Phosphogypsum harmless intelligent treatment system

Abstract

A phosphogypsum harmless intelligent treatment system comprises a stirring tank, a first electric valve, a buffer tank, a slurry pump and a plate-and-frame filter press which are sequentially connected through pipelines, a belt conveyor is arranged below the plate-and-frame filter press, and the upper end of the stirring tank is communicated with a washing water source, a phosphogypsum filling part, a pour point depressant adding device and a fluorine removal agent adding device through pipelines. A phosphorus detector and a fluorine monitor are installed on the stirring tank, a weighing sensor is arranged between a tank body of the stirring tank and the support, a second electric valve is installed on a pipeline through which the washing water source is communicated with the stirring tank, the system further comprises a PLC, and the weighing sensor, the phosphorus detector and the fluorine monitor are connected with the input end of the PLC. The phosphogypsum harmless treatment device can effectively remove phosphorus, fluorine and other harmful ingredients in phosphogypsum, achieves harmless treatment of phosphogypsum through intelligent control and multi-stage treatment, has the advantages of being high in treatment efficiency, good in stability, easy and convenient to operate and the like, and can be widely applied to the phosphorus chemical industry.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of phosphogypsum harmless intelligent processing system. BACKGROUND

[0002] Phosphogypsum is a kind of waste residue generated in the production process of phosphate fertilizer, which contains harmful components such as phosphorus, fluorine and heavy metals. If it is directly discharged, it will cause serious pollution to environmental elements such as soil and water, leading to a series of environmental problems such as ecological system destruction and water resource shortage. At present, the treatment of phosphogypsum mainly faces the following challenges: the content of phosphorus and fluorine does not meet the standard, which limits its resource utilization; the treatment process is not intelligent enough, making it difficult to accurately control the amount of reagent addition and treatment effect; there is a lack of comprehensive treatment of waste gas and wastewater, which is easy to cause secondary pollution. Therefore, it is of great significance to develop a system that can efficiently and intelligently treat phosphogypsum to meet the harmless standard and realize resource utilization. SUMMARY

[0003] The purpose of the utility model is to provide a kind of phosphogypsum harmless intelligent processing system, for solving the problem of phosphorus, fluorine and heavy metals and other harmful components in phosphogypsum being difficult to remove efficiently, leading to leaching toxicity exceeding the standard, and traditional process lacking in intelligence, causing reagent waste.

[0004] To solve the above problems, the technical scheme of the utility model is as follows:

[0005] A kind of phosphogypsum harmless intelligent processing system, comprising stirring tank, first electric valve, buffer tank, slurry pump and plate and frame filter press connected by pipeline in sequence, belt conveyor is arranged below plate and frame filter press, the upper end of stirring tank is communicated with washing water source, phosphogypsum adding part, coagulant additive device and fluorine removal agent adding device through pipeline, phosphorus detector and fluorine monitor are installed on stirring tank, weighing sensor is arranged between stirring tank body and support, second electric valve is installed on the pipeline connecting stirring tank and washing water source, and the system further comprises PLC controller, the input end of PLC controller is connected with weighing sensor, phosphorus detector and fluorine monitor, and PLC controller controls first electric valve, second electric valve, phosphogypsum adding part, coagulant additive device and fluorine removal agent adding device.

[0006] Further, it further comprises chelating agent adding device communicated with stirring tank, heavy metal sensor and PH sensor are installed on stirring tank, the input end of heavy metal sensor and PH sensor is connected with PLC controller, and PLC controller controls chelating agent adding device.

[0007] Further, the stirrer in stirring tank is magnetic stirrer, and magnetic field generator is arranged on the inner wall of stirring tank.

[0008] Further, the magnetic field strength of the magnetic field generator can be adjusted to 0.5-2T.

[0009] Further, a jacket is arranged outside the stirring tank.

[0010] Further, the system further comprises a waste gas treatment system, the waste gas treatment system comprising an activated carbon adsorption tower, an alkali washing spray tower and a catalytic oxidation reactor connected in sequence through pipelines, and the activated carbon adsorption tower being connected with the stirring tank and the buffer tank through pipelines.

[0011] Further, the system further comprises a waste water pool, and the waste water pool being connected with the plate-and-frame filter press.

[0012] The system can effectively solve the technical problems in the treatment of phosphogypsum slurry through intelligent control and multi-stage treatment, and can realize efficient removal of harmful components such as phosphorus and fluorine in the phosphogypsum, so that the phosphogypsum reaches the harmless standard and meets the environmental protection requirements. Meanwhile, through intelligent and automatic control of the PLC controller, the addition amount of reagent and the treatment process can be accurately controlled, and the treatment efficiency and stability are improved, and the manual operation strength and error are reduced. In addition, the waste gas treatment system and the waste water pool provided by the system can comprehensively treat the waste gas and waste water generated in the treatment process, avoid secondary pollution, and realize green production. The system can be widely applied to the phosphorus chemical industry, and is especially suitable for treating the phosphogypsum slurry generated in the production process of phosphate fertilizer, and has important significance for promoting the sustainable development of the phosphorus chemical industry and protecting the environment. BRIEF DESCRIPTION OF DRAWINGS

[0013] The utility model will be further described in connection with the drawings:

[0014] Figure 1 is the structural schematic view of the utility model,

[0015] Figure 2 is the connection relation schematic view between each electric device of the utility model.

[0016] In the drawing: phosphogypsum slurry tank 1, mud pump 2, washing water source 3, second electric valve 4, stirring tank 5, magnetic stirrer 6, activated carbon adsorption tower 7, alkali washing spray tower 8, catalytic oxidation reactor 9, pour point depressant adding device 10, fluorine removal agent adding device 11, chelating agent adding device 12, plate-and-frame filter press 13, belt conveyor 14, buffer tank 15, slurry pump 16, weighing sensor 17, phosphorus detector 18, fluorine monitor 19, first electric valve 20, magnetic generator 21, heavy metal sensor 22, PH sensor 23, support 24, touch screen 25. DETAILED DESCRIPTION

[0017] Clearly, the described embodiments are merely a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0018] The phosphogypsum harmless intelligent treatment system comprises a stirring tank 5, a first electric valve 20, a buffer tank 15, a slurry pump 16 and a plate-and-frame filter press 13 which are sequentially connected through pipelines, a belt conveyor 14 is arranged below the plate-and-frame filter press 13, the upper end of the stirring tank 5 is communicated with a washing water source 3, a phosphogypsum adding part, a pour point depressant adding device 10 and a defluorination agent adding device 11 through pipelines, a phosphorus detector 18 and a fluorine monitor 19 are arranged on the stirring tank 5, a weighing sensor 17 is arranged between the stirring tank 5 and a support 24, a second electric valve 4 is arranged on the pipeline communicating the stirring tank 5 with the washing water source 3, and the system further comprises a PLC controller, the weighing sensor 17, the phosphorus detector 18 and the fluorine monitor 19 are connected with the input end of the PLC controller, and the PLC controller controls the first electric valve 20, the second electric valve 4, the phosphogypsum adding part, the pour point depressant adding device and the defluorination agent adding device 11.

[0019] The phosphogypsum adding part comprises a phosphogypsum slurry tank 1, a mud pump 2 is arranged in the slurry tank 1, the mud pump 2 is communicated with the stirring tank 5 through a pipeline, the mud pump 2 is connected with the output end of the PLC controller, and the start and stop of the mud pump 2 are controlled by the PLC controller, so that the adding amount of the phosphogypsum added into the stirring tank 5 is controlled, and the phosphogypsum slurry produced in the workshop is sent into the slurry tank 1.

[0020] The pour point depressant adding device 10 and the defluorination agent adding device 11 have the same structure as the following chelating agent adding device 12, and the structure of the pour point depressant adding device 10 refers to the patent “CN221714061U, a full-automatic dosing integrated device for phosphorus removal agent”, the dosing integrated device comprises a storage tank, a mixing cylinder and a feeding pump, the feeding pump is connected with the output end of the PLC controller, and the start and stop of the feeding pump are controlled by the PLC controller, so that the pour point depressant adding device 10 is controlled.

[0021] The working process of the present application is as follows:

[0022] S1. Phosphogypsum slurry conveying:

[0023] The mud pump 2 sends the phosphogypsum slurry in the slurry tank 1 into the stirring tank 5. In the conveying process, the adding amount of the phosphogypsum slurry is detected in real time by the weighing sensor 17, and after the phosphogypsum slurry reaches the preset weight is detected, the PLC controller controls the mud pump 2 in the phosphogypsum slurry tank 1 to stop.

[0024] S2. Preliminary stirring and dilution:

[0025] After the phosphogypsum slurry enters the stirring tank 5, the stirrer in the stirring tank 5 is started to preliminarily stir the slurry, so that the phosphogypsum particles are uniformly dispersed in the liquid to avoid caking or precipitation. Then the PLC controller controls the second electric valve 4 to open, and the washing water source 3 injects an appropriate amount of washing water (such as tap water or NaOH solution) into the stirring tank 5, and the washing water dilutes the phosphogypsum slurry. The slurry concentration after dilution is suitable for the subsequent chemical treatment process, which is beneficial to improve the contact effect and reaction rate of the reagent and phosphogypsum.

[0026] S3. Intelligent addition of a coagulant and a fluorine removal agent:

[0027] The PLC controller controls the operation of the coagulant adding device 10 and the fluorine removal agent adding device 11. The coagulant and the fluorine removal agent are added to the phosphogypsum slurry in the stirring tank 5. The role of the coagulant is to reduce the viscosity of the phosphogypsum slurry and improve its fluidity, which is beneficial to subsequent transportation and processing; the fluorine removal agent is specially used to remove fluorine components in the phosphogypsum to reduce the pollution of fluorine to the environment. The coagulant adding device 10 used is polyacrylamide (PAM), which reduces the viscosity of the slurry and promotes particle flocculation. The fluorine removal agent used is calcium chloride (CaCl2), which reacts with fluoride ions to generate calcium fluoride precipitate (CaF2), and the chemical equation is: Ca 2+ +2F - →CaF2↓.

[0028] S4. Real-time monitoring and automatic regulation:

[0029] During the stirring process, the phosphorus detector 18 and the fluorine monitor 19 installed on the stirring tank 5 monitor the content of phosphorus and fluorine in the slurry in real time. These monitoring instruments transmit the detected data to the PLC controller in real time. After receiving these data, the PLC controller automatically starts and stops the addition of the coagulant and the fluorine removal agent according to the monitoring results. For example: if the content of phosphorus or fluorine is higher than the set value, the PLC controller continues to increase the addition of the corresponding reagent; otherwise, the addition is stopped. This real-time monitoring and automatic regulation mechanism ensures the accuracy of reagent addition and improves the effect and efficiency of phosphogypsum treatment.

[0030] S5. Transportation of the treated slurry:

[0031] After the phosphogypsum slurry is fully reacted and mixed in the agitator tank 5, the first electric valve 20 is opened, and the slurry then flows into the buffer tank 15, while the weighing sensor 17 detects the weight of the agitator tank 5. After detecting that the agitator tank 5 is empty, the PLC controller controls the first electric valve 20 to be closed, and then the slurry processing is poured into the agitator tank 5 again. The slurry in the buffer tank 15 is temporarily stored in the buffer tank 15, ready for subsequent transportation.

[0032] S6. Slurry pump 16 transports and plate-and-frame filter press 13 processes

[0033] The phosphogypsum slurry in the buffer tank 15 is pressurized by the slurry pump 16 and transported to the plate-and-frame filter press 13. In the plate-and-frame filter press 13, the phosphogypsum slurry is separated into solid and liquid under high pressure. The solid part (i.e., the treated phosphogypsum) is intercepted by the filter plate and filter cloth of the filter press, forming a filter cake, which is sent to the stockpile by the belt conveyor 14 or discharged to the engineering vehicle for direct use; the liquid part is sent to the workshop for repeated use, completing the separation process.

[0034] Further, a chelating agent adding device 12 is further included in communication with the agitator tank 5, and a heavy metal sensor 22 and a PH sensor 23 are installed on the agitator tank 5, wherein the heavy metal sensor 22 and the PH sensor 23 are connected to the input end of the PLC controller, and the PLC controller controls the chelating agent adding device 12.

[0035] The heavy metal sensor 22 monitors the concentration of heavy metal ions in the phosphogypsum slurry in real time and feeds back the data to the PLC controller. The PLC controller dynamically adjusts the dosage of the chelating agent adding device 12 according to the concentration of heavy metal ions. In practice, sodium diethyl dithiocarbamate (DDTC) is added to the agitator tank 5. DDTC reacts with heavy metal ions (such as Pb 2+ , Cd 2+ , etc.) to form stable complexes, avoiding leaching of heavy metal ions in the subsequent process. Taking lead ions as an example, the reaction equation is: Pb 2+ + 2DDTC - → Pb (DDTC)2↓.

[0036] On the other hand, the PH sensor 23 continuously monitors the acidity and alkalinity of the phosphogypsum slurry and transmits the data to the PLC controller. According to the monitoring results, the PLC controller controls the flow of washing water or adds alkaline reagents (such as NaOH) to stabilize the PH value of the slurry between 6.5-8.5, providing the best reaction conditions for the precipitation reaction and the chelation reaction.

[0037] Further, the stirrer in the stirring tank 5 is a magnetic stirrer 6, and a magnetic field generator 21 is arranged in the stirring tank 5. The magnetic stirring drives the stirring rod through a rotating magnetic field, so that the uniformity of the slurry is improved, and the reaction time is shortened under the cooperation of the magnetic field generator 21, the slurry flow is strengthened, and the growth of calcium fluoride crystals is promoted.

[0038] Further, the magnetic field strength of the magnetic stirrer 6 can be adjusted to 0.5-2T. The 0.5-2T magnetic field improves the reaction rate constant of DDTC and heavy metal ions.

[0039] Further, a jacket is arranged outside the stirring tank 5. During use, hot water at 40-60°C is continuously fed into the jacket, and the hot water exchanges heat with the phosphogypsum slurry in the stirring tank 5 through the inner wall of the jacket, so that the temperature of the slurry is maintained at about 50°C. After the temperature rises, the mass transfer is strengthened by the magnetic field, the dispersing efficiency of the reagent is improved, the growth of calcium fluoride crystals is promoted, and the entrainment of fine particles is reduced.

[0040] Further, it also includes a waste gas treatment system, which includes an activated carbon adsorption tower 7, an alkali washing spray tower 8 and a catalytic oxidation reactor 9 connected in sequence through pipelines, and the activated carbon adsorption tower 7 is connected with the stirring tank 5 and the buffer tank 15 through pipelines. During the treatment of phosphogypsum, especially in equipment such as the stirring tank 5 and the buffer tank 15, a certain amount of waste gas will be generated. These waste gases are collected and transported to the waste gas treatment system through pipelines.

[0041] The waste gas treatment process is as follows:

[0042] S1, the waste gas first enters the activated carbon adsorption tower 7. The activated carbon has a large specific surface area and a rich pore structure, which can effectively adsorb organic matter and part of volatile pollutants in the waste gas, reducing the VOCs content in the waste gas.

[0043] S2, the waste gas after activated carbon adsorption enters the alkali washing spray tower 8. In the alkali washing spray tower 8, NaOH solution is uniformly sprayed in the waste gas through the spraying device, and neutralization reaction occurs with HF in the waste gas, which is converted into harmless salt and water, and the reaction equation is: HF + NaOH→NaF + H2O.

[0044] S3, the waste gas after alkali washing enters the catalytic oxidation reactor 9. Under the action of noble metal catalyst at a high temperature of 200-300°C, the residual organic matter in the waste gas is oxidized and decomposed, and is converted into harmless substances such as carbon dioxide and water. After multi-stage purification treatment, the emission concentration of HF in the waste gas is ≤1ppm, and the emission concentration of VOCs is ≤50mg / m³, which meets the requirements of the national relevant environmental protection standards, and is finally discharged through the chimney.

[0045] Further, a wastewater tank is further included, and the wastewater tank is communicated with the plate-and-frame filter press 13. The wastewater tank is used to temporarily store the wastewater discharged by the plate-and-frame filter press 13. The wastewater in the wastewater tank can be further treated, such as by physical sedimentation, chemical oxidation-reduction, biological treatment and the like, to further remove residual pollutants therein, so as to reach a recycling standard or a discharge standard. The recycled wastewater can be pumped to the workshop as washing water to be used again in the dilution process of the phosphogypsum slurry, so as to realize the recycling of water resources and reduce the production cost.

[0046] Further, the PLC controller is connected with the touch screen 25 through an RS485 / Modbus protocol. Workers can conveniently set parameters and view real-time data through the HMI human-machine interface. Such an intuitive operation mode reduces the operation difficulty, improves the usability and operation efficiency of the system, and meanwhile, the visual function of the touch screen enables the operator to monitor the running state of the system in real time, discover and handle problems in time, and enhances the manageability of the system.

[0047] The content described in the embodiments of the specification is only a list of implementation forms of the utility model concept, and the protection scope of the utility model should not be regarded as being limited to the specific forms stated in the embodiments, and the protection scope of the utility model also extends to equivalent technical means that can be thought of by those skilled in the art according to the utility model concept.

Claims

1. A phosphogypsum harmless intelligent treatment system, characterized in that: The device comprises a stirring tank, a first electric valve, a buffer tank, a slurry pump and a plate-frame filter connected in sequence by pipelines, a belt conveyor is arranged below the plate-frame filter, the upper end of the stirring tank is communicated with a washing water source, a phosphogypsum adding part, a pour point depressant adding device and a fluoride removing agent adding device through pipelines, a phosphorus detector and a fluorine monitor are installed on the stirring tank, a weighing sensor is arranged between the stirring tank body and a support, a second electric valve is installed on the pipeline connecting the stirring tank with the washing water source, and the device further comprises a PLC controller, the weighing sensor, the phosphorus detector and the fluorine monitor are connected with the input end of the PLC controller, and the PLC controller controls the first electric valve, the second electric valve, the phosphogypsum adding part, the pour point depressant adding device and the fluoride removing agent adding device.

2. The phosphogypsum harmless intelligent treatment system according to claim 1, characterized in that: The device further comprises a chelating agent adding device communicated with the stirring tank, a heavy metal sensor and a PH sensor are installed on the stirring tank, the heavy metal sensor and the PH sensor are connected with the input end of the PLC controller, and the PLC controller controls the chelating agent adding device.

3. The phosphogypsum harmless intelligent treatment system according to claim 2, characterized in that: The stirrer in the stirring tank is a magnetic stirrer, and a magnetic field generator is arranged in the stirring tank.

4. The phosphogypsum harmless intelligent treatment system according to claim 3, characterized in that: The magnetic field strength of the magnetic field generator can be adjusted to 0.5-2T.

5. The intelligent harmless treatment system for phosphogypsum according to any one of claims 1 to 4, characterized in that: A jacket is arranged outside the stirring tank.

6. The intelligent harmless treatment system for phosphogypsum according to any one of claims 1 to 4, characterized in that: The device further comprises a waste gas treatment system, the waste gas treatment system comprises an activated carbon adsorption tower, an alkali washing spray tower and a catalytic oxidation reactor communicated in sequence by pipelines, and the activated carbon adsorption tower is communicated with the stirring tank and the buffer tank through pipelines.

7. The intelligent harmless treatment system for phosphogypsum according to any one of claims 1 to 4, characterized in that: The device further comprises a wastewater pool, and the wastewater pool is communicated with the plate-frame filter.

8. The intelligent harmless treatment system for phosphogypsum according to any one of claims 1 to 4, characterized in that: The PLC controller is connected with a touch screen through an RS485 / Modbus protocol.

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