A method and device for preparing fluorite balls

Abstract

The application relates to the technical field of sewage treatment, and provides a preparation method and device of fluorite balls, the preparation method of the fluorite balls comprises the following steps: preparing slurry from defluorination sludge, adjusting the slurry to be alkaline by sodium hydroxide, and obtaining a first suspension; adding fluorinated salt into the first suspension to generate a second suspension containing calcium fluoride, a mineralizer and water-soluble sulfate by a double decomposition reaction; separating the second suspension to obtain a first solid and a first liquid; and performing ball pressing and calcination on the first solid to obtain fluorite balls. The preparation method of the fluorite balls can effectively remove sulfur in artificial fluorite powder, introduce the mineralizer, improve the grade of the artificial fluorite powder, and reduce the ball forming difficulty of the fluorite powder.

Description

Technical Field

[0001] This application relates to wastewater treatment technology. In particular, it relates to a method and apparatus for preparing fluorite spheres. Background Technology

[0002] Fluoride removal from semiconductor industry wastewater includes adsorption using inorganic adsorbents, bioadsorbents, or ion exchange resins, coagulation / precipitation / crystallization, electrocoagulation, and membrane treatment. Traditionally, coagulation-precipitation processes using calcium compounds (typically lime and / or calcium chloride) are widely used to remove fluorides, separating them from the aqueous phase as fluorite precipitates. However, the precipitation process generates a large amount of fluorite sludge, a major byproduct of fluoride-containing wastewater treatment and a primary target for recycling. Recovered fluorite sludge can be reused as an additive in cement, concrete, brick, and ceramics production to improve compressive strength and lower sintering melting points. Natural fluorite, especially low-grade fluorite ore, contains minerals such as quartz, calcite, barite, and sulfides. Foam flotation, gravity separation, and magnetic separation are industrial techniques used to purify fluorite. Among these, foam flotation is the most widely used due to its cost-effectiveness and ease of operation.

[0003] While fluorite sludge can be purified using the same methods as fluorite ore, the composition of the sludge can differ significantly from that of the mineral ore, depending on the source of the wastewater. The use of coagulants and flocculants during coagulation and sedimentation can lead to a more complex composition and elemental bonding in the fluorite sludge. Furthermore, fluoride-containing wastewater often contains other acids such as sulfuric acid, nitric acid, and phosphoric acid. Impurities in fluorite sludge can also differ considerably from those in fluorite ore. Therefore, exploring methods specifically designed for the purification of fluorite sludge is crucial. Summary of the Invention

[0004] This application provides a method and apparatus for preparing fluorite spheres, which effectively removes sulfur from artificial fluorite powder while introducing mineralizers and improving the grade of artificial fluorite powder, thereby reducing the difficulty of sphere formation from fluorite powder.

[0005] To achieve the above objectives, this application adopts the following technical solution:

[0006] This application provides a method for preparing fluorite spheres, comprising:

[0007] The fluoride-removed sludge was pulped, and the pH of the sludge slurry was adjusted to be alkaline using sodium hydroxide to obtain the first suspension.

[0008] Fluoride salts are added to the first suspension to carry out a metathesis reaction to generate a second suspension containing calcium fluoride, a mineralizing agent, and a water-soluble sulfate.

[0009] The second suspension is separated to obtain the first solid and the first liquid;

[0010] The first solid was calcined by granulation to obtain fluorite spheres.

[0011] In some embodiments, the pH is 12 to 13.5.

[0012] In some embodiments, the fluoride salt is magnesium fluoride, and the mineralizing agent is magnesium hydroxide;

[0013] Alternatively, the fluoride salt is sodium fluorosilicate, and the mineralizing agent is silicon dioxide.

[0014] In some embodiments, the weight of the fluoride salt is 1% to 2% of the weight of the defluorinated sludge.

[0015] In some embodiments, when a fluoride salt is added to the first suspension, the mixture of the first suspension and the fluoride salt is heated and pressurized to 80°C to 100°C and pressurized to 0.15 to 0.2 MPa.

[0016] In some embodiments, it also includes:

[0017] The first liquid is evaporated to precipitate sulfate crystals, resulting in a third suspension.

[0018] The third suspension was separated to obtain sulfate crystals and a second liquid.

[0019] In some embodiments, it also includes:

[0020] Add the second liquid to the first suspension.

[0021] This application provides an apparatus for preparing fluorite spheres, used in the above-mentioned method for preparing fluorite spheres, comprising:

[0022] The container assembly is provided with a pretreatment chamber, a desulfurization chamber and a settling chamber arranged side by side. The desulfurization chamber is connected to the pretreatment chamber, and the settling chamber is connected to the desulfurization chamber.

[0023] A first microporous filter membrane is located in the settling cavity to divide the settling cavity into a first part and a second part side by side, the first part being connected to the desulfurization cavity;

[0024] A power pump is connected to the second part. The power pump drives the first suspension in the pretreatment chamber to enter the desulfurization chamber. The second suspension in the desulfurization chamber enters the sedimentation chamber. The second suspension is separated into the first liquid and the first solid in the sedimentation chamber.

[0025] The first collector is located at the bottom of the first part, and its inner cavity is connected to the first part to collect the first solid.

[0026] In some embodiments, the container assembly is provided with a first communication port, which is located at the lower part of the pretreatment cavity and is connected to both the pretreatment cavity and the desulfurization cavity.

[0027] The container assembly is provided with a second connection port, which is located at the upper part of the desulfurization inner cavity and is connected to both the desulfurization inner cavity and the settling inner cavity.

[0028] In some embodiments, it also includes:

[0029] At least two first inclined partitions are provided, the first inclined partitions are located in the first part, the extension plane of the first inclined partition has an angle with the extension plane of the first microporous filter membrane, the top of the first inclined partition has a gap with the top of the sedimentation cavity, and part of the first inclined partition is located below the second communication port; at least two first inclined partitions are arranged side by side and spaced apart.

[0030] The first vertical partition is located in the first part. The extension plane of the first vertical partition is parallel to the extension plane of the first microporous filter membrane. The first vertical partition is located below the first inclined partition. The first vertical partition and the first inclined partition have a gap. The bottom of the first vertical partition is connected to the bottom of the sedimentation cavity.

[0031] In some embodiments, a first stirring device is also included, which is located in the pretreatment cavity;

[0032] And / or, it also includes a pH sensor, which is located in the pretreatment cavity;

[0033] And / or, it also includes a first heating element located in the desulfurization cavity;

[0034] And / or, it also includes a second stirring device located in the desulfurization chamber;

[0035] And / or, it also includes a first temperature sensor located in the desulfurization cavity;

[0036] And / or, also includes an air blower connected to the bottom of the container assembly, the air blower being configured to blow air into the desulfurization chamber to increase the air pressure inside the desulfurization chamber;

[0037] And / or, also includes a liquid seal structure connected to the top of the container assembly, the liquid seal structure being configured to control communication or non-communication between the desulfurization interior and the outside of the container assembly.

[0038] In some embodiments, the container assembly is provided with a precipitation cavity;

[0039] Also includes:

[0040] The second microporous filter membrane is located in the precipitation cavity to divide the precipitation cavity into a third part and a fourth part side by side. The third part is connected to the second part, and the fourth part is connected to the pretreatment cavity.

[0041] The second heating element is located in the third part;

[0042] The second collector, located at the bottom of the third part, has its inner cavity connected to the first part to collect sulfate crystals.

[0043] In some embodiments, a connecting pipe is also included, the lumen of which is connected to the fourth part and the pretreatment cavity, respectively.

[0044] The third microporous filter membrane is located in the lumen, and the pore size of the third microporous filter membrane is smaller than that of the second microporous filter membrane.

[0045] The third collecting element is located at the bottom of the connecting pipe and below the third microporous filter membrane. The inner cavity of the third collecting element is connected to the pipe cavity to collect sulfate crystals.

[0046] In some embodiments, it also includes:

[0047] At least two second inclined septa, the second inclined septa being located in the third part, the extending plane of the second inclined septa having an angle with the extending plane of the second microporous filter membrane, and the top of the second inclined septa having a gap with the top of the precipitation cavity; at least two second inclined septa are arranged side by side and spaced apart;

[0048] The second vertical septum is located in the third part. The extension plane of the second vertical septum is parallel to the extension plane of the second microporous filter membrane. The second vertical septum is located below the second inclined septum. The second vertical septum and the second inclined septum have a gap. The bottom of the second vertical septum is connected to the bottom of the precipitation cavity.

[0049] The third vertical septum is located in the third part. The extension plane of the third vertical septum is parallel to the extension plane of the second microporous filter membrane. The third vertical septum is located on the side of the second vertical septum away from the second microporous filter membrane. The top of the third vertical septum is connected to the top of the precipitation cavity, and the bottom of the third vertical septum is spaced from the bottom of the precipitation cavity.

[0050] This application provides a method and apparatus for preparing fluorite spheres. The method includes: slurrying defluorinated sludge and adjusting the pH to alkalinity using sodium hydroxide to obtain a first suspension; adding fluoride salts to the first suspension to conduct a metathesis reaction to generate a second suspension containing calcium fluoride, a mineralizing agent, and water-soluble sulfates; separating the second suspension to obtain a first solid and a first liquid; and calcining the first solid to obtain fluorite spheres. In this way, adjusting the pH can inhibit the dissolution of calcium fluoride and increase the solubility of fluoride salts. The calcium fluoride produced by the metathesis reaction increases the calcium fluoride content in the first solid, while simultaneously generating a mineralizing agent. During the calcination process, the mineralizing agent produces a eutectic, which lowers the calcination temperature of the first solid. Filtering the second suspension removes the water-soluble sulfate liquid, thus achieving sulfur removal. Furthermore, the price of fluoride salts is lower than that of sodium D-gluconate. Attached Figure Description

[0051] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0052] Figure 1 The method for preparing fluorite spheres provided in the embodiments of this application;

[0053] Figure 2 An apparatus for preparing fluorite spheres provided in the embodiments of this application.

[0054] Explanation of reference numerals in the attached figures:

[0055] 100 - Container assembly; 110 - Pretreatment chamber; 120 - Desulfurization chamber; 130 - Settling chamber; 140 - First connecting port; 150 - Second connecting port; 160 - Precipitation chamber; 200 - First microporous filter membrane; 300 - Power pump; 400 - First collecting element; 500 - First inclined baffle; 600 - First vertical baffle; 700 - First stirring device; 800 - Acidity / alkalinity sensor; 900 - First heating element; 1000 - Second stirring device; 1100- First temperature sensor; 1200- Air blower; 1300- Gas distributor; 1400- Liquid seal structure; 1500- Second microporous filter membrane; 1600- Second heating element; 1700- Second collecting element; 1800- Connecting pipe; 1900- Third microporous filter membrane; 2000- Third collecting element; 2100- Second vertical partition; 2200- Second inclined partition; 2300- Third vertical partition. Detailed Implementation

[0056] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0057] In existing technologies, sodium carbonate (Na₂CO₃) is used for carbonation to remove sulfates from fluorite sludge. By adjusting the solid-liquid ratio of the sodium carbonate solution and the calcium fluoride sludge, calcium sulfate (CaSO₄) is dissolved in carbonate-rich water, simultaneously forming calcium carbonate (CaCO₃). The sodium sulfate dissolves in the solution, achieving sulfur removal. However, the resulting calcium carbonate decomposes at high temperatures to form quicklime, which affects the strength of the sludge and is detrimental to the preparation of artificial fluorite spheres.

[0058] Taking advantage of sodium D-gluconate's high selectivity for CaSO4 (calcium sulfate) and low chelation reactivity with CaF2 (calcium fluoride), sodium D-gluconate can be used as a desulfurizing agent to purify calcium fluoride sludge. The resulting Ca(C6H)2... 11 O7)2 (calcium gluconate) dissolves in water, effectively preventing the formation of inert, insoluble solids that can encapsulate CaSO4 (calcium sulfate) particles. However, this process is currently only in the experimental stage. The reaction time between sodium D-gluconate and calcium sulfate is too long, and the high price of sodium D-gluconate increases desulfurization costs, limiting its industrialization progress.

[0059] Furthermore, when producing fluorite balls from calcium fluoride sludge, temperatures often need to be raised to 1000℃ to obtain high-strength, qualified products. This is because the sludge contains many impurities, which interfere with the aggregation and growth of calcium fluoride microcrystals at 800℃, instead forming brittle mineral phases such as aragonite, while the calcium fluoride remains in a free state, resulting in insufficient strength. Sufficiently high temperatures are needed to overcome these obstacles and promote the movement and aggregation of calcium fluoride microcrystals. This increases energy consumption and costs compared to using natural mineral powder in the calcium fluoride sludge production process. Reducing the calcination temperature of calcium fluoride sludge is a key challenge that many companies are currently seeking to overcome.

[0060] To overcome the deficiencies in the prior art, this application provides a method and apparatus for preparing fluorite spheres. The method includes: slurrying defluorinated sludge and adjusting the pH to alkalinity using sodium hydroxide to obtain a first suspension; adding fluoride salts to the first suspension to conduct a metathesis reaction to generate a second suspension comprising calcium fluoride, a mineralizing agent, and water-soluble sulfates; separating the second suspension to obtain a first solid and a first liquid; and calcining the first solid to obtain fluorite spheres. In this way, by adjusting the pH, the dissolution of calcium fluoride can be suppressed, and the solubility of fluoride salts can be increased. The calcium fluoride produced by the metathesis reaction increases the calcium fluoride content in the first solid, while simultaneously generating a mineralizing agent. During the calcination process, the mineralizing agent generates a eutectic, which lowers the calcination temperature of the first solid. Filtering the second suspension removes the water-soluble sulfate liquid, thereby achieving sulfur removal. Furthermore, the price of fluoride salts is lower than that of sodium D-gluconate.

[0061] The contents of this application will now be described in detail with reference to the accompanying drawings, so that those skilled in the art can have a clearer and more detailed understanding of the contents of this application.

[0062] See Figure 1 As shown, this application provides a method for preparing fluorite spheres, comprising:

[0063] S101. The fluoride-removed sludge is pulped and the pH is adjusted to be alkaline with sodium hydroxide to obtain the first suspension.

[0064] The fluoride-removing sludge can come from various industries, and contains 60%-90% calcium fluoride and about 1% sulfur.

[0065] S102. Fluoride salt is added to the first suspension to carry out a metathesis reaction to generate a second suspension containing calcium fluoride, a mineralizing agent and a water-soluble sulfate.

[0066] S103. Separate the second suspension to obtain the first solid and the first liquid.

[0067] S104. The first solid is calcined by pressing to obtain fluorite spheres.

[0068] Understandably, adjusting the pH can inhibit the dissolution of calcium fluoride and increase the solubility of fluoride salts. The calcium fluoride produced by the metathesis reaction increases the calcium fluoride content in the first solid, while also generating a mineralizing agent. This mineralizing agent produces a eutectic during the briquetting and calcination process, thus lowering the calcination temperature of the first solid. Filtering the second suspension removes water-soluble sulfate liquid, thereby achieving sulfur removal.

[0069] It should be noted that the reason for choosing NaOH is not only to adjust the suspension to alkalinity, but also to ensure the smooth formation of NaF. NaF is the key to the desulfurization process in converting sparingly soluble sulfates into readily soluble sulfates for removal.

[0070] In some embodiments, the pH is 12 to 13.5.

[0071] For example, the pH can be 12, 12.5, 13 or 13.5.

[0072] When the pH is between 12 and 13.5, The concentration is high enough to fully promote precipitation formation while effectively avoiding side reactions.

[0073] When the pH is less than 12 Insufficient concentration leads to incomplete precipitation of Mg(OH)2 and a low reaction rate.

[0074] When the pH is greater than 13.5, the extremely high alkalinity leads to the formation of byproducts (such as Na2MgO2) or colloidal encapsulation, which hinders mass transfer.

[0075] Among them, fluoride salts refer to magnesium fluoride or sodium fluorosilicate, because the introduction of Mg or Si is a necessary condition for the formation of a low-eutectic stable crystalline phase, while other salts such as Al cannot form a high-strength stable crystalline phase. In addition, although fluoride salts such as ammonium fluoride can also form sodium fluoride for desulfurization, the generation of ammonia gas will pollute the environment.

[0076] In some embodiments, the fluoride salt is magnesium fluoride, and the mineralizing agent is magnesium hydroxide. The reaction involved is:

[0077]

[0078]

[0079] During the calcination process of the first solid pellet, Mg(OH)2 first forms MgO, and then reacts with CaO and SiO2 at a lower temperature to form a eutectic mineral phase, thereby reducing the forming temperature of the fluorite pellets and increasing their forming strength. MgO is an excellent flux, which can react with components in sludge to form mineral phases such as diopside (CaMgSi2O6), which can melt at a lower temperature, increasing density and reducing the difficulty of forming fluorite pellets.

[0080] In some embodiments, the fluoride salt is sodium fluorosilicate, and the mineralizing agent is silicon dioxide. The reaction involved is as follows:

[0081]

[0082]

[0083] During the calcination process of the first solid pellet, SiO2 precipitates concentrate on the surface of the particles (surface nucleation), increasing the specific surface area and leading to a faster crystallization process that is completed at a relatively low temperature. At the same time, after SiO2 melts, the flow rate is slow, making it easier to fill the gaps between particles. After cooling, a dense phase is formed, increasing density and reducing the difficulty of forming fluorite spheres.

[0084] In some embodiments, the weight of the fluoride salt is 1% to 2% of the weight of the defluorinated sludge, and Mg2O3 or SiO2 is finally introduced to promote the formation of a eutectic phase, thereby reducing the calcination temperature of the raw material by forming a high-strength, low-eutectic phase with calcium fluoride.

[0085] When the weight of fluoride salt is less than 1% of the weight of defluorinated sludge, the amount of eutectic material introduced is too small, making it difficult to fully exert its effect and thus effectively reduce the calcination temperature of the raw material.

[0086] When the weight of fluoride salts exceeds 2% of the weight of defluorinated sludge, it can easily hinder the sintering of calcium fluoride, and the resulting eutectic phase is not the desired phase, ultimately reducing the strength of the calcined product.

[0087] In some embodiments, when a fluoride salt is added to the first suspension, the mixture of the first suspension and the fluoride salt is heated and pressurized to 80°C to 100°C and pressurized to 0.15 to 0.2 MPa.

[0088] For example, the mixture of the first suspension and the fluoride salt is heated to 80°, 90°, or 100°. The mixture of the first suspension and the fluoride salt is pressurized until the pressure inside the container reaches 0.18 MPa.

[0089] It is understandable that heating to 80°C to 100°C and pressurizing to 0.15 to 0.2 MPa can improve the reaction efficiency of the metathesis reaction.

[0090] When the heating temperature is below 80℃, the effect of improving the reaction efficiency of the metathesis reaction is relatively poor.

[0091] When the heating temperature exceeds 100℃, energy consumption is high, which is not conducive to energy saving. Furthermore, the solubility of fluoride salts is low, and water evaporates at high temperatures, which is not conducive to the reaction.

[0092] When the applied pressure is too low, it is not conducive to fully exerting the pressurizing effect and to achieving the goal of promoting the reaction rate.

[0093] When the applied pressure is greater than 0.2 MPa, the liquid seal of the liquid seal structure is easily broken, which will cause the reaction solution to overflow and air to pour in and contaminate the reaction solution.

[0094] In some embodiments, it also includes:

[0095] The first liquid is evaporated to allow sulfate crystals to precipitate or the first liquid is concentrated to a target level to obtain a third suspension.

[0096] Specifically, the volume of the first liquid is observed during heating and evaporation, and evaporation is stopped when crystals begin to appear on the surface of the first liquid. Alternatively, evaporation is stopped when the first liquid has been concentrated to the target level by density measurement.

[0097] The third suspension was separated to obtain sulfate crystals and a second liquid.

[0098] Understandably, sulfate crystals can be sold as a product to increase profits.

[0099] In some embodiments, it also includes:

[0100] Add the second liquid to the first suspension.

[0101] Understandably, the second liquid after separation is alkaline. Adding the second liquid to the first suspension can reduce the amount of sodium hydroxide used and save water resources.

[0102] The following describes a specific embodiment of the preparation method of fluorite balls. It should be noted that the defluorination sludge is from the same batch, in which the calcium fluoride content is 75% and the sulfur content is 1%.

[0103] Example 1

[0104] This embodiment provides a method for preparing fluorite spheres, including the following steps:

[0105] 1. pH adjustment. Add 100 kg of defluorinated sludge, and continuously add water and NaOH. Stir thoroughly with a stirrer at 10,000 rpm to prepare a calcium fluoride sludge suspension. Control the pH to 10 using a pH sensor to obtain the first suspension.

[0106] 2. Sludge desulfurization. Add 2 kg of magnesium fluoride to the first suspension and heat and pressurize to 80°C and 0.15 MPa. Through a metathesis reaction, a second suspension is generated, consisting of calcium fluoride, magnesium hydroxide, and water-soluble sodium sulfate.

[0107] The reactions involved are

[0108]

[0109]

[0110] 3. Desulfurization sludge settling. Separate the second suspension to obtain the first solid and the first liquid.

[0111] 4. Briquetting and calcination. Glass powder at 6% of the weight of the defluorinated sludge is added to the first solid and briquetted and calcined to obtain fluorite spheres.

[0112] When the amount of glass powder added is less than 6%, it is not easy to successfully form a high-strength eutectic phase, and the resulting product has low strength and is easily broken.

[0113] When the amount of glass powder added is higher than 6%, the Si content of the resulting product is likely to exceed the standard. When used as a metallurgical mineralizer, it will reduce the continuity of the metal matrix, causing problems such as thickening of the slag, poor fluidity, and difficulty in slag-iron separation.

[0114] The calcination temperature is 700℃-800℃. If the temperature is below 700℃, it is not easy to effectively form a eutectic. If the temperature is too high, overheating will occur, and the sample will be collapsed and porous, making it difficult to produce spherical products.

[0115] 5. Resource utilization of desulfurization solution. The first liquid after separation is heated to 90°C through heating electrodes and continuously evaporated and concentrated. The solution volume is observed, and evaporation is stopped when crystals begin to appear on the solution surface, yielding the third suspension.

[0116] Maintain the temperature of the third suspension and separate the third suspension to obtain sodium sulfate crystals (mainly anhydrous Na2SO4) and the second liquid.

[0117] It should be noted that during the calcination process of the first solid pellet, Mg(OH)2 first forms MgO, and then reacts with CaO and SiO2 at a lower temperature to form a eutectic mineral phase, thereby reducing the forming temperature of the fluorite pellets and increasing their forming strength. MgO is an excellent flux, which can react with components in the sludge to form mineral phases such as diopside (CaMgSi2O6), which can melt at a lower temperature, increasing density and reducing the difficulty of forming the fluorite pellets.

[0118] Example 2

[0119] This embodiment provides a method for preparing fluorite spheres, including the following steps:

[0120] 1. pH adjustment. Add 100 kg of defluorinated sludge, and continuously add water and NaOH. Stir thoroughly with a stirrer at 10000 rpm / h to prepare a calcium fluoride sludge suspension. Control the pH to 10 using a pH sensor to obtain the first suspension.

[0121] 2. Sludge desulfurization. Add 2 kg of sodium fluorosilicate to the first suspension and heat and pressurize to 80°C and 0.15 MPa. Through a metathesis reaction, a second suspension is generated, consisting of calcium fluoride, magnesium hydroxide, and water-soluble sodium sulfate.

[0122] The reactions involved are

[0123]

[0124]

[0125] 3. Desulfurization sludge settling. Separate the second suspension to obtain the first solid and the first liquid.

[0126] 4. Briquetting and calcination. Glass powder at 6% of the weight of the defluorinated sludge is added to the first solid and briquetted and calcined to obtain fluorite spheres.

[0127] It should be noted that the amount of glass powder added remains unchanged here. This is because, based on experimental results, without the addition of MgO, a glass powder content of over 6% is required to achieve good product strength after calcination, and the SiO2 generated by the reaction precisely compensates for this. However, this process is highly prone to causing excessive Si content, and the resulting product requires strict control of the Si content to effectively avoid reducing the continuity of the metal matrix and deteriorating slag fluidity in metallurgy.

[0128] The calcination temperature is 700℃-800℃. If the temperature is below 700℃, it is not easy to effectively form a eutectic. If the temperature is too high, overheating will occur, and the sample will be collapsed and porous, making it difficult to produce spherical products.

[0129] 5. Resource utilization of desulfurization solution. The first liquid after separation is heated to 90°C through heating electrodes and continuously evaporated and concentrated. The solution volume is observed, and evaporation is stopped when crystals begin to appear on the solution surface, yielding the third suspension.

[0130] Maintain the temperature of the third suspension and separate the third suspension to obtain sodium sulfate crystals (mainly anhydrous Na2SO4) and the second liquid.

[0131] It should be noted that the SiO2 generated by the reaction precipitates and concentrates on the surface of the particles (surface nucleation), increasing the specific surface area and causing the crystallization process to be completed more quickly and at a relatively low temperature. After the SiO2 melts together with the glass powder, the flow rate is slow, making it easier to fill the gaps between the particles. After cooling, a dense phase is formed, increasing the density and reducing the difficulty of forming fluorite spheres.

[0132] Referring to the process of Example 1, the artificial fluorite powder desulfurization method of Examples 2-21 was carried out respectively. The parameters of each example, such as the type of fluoride salt, the type of mineralizing agent generated, the type of sulfate generated, pH, weight ratio of fluoride salt to defluorinated sludge, temperature during metathesis reaction, pressure during metathesis reaction, heating temperature during first liquid evaporation, and calcination temperature, are summarized in Table 1.

[0133] Table 1

[0134]

[0135] Comparative Example 1

[0136] Currently, Na2CO3 carbonation can be used to remove sulfates from fluorite sludge.

[0137] A mixture was formed by adding Na₂CO₃ solution to fluoride-containing sludge. The solid-liquid ratio of the fluoride-containing sludge to the sodium carbonate solution was 30 g / L, and the concentration of the sodium carbonate solution was 0.02 mol / L. The mixture was stirred at 200 rpm / h for 1 hour at room temperature (25°C). Calcium in the fluoride-containing sludge, existing as calcium sulfate, was converted to calcium carbonate, resulting in a solid-liquid mixture. This mixture was then filtered, and the sodium sulfate dissolved in the solution, achieving sulfur removal. The reactions involved are as follows:

[0138]

[0139] The solid obtained by filtering the solid-liquid mixture was briquetting and calcined at a temperature of 1000℃.

[0140] Comparative Example 2 differs from Comparative Example 1 in that the calcination temperature is 800 degrees Celsius.

[0141] Comparative Example 3

[0142] Taking advantage of the high selectivity of sodium D-gluconate for CaSO4 and its low chelation reactivity for CaF2, sodium D-gluconate can be used as a desulfurizing agent to purify calcium fluoride sludge.

[0143] Fluoride-containing sludge was added to a 0.03 mol / L sodium D-gluconate solution with a solid-liquid ratio of 30 g / L.

[0144] The mixture of fluoride-containing sludge and sodium D-gluconate was stirred at 200 rpm for 201 hours at room temperature, and then filtered. Sodium sulfate dissolved in water achieved desulfurization, and the resulting Ca(C6H)₂... 11 O7)2 dissolves in water, effectively preventing the formation of inert, insoluble solids that can encapsulate CaSO4 particles.

[0145] The filtered solid was briquetting and calcined at a temperature of 1000℃.

[0146] Comparative Example 4 differs from Comparative Example 3 in that the calcination temperature is 800 degrees Celsius.

[0147] The parameters of additives, reaction temperature, reaction pressure, calcination temperature, etc. for each comparative example are summarized in Table 2.

[0148] Table 2

[0149]

[0150] Test case

[0151] 1. The following parameters of the above embodiments and comparative examples were tested:

[0152] 1) Strength of fluorite spheres: The strength of the produced fluorite spheres was tested, and the strength was expressed in the form of Mohs hardness. The specific testing method was to place the sample stably on the test table, select different Mohs hardness pens from small to large, and use your hand to apply uniform force vertically to scratch the sample surface until a clear single-line scratch mark appeared on the sample surface. The strength of the fluorite spheres was obtained in this way. According to experimental experience, if the strength of the fluorite sphere products is to meet the requirements of the drop test, the Mohs hardness must be ≥2.5. The specific results are shown in Table 2.

[0153] 2) Grade of fluorite spheres: The calcium fluoride content and sulfur content in the produced fluorite spheres were tested; the specific results are shown in Table 3.

[0154] 2. Test Results

[0155] Table 3. Strength and Grade of Fluorite Spheres

[0156]

[0157] Data Analysis:

[0158] The defluorinated sludge is pulped and its pH is adjusted to alkalinity using sodium hydroxide to obtain a first suspension. Fluoride salts are added to the first suspension to initiate a metathesis reaction, generating a second suspension containing calcium fluoride, a mineralizing agent, and water-soluble sulfates. The second suspension is separated to obtain a first solid and a first liquid. The first solid is then calcined to obtain fluorite spheres. This pH adjustment inhibits the dissolution of calcium fluoride and increases the solubility of the fluoride salts. The calcium fluoride produced by the metathesis reaction increases the calcium fluoride content in the first solid, while also generating a mineralizing agent. During calcination, the mineralizing agent produces a eutectic, which lowers the calcination temperature of the first solid. Filtering the second suspension removes the water-soluble sulfate liquid, thus achieving sulfur removal. Furthermore, fluoride salts are more cost-effective than sodium D-gluconate, which costs approximately 148 yuan / kg, while magnesium fluoride and sodium fluorosilicate cost 10 yuan / kg and 2.5 yuan / kg, respectively.

[0159] Furthermore, although sodium D-gluconate and sodium carbonate have successfully achieved desulfurization, the product still requires a high temperature of 1000°C to be formed after desulfurization, while this application can reduce this temperature to 700 to 800°C.

[0160] See Figure 2 As shown, this application provides an apparatus for preparing fluorite spheres, which is used in the above-described method for preparing fluorite spheres.

[0161] The apparatus for preparing fluorite spheres includes a container assembly 100.

[0162] It should be noted that container component 100 may include one, two, or more containers.

[0163] The container assembly 100 is provided with a pretreatment inner cavity 110, a desulfurization inner cavity 120 and a settling inner cavity 130 arranged side by side. The desulfurization inner cavity 120 is connected to the pretreatment inner cavity 110 and the settling inner cavity 130 is connected to the desulfurization inner cavity 120.

[0164] The pretreatment chamber 110, desulfurization chamber 120 and settling chamber 130 can be located in the same container, and the pretreatment chamber 110, desulfurization chamber 120 and settling chamber 130 are arranged side by side along the direction shown by the X-axis in the figure.

[0165] Specifically, the container assembly 100 is provided with an inlet, a sludge addition port, and an alkali addition port, all of which are connected to the pretreatment cavity 110.

[0166] In some embodiments, the apparatus for preparing fluorite spheres includes a first microporous filter membrane 200.

[0167] A first microporous filter membrane 200 is located in the settling cavity 130 to divide the settling cavity 130 into a first part and a second part side by side, the first part being in communication with the desulfurization cavity 120. The pore size of the first microporous filter membrane 200 is 1 to 10 micrometers.

[0168] In some embodiments, the apparatus for preparing fluorite spheres includes a power pump 300.

[0169] The power pump 300 is connected to the second part. The power pump 300 drives the first suspension in the pretreatment inner cavity 110 into the desulfurization inner cavity 120. The second suspension in the desulfurization inner cavity 120 enters the sedimentation inner cavity 130. The second suspension is separated into the first liquid and the first solid in the sedimentation inner cavity 130.

[0170] Specifically, the power pump 300 can be a general alkali-resistant liquid pump, such as a corrosion-resistant centrifugal pump.

[0171] In some embodiments, the apparatus for preparing fluorite spheres includes a first collector 400.

[0172] The first collecting element 400 may be located at the bottom of the first part, and the inner cavity of the first collecting element 400 is connected to the first part to collect the first solid. The first collecting element 400 may be a collecting bag.

[0173] In some embodiments, the container assembly 100 is provided with a first communication port 140, which is located at the lower part of the pretreatment cavity 110 and is connected to the pretreatment cavity 110 and the desulfurization cavity 120 respectively.

[0174] The container assembly 100 is provided with a second communication port 150, which is located at the upper part of the desulfurization inner cavity 120 and is connected to the desulfurization inner cavity 120 and the settling inner cavity 130 respectively.

[0175] It is understandable that the first connecting port 140 is located at the lower part of the pretreatment inner cavity 110, and the second connecting port 150 is located at the upper part of the desulfurization inner cavity 120. In this way, the path of the first suspension in the pretreatment inner cavity 110 into the desulfurization inner cavity 120 and the path of the second suspension in the desulfurization inner cavity 120 into the sedimentation inner cavity 130 are more tortuous and complex, which is conducive to a more complete reaction.

[0176] In some embodiments, the apparatus for preparing fluorite spheres includes at least two first inclined partitions 500.

[0177] The first inclined partition 500 is located in the first part, the extension plane of the first inclined partition 500 has an angle with the extension plane of the first microporous filter membrane 200, the top of the first inclined partition 500 has a gap with the top of the sedimentation cavity 130, and part of the first inclined partition 500 is located below the second connecting port 150.

[0178] In this configuration, at least two first inclined partitions 500 are arranged side-by-side and spaced apart. For example, there are three first inclined partitions 500, and the extending planes of the three first inclined partitions 500 are parallel. The three first inclined partitions 500 are spaced apart along the direction indicated by the X-axis.

[0179] In some embodiments, the apparatus for preparing fluorite spheres includes a first vertical partition 600.

[0180] The first vertical partition 600 is located in the first part. The extension plane of the first vertical partition 600 is parallel to the extension plane of the first microporous filter membrane 200. The first vertical partition 600 is located below the first inclined partition 500. The first vertical partition 600 and the first inclined partition 500 have a gap. The bottom of the first vertical partition 600 is connected to the bottom of the settling cavity 130.

[0181] The function of the first inclined septum 500 is to initially intercept a portion of the solids in the suspension and prolong the residence time of the suspension to ensure sufficient reaction. Therefore, in this embodiment, the angle between the extended plane of the inclined septum and the extended plane of the first microporous filter membrane 200 is not specifically limited.

[0182] It is understandable that by setting at least two first inclined baffles 500 and first vertical baffles 600, the path of the second suspension after entering the sedimentation cavity 130 can be more tortuous and complex, which is conducive to effectively blocking the first solid, and to separating the first solid so that the first liquid flows toward the first microporous filter membrane 200 and the first solid falls into the first collection member 400.

[0183] In some embodiments, the apparatus for preparing fluorite spheres includes a first stirring device 700.

[0184] The first stirring device 700 is located in the pretreatment cavity 110. The stirring of the first stirring device 700 facilitates the thorough mixing of the defluorinated sludge, water, and sodium hydroxide to form the first suspension.

[0185] The first stirring device 700 can rotate at a speed of 10,000 rpm (revolutions per minute).

[0186] In some embodiments, the apparatus for preparing fluorite spheres includes a pH sensor 800 located in the pretreatment chamber 110. The pH sensor 800 can detect the pH of the first suspension.

[0187] In some embodiments, the apparatus for preparing fluorite spheres includes a first heating element 900. The first heating element 900 is located in the desulfurization cavity 120.

[0188] The first heating element 900 can be a heating electrode. The first heating element 900 heats the mixture in the desulfurization cavity 120, thereby increasing the rate of the metathesis reaction.

[0189] In some embodiments, the apparatus for preparing fluorite balls includes a second stirring device 1000, which is located in the desulfurization chamber 120.

[0190] The second stirring device 1000 stirs the mixture, which helps to fully mix the mixture in the desulfurization chamber 120 and improves the speed and extent of the metathesis reaction.

[0191] In some embodiments, the apparatus for preparing fluorite spheres includes a first temperature sensor 1100 located in the desulfurization chamber 120. The first temperature sensor 1100 is used to detect the temperature of the mixture within the desulfurization chamber 120. Furthermore, the temperature can be fed back to a controller, which controls the operation of the first heating element 900.

[0192] In some embodiments, the container assembly 100 is provided with a gas pressurization port, a desulfurizing agent feeding port, and a liquid seal exhaust port, all of which are in communication with the desulfurization inner cavity 120. The gas pressurization port is located at the bottom of the desulfurization inner cavity 120, while the desulfurizing agent feeding port and the liquid seal exhaust port are located at the top of the desulfurization inner cavity 120, respectively.

[0193] In some embodiments, the apparatus for preparing fluorite spheres includes an air blower 1200 connected to the bottom of a container assembly 100. The air blower 1200 is configured to blow air into a desulfurization chamber 120 to increase the air pressure inside the desulfurization chamber 120. The air blower 1200 is connected to an air pressurization port.

[0194] Specifically, the air blower 1200 can be a blower.

[0195] Understandably, by placing the air blower 1200 at the bottom of the container assembly 100, air can be blown in from the bottom to allow the gas to pass fully through the solution, thereby pressurizing the solution as a whole.

[0196] In some embodiments, the apparatus for preparing fluorite spheres includes a gas distributor 1300 located within the desulfurization chamber 120. The gas distributor 1300 is provided with a plurality of spaced-apart gas outlets. This facilitates a more uniform dispersion of the blown-in air within the second suspension.

[0197] In some embodiments, the apparatus for preparing fluorite spheres includes a liquid seal structure 1400. The liquid seal structure 1400 is connected to the top of the container assembly 100 and is configured to control whether the desulfurization chamber 120 is in communication with or not in communication with the outside of the container assembly 100. The liquid seal structure 1400 is in communication with a liquid seal exhaust port.

[0198] It should be noted that the liquid seal structure 1400 includes a U-shaped tube, the interior of which is filled with a liquid seal medium to a specific height. This device utilizes the unique geometry of the U-shaped tube to form a liquid column barrier, and its working principle is based on the principle of hydrostatic equilibrium. When the internal pressure of the reactor increases, the gas can overcome the hydrostatic pressure of the liquid column and be discharged through the U-shaped tube in the form of bubbles. When the internal pressure of the reactor decreases or the external pressure increases, the hydrostatic pressure formed by the liquid column becomes an effective barrier, effectively preventing external gas from flowing back into the reactor. The liquid seal device can be any commonly used liquid seal device in related technologies, and U-shaped or double U-shaped liquid seal devices are optional.

[0199] Understandably, the pressure applied to the second suspension can be adjusted by controlling the blower speed and the exhaust speed of the liquid seal structure 1400.

[0200] In some embodiments, the container assembly 100 is provided with a precipitation chamber 160. The precipitation chamber 160 may be located in a different container from the pretreatment chamber 110, the desulfurization chamber 120, and the settling chamber 130.

[0201] In some embodiments, the apparatus for preparing fluorite spheres includes a second microporous filter membrane 1500.

[0202] The second microporous filter membrane 1500 is located in the precipitation cavity 160 to divide the precipitation cavity 160 into a third part and a fourth part side by side. The third part is connected to the second part, and the fourth part is connected to the pretreatment cavity 110.

[0203] Specifically, the second microporous filter membrane 1500 has a pore size of 1 to 10 micrometers.

[0204] In some embodiments, the apparatus for preparing fluorite spheres includes a second heating element 1600.

[0205] The second heating element 1600 is located in the third part. The second heating element 1600 is used to heat the first liquid to achieve evaporation of the first liquid and cause sulfate crystals to precipitate.

[0206] Specifically, the second heating element 1600 can be a heating electrode.

[0207] In some embodiments, the apparatus for preparing fluorite spheres includes a second collector 1700.

[0208] The second collector 1700 is located at the bottom of the third part, and the inner cavity of the second collector 1700 is connected to the first part to collect sulfate crystals.

[0209] Specifically, the second collection component 1700 can be a collection bag.

[0210] It should be noted that the fourth part is connected to the pretreatment chamber 110, and the second liquid can flow into the pretreatment chamber 110. The second liquid is alkaline. Adding the second liquid to the first suspension can reduce the amount of hydroxide used and save water resources.

[0211] In some embodiments, the apparatus for preparing fluorite spheres includes a connecting pipe 1800, the lumen of which is connected to the fourth part and the pretreatment inner cavity 110, respectively.

[0212] In some embodiments, the apparatus for preparing fluorite spheres includes a third microporous filter membrane 1900.

[0213] The third microporous filter membrane 1900 is located in the lumen, and the pore size of the third microporous filter membrane 1900 is smaller than that of the second microporous filter membrane 1500.

[0214] Specifically, the second microporous filter membrane 1500 has a pore size of 2nm.

[0215] In some embodiments, the apparatus for preparing fluorite spheres includes a third collector 2000.

[0216] The third collecting element 2000 is located at the bottom of the connecting pipe 1800 and below the third microporous filter membrane 1900. The inner cavity of the third collecting element 2000 is connected to the pipe cavity to collect sulfate crystals.

[0217] For example, the sulfate crystals are sodium sulfate crystals, which settle into the second collector 1700 and the third collector 2000. Using this method, approximately 0.6 kg of sodium sulfate can be recovered for sale as a commodity for every 100 kg of sludge treated, with a selling price of 2000-2500 yuan / ton.

[0218] It should be noted that the second liquid contains trace amounts of sodium sulfate, MgF2, CaF2, etc., and can be recycled back to the reflux point. During the reflux process, the residual sodium sulfate is further filtered out by a second microporous membrane 1500 with a pore size of 2 nm.

[0219] In some embodiments, the apparatus for preparing fluorite spheres includes at least two second inclined partitions 2200.

[0220] The second inclined septum 2200 is located in the third part. The extending plane of the second inclined septum 2200 forms an angle with the extending plane of the second microporous filter membrane 1500, and the top of the second inclined septum 2200 is spaced from the top of the precipitation cavity 160. At least two second inclined septums 2200 are arranged side by side and spaced apart.

[0221] In some embodiments, the apparatus for preparing fluorite spheres includes a second vertical partition 2100.

[0222] The second vertical partition 2100 is located in the third part. The extending plane of the second vertical partition 2100 is parallel to the extending plane of the second microporous filter membrane 1500. The second vertical partition 2100 is located below the second inclined partition 2200. The second vertical partition 2100 and the second inclined partition 2200 have a gap. The bottom of the second vertical partition 2100 is connected to the bottom of the precipitation cavity 160.

[0223] In some embodiments, the apparatus for preparing fluorite spheres includes a third vertical partition 2300.

[0224] The third vertical partition 2300 is located in the third part. The extending plane of the third vertical partition 2300 is parallel to the extending plane of the second microporous filter membrane 1500. The third vertical partition 2300 is located on the side of the second vertical partition 2100 away from the second microporous filter membrane 1500. The top of the third vertical partition 2300 is connected to the top of the precipitation cavity 160, and the bottom of the third vertical partition 2300 is spaced from the bottom of the precipitation cavity 160.

[0225] The function of the second inclined septum 2200 is to initially intercept a portion of the solids in the suspension and prolong the residence time of the suspension. Therefore, this embodiment does not specifically limit the angle between the extended plane of the second inclined septum 2200 and the extended plane of the second microporous filter membrane 1500.

[0226] It is understandable that by setting at least two second inclined baffles 2200, a second vertical baffle 2100, and a third vertical baffle 2300, the path of the third suspension after entering the sedimentation chamber 130 can be made more tortuous and complex, which is conducive to effectively blocking the sulfate crystals and separating the sulfate crystals so that the second liquid flows toward the first microporous filter membrane 200, and the sulfate crystals fall into the second collection member 1700.

[0227] It should be noted that the terms "one embodiment," "embodiment," "exemplary embodiment," "some embodiments," etc., mentioned in the specification indicate that the described embodiment may include a specific feature, structure, or characteristic, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments, whether explicitly described or not, is within the knowledge scope of those skilled in the art.

[0228] Generally speaking, terms should be understood at least in part by their use in context. For example, at least in part by context, the term "one or more" as used in the text can be used to describe any feature, structure, or characteristic of the singular meaning, or a combination of features, structures, or characteristics of the plural meaning. Similarly, at least in part by context, terms such as "a" or "the" can also be understood to convey either singular or plural usage.

[0229] It should be readily understood that the terms “on,” “above,” and “on top of” in this application should be interpreted in the broadest possible sense, such that “on” means not only “directly on something” but also “on something” with an intermediate feature or layer therebetween, and that “above” or “on top of” means not only “on something” but also “on something” without an intermediate feature or layer therebetween (i.e., directly on something).

[0230] Furthermore, for ease of explanation, spatially relative terms such as "below," "below," "under," "above," and "above" may be used to describe the relationship of one element or feature relative to other elements or features as shown in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation other than those shown in the figures. The device may have other orientations (rotated 90° or in other orientations), and the spatially relative descriptive terms used herein may be interpreted accordingly.

[0231] It should be noted that the brief descriptions of terms in this application are only for the convenience of understanding the embodiments described below, and are not intended to limit the embodiments of this application. Unless otherwise stated, these terms should be understood in their ordinary and common meaning.

[0232] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover but not exclusively include, for example, a product or device that includes a series of components is not necessarily limited to those that are explicitly listed, but may include other components that are not explicitly listed or that are inherent to such product or device.

[0233] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0234] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0235] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0236] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for preparing fluorite spheres, characterized in that, include: The fluoride-removed sludge was pulped, and the pH of the sludge slurry was adjusted to be alkaline using sodium hydroxide to obtain the first suspension. Fluoride salts are added to the first suspension to carry out a metathesis reaction to generate a second suspension containing calcium fluoride, a mineralizing agent, and a water-soluble sulfate. The second suspension is separated to obtain a first solid and a first liquid; The first solid was subjected to pelletizing and calcination to obtain fluorite spheres; Wherein, the fluoride salt is magnesium fluoride, and the mineralizing agent is magnesium hydroxide; Alternatively, the fluoride salt may be sodium fluorosilicate, and the mineralizing agent may be silicon dioxide.

2. The method for preparing fluorite spheres according to claim 1, characterized in that, The pH value is between 12 and 13.

5.

3. The method for preparing fluorite spheres according to claim 1, characterized in that, The weight of the fluoride salt is 1% to 2% of the weight of the defluorinated sludge.

4. The method for preparing fluorite spheres according to claim 1, characterized in that, When adding fluoride salt to the first suspension, the mixture of the first suspension and the fluoride salt is heated and pressurized to 80°C to 100°C and pressurized to 0.15 to 0.2 MPa.

5. The method for preparing fluorite spheres according to any one of claims 1 to 4, characterized in that, Also includes: The first liquid is evaporated to precipitate the sulfate crystals, resulting in a third suspension; The third suspension is separated to obtain the sulfate crystals and a second liquid.

6. The method for preparing fluorite spheres according to claim 5, characterized in that, Also includes: The second liquid is added to the first suspension.

7. An apparatus for preparing fluorite spheres, used in the method for preparing fluorite spheres according to any one of claims 1 to 6, characterized in that, include: The container assembly is provided with a pretreatment inner cavity, a desulfurization inner cavity and a settling inner cavity arranged side by side, wherein the desulfurization inner cavity is connected to the pretreatment inner cavity and the settling inner cavity is connected to the desulfurization inner cavity; A first microporous filter membrane is located in the settling cavity to divide the settling cavity into a first part and a second part side by side, the first part being in communication with the desulfurization cavity; A power pump, connected to the second part, drives the first suspension in the pretreatment chamber into the desulfurization chamber, and the second suspension in the desulfurization chamber into the sedimentation chamber, where the second suspension is separated into a first liquid and a first solid. A first collecting element is located at the bottom of the first part, and the inner cavity of the first collecting element is in communication with the first part to collect the first solid. The container assembly is provided with a first communication port, which is located at the lower part of the pretreatment inner cavity and is connected to both the pretreatment inner cavity and the desulfurization inner cavity. The container assembly is provided with a second communication port, which is located at the upper part of the desulfurization inner cavity and is connected to both the desulfurization inner cavity and the settling inner cavity. At least two first inclined septa, the first inclined septa being located in the first portion, the extending plane of the first inclined septa having an angle with the extending plane of the first microporous filter membrane, the top of the first inclined septa being spaced from the top of the settling cavity, and a portion of the first inclined septa being located below the second communication port; The at least two first inclined partitions are arranged side by side and spaced apart; A first vertical partition is located in the first part. The extending plane of the first vertical partition is parallel to the extending plane of the first microporous filter membrane. The first vertical partition is located below the first inclined partition. The first vertical partition and the first inclined partition have a gap. The bottom of the first vertical partition is connected to the bottom of the sedimentation cavity.

8. The apparatus for preparing fluorite spheres according to claim 7, characterized in that, It also includes a first stirring device, which is located in the pretreatment cavity; And / or, it also includes a pH sensor located in the pretreatment cavity; And / or, it also includes a first heating element located in the desulfurization cavity; And / or, it also includes a second stirring device located in the desulfurization chamber; And / or, it also includes a first temperature sensor located in the desulfurization cavity; And / or, it also includes an air blower connected to the bottom of the container assembly, the air blower being configured to blow air into the desulfurization cavity to increase the air pressure inside the desulfurization cavity; And / or, it also includes a liquid seal structure connected to the top of the container assembly, the liquid seal structure being configured to control communication or non-communication between the desulfurization cavity and the outside of the container assembly.

9. The apparatus for preparing fluorite spheres according to claim 7, characterized in that, The container assembly is provided with a precipitation cavity; Also includes: A second microporous filter membrane is located in the precipitation cavity to divide the precipitation cavity into a third part and a fourth part side by side. The third part is connected to the second part, and the fourth part is connected to the pretreatment cavity. The second heating element is located in the third part; The second collector, located at the bottom of the third part, has an inner cavity that communicates with the first part to collect sulfate crystals.

10. The apparatus for preparing fluorite spheres according to claim 9, characterized in that, It also includes connecting pipes, the lumens of which are respectively connected to the fourth part and the pretreatment inner cavity; A third microporous filter membrane is located in the lumen, and the pore size of the third microporous filter membrane is smaller than that of the second microporous filter membrane; The third collecting element is located at the bottom of the connecting pipe and below the third microporous filter membrane. The inner cavity of the third collecting element is connected to the lumen of the pipe to collect sulfate crystals.

11. The apparatus for preparing fluorite spheres according to claim 9, characterized in that, Also includes: At least two second inclined septa are located in the third part. The extending plane of the second inclined septa forms an angle with the extending plane of the second microporous filter membrane. The top of the second inclined septa is spaced from the top of the precipitation cavity. The at least two second inclined septa are arranged side by side and spaced apart. The second vertical septum is located in the third part. The extending plane of the second vertical septum is parallel to the extending plane of the second microporous filter membrane. The second vertical septum is located below the second inclined septum. The second vertical septum and the second inclined septum have a gap. The bottom of the second vertical septum is connected to the bottom of the precipitation cavity. The third vertical partition is located in the third part. The extending plane of the third vertical partition is parallel to the extending plane of the second microporous filter membrane. The third vertical partition is located on the side of the second vertical partition away from the second microporous filter membrane. The top of the third vertical partition is connected to the top of the precipitation cavity, and the bottom of the third vertical partition is spaced from the bottom of the precipitation cavity.

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