[0098] Confirm the circulation, and after judging that the circulation conditions are met, start the circulation pump to circulate the materials in the kettle, and at the same time, gradually increase the frequency of the pump to the set value. Open the feeding valve to feed the slurry in the slurry tank into the aging kettle. After the feeding is completed, close the feeding valve. After the timing reaches the process setting value, perform temperature rise confirmation. After the program automatically heats to the set temperature at the preset heating rate, the timing is 30 minutes, and the heating steam valve is automatically closed at the preset frequency. After the slurry is kept warm, process sampling is performed to confirm whether the discharge conditions are met.

[0099] S10: Heating, aging and crystal transformation for external delivery:

[0100] When the sampling test results meet the discharge requirements, the program is ready for external delivery. The program automatically starts the delivery pump to deliver the reaction liquid after confirming the reaction liquid delivery. When the liquid level in the aging kettle is less than 15%, delivery is stopped. The program automatically replenishes water and replaces the pipeline. When the liquid level is less than 15% again, replacement is stopped and the program ends.

[0101] This program solves the problems of frequent single-pot and single-batch operations, high intensity of manual operation, the need for manual operation for the addition of raw materials such as ferrous sulfate, monoammonium phosphate, hydrogen peroxide, pure water, phosphoric acid, etc. during the synthesis operation, many control points for manual synthesis operation, excessive addition of materials, excessive temperature control, unstable aging time, and misoperation in formula input, etc., which are prone to occur during the process. It avoids misoperation and accidents that affect product quality.

[0102] Example 2

[0103] The specific operation process includes the following steps:

[0104] Step S1: Participate Figure 1 , in such Figure 1 The operations are performed on the cross section shown as follows;

[0105] Click the synthesis sequence manual button, the button changes from manual to automatic and the button color changes from red to green. Click the R201D(1) synthesis program control start button, the sequence control starts automatically and the button color changes from gray to green. The sequence control program automatically determines that the sequence control conditions are met and then pops up the R201D(1) synthesis formula setting button. The button color changes from gray to green to display the current step and pops up the single kettle single batch and current formula input operation box. The process operator enters the concentration, density, and formula setting values ​​of each synthetic material.

[0106] The program automatically calculates whether the parameters of the input formula are correct. If the formula is entered incorrectly, the program prompts the error and the operator corrects the input value and repeats the above judgment until the input is vertically correct. Then the ferrous sulfate batch feed button and the MAP batch feed button turn green. After clicking each button, the sequential control program automatically performs ferrous sulfate and MAP program-controlled feed according to the sequence and conditions.

[0107] If an unexpected abnormal situation occurs during the feeding process, the process operator presses the ferrous phosphate pause button. After pressing the pause button, the sequential control program remains at the current step, and all valve switch status modes are released from the program-controlled automatic mode to the manual mode. The process operator performs relevant safety operations according to the on-site working conditions.

[0108] After the working condition returns to normal, the process personnel continues to click the pause button, and the text display continues the sequential control after the pause. The sequential control at the end of each medium addition will compare the cumulative amount of addition with the SV value, determine whether it is abnormal or normal, and provide prompts for operation.

[0109] According to Figure 4 For example, if you click the "mixed liquid" feeding button, the corresponding materials will be added and the corresponding parameters will be judged according to the above operations. When the judgment result meets the requirements, the operation is completed.

[0110] When the feeding is abnormal, it is necessary to add hydrogen peroxide, and the operator will be prompted to perform the adding operation.

[0111] When the program determines that the preparation process of the material, such as the mixed liquid, is completed, it will automatically jump to the reaction liquid delivery button and activate it in green. After the operator clicks the reaction liquid delivery button, the relevant reaction liquid delivery program execution action is performed, and the synthesis feeding and synthesis reaction process is completed and sent to the next process.

[0112] Step S2: Figure 2 Perform the following operations on the interface shown:

[0113] Click the manual button for re-pulping sequence control, the button changes from manual to automatic and the button color changes from red to green. Click the V0202E(1) re-pulping program control start button, the sequence control starts automatically and the button color changes from gray to green. After the sequence control program automatically determines that the sequence control conditions are met, it jumps to the re-pulping confirmation button. The button color changes from gray to green to display the current step. After re-pulping water replenishment and circulation, it jumps to the plate frame unloading satisfaction confirmation button. Click this button. After the program control unloads the plate frame material to the re-pulping tank and completes the relevant steps, it jumps to the 85 phosphoric acid batch feeding confirmation button. Click this button. The program control makes relevant condition judgments, enters the formula phosphoric acid SV value and displays the cumulative amount value. After the feeding is completed, the sequence control determines whether the feeding is normal or abnormal and prompts.

[0114] After the amount is added normally, it jumps to the confirm discharge button. Click this button and the program will execute the discharge steps. After completing the confirmation of discharge, it jumps to the pipeline replacement button. Click this button and the program will execute the corresponding steps and judgments. After completion, the re-pulping process ends and the material is sent to the next process.

[0115] Step S3: The specific operation interface is as follows Figure 3 Perform the following operations as shown:

[0116] Click the manual button of the standby kettle sequence control, the button changes from manual to automatic and the button color changes from red to green. Click the R0202C_04 standby kettle program control start button, the sequence control starts automatically and the button color changes from gray to green. After the sequence control program automatically determines that the sequence control conditions are met, it automatically jumps to the re-pulping water replenishment start button. Click this button, the button color changes from gray to green, and it shows that the current step is to replenish the standby kettle with water. Then jump to the confirmation cycle button. After clicking the confirmation cycle button, the program control completes the relevant steps and jumps to the confirmation feeding button. The process operator The preset time for sequential control feeding can be set on the screen, and the screen will display the actual running time of feeding. When the conditions are met, click the button to confirm that feeding is completed. The program control will perform relevant steps and condition judgments. After completion, the screen will prompt that feeding is completed and jump to the confirmation button for crystal transfer completion. Click this button, and the program control will perform relevant steps and executions. The screen will display the heating timing and crystal transfer timing time. After completion, click the discharge button, and the program control will judge the relevant discharge conditions. The program control will execute the relevant discharge steps and sequential control judgments, ending the aging, heating, crystal transfer and discharge process of the standby kettle, and sending the materials to the next process.

[0117] Comparative Example

[0118] The difference from Example 1 is that only the Zhejiang SUPCON ECS700 DCS system is used to produce iron phosphate, and manual control of material feeding and feeding in each link is adopted.

[0119] Raw material preparation time: The preparation time of Example 1 is shortened to 40 minutes relative to Comparative Example 1.

[0120] Fe and P content index of the slurry in the synthesis reactor: The qualified rate of the slurry obtained by the method of Example 1 was increased from 80.63% to 99.64%. The qualified index is that the Fe and P content in the slurry is less than 0.1%, which is considered to be qualified slurry.

[0121] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for producing an automated control program for ferric phosphate synthesis, characterized in that: The following steps are involved: Step S1: Obtain the formula, formula sheet, and formula number used in each production kettle in the two-step ferric phosphate production, and calculate the preset value (SV) of each raw material addition amount of the synthesis kettle, aging kettle, and reaction kettle through the formula calculation module according to the raw material concentration required for production; Step S2: Before adding materials, the program automatically determines the initial conditions and operation buttons. When the conditions are met, the formula calculation module is run to obtain the addition SV value of each raw material of the "ferrous sulfate solution" according to the input raw material concentration and single-pot target output, and then the addition of materials is started. During the addition process, the addition SV of each raw material is set to the function of climbing and precise addition. After the addition is completed, stirring is started to obtain the "ferrous sulfate solution"; Step S3: Before MAP is added, the program automatically determines the initial conditions and operation buttons. When the conditions are met, the formula calculation module is run to obtain the SV value of the addition amount of the monoammonium phosphate solution in each mixed liquid tank according to the input MAP concentration and density, and then the monoammonium phosphate solution is added to the mixed liquid tank, and the agitator is turned on to obtain the "monoammonium phosphate finished product". During the addition of each raw material, the feeding SV is set to have the function of climbing and precise feeding; Before adding MAP, obtain and store the residual liquid in the mixed liquid tank of each raw material. During the adding process, make real-time judgments, automatically deduct, assign values ​​and calculate to ensure that the accumulated weight of MAP is consistent with the program-controlled set value. Step S4: Determine whether the "mixed liquid" meets the initial conditions for adding hydrogen peroxide. If it meets the requirements of the process adding steps, the hydrogen peroxide adding is performed sequentially, and the hydrogen peroxide adding SV is set to the ramp and precise adding functions until the adding is completed; The "initial condition for adding hydrogen peroxide" is that all manual valves on site are in the open state, the instrument and automatic valve are debugged to be qualified, and the temperature of the synthesis kettle reaches 25-40℃; Before adding hydrogen peroxide, obtain and store the residual liquid in the mixed liquid tank. During the adding process, automatically deduct, assign and calculate in real time to ensure that the cumulative weight of hydrogen peroxide added is consistent with the program control setting value. Step S5: After the "mixed liquid" is prepared and before it is sent into the synthesis kettle, the temperature of the synthesis kettle is obtained in real time. After confirming that the synthesis kettle is heated to 25-40°C, the agitator is started in sequence, the "mixed liquid" feed valve is opened, and the "mixed liquid" delivery pump is started. The weight of the mixed liquid tank is obtained. When the weight is less than 355Kg, the "mixed liquid" delivery pump is stopped, the valve is closed to stop adding the "mixed liquid", and the ferrous ion content of the material in the kettle is sampled and analyzed. The reaction is normal or abnormal based on the presence or absence of ferrous ions. If the judgment result is that there are ferrous ions, hydrogen peroxide is added, and the reaction is recirculated to determine whether it is normal; if the judgment result is that there are no ferrous ions, the discharge conditions are met, and the discharge is sent to the next process; Step S6: After confirming that the reaction liquid meets the discharge conditions, the reaction liquid is pumped until the liquid level in the synthesis reactor is less than 12%, then the external delivery is stopped, the water replenishment pump is started, and the residual solution in the pipeline is replaced. When the water replenishment reaches the liquid level of 15%, the water replenishment is stopped, and the discharge pump is started until the liquid level in the synthesis reactor is less than 11% again, and then the replacement is stopped and the discharge is ended; Step S7: When the liquid level in the re-slurry tank is less than 13%, water is automatically added. When the liquid level meets the process requirements, water addition is stopped and stirring is started. After the re-slurry treatment conditions are met, the filter cake obtained by the primary plate and frame filtration is transported to the re-slurry tank through a belt unloader. After the re-slurry stirring timing is at least 30 minutes, water is added again. When the liquid level meets the process requirements again, the water inlet valve is closed, and after another 30 minutes of timing, the next step is entered; Step S8: Obtaining a preset value of phosphoric acid addition according to the formula calculation module, adding phosphoric acid to the reslurry tank, and then entering the next process section; Step S9: Perform temperature rise aging and crystal transformation. First, obtain and determine in real time whether the material level in the aging kettle is less than 10%. If so, add water to the aging kettle for the first time. When the accumulated water flow reaches the aging kettle water addition SV setting value, close the water inlet valve. Determine whether the circulation conditions are met. If yes, start the circulation pump to circulate the materials in the kettle, and gradually increase the frequency conversion of the circulation pump to the set value; The slurry in the re-slurry tank is introduced into the aging kettle. After the addition is completed and the timing reaches the process setting value, the program automatically heats up to the set temperature at the preset heating rate. After 30 minutes of timing, the heating steam valve is automatically closed at the preset frequency. The slurry is kept warm and then the process sampling is taken to confirm whether it meets the discharge conditions. If it meets the conditions, the material is discharged to the secondary plate and frame filtration for washing; This method is used in the production of iron phosphate by Zhejiang SUPCON ECS700 DCS system.

2. The method for producing an automated control program for ferric phosphate synthesis according to claim 1, characterized in that: Step S2 also includes the following steps: Step S21: During the feeding process, the opening of the control valve on each material adding pipeline is adjusted according to the cumulative amount of the feeding: when the cumulative amount of the feeding is 80-90% of the preset amount of the feeding, the opening of the control valve is reduced; Step S22: After the addition is completed, the difference between the SV set addition amount and the actual addition cumulative amount is obtained as the addition difference. If the addition difference is within the process allowable error range, the batch is marked. The "ferrous sulfate finished product" is qualified and continues with the subsequent operation; Step S23: If the addition difference exceeds the allowable error range of the process, it is determined to be abnormal. The system issues an abnormal addition amount prompt and alarm for the batch of "ferrous sulfate finished products", prompting the operator to check the actual addition amount of the batch of "ferrous sulfate finished products", make adjustments and then proceed to the next step.

3. The method for producing an automated control program for ferric phosphate synthesis according to claim 1, characterized in that: The feeding process of step S3 also includes the following operations: Step S31: During the feeding process of each raw material, the opening of the control valve on each material feeding pipeline is adjusted according to the cumulative amount of the feeding. When the cumulative amount of the feeding is 80-90% of the preset amount of the feeding, the opening of the control valve is reduced; Step S32: After the addition is completed, the difference between the SV set addition amount of each raw material and the actual addition cumulative amount is obtained. If the difference is within the allowable process error range, the batch of "monoammonium phosphate finished product" is marked as qualified and the subsequent operation is continued; Step S33: If the difference exceeds the allowable error range of the process, it is determined to be abnormal, and the system issues an abnormal addition amount prompt and alarm to the batch of "monoammonium phosphate finished products", prompting the operator to manually discharge or add MAP solution.

4. The method for producing an automated control program for ferric phosphate synthesis according to claim 1, characterized in that: The feeding process of step S4 includes: Step S41: During the feeding process, when the cumulative amount of hydrogen peroxide added reaches 90% of the preset value When the valve is opened, gradually reduce the valve opening; Step S42: After the addition is completed, the difference between the set amount of hydrogen peroxide SV added and the actual cumulative amount of added is obtained. If the difference is within the allowable error range of the process, it is marked as normal material for subsequent operations; Step S43: If the difference exceeds the range, it is determined to be abnormal, and the system gives an abnormal addition amount prompt and an alarm, prompting the operator to manually add hydrogen peroxide.

5. The method for producing an automated control program for ferric phosphate synthesis according to claim 1, characterized in that: The repulping process in step S7 includes: Step S71: when the liquid level in the re-slurry tank is less than 13% during the feeding process, water is automatically added. When the liquid level meets the process requirements, water addition is stopped and stirring is started until the re-slurry processing conditions are met; Step S72: The filter cake obtained by the primary plate and frame filtration is conveyed to the re-slurry tank through a belt unloader. After the re-slurry stirring is automatically timed for at least 30 minutes, water is automatically replenished again. When the liquid level meets the process requirements again, the water inlet valve is closed. After another 30 minutes of timing, the next step is entered.

6. The method for producing an automated control program for ferric phosphate synthesis according to claim 1, characterized in that: The phosphoric acid addition process in step S8 includes: obtaining the difference between the phosphoric acid SV setting value and the cumulative amount of added material in real time, and if the difference is within the process allowable error range, performing subsequent operations; If the addition difference exceeds the allowable error range, it is judged as abnormal, and an abnormal addition amount prompt and alarm are issued to prompt the operator to manually add phosphoric acid.

7. The method for producing an automated control program for ferric phosphate synthesis according to claim 1, characterized in that: The method also includes: during the heating process of step S10: obtaining the material temperature in the aging kettle in real time, and after the material addition is completed and the timing reaches the process setting value, the program automatically heats up to the set temperature at a preset heating rate, and automatically closes the heating steam valve at a preset frequency after timing for 30 minutes.

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