TWI639552B - A method of synthesizing homogeneous barium perborate particles by using fluidized-bed crystallization technology - Google Patents

Abstract

The present invention relates to a method for synthesizing bismuth borate homogenous particles by fluidized bed crystallization techniques. The method comprises providing at least two fluidized bed reaction tanks in series, the method further comprising a homogeneous granulation step of reacting hydrogen peroxide with boron ions and adding cerium ions as a coagulant in the fluidized bed reaction tank to produce water Homogeneous particles of barium perborate having a rate of less than 5% and a particle size greater than 0.5 mm. The method has high utilization potential and can be applied to chemical product synthesis or wastewater treatment.

Description

Method for synthesizing bismuth borate homogenized particles by fluidized bed crystallization technique

The invention relates to a method for synthesizing barium perborate homogenate particles by a fluidized bed crystallization technique, in particular, using a fluidized bed homogenization granulation technique to recover boron in a boron-containing wastewater having a boron content of several hundred to several thousand ppm. The moisture-containing perborate homogenized granule product has the characteristics of volume reduction and high purity, which is convenient for subsequent recycling processing.

Boron related compounds have a wide range of applications in modern industries, including thermal and nuclear power plants, glass plants, ceramic glaze plants, boron mines, tanneries and TFT-LCD industry polarizing film processes, and livelihood products such as bleaching powder , laundry detergents, fertilizers, pesticides, etc. all have the presence of boride. If the waste and wastewater generated by it directly flow into the environment without treatment, the boron in the water easily forms a complex mixture with heavy metals, causing serious environmental problems. Therefore, boron-containing waste and wastewater must be properly disposed of.

The current boron removal technology can be roughly divided into six types, namely chemical precipitation method, ion exchange method, adsorption method, reverse osmosis, extraction method and electric coagulation method, but each method has its limitations. The ion exchange method, adsorption method and reverse osmosis are suitable for low concentration boron-containing waste liquid. The ion exchange method and the adsorption method have excellent selectivity, and commercially available resins and adsorbent materials can be purchased on the market, but most of them are not expensive. Fiji is not easy to regenerate. Reverse osmosis is currently the most widely traded technology, but it is limited to low concentration of boron-containing wastewater or seawater desalination, especially in order to increase the boron removal effect, the pH is often adjusted to more than 10 to produce a negative borate ion. However, if the hardness is too high, it will cause the problem of film fouling. The electric coagulation method is suitable for low-concentration boron-containing wastewater, and the effect on the treatment of high-concentration boron-containing wastewater will be drastically reduced, and the cost of the sacrificial anode will be considered in application, and the equipment cost is high. Both chemical precipitation method and extraction method are very suitable for the treatment of high concentration boron-containing wastewater. The solvent used in the extraction method is mostly dihydric alcohol, but the toxicity and subsequent treatment of the solvent are relatively difficult; and the chemical precipitation method is the most widely used in the industry. Acceptable techniques, but traditional coagulation precipitation methods often require high temperature conditions to simulate hydrothermal methods to produce poorly soluble species.

Furthermore, although there is a method for treating boron-containing wastewater by fluidized bed technology, the boron granulation rate and boron removal rate which can be achieved are not high (generally about 50%, respectively), and heterogeneous burden must also be used. The body is too costly and the resulting crystalline particles are not of high purity. In addition, the use of a single fluidized bed reactor to treat boron-containing wastewater also has a maximum processing load limit, specifically, when the boron wastewater feed has a boron concentration greater than 700 ppm or a feed cross-section load greater than 1600 g/m2hr. When the supersaturation is too high, the resulting barium perborate tends to produce sludge, and the total boron removal rate of the fluidized bed reactor can be maintained, but the granulation rate is greatly reduced.

Therefore, how to provide a method for synthesizing homogenous particles of barium perborate from boron-containing wastewater, to achieve the use of reducing chemical agents, without the use of heterogeneous supports, and to obtain high-purity crystalline particles, and to solve the maximum feed processing load The issue of restriction is one of the most important issues at present.

Accordingly, the present invention mainly provides a method for synthesizing persimmonous borate homogenized particles by a fluidized bed crystallization technique, which can greatly improve the effect of treating the boron-containing wastewater by the existing fluidized bed homogeneous granulation technology, and recoverable moisture content. The bismuth borate bismuth salt is less than 5%, the particle size is more than 0.5 mm, and the purity is high. In addition, the method can solve the problem of the maximum feed processing load limitation.

According to an embodiment of the present invention, the method for synthesizing bismuth borate homogenate particles by fluidized bed crystallization technique comprises: providing first and second reaction tanks, each reaction tank having a tubular lower section and a tubular upper section, the upper section being external The diameter is larger than the outer diameter of the lower section, and the lower section of each reaction tank is provided with a boron-containing solution inlet port and a coagulant inlet port, and the upper section of each reaction tank is provided with a water outlet, and between the lower section and the upper section of each reaction tank a return line, and a water supply port of the first reaction tank and a boron-containing solution inlet port of the second reaction tank have a feed line communication; the hydrogen peroxide and the boron-containing solution are continuously fed and mixed After mixing in the tank for pretreatment, the boron-containing solution inlet port of the first reaction tank is introduced into the lower portion of the first reaction tank, and the boron concentration of the boron-containing solution is between 100 and 15000 ppm; The coagulant is introduced into the lower portion of the first and second reaction tanks from the coagulant inlet ports of the first and second reaction tanks respectively, wherein the cerium salt coagulant introduced into the first reaction tank is mixed with the boron-containing solution and The lower section of the first reaction tank flows upward, The portion of the boron-containing solution of the mixed cerium salt coagulant is refluxed to the lower portion of the first reaction tank through a reflux line of the first reaction tank to be circulated, so that boron ions and cerium in the boron-containing solution in the first reaction tank The salt coagulant is subjected to a granulation reaction to produce solid particles of barium perborate salt; and the boron-containing solution of the mixed barium salt coagulant is discharged from the water outlet of the first reaction tank and introduced into the lower portion of the second reaction tank via the feed line Mixing with the strontium salt coagulant and flowing from the lower section of the second reaction tank to the upper section, and then flowing back to the lower section of the second reaction tank through the reflux line of the second reaction tank to circulate, so that the second reaction tank The boron ion of the boron-containing solution is granulated with the cerium salt coagulant to produce solid particles of barium perborate salt.

In one embodiment, the cerium salt coagulant is a cerium-containing compound, and the molar ratio of cerium ions in the total cerium salt coagulant to boron ions in the boron-containing solution is between 0.5 and 2, and the value thereof is affected. The granulation efficiency of barium perborate salt and the removal effect of boron.

The method for synthesizing barium perborate homogenate particles by a fluidized bed crystallization technique further comprises a hydrogen peroxide concentration control step to maintain the hydrogen peroxide concentration stable in the granulation reaction. In one embodiment, the Mohr concentration ratio of hydrogen peroxide to boron ions in the boron-containing solution is between 0.5 and 3, the value of which affects the granulation efficiency of the barium perborate salt and the boron removal effect.

The method for synthesizing barium perborate homogenate by fluidized bed crystallization technology further comprises a flow acid pH control step to maintain the proper pH value of the fluidized bed to maintain a high boron granulation. rate. In one embodiment, the pH of the outlet water of the second reaction tank is controlled between 8.5 and 12, the value of which affects the granulation efficiency of the barium perborate salt and the removal effect of boron.

In a preferred embodiment, each reaction tank does not have a heterogeneous support, and the boron-containing solution and the cerium salt coagulant are first used before the boron-containing solution in which the cerium salt coagulant is mixed is operated in a reflux cycle. The reaction tank is mixed to produce homogenous crystalline particles of barium perborate salt as a support, and the initial static bed height of the particles controlling the first and second reaction tanks is controlled to be 0.25- of the length of the lower section of the first and second reaction tanks. Between 0.75 to obtain high boron ion removal rate and crystallization ratio.

In a preferred embodiment, the boron-containing wastewater and the hydrogen peroxide are pumped into a mixing tank for mixing reaction, and the pretreatment time of the mixing tank is controlled for 10 to 30 minutes.

In a preferred embodiment, the first and second reaction tanks have a hydraulic retention time of more than 10 minutes. The hydraulic retention time of the first reaction tank is greater than the hydraulic retention time of the second reaction tank.

In a preferred embodiment, the feed rate of the boron-containing solution is controlled to be greater than or equal to the total feed rate of the cerium salt coagulant.

Other objects, advantages and features of the present invention will become apparent from

The invention provides a method for synthesizing bismuth borate homogenate particles by fluidized bed crystallization technology, which utilizes crystal granulation to recover boron in a boron-containing solution (for example, boron-containing wastewater) into high purity and low water content. The homogenized particles of barium perborate salt achieve the effect of reducing volume and recycling of waste, and at the same time solve the problem of the maximum feed processing load limitation of the traditional fluidized bed crystallization technology. In conjunction with the system of Figure 1, the method of the present invention comprises the steps of providing a fluidized bed first and second reaction tanks 10A, 10B, each reaction tank 10A, 10B having a tubular lower section 12 and a tubular upper section 14, upper section The outer diameter of 14 is larger than the outer diameter of the lower section 12, and the lower section 12 of each reaction tank 10A, 10B is provided with a boron-containing solution inlet 16 and a coagulant inlet 18, and the upper section 14 of each reaction tank 10A, 10B is provided with a The water outlet 20 and a pH value detector 21 are used to monitor the outlet pH, and a return line 22 is provided between the lower section 12 and the upper section 14 of each of the reaction tanks 10A, 10B, and the first reaction tank 10A Between the water outlet 20 and the boron-containing solution inlet 16 of the second reaction tank 10B, there is a feed line 24, in the present embodiment, an intermediate tank 25 is provided on the feed line 24; 26, 27, respectively, the hydrogen peroxide 28 and the boron-containing solution 30 are fed to a continuous feeding step for mixing in a mixing tank 32 for pretreatment, and then introduced into the first inflow port 16 of the boron containing solution of the first reaction tank 10A. In the lower section 12 of the reaction tank 10A; and using the pumps 34, 36 to separate the strontium salt coagulant 38 from the first and second counters, respectively The coagulant inlet 18 of the tanks 10A, 10B is introduced into the lower section 12 of the first and second reaction tanks 10A, 10B, wherein the phosphonium salt coagulant 38 introduced into the first reaction tank 10A is mixed with the boron-containing solution 30 and Flowing together from the lower section 12 of the first reaction tank 10A to the upper section 14, and returning to the lower section 12 of the first reaction tank 10A via the reflux line 22 to circulate, so that the boron ions of the boron-containing solution 30 in the first reaction tank 10A The granulation reaction with the cerium salt coagulant 38 is carried out to produce solid particles of barium perborate salt; then, the boron-containing solution 30 reacted with the cerium salt coagulant 38 is discharged from the water outlet 20 of the first reaction tank 10A (when When the water level in the reaction tank 10A reaches the water outlet 20) and is introduced into the lower section 12 of the second reaction tank 10B via the feed line 24, it is mixed with the cerium salt coagulant 38, and is branched from the lower section 12 of the second reaction tank 10B. 14 flows, and then returns to the lower stage 12 of the second reaction tank 10B via the reflux line 22 to circulate, so that the boron ions of the boron-containing solution 30 in the second reaction tank 10B are again granulated with the cerium salt coagulant 38. To produce solid particles of barium perborate salt, wherein the water outlet from the first reaction tank 10A The effluent boron-containing solution 30 may be temporarily sent to the intermediate tank 25 for temporary buffering, and then introduced into the lower portion 12 of the second reaction tank 10B from the boron-containing solution inlet 16 of the second reaction tank 10B by the pump 40. .

The feed line 24 is connected to the water outlet 20 of the first reaction tank 10A and the boron-containing solution inlet 16 of the second reaction tank 10B, and the bismuth salt coagulant is introduced into the first and second reaction tanks 10A, 10B, respectively. Mixing 38 with the boron-containing solution 30 allows the boron ions in the boron-containing solution 30 and the cerium salt coagulant 38 to pass through sufficient collision to form homogeneous particles having a low water content to remove boron ions in the boron-containing solution 30 and disperse them. The supersaturation of barium borate is controlled so that the supersaturation is controlled to an appropriate range, and the boron in the boron-containing solution 30 is recovered as a homogeneous particle growth method to solve the problem of the maximum feed processing load limitation. In the present embodiment, the cerium salt coagulant 38 is a cerium-containing compound (e.g., cerium chloride).

According to the method of the present invention, the Mohr concentration ratio (H2O2/B) of the added hydrogen peroxide to the boron ion in the boron-containing solution 30, and the cerium ion in the total cerium salt coagulant 38 relative to the boron-containing solution 30 The Mohr concentration ratio of boron ion (Ba/B), the final outlet water pH value (pHe), and the bed of static particles of each reaction tank 10A, 10B are high (the particles in the fluidized bed at rest are piled up in each reactor) The internal height) will affect the boron ion removal rate (boron removal efficiency) and the granulation rate (crystallization ratio) in the boron-containing solution 30, respectively. According to the test results, the optimal Mohr concentration ratio of H2O2/B is between 0.5 and 3, and the optimal Mohr concentration ratio of Ba/B (the total amount of the first and second reaction tanks 10A and 10B) is Between 0.5 and 2, the final outlet water pH (pHe) of the second reaction tank 10B should be controlled between 8.5 and 12. Furthermore, in the method of the present invention, the boron-containing solution 30 and the cerium salt coagulant 38 may be separately introduced into the first and second reaction tanks 10A, 10B to be generated in a state where the reflux is operated or not. The bismuth perborate salt homogenous particles are used as a support to provide a sufficient crystal growth surface area to facilitate the adhesion of newly formed crystal particles to regenerate new particles, thereby avoiding the formation of gelatinous precipitates containing a large amount of water. The particle bed heights of the first and second reaction tanks 10A, 10B should be controlled between 0.25 and 0.75 of the length of the lower section 12, respectively. In the present embodiment, the lower section 12 of the first and second reaction tanks 10A, 10B has a length of about 80 cm, and thus the particle bed height is preferably controlled to be higher than 45 cm, respectively. In addition, the reaction time of the pretreatment of the hydrogen peroxide 28 and the boron-containing solution 30 in the mixing tank 32 is preferably controlled between 10 and 30 minutes. If the time is insufficient, the boron removal effect is not good, if the time is too long, the peroxide is excessive. The peroxygen concentration of hydrogen degrades, resulting in poor boron removal and can result in unnecessary waste of the agent.

Please refer to FIG. 2, which shows the control of the hydraulic retention time in the fluidized bed homogenization granulation step of 18 min, and in the total Ba/B=0.74, H2O2/B=1.5, and the final outflow water acid of the second reaction tank 10B. Under the operating conditions of a base value of pHe = 9.8 and an initial boron concentration of 651 ppm, the TR (%) and GR (%) will change as the bed height of the stationary particles changes. When the particle bed heights of the first and second reaction tanks 10A, 10B are less than 40 cm, the total surface area of the reaction provided by the particles representing the inside of the first and second reaction tanks 10A, 10B is insufficient, resulting in a large decrease in the granulation rate. The operation should be such that the particle bed height of each reaction tank is greater than 45 cm, and the effect of avoiding boron granulation rate is not good. In one embodiment, the hydraulic retention time is controlled to 18 minutes in the fluidized bed homogenization granulation step, and the total outlet water pH value pHe of the second reaction tank 10B in total Ba/B=0.84, H2O2/B=1.71, and the second reaction tank 10B. =10, under the operating conditions of initial boron concentration of 630 ppm, the TR (%) and GR (%) are 81.00% and 78.68%, respectively, compared with the homogeneous granulation of fluidized bed with calcium salt as coagulant. The good TR (%) and GR (%) are 55% and 50%, respectively, and the effect is significantly improved.

Referring to FIG. 3, it is shown that the hydraulic retention time of the first and second reaction tanks 10A is controlled to be 24 min, 18 min, respectively, in the fluidized bed homogenization granulation step, and Ba/B in the total antimony salt coagulant 38. =0.75, H2O2/B=1.5, final pHe=9.8, under the operating conditions of the upper flow velocity of the lower section 12 of the first and second reaction tanks 10A, 10B of 44.5 m/hr, TR(%) and GR(%) would The boron concentration varies with the different feed boron-containing solution 30; the leftmost data in Figure 3 is the TR and GR obtained when using a single fluidized bed reactor, and the multiple data in the right side of Figure 3 TR and GR obtained by treating the different boron concentration wastewaters in series with the first and second reaction tanks 10A, 10B of the fluidized bed, and it can be found that when the boron concentration of the boron-containing solution 30 is about 700 ppm, the first in series And the second reaction tanks 10A, 10B can provide the best TR and GR, wherein the first reaction tank 10A contributes about 60% of the GR, the second reaction tank 10B contributes about 20%, and the ratio is increased to 1000 ppm. Still the same when left and right.

Please refer to Fig. 4(a), (b) and (c), wherein Fig. 4(a) shows the total Ba/B=0.75, H2O2/B=1.5 in the fluidized bed homogeneous granulation step. At the final pHe = 9.8 and the upflow velocity of the lower section 12 is 44.5 m / hr, when the boron concentration of the boron-containing solution 30 is between 600 and 1000 ppm, both TR (%) and GR (%) can be maintained. About 80% (showing that most of the boron is effectively recovered as homogeneous particles); and Figure 4(b) shows the treatment of different feed boron concentrations in a conventional single fluidized bed reactor under about the same operating conditions. TR (%) and GR (%) performance, it can be found that when the boron concentration is greater than 700 ppm, although the boron removal rate TR (%) can be maintained, the granulation rate GR (%) will be greatly reduced; Figure 4 (c) changes the representation of Figure 4 (b) to the feed section load, from which it can be found that when the feed section load is greater than 1600 g/m2hr, the degree of supersaturation is too high, resulting in a tendency to produce barium perborate. When the sludge is produced, the removal rate of boron TR (%) can be maintained, but the granulation rate GR (%) is greatly reduced. From the comparison of Fig. 4 (a), (b), (c), it can be confirmed that the method of the present invention can solve the problem of the maximum feed processing load limitation.

In the embodiment of Fig. 4(a), the first and second reaction tanks 10A, 10B connected in series have the same size and are internally filled with a sufficient amount of homogeneous particles, and the cerium salt coagulant 38 is divided into two injections. In the first and second reaction tanks 10A, 10B, the boron in the boron-containing solution 30 is recovered in such a manner that the boron in the boron-containing solution 30 grows as homogeneous particles. In addition, it can be seen from Fig. 4(b) that the single fluidized bed reactor can handle a boron concentration of up to about 700 ppm (converted section load of 1600 gB/m2h), and the boron concentration of the boron-containing solution 30 to be treated is quite high. (eg, up to 3500 ppm), the system in accordance with the method of the present invention can increase the number of fluidized bed reactors in series (eg, 5 fluidized bed reactors in series, ie, in the second reactor 10B) The third, fourth and fifth reaction tanks are connected in series, so that each fluidized bed reaction tank is treated with about 700 ppm, but the optimum Mohr concentration ratio of Ba/B is still between 0.3 and 2, and The strontium salt coagulant 38 is evenly pumped into each fluidized bed reaction tank.

Please refer to Figure 5, which shows that the cause of hydraulic retention time also affects the removal rate and granulation rate of boron. In a single reaction tank experiment, the initial boron concentration was 652 ppm, Ba/B = 0.72, H2O2/B = 2.0, pHe = 10.3, and the feed flow rate of the boron-containing wastewater 30 and the cerium salt coagulant 38 (ml) /min) Under the operating conditions of QB/QBa=1 and the upper flow velocity U=42.4 m/hr of the down tube 12, it was found that the hydraulic stagnation time was controlled for more than 10 minutes, and the removal rate and granulation rate of boron did not decrease.

In the embodiment of Fig. 4(a), the feed flow rate (QB) of the boron-containing solution 30 is 40 ml/min, and the cesium salt feed flow rate into the first and second reaction tanks 10A, 10B ( QBa-1, QBa-2) are 20 ml/min, that is, QB: QBa-1: QBa-2 = 2:1:1. Furthermore, the hydraulic retention times of the first and second reaction tanks 10A, 10B are controlled to 24 min, 18 min, respectively, that is, in the present embodiment, the feed flow rate (QB) of the boron-containing solution is controlled to be The total salt flow rate (QBa) is the same, wherein the cesium salt coagulant 38 is equally divided into the first and second reaction tanks 10A, 10B, and the feed flow rate is 0.5QBa, and thus, the total intake enters the first The feed flow rate of the reaction tank 10A is QB+0.5QBa, and the boron-containing solution 30 which flows out of the first reaction tank 10A into the second reaction tank 10B is mixed with the cesium salt coagulant 38 of 0.5QBa, thereby causing the entry into the first The feed flow rate of the two reaction tanks 10B is QB+QBa, so that the hydraulic retention time (HRT) of the first and second reaction tanks 10A, 10B is different (HRT is the reaction tank volume divided by the inflow flow rate), and the first The hydraulic retention time of the reaction tank 10A is greater than the hydraulic retention time of the second reaction tank 10B. However, in a possible embodiment, in order to avoid dilution, the feed flow rate (QB) of the boron-containing solution may be controlled to be greater than the total feed flow rate (QBa) of the cerium salt coagulant, in a specific In the embodiment, QBa = 0.1QB can be controlled, and as a result, the phenomenon of the flow rate difference caused by the series connection is also lowered, and the HRT can be controlled in a closer interval.

In the foregoing specification, the invention has been described in terms of a particular embodiment, and various changes or modifications may be made in accordance with the features of the invention. Thus, obvious substitutions and modifications may be made by those skilled in the art, which are still within the scope of the claimed invention.

10A‧‧‧First reaction tank

10B‧‧‧Second reaction tank

12‧‧‧ lower section

14‧‧‧上段

16‧‧‧ Boron-containing solution inlet

18‧‧‧Coagulant inlet

20‧‧‧Water outlet

21‧‧‧pH detector

22‧‧‧Return line

24‧‧‧Feeding line

25‧‧‧Intermediate trough

26‧‧‧

27‧‧‧

28‧‧‧ Hydrogen peroxide

30‧‧‧Boron containing solution

32‧‧‧ mixing tank

34‧‧‧

36‧‧‧

38‧‧‧钡 salt coagulant

40‧‧‧ pump

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic illustration of a fluidized bed reaction cell system for use in a method in accordance with an embodiment of the present invention.

Figure 2 is a graph showing the relationship between the removal rate of boron and the granulation rate of different initial static particles in the fluidized bed homogenization granulation step; the particle bed height is the accumulation of particles in each reactor when the fluidized bed is stationary. the height of.

Figure 3 is a graph showing the relationship between boron removal rate and granulation rate of different feeds in the fluidized bed homogenization granulation step; wherein CB,in represents the boron concentration of different feeds.

Figure 4 (a) and (b) show the TR and GR performance of a fluidized bed reaction tank according to the present invention and a conventional single fluidized bed reaction tank in treating different feed boron concentrations, respectively.

Figure 4(c) shows the TR and GR performance of a conventional single fluidized bed reactor for different feed cross-section loads.

Figure 5 is a graph showing the removal rate of boron and the granulation rate of the single reaction tank hydraulic retention time.

Claims (10)

A method for synthesizing barium perborate homogenate particles by a fluidized bed crystallization technique, comprising: providing first and second reaction tanks, each reaction tank having a tubular lower section and a tubular upper section, wherein an outer diameter of the upper section is larger than an outer diameter of the lower section, each The lower section of the reaction tank is provided with a boron-containing solution inlet port and a coagulant inlet port. The upper section of each reaction tank is provided with a water outlet, and a reflux line is provided between the lower section and the upper section of each reaction tank, and the first reaction The water outlet of the tank is connected with the feed port of the boron-containing solution of the second reaction tank; the hydrogen peroxide and the boron-containing solution are continuously fed and mixed in a mixing tank for pretreatment, and then Introducing into the lower stage of the first reaction tank from the inflow port of the boron-containing solution of the first reaction tank, the boron concentration of the boron-containing solution is between 100 and 15000 ppm; and the strontium salt coagulant is respectively from the first and the second The coagulant inlet of the reaction tank is introduced into the lower section of the first and second reaction tanks, wherein the cerium salt coagulant introduced into the first reaction tank is mixed with the boron-containing solution and together from the lower section of the first reaction tank Parallel flow and coagulation of mixed strontium salt The boron-containing solution is refluxed to the lower portion of the first reaction tank through a reflux line of the first reaction tank to be circulated, so that boron ions in the boron-containing solution in the first reaction tank are granulated with the cerium salt coagulant to Producing a solid particle of perovskite salt; and a portion of the boron-containing solution of the mixed barium salt coagulant flowing out of the water outlet of the first reaction tank and introduced into the lower portion of the second reaction tank via the feed line with the barium salt coagulant Mixing, and flowing from the lower section of the second reaction tank to the upper section, and then flowing back to the lower section of the second reaction tank through the reflux line of the second reaction tank to circulate, so that the boron ions of the boron-containing solution in the second reaction tank are The cerium salt coagulant is subjected to a granulation reaction to produce solid particles of barium perborate salt, wherein the cerium ions in the total cerium salt coagulant of the first and second reaction tanks are opposite to the boron ions of the boron-containing solution The concentration ratio is between 0.5 and 2, and the pH of the outlet water of the second reaction tank is controlled between 8.5 and 12. The method of claim 1, wherein the cerium salt coagulant is a cerium-containing compound. The method of claim 1, wherein the molar ratio of hydrogen peroxide to boron ions in the boron-containing solution is between 0.5 and 3. The method of claim 1, wherein the reaction tank does not have a heterogeneous support, and the boron-containing solution and the cerium salt coagulant are first mixed in the first and second reaction tanks to form bismuth borate. The salt homogeneous crystalline particles are used as a support, and the initial static bed height of the controlled particles is controlled between 0.25 and 0.75 of the length of the lower section of the first and second reaction tanks. The method of claim 1, wherein the first and second reaction tanks have a hydraulic retention time of more than 10 minutes. The method of claim 1, wherein the first reaction tank has a hydraulic retention time greater than a hydraulic retention time of the second reaction tank. The method of claim 6, wherein the first reaction tank hydraulic retention time is controlled to be more than 24 minutes, and the second reaction tank hydraulic retention time is controlled to be more than 18 minutes. The method of claim 1, wherein the time during which the hydrogen peroxide and the boron-containing solution are mixed and reacted in the mixing tank is controlled to be between 10 and 30 minutes. The method of claim 1, wherein the feed rate of the boron-containing solution is controlled to be greater than or equal to the total feed rate of the cerium salt coagulant. The method of claim 1, wherein the feed line has an intermediate tank, and the boron-containing solution flowing out of the water outlet of the first reaction tank is first sent to the intermediate tank for temporary storage, and then the feed is passed through the feed. A line is introduced into the lower section of the second reaction tank.