Iron phosphate calcination section tail powder recovery device
By integrating existing equipment such as rotary kilns and drying bag filters, tailings powder is directly introduced into the drying process for mixing, solving the problem of high operating costs of tailings powder recovery devices, achieving efficient and safe tailings powder recovery, reducing operating costs and improving recovery efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- GUIZHOU PHOSPHATING NEW MATERIAL TECH CO LTD
- Filing Date
- 2025-08-28
- Publication Date
- 2026-07-21
AI Technical Summary
The existing tailings recovery device for ferric phosphate calcination has high operating costs, and the tailings collection process is harmful to the health of employees and difficult to collect.
By directly introducing the tail powder from the tailings bag filter into the drying bag filter for mixing, and utilizing existing equipment to achieve real-time recovery of the tail powder, including the integration of rotary kiln, drying bag filter, drying circulating fan, flash dryer, tailings bag filter and exhaust fan, the addition of additional equipment is avoided.
It achieves efficient recycling of tailings powder, reduces operating costs, reduces employee workload and health risks during collection, and improves recycling efficiency.
Smart Images
Figure CN224524257U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of iron phosphate production and preparation technology, specifically to a device for recovering tail powder from the iron phosphate calcination process. Background Technology
[0002] The production process of ferric phosphate includes raw material dissolution, reaction vessel synthesis, aging, pressure filtration, slurrying, washing and pressure filtration, flash drying, and calcination. Among these, the ferric phosphate calcination section involves placing the dried ferric phosphate into a muffle furnace or rotary kiln for high-temperature calcination to obtain wastewater ferric phosphate product. During the high-temperature calcination process, a large amount of tailings are generated. These tailings are small particulate powders carried in the calcination exhaust gas, which are essentially high-sulfur small particulate target products. Since the sulfur content in the tailings is above 10,000 ppm, directly returning the tailings to the production system would cause the sulfur content of the product to exceed the standard. However, if the tailings cannot be returned to the system, it will cause the loss of usable materials and excessive raw material consumption.
[0003] Our company initially designed a baghouse dust collector to connect with the exhaust gas from the dehydration and calcination section. However, during actual exhaust gas collection, the following drawbacks were discovered: Since the exhaust gas contains a significant amount of recyclable ferric phosphate raw material, to save raw materials and reduce costs, the company planned to recycle the collected exhaust gas and design a recycling process for reuse. The exhaust gas recycling point was located within the existing ferric phosphate production process. However, the existing baghouse dust collector is located after the dehydration and calcination section, requiring substantial manpower to collect the exhaust gas separated by the baghouse dust collector and then transport it back to the upstream process of the ferric phosphate process. Furthermore, the lack of protective measures below the baghouse dust collector during collection, coupled with the high calcination temperature (up to 600 degrees Celsius), and the high ambient temperature during exhaust gas collection, increases the difficulty of collection. The dust during collection also poses a significant health risk to personnel. Therefore, our company now proposes to modify some existing equipment to achieve automated collection, storage, and recycling of the exhaust gas generated by the baghouse dust collector, thereby reducing the workload of employees and addressing the harsh working environment during collection.
[0004] Patent CN222900520U discloses a tailings recycling device, including a first bag filter, a tail gas scrubbing fan, and a second bag filter. The first and second bag filters each include a dust-laden gas inlet, a clean gas outlet, a dust outlet, and a star-shaped unloader on the dust outlet. The dust outlet of the first bag filter is connected to a sealed collection tank. The bottom of the collection tank is connected to the dust-laden gas inlet of the second bag filter via a pipe. A solenoid valve is installed on the pipe near the collection tank. The clean gas outlet of the second bag filter is connected to the bag filter scrubbing fan. The bag filter scrubbing fan is connected to the collection tank via a pipe, and a second solenoid valve is installed on the pipe near the collection tank. The dust outlet of the second bag filter is connected to a temporary storage bin via the star-shaped unloader. A screw feeder is connected to the bottom of the temporary storage bin, and a tailings re-slurry tank is connected to the lower part of the screw feeder. This solution has the following drawbacks: The waste material is collected via a bag filter, then transported to a re-slurry tank for pulping, and finally to the washing process for blending. This requires additional equipment such as collection tanks, temporary storage bins, solenoid valves, and discharge valves, increasing operating costs. Utility Model Content To address the shortcomings of existing technologies, the technical problem solved by this utility model is to provide a tailings recovery device for ferric phosphate calcination process, thereby solving the problem of high operating costs of existing tailings recovery devices for ferric phosphate calcination process.
[0005] To solve the above problems, the technical solution adopted by this utility model is: a tailings recovery device for ferric phosphate calcination section, including a rotary kiln, a drying bag filter, a drying circulating fan, a flash dryer, a tailings bag filter, and a tail gas fan. The outlet of the drying bag filter is connected to the material inlet of the rotary kiln, allowing ferric phosphate from the drying process to be introduced into the rotary kiln for calcination. The inlet of the drying bag filter is connected to the flash dryer. The drying bag filter is connected to the drying circulating fan. The tailings bag filter is connected to the tailings outlet of the rotary kiln and is connected to the tail gas fan. A discharge valve is provided at the lower end of the tailings bag filter, and the discharge valve of the tailings bag filter is connected to the inlet of the drying bag filter via a pipe.
[0006] Furthermore, the flash dryer is equipped with a centrifuge at the inlet end, which is used to separate the ferric phosphate slurry into solid and liquid components.
[0007] Furthermore, a heater is provided between the flash dryer and the drying circulation fan, and the heater is connected to external steam to provide heat.
[0008] Furthermore, an exhaust duct is provided between the drying circulating fan and the heater.
[0009] Furthermore, the flash dryer is equipped with a feeder at its inlet end, which is connected to the outlet end of the centrifuge. The feeder is a screw conveyor.
[0010] The beneficial effects of this plan are: 1. This solution directly introduces the tail powder from the tail material bag filter into the existing drying bag filter in the drying process for mixing, and then into the rotary kiln. The tail powder can be recovered and reused in real time without the need to add new equipment for collection and processing, which greatly reduces the recycling and operating costs. 2. Compared with the existing tailings recycling devices that transport tailings to a re-pulping tank for pulping and then to the washing process for mixing, this solution has fewer recycling steps and can directly recycle in the previous process, which can increase recycling efficiency. Attached Figure Description
[0011] Figure 1 This is a schematic diagram of an embodiment of the present utility model; In the diagram: 1. Rotary kiln; 2. Drying bag filter; 3. Drying circulating fan; 4. Flash dryer; 5. Tail material bag filter; 6. Tail gas fan; 7. Centrifuge; 8. Heater; 9. Feeder; 501. Discharge valve. Detailed Implementation
[0012] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0013] Implementation, for example, attached Figure 1The diagram shows a tailings recovery device for a ferric phosphate calcination process, comprising a rotary kiln 1, a drying bag filter 2, a drying circulating fan 3, a flash dryer 4, a tailings bag filter 5, and a tail gas fan 6. The outlet of the drying bag filter 2 is connected to the material inlet of the rotary kiln 1, guiding the ferric phosphate from the drying process into the rotary kiln 1 for calcination. The inlet of the drying bag filter 2 is connected to the flash dryer 4. The drying bag filter 2 is connected to the drying circulating fan 3. Providing negative pressure, the tail material bag filter 5 is connected to the tail material outlet of the rotary kiln 1. The tail material bag filter 5 is equipped with a tail gas fan 6 to collect the tail powder from the calcination tail material generated in the rotary kiln 1. A discharge valve 501 is located at the lower end of the tail material bag filter 5. The discharge valve 501 is connected to the inlet end of the drying bag filter 2 via a pipe. When the discharge valve 501 is opened, the negative pressure generated by the drying circulating fan 3 draws the tail powder collected in the tail material bag filter 5 into the air. After filtration in the drying bag filter 2, the powder re-enters the rotary kiln 1, achieving real-time recovery and utilization of the tail powder. This solution makes full use of existing equipment without introducing new equipment, which can greatly save operating costs. The inlet end of the flash dryer 4 is equipped with a centrifuge 7. The centrifuge 7 separates the iron phosphate slurry into solid and liquid and then enters the flash dryer 4 for drying. A heater 8 is provided between the flash dryer 4 and the drying circulating fan 3. The heater 8 is connected to external steam to provide heat. In addition to providing heat itself, the heater 8 can also collect heat from the flash dryer 4 and introduce it into the drying bag filter 2 through the drying circulating fan 3, which can achieve the effect of saving energy. An exhaust channel is provided between the drying circulating fan 3 and the heater 8. During the drying process, the moisture containing water vapor is discharged through the exhaust channel. The inlet end of the flash dryer 4 is equipped with a feeder 9, which is connected to the outlet end of the centrifuge 7. The feeder 9 is a screw conveyor controlled by a stepless speed regulating motor, which facilitates the control of the feeding speed.
[0014] The specific implementation process is as follows: After solid-liquid separation in centrifuge 7, the ferric phosphate slurry enters flash dryer 4 for drying. The dried ferric phosphate material is then filtered in drying baghouse dust collector 2, and subsequently calcined in rotary kiln 1 to produce anhydrous ferric phosphate. The tailings generated during calcination are filtered in tailings baghouse dust collector 5. The collected tailings powder is returned to drying baghouse dust collector 2 via discharge valve 501 and pipeline, where it is mixed with the ferric phosphate material and then calcined again in rotary kiln 1. This scheme's ferric phosphate calcination section tailings powder recovery device includes a drying baghouse dust collector... The bag filter 2, drying circulating fan 3, flash dryer 4, heater 8, and feeder 9 are all existing equipment in the flash drying process, and the tail powder bag filter is existing equipment in the calcination process. No new equipment needs to be added to achieve real-time recycling of tail powder, which greatly reduces operating costs. Compared with the tail material recycling device in the existing technology, which transports the tail material to the re-pulping tank for pulping and then to the washing process for mixing, this solution reduces the recycling process and improves recycling efficiency. There is no need for transfer during the recycling process, which avoids the risk of foreign matter being introduced during the processing.
[0015] The above descriptions are merely embodiments of this utility model, and common knowledge regarding specific structures and characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of this utility model, and these should also be considered within the scope of protection of this utility model. These modifications will not affect the effectiveness of the implementation of this utility model or the practicality of the patent. The scope of protection claimed in this application shall be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.
Claims
1. A tailings recovery device for ferric phosphate calcination section, comprising a rotary kiln, a drying bag filter, a drying circulating fan, a flash dryer, a tailings bag filter, and a tail gas fan, wherein the outlet of the drying bag filter is connected to the material inlet of the rotary kiln to guide ferric phosphate from the drying process into the rotary kiln for calcination; the inlet of the drying bag filter is connected to the flash dryer; the drying bag filter is connected to the drying circulating fan; the tailings bag filter is connected to the tailings outlet of the rotary kiln; the tailings bag filter is connected to the tail gas fan; and a discharge valve is provided at the lower end of the tailings bag filter. The discharge valve of the tailings bag filter is connected to the inlet end of the drying bag filter via a pipe.
2. The tailings recovery device for the calcination section of ferric phosphate as described in claim 1, characterized in that: The flash dryer is equipped with a centrifuge at the inlet end, which is used to separate the ferric phosphate slurry into solid and liquid components.
3. The tailings recovery device for the calcination section of ferric phosphate as described in claim 1, characterized in that: A heater is provided between the flash dryer and the drying circulation fan, and the heater is connected to external steam to provide heat.
4. The tailings recovery device for the calcination section of ferric phosphate as described in claim 1, characterized in that: An exhaust duct is provided between the drying circulating fan and the heater.
5. The tailings recovery device for the calcination section of ferric phosphate as described in claim 1, characterized in that: The flash dryer is equipped with a feeder at its inlet end, which is connected to the outlet end of the centrifuge. The feeder is a screw conveyor.