Iron removal device for acidizing countercurrent boron extraction process

Abstract

The application relates to the technical field of boron ore processing, in particular to an iron removal device for an acidification countercurrent boron extraction process, which comprises a steam direct injection heating unit, a circulating filtration unit, a two-stage fiber bundle filtration unit, a three-stage gradient magnetic removal unit, an automatic backwashing unit and an inhibitor dispensing unit; the steam direct injection heating unit, the circulating filtration unit, the two-stage fiber bundle filtration unit and the three-stage gradient magnetic removal unit are sequentially connected through pipelines; the circulating filtration unit and the two-stage fiber bundle filtration unit are connected with the automatic backwashing unit and form a circulating system with the automatic backwashing unit; and the inhibitor dispensing unit is connected with the circulating filtration unit, the two-stage fiber bundle filtration unit and the three-stage gradient magnetic removal unit through pipelines. The application has the effects of improving the filtration efficiency and the iron ion removal rate.

Description

Technical Field

[0001] This application relates to the field of boron ore processing technology, and in particular to an iron removal device for an acidification countercurrent boron extraction process. Background Technology

[0002] In the acidification countercurrent boron extraction process, the raw materials typically contain a certain amount of iron impurities. If these iron impurities are not removed promptly, they can severely impact the quality of the boron product, leading to decreased purity and consequently affecting its application in various fields. Existing acidification countercurrent boron extraction processes are prone to significant increases in brine turbidity under windy and sandy weather conditions, resulting in excessive iron ion content (>10 ppm) in the boric acid product. Traditional treatment methods mainly rely on single filtration or chemical precipitation, which have the following drawbacks: conventional plate and frame filter presses have poor retention of colloidal iron impurities, requiring frequent shutdowns for cleaning, affecting production continuity, and resulting in low filtration efficiency; fiber bundle filtration is susceptible to high-turbidity brine impacts, leading to large fluctuations in iron ion removal rates; furthermore, residual iron in the filter cake is easily leached out again during backwashing, causing a rebound in the iron content of the final product and resulting in iron contamination during the countercurrent washing stage. Utility Model Content

[0003] To improve filtration efficiency and iron ion removal rate, this application provides an iron removal device for an acidification countercurrent boron extraction process.

[0004] The iron removal device for the acidification countercurrent boron extraction process provided in this application adopts the following technical solution:

[0005] An iron removal device for an acidification countercurrent boron extraction process includes a steam direct injection heating unit, a circulating filtration unit, a two-stage fiber bundle filtration unit, a three-stage gradient demagnetization unit, an automatic backwashing unit, and a corrosion inhibitor preparation unit. The steam direct injection heating unit, the circulating filtration unit, the two-stage fiber bundle filtration unit, and the three-stage gradient demagnetization unit are sequentially connected through pipelines. The circulating filtration unit and the two-stage fiber bundle filtration unit are both connected to the automatic backwashing unit and form a circulation system with the automatic backwashing unit. The corrosion inhibitor preparation unit is connected to the circulating filtration unit, the two-stage fiber bundle filtration unit, and the three-stage gradient demagnetization unit through pipelines.

[0006] The brine temperature is raised to 20-30℃ by a direct steam injection heating unit to promote colloidal iron flocculation. Then, it undergoes primary circulation filtration to reduce turbidity. A second-stage fiber bundle filtration unit further reduces turbidity, and finally, a tertiary gradient demagnetization unit performs deep iron removal. This synergistic iron removal process, combining pretreatment and countercurrent washing, integrates steam heating, multi-stage filtration, and gradient demagnetization to achieve a three-stage purification of iron impurities: flocculation, interception, and adsorption. This method solves the problem of excessive iron ions in high-turbidity brine and offers advantages such as high process integration, stable iron removal efficiency, and low operating costs. It is suitable for boron extraction from salt lakes and deep iron removal in similar high-turbidity iron-containing mineralized water.

[0007] In addition, the automatic backwashing unit can flush the circulating filter unit, the two-stage fiber bundle filter unit and the three-stage gradient demagnetizing unit at any time, thereby reducing the risk of equipment blockage. The corrosion inhibitor preparation unit can add corrosion inhibitors to each piece of equipment at regular intervals, thereby reducing the corrosion of the equipment by acid in the brine.

[0008] Optionally, the three-stage gradient demagnetization unit includes a permanent magnet drum, an electromagnetic separator, and a superconducting magnetic separator, which are connected in sequence via pipelines.

[0009] By adopting the above technical solutions, the magnetic field strength of the permanent magnet drum, the electromagnetic separator, and the superconducting magnetic separator is increased sequentially. The magnetic field strength of the permanent magnet drum is 8000 Gs, which can adsorb large iron particles. The magnetic field strength of the electromagnetic separator is 12000 Gs, which can capture colloidal iron. The magnetic field strength of the superconducting magnetic separator is 15000 Gs, which can deeply remove ionic iron, thereby achieving the removal of iron coefficients from large particles to ionic states one by one.

[0010] Optionally, the direct steam injection heating unit employs a spiral steam injector.

[0011] By adopting the above technical solution, the spiral steam ejector can accelerate the mixing of brine using the kinetic energy of steam. When the steam is accelerated in the nozzle, its speed will decrease sharply, and the kinetic energy will be converted into pressure energy. At the same time, the brine is drawn into the nozzle, which can mix the brine and cause the fluid temperature to rise sharply, thereby raising the brine temperature to 20-30°C and promoting the coagulation of colloidal iron.

[0012] Optionally, the superconducting magnetic separator is equipped with an online iron ion monitor at the liquid outlet end.

[0013] By adopting the above technical solution, an online iron ion monitor can be connected to the final outlet of the equipment to measure or control dissolved ferrous and ferric ions in water, thereby enabling real-time monitoring of the iron content in the brine and determining whether the iron ion removal rate meets the standard.

[0014] Optionally, the end of the three-stage gradient demagnetizing unit is connected to a reflux circulation pipe, which is connected to the front end of the steam direct injection heating unit. The reflux circulation pipe is equipped with a switch valve and a delivery pump.

[0015] By adopting the above technical solution, if the iron ion removal rate in the brine does not meet the standard requirements, the brine can be returned to the front end of the steam direct injection heating unit for secondary purification through the reflux circulation pipeline, so that the iron ion removal rate can meet the standard requirements.

[0016] Optionally, the inlet end of the automatic backwashing unit is connected to tap water, the outlet end of the automatic backwashing unit is connected to a filter, and the outlet end of the automatic backwashing unit is also provided with multiple flushing pipes. The multiple flushing pipes are connected to the inlet or outlet end of each filter device, and the multiple flushing pipes are equipped with a water pump, a regulating valve, an inlet valve and a drain valve.

[0017] By adopting the above technical solutions, the automatic backwashing unit washes away pollutants accumulated on or inside the filter media (such as sand, activated carbon, membranes, etc.) through reverse water flow, air flushing, or mechanical scraping, without the need for manual disassembly and cleaning. This removes impurities trapped by filter media (such as filter screens, filter cartridges, filter materials, etc.), restores filtration performance, and extends the service life of the equipment.

[0018] Optionally, the circulating filtration unit is a plate and frame filter press.

[0019] By adopting the above technical solution, the plate and frame filter press uses mechanical extrusion and the action of the filter medium (filter cloth) to trap solid particles in high-turbidity brine, forming a filter cake. The filtrate is then discharged through the filter cloth, thereby achieving coarse filtration of impurities in high-turbidity brine and reducing equipment pollution in subsequent processes.

[0020] Optionally, a secondary circulation pipe is provided at the end of the plate and frame filter press, and the secondary circulation pipe is connected to the front end of the plate and frame filter press.

[0021] By adopting the above technical solution, a secondary circulation pipeline is set at the end of the plate and frame filter press, and the filtrate can be circulated and filtered multiple times, thereby improving the impurity removal rate and reducing the risk of blockage in subsequent process equipment.

[0022] In summary, this application includes at least one of the following beneficial technical effects:

[0023] 1. The brine temperature is raised to 20-30℃ by a direct steam injection heating unit to promote colloidal iron flocculation. Then, it undergoes primary circulation filtration through a circulating filtration unit to reduce turbidity. Next, it undergoes secondary filtration through a two-stage fiber bundle filtration unit to further reduce turbidity. Finally, it undergoes deep iron removal through a three-stage gradient demagnetization unit. This synergistic iron removal process of pretreatment and countercurrent washing integrates steam heating, multi-stage filtration, and gradient demagnetization to achieve three-stage purification of iron impurities: flocculation, interception, and adsorption. This solves the problem of excessive iron ions in high-turbidity brine and has the advantages of high process integration, stable iron removal efficiency, and low operating costs. It is suitable for boron extraction from salt lakes and deep iron removal in similar high-turbidity iron-containing mineralized water.

[0024] 2. By setting up a permanent magnet drum, an electromagnetic separator, and a superconducting magnetic separator with progressively increasing magnetic field strength, the permanent magnet drum has a magnetic field strength of 8000 Gs, which can adsorb large iron particles; the electromagnetic separator has a magnetic field strength of 12000 Gs, which can capture colloidal iron; and the superconducting magnetic separator has a magnetic field strength of 15000 Gs, which can deeply remove ionic iron, thereby achieving the removal of iron coefficients from large particles to ionic states one by one.

[0025] 3. By connecting an online iron ion monitor to the final outlet of the equipment, it can be used to measure or control dissolved ferrous and ferric ions in water, thereby enabling real-time monitoring of the iron content in the brine and determining whether the iron ion removal rate meets the standard. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the iron removal device for an acidification countercurrent boron extraction process according to this application.

[0027] Explanation of reference numerals in the attached diagram: 1. Steam direct injection heating unit; 2. Circulating filtration unit; 3. Two-stage fiber bundle filtration unit; 4. Three-stage gradient demagnetization unit; 41. Permanent magnet drum; 42. Electromagnetic iron separator; 43. Superconducting magnetic separator; 5. Automatic backwashing unit; 6. Corrosion inhibitor preparation unit; 7. Wire iron ion monitor; 8. Backflow circulation pipeline; 81. Switch valve; 82. Transfer pump; 9. Filter; 10. Flushing pipeline; 101. Water pump; 11. Secondary circulation pipeline. Detailed Implementation

[0028] The following is in conjunction with the appendix Figure 1 This application will be described in further detail.

[0029] This application discloses an iron removal device for an acidification countercurrent boron extraction process. Through pretreatment and countercurrent washing, iron removal is achieved, ensuring the iron ion content is stably controlled below 10 ppm. (See reference...) Figure 1 An iron removal device for an acidification countercurrent boron extraction process includes a steam direct injection heating unit 1, a circulating filtration unit 2, a two-stage fiber bundle filtration unit 3, a three-stage gradient demagnetization unit 4, an automatic backwashing unit 5, and a corrosion inhibitor preparation unit 6. The steam direct injection heating unit 1, the circulating filtration unit 2, the two-stage fiber bundle filtration unit 3, and the three-stage gradient demagnetization unit 4 are connected sequentially through pipelines. The circulating filtration unit 2, the two-stage fiber bundle filtration unit 3, and the three-stage gradient demagnetization unit 4 are all connected to the automatic backwashing unit 5 and form a circulation system with the automatic backwashing unit 5. The corrosion inhibitor preparation unit 6 is connected to the circulating filtration unit 2, the two-stage fiber bundle filtration unit 3, and the three-stage gradient demagnetization unit 4 through pipelines.

[0030] In this application, the steam direct injection heating unit 1 uses a spiral steam ejector, the circulating filtration unit 2 uses a plate and frame filter press with a filtration area of ​​32㎡ and a pressure of 0.8MPa; the two-stage fiber bundle filtration unit 3 uses a two-stage fiber bundle filter with modified polypropylene fiber as the filter element and a filtration rate of 40m³ / h. The corrosion inhibitor preparation unit 6 uses a slow-release tank for preparing corrosion inhibitors. The three-stage gradient demagnetization unit 4 includes a permanent magnet drum 41, an electromagnetic separator 42, and a superconducting magnetic separator 43. The permanent magnet drum 41, electromagnetic separator 42, and superconducting magnetic separator 43 are connected sequentially by pipelines. The magnetic field strength of the three-stage gradient demagnetization unit 4 increases from 8000Gs to 15000Gs, covering iron impurities of all particle sizes from micron-sized to ionic state. The high-turbidity brine passes sequentially through a spiral steam ejector, a plate and frame filter press, a two-stage fiber bundle filter, a permanent magnet drum 41, an electromagnetic iron separator 42, and a superconducting magnetic separator 43. It undergoes pretreatment at high temperature to promote flocculation and countercurrent washing at low temperature to inhibit iron dissolution, forming a temperature gradient synergistic effect. This integrates steam heating, multi-stage filtration, and gradient demagnetization to achieve three-stage purification of iron impurities: flocculation, interception, and adsorption.

[0031] The three-stage gradient demagnetizing unit 4 is connected to a reflux circulation pipe 8 at its end. The reflux circulation pipe 8 is connected to the front end of the steam direct injection heating unit 1. A switch valve 81 and a transfer pump 82 are installed on the reflux circulation pipe 8. An online iron ion monitor 7 is installed at the liquid outlet end of the superconducting magnetic separator 43. That is, the online iron ion monitor 7 can detect the iron content in the filtrate. If the iron content does not meet the standard, the above process steps can be repeated through the reflux circulation pipe 8 until the iron content meets the standard.

[0032] The inlet of the automatic backwashing unit 5 is connected to tap water, and the outlet of the automatic backwashing unit 5 is connected to the filter 9. The outlet of the automatic backwashing unit 5 is also equipped with multiple flushing pipes 10, which are connected to the inlet or outlet of the plate and frame filter press and the two-stage fiber bundle filter. Each flushing pipe 10 is equipped with a water pump 101, a regulating valve, an inlet valve, and a drain valve. In this application, the two-stage fiber bundle filter uses a combined air-water backwash to restore its filtration performance, with an air flushing intensity of 15 L / (m²·s) and a water flushing intensity of 8 L / (m²·s), and a backwashing cycle of 8 hours.

[0033] A secondary circulation pipe 11 is provided at the end of the plate and frame filter press, and the secondary circulation pipe 11 is connected to the front end of the plate and frame filter press. In this way, the brine can be filtered through multiple cycles, and the preferred number of cycles in this application is 3 times.

[0034] This application has been implemented in the boric acid production line of Qinghai Lithium Industry, which processes 300,000 cubic meters of brine annually, increasing the rate of superior products from 65% to 98%.

[0035] The implementation principle of the iron removal device in the acidification countercurrent boron extraction process of this application embodiment is as follows:

[0036] The brine is heated to 20-25°C by a spiral steam injector and then circulated through a plate and frame filter press (3 cycles), reducing the turbidity from 70 NTU to 7 NTU. It then passes through a two-stage fiber bundle filter, stabilizing the turbidity at 4 NTU and reducing the iron ion concentration from 20 ppm to 7 ppm. The boron-containing filter cake comes into contact with the demagnetized mother liquor during countercurrent washing, with the three-stage gradient demagnetization unit 4 operating sequentially. The final boric acid product has an iron content of 5 ppm, meeting the superior grade standard.

[0037] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. An iron removal device for an acidification countercurrent boron extraction process, characterized in that: The system includes a steam direct injection heating unit (1), a circulating filtration unit (2), a two-stage fiber bundle filtration unit (3), a three-stage gradient demagnetizing unit (4), an automatic backwashing unit (5), and a corrosion inhibitor preparation unit (6). The steam direct injection heating unit (1), the circulating filtration unit (2), the two-stage fiber bundle filtration unit (3), and the three-stage gradient demagnetizing unit (4) are connected in sequence through pipelines. The circulating filtration unit (2) and the two-stage fiber bundle filtration unit (3) are both connected to the automatic backwashing unit (5) and form a circulation system with the automatic backwashing unit (5). The corrosion inhibitor preparation unit (6) is connected to the circulating filtration unit (2), the two-stage fiber bundle filtration unit (3), and the three-stage gradient demagnetizing unit (4) through pipelines.

2. The iron removal device for an acidification countercurrent boron extraction process according to claim 1, characterized in that: The three-stage gradient demagnetization unit (4) includes a permanent magnet drum (41), an electromagnetic separator (42), and a superconducting magnetic separator (43), which are connected in sequence by pipes.

3. The iron removal device for the acidification countercurrent boron extraction process according to claim 1, characterized in that: The steam direct injection heating unit (1) adopts a spiral steam injector.

4. The iron removal device for an acidification countercurrent boron extraction process according to claim 2, characterized in that: The superconducting magnetic separator (43) is equipped with an online iron ion monitor (7) at the liquid outlet end.

5. The iron removal device for an acidification countercurrent boron extraction process according to claim 4, characterized in that: The end of the three-stage gradient demagnetizing unit (4) is connected to a reflux circulation pipe (8), which is connected to the front end of the steam direct injection heating unit (1). The reflux circulation pipe (8) is equipped with a switch valve (81) and a delivery pump (82).

6. The iron removal device for an acidification countercurrent boron extraction process according to claim 1, characterized in that: The inlet of the automatic backwash unit (5) is connected to tap water, and the outlet of the automatic backwash unit (5) is connected to the filter (9). The outlet of the automatic backwash unit (5) is also provided with multiple flushing pipes (10). The multiple flushing pipes (10) are connected to the inlet or outlet of each filter device. The multiple flushing pipes (10) are equipped with a water pump (101), a regulating valve, an inlet valve and a drain valve.

7. The iron removal device for an acidification countercurrent boron extraction process according to claim 1, characterized in that: The circulating filtration unit (2) adopts a plate and frame filter press.

8. The iron removal device for an acidification countercurrent boron extraction process according to claim 7, characterized in that: The plate and frame filter press is provided with a secondary circulation pipe (11) at the end, and the secondary circulation pipe (11) is connected to the front end of the plate and frame filter press.

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