Method for purifying beryllium glass leach

Abstract

The application provides a beryllium glass leaching solution purification method, and belongs to the technical field of hydrometallurgy, and comprises the following steps: the beryllium glass leaching solution is heated to a preset temperature, and an alkaline calcium-based ore slurry is added to carry out pre-neutralization reaction to obtain a pre-neutralized solution; the pre-neutralized solution is subjected to first liquid-solid separation treatment to obtain a pre-neutralized liquid and a filter residue; the pre-neutralized liquid is subjected to deep iron and aluminum removal treatment according to a first deep iron and aluminum removal route or a second deep iron and aluminum removal route to obtain a beryllium-containing leaching solution and an iron and aluminum-containing leaching residue, so as to complete the purification of the beryllium glass leaching solution; the first deep iron and aluminum removal route comprises neutralization reaction treatment, second liquid-solid separation treatment and first pressure leaching treatment; the second deep iron and aluminum removal route comprises oxidation neutralization reaction treatment and second pressure leaching treatment. The application can solve the problems of existing technologies, such as the introduction of impurities, strict control, complex process and large beryllium loss.

Description

Technical Field

[0001] This invention relates to the field of hydrometallurgical technology, and more specifically, to a method for purifying beryllium glass leachate. Background Technology

[0002] Beryllium glass is an important intermediate product in beryllium smelting. Industrially, it is generally treated with sulfuric acid aging and water leaching processes. Sulfuric acid aging can convert silicon and calcium into insoluble calcium sulfate and silicon dioxide, achieving the initial separation of silicon, calcium and beryllium. However, almost all impurities such as iron and aluminum enter the leaching solution. Therefore, the core challenge of subsequent purification is to efficiently and deeply remove iron and aluminum impurities.

[0003] Traditional mainstream purification processes include aluminum removal via evaporation and crystallization of ammonium sulfate, and iron removal via sulfite reduction. In the aluminum removal process, ammonium sulfate is added to the aluminum-containing sulfuric acid solution. + With NH4 + SO4² - It forms aluminum ammonium alum (alum, NH4Al(SO4)2) with low solubility. The solubility of 12H2O decreases significantly with decreasing temperature. In the process, the leachate needs to be evaporated and concentrated to a specific gravity of 1.2–1.5. Then, 150–400 g / L of ammonium sulfate is added while hot. After cooling to 25°C, aluminum ammonium alum crystallizes out. The aluminum is then removed by filtration. The main reaction is as follows: During the iron removal process, ferric iron in the solution after aluminum removal will co-precipitate during beryllium precipitation, affecting the purity of beryllium oxide. Therefore, sulfite is added to remove Fe³⁺. + Reduced to Fe² + Fe² + The large difference between the precipitation pH and the beryllium precipitation pH can reduce interference with the beryllium precipitation. The main reaction is as follows: Although this process has high pH control precision and simple iron removal operation, it has drawbacks such as large volume of ammonium salt waste liquid, high cost of ammonia nitrogen treatment, insufficient aluminum removal depth, high energy consumption, low beryllium recovery rate, and poor product purity.

[0004] In recent years, the industry has gradually explored alternative processes such as extraction, goethite extraction and cryolite extraction, and chlorination system extraction. Among them, the extraction process for removing iron and aluminum involves using an extractant to remove Fe³⁺. + Al³ + With Be² + Separation is achieved by different extraction selectivity, and commonly used systems include P204 (di(2-ethylhexyl)phosphoric acid): selective extraction of Fe³⁺ at low pH (<1.5). +Naphthenic acid, alcohol, and kerosene system: beryllium is extracted at pH 5-8, while iron and aluminum remain in the raffinate; BC196 (carboxylic acid) and P204 co-extraction: iron enters the organic phase, aluminum remains in the raffinate, and iron and aluminum are separated simultaneously. Advantages include high separation selectivity, recyclable extractant, and easy resource recovery of iron and aluminum; disadvantages include high cost, delicate operation, limited impurity removal depth, and large equipment investment, as exemplified by a method for extracting and separating beryllium disclosed in patent CN102851502B and a clean smelting method for beryllium oxide and beryllium oxide disclosed in patent CN117228696B.

[0005] In the goethite method for iron removal and the cryolite method for aluminum removal, the goethite method uses ZnS or iron powder to remove Fe³⁺. + Reduced to Fe² + Fe²⁺ was slowly oxidized by passing air through a controlled environment at pH 4.5–5.0 and 60–80°C. + Fe³ + Low concentration of Fe³ + Hydrolysis produces well-crystallized goethite (α-FeOOH) precipitate, which has good slag filterability, low beryllium entrainment, and can be used as iron ore raw material; the disadvantages are that it requires two steps of reduction and oxidation, strict pH control, high energy consumption, and long cycle, such as the clean smelting method of beryllium oxide and beryllium oxide disclosed in patent CN117228696B.

[0006] The cryolite method involves adding fluoride salts to the liquid after iron removal, Al³ + With F - The formation of sparingly soluble hexafluoroaluminate (cryolite, such as (NH4)3AlF6) precipitate is achieved through the following reaction: The advantages are that aluminum can be recycled, precipitation and filtration are good, and beryllium loss is small; the disadvantages are that fluoride ions are introduced, equipment is highly corrosive, fluoride-containing wastewater needs to be treated, ammonium fluoride is expensive, and beryllium is carried in cryolite slag, such as the beryllium sulfate solution pretreatment method disclosed in patent CN 118108244 A.

[0007] In the process of removing iron and aluminum through extraction using a chlorination system, the sulfuric acid leachate is converted into a chlorination system, and Fe³⁺ is removed. + Formation of stable chloride complexes ([FeCl4)) - [FeCl3]), which is efficiently extracted by extractants such as TBP and MIBK, Be² + Al³ + The advantages of using an aqueous phase are extremely high selectivity for iron and beryllium, simple back-extraction, and low energy consumption. The disadvantages are that the process becomes longer, HCl is volatile, equipment sealing and material requirements are high, and chloride ion residue affects the performance of high-purity beryllium oxide, such as the method disclosed in patent CN116282090B that uses a chlorination system to separate beryllium from beryllium containing heterohydric hydroxide.

[0008] It is evident that existing beryllium glass leaching solution purification processes generally suffer from drawbacks such as impurity introduction, high energy consumption, large wastewater volume, high beryllium loss, low product purity, and difficulty in industrialization, as detailed below: 1. High energy consumption: The ammonium process for aluminum removal requires a large amount of evaporation and concentration of the leachate to meet the crystallization conditions of aluminum ammonium alum. The evaporation process has high energy consumption, and the high-temperature acidic medium aggravates equipment corrosion, resulting in high maintenance costs.

[0009] 2. Introduction of impurities and large wastewater volume: Processes such as ammonium process, saponification extraction, and cryolite process introduce large amounts of NH4. + Na + F - Cl - Impurity ions, such as ammonia nitrogen, fluorine, and salt, form waste liquid with high concentrations of these substances, making it difficult to treat and costly to protect the environment.

[0010] 3. Narrow process control window and poor stability: Sulfite reduction, goethite method, extraction saponification and other processes are sensitive to temperature, pH and reagent dosage, and have a narrow operating range. They are prone to problems such as incomplete reduction, incomplete impurity removal and emulsification phase separation, resulting in large fluctuations in product quality.

[0011] 4. High beryllium loss and low recovery rate: Factors such as evaporation and concentration, extraction and emulsification, slag entrainment, and improper pH control can all lead to beryllium loss. The existing process has a beryllium recovery rate of only 73% to 79%, resulting in low resource utilization.

[0012] 5. Limited product purity: Residual impurity ions and incomplete removal of iron and aluminum lead to excessive levels of impurities such as Al, Fe, Na, and Si in industrial beryllium oxide, making it difficult to meet the requirements for high-purity, nuclear-grade, and electronic-grade products.

[0013] 6. Complex processes and high difficulty in industrialization: Extraction methods require multi-stage extraction and back-extraction, and large equipment investment; goethite and cryolite methods have many steps, long cycles, and high hazardous waste disposal costs; chlorination systems are highly corrosive and require high-quality equipment materials, all of which are not conducive to large-scale industrial applications.

[0014] In summary, current purification processes for beryllium glass leachate have problems such as introducing impurities, requiring stringent control, complex processes, and significant beryllium loss.

[0015] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of the present invention, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0016] In view of the above problems, the purpose of this invention is to provide a purification method for beryllium glass leachate, so as to solve the problems of introducing impurities, strict control, complex process and large beryllium loss in the purification process of beryllium glass leachate in the prior art.

[0017] This invention provides a method for purifying beryllium glass leachate, comprising the following steps: S1. Heat the beryllium glass leaching solution to a preset temperature and add alkaline calcium-based slurry for pre-neutralization reaction to obtain pre-neutralized solution; S2. Perform a first liquid-solid separation treatment on the pre-neutralized liquid to obtain pre-neutralized liquid and filter residue; S3. The pre-neutralized liquid is subjected to deep iron and aluminum removal treatment according to either the first deep iron and aluminum removal route or the second deep iron and aluminum removal route to obtain a beryllium-containing leachate and an iron and aluminum-containing leachate residue, thereby completing the purification of the beryllium glass leachate; wherein, The first deep iron and aluminum removal route includes: adding a first neutralizing agent to the pre-neutralized liquid to perform a neutralization reaction treatment on the pre-neutralized liquid, performing a second liquid-solid separation treatment on the neutralized slurry obtained from the neutralization reaction treatment, and performing a first pressure leaching treatment on the neutralized residue obtained from the second liquid-solid separation treatment after adding water and sulfuric acid to adjust the slurry, to obtain a beryllium-containing leaching solution and an iron and aluminum-containing leaching residue; The second deep iron and aluminum removal route includes: adding an oxidant and a second neutralizer to the pre-neutralized liquid to perform an oxidation-neutralization reaction treatment on the pre-neutralized liquid, and performing a second pressure leaching treatment on the oxidation-neutralized slurry obtained from the oxidation-neutralization treatment to obtain a beryllium-containing leaching solution and an iron-aluminum-containing leaching residue.

[0018] In addition, a preferred embodiment is that the beryllium glass leachate is prepared by successively melting beryl and alkaline flux and water quenching to obtain beryllium glass, and then successively ball milling, grading, sulfuric acid aging and water leaching of the beryllium glass; wherein, the initial sulfuric acid concentration of the system in the sulfuric acid aging stage is ≥150g / L.

[0019] Furthermore, a preferred approach is to heat the beryllium glass leaching solution to a preset temperature and add alkaline calcium-based slurry for a pre-neutralization reaction to obtain the pre-neutralized solution. The preset temperature is 80–95°C; The alkaline calcium-based slurry is a calcium carbonate slurry or a calcium hydroxide slurry with a mass fraction of 10% to 30%. At the end of the pre-neutralization reaction, the pH of the beryllium glass leachate is 1.8 to 2.0.

[0020] Furthermore, a preferred embodiment is that the first liquid-solid separation process is filtration or pressure filtration.

[0021] Furthermore, a preferred approach is to perform deep iron and aluminum removal treatment on the pre-neutralized liquid according to either a first-depth iron and aluminum removal route or a second-depth iron and aluminum removal route to obtain a beryllium-containing leachate and an iron and aluminum-containing leachate residue, thereby completing the purification process of the beryllium glass leachate. When the mass ratio of iron to beryllium in the pre-neutralized liquid is greater than or equal to 0.5, the pre-neutralized liquid is subjected to deep iron and aluminum removal treatment according to the first deep iron and aluminum removal route; When the mass ratio of iron to beryllium in the pre-neutralized liquid is less than 0.5, the pre-neutralized liquid is subjected to deep iron and aluminum removal treatment according to the second deep iron and aluminum removal route.

[0022] Furthermore, a preferred embodiment is that during the process of adding a first neutralizing agent to the pre-neutralized liquid to perform a neutralization reaction, The first neutralizing agent is a sodium carbonate solution with a mass fraction of 10% to 30% or a sodium bicarbonate solution with a mass fraction of 10% to 30%. At the endpoint of the neutralization reaction, the pH of the pre-neutralized solution is ≥7.5; The neutralization reaction process takes 2 to 5 hours.

[0023] Furthermore, a preferred embodiment is that during the second liquid-solid separation process of the neutralized slurry obtained from the neutralization reaction, The second liquid-solid separation process is filtration or pressure filtration; The neutralized liquid obtained from the second liquid-solid separation process is used to prepare the first neutralizing agent.

[0024] Furthermore, a preferred embodiment is that, after the neutralized residue obtained from the second liquid-solid separation treatment is slurried with water and sulfuric acid, it undergoes a first pressure leaching treatment to obtain a beryllium-containing leachate and an iron-aluminum-containing leaching residue. The mass ratio of sulfuric acid to the neutralization residue is 100–1200 kg / t; The liquid phase composed of water and sulfuric acid has a liquid-solid mass ratio of 6 to 8:1 with respect to the neutralization residue. The first pressure leaching treatment is carried out in a pressure vessel at a temperature of 180–250°C for 1–2 hours.

[0025] Furthermore, a preferred approach is that during the process of adding an oxidant and a second neutralizing agent to the pre-neutralized liquid to perform an oxidative neutralization reaction, The oxidant is hydrogen peroxide or oxygen; wherein, when the oxidant is hydrogen peroxide, 2-5g of hydrogen peroxide is added per liter of the pre-neutralized solution, and the mass concentration of the hydrogen peroxide is 30%; when the oxidant is oxygen, the oxygen flow rate is 200-1000mL / min based on the pre-neutralized solution, and the purity of the oxygen is 100%. The second neutralizing agent is a sodium carbonate solution with a mass fraction of 10% to 30% or a sodium bicarbonate solution with a mass fraction of 10% to 30%. At the endpoint of the oxidation-neutralization reaction, the pH of the pre-neutralized solution is 3.0–3.2. The oxidation-neutralization reaction takes 2 to 4 hours.

[0026] Furthermore, a preferred embodiment is that, during the second pressure leaching treatment of the oxidized and neutralized slurry obtained from the oxidation and neutralization treatment to obtain a beryllium-containing leachate and an iron-aluminum-containing leaching residue, The second pressure leaching treatment is carried out in a pressure vessel at a temperature of 180–250°C for 1–2 hours.

[0027] As can be seen from the above technical solution, the purification method for beryllium glass leachate provided by the present invention first performs a pre-neutralization reaction on the beryllium glass leachate to reduce its acidity, adjust its state, and stabilize subsequent process parameters to reduce subsequent beryllium loss; a small amount of precipitated iron slag is removed through a first liquid-solid separation treatment to obtain a pre-neutralized liquid with significantly reduced acidity, providing a stable feed solution for subsequent deep iron and aluminum removal; either a first deep iron and aluminum removal route or a second deep iron and aluminum removal route can be flexibly adopted for deep iron and aluminum removal treatment, and NH4 is not introduced throughout the entire process, regardless of whether it is the first or second deep iron and aluminum removal route. + F - Cl - Impurity ions such as iron and aluminum can be efficiently removed under mild conditions, thereby significantly improving beryllium recovery rate and product purity. It has the advantages of wide process control window, mild conditions, short process, high beryllium recovery rate, good iron and aluminum removal effect, easy wastewater treatment, and strong industrial implementation. It can effectively solve the problems of introducing impurities, strict control, complex process, and large beryllium loss in existing technologies.

[0028] To achieve the foregoing and related objectives, and in accordance with one or more aspects of the invention, the features described in detail below are included. Certain exemplary aspects of the invention are illustrated in detail below with reference to the accompanying drawings. However, these aspects indicate only a few of the various ways in which the principles of the invention can be used. Furthermore, the invention is intended to encompass all such aspects and their equivalents. Attached Figure Description

[0029] Other objects and results of the invention will become more apparent and readily understood with reference to the following description taken in conjunction with the accompanying drawings, and with a more complete understanding of the invention.

[0030] Figure 1 A flowchart illustrating a method for purifying beryllium glass leachate according to an embodiment of the present invention; Figure 2 This is a technical roadmap for a method of purifying beryllium glass leachate according to an embodiment of the present invention. Detailed Implementation

[0031] In the following description, numerous specific details are set forth for illustrative purposes and to provide a thorough understanding of one or more embodiments. However, it will be apparent that these embodiments may also be implemented without these specific details.

[0032] In view of the problems of introducing impurities, strict control, complex process and large beryllium loss in the purification process of beryllium glass leachate in the aforementioned prior art, the present invention provides a purification method for beryllium glass leachate.

[0033] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0034] To illustrate the purification method for beryllium glass leachate provided by this invention, Figure 1 A flowchart of a method for purifying beryllium glass leachate according to an embodiment of the present invention is shown; Figure 2 The technical route of a method for purifying beryllium glass leachate according to an embodiment of the present invention is shown.

[0035] like Figure 1 Combination Figure 2 As shown in the figure, the purification method for beryllium glass leachate provided by the present invention mainly includes the following steps: Step S1: Heat the beryllium glass leaching solution to a preset temperature and add alkaline calcium-based slurry for pre-neutralization reaction to obtain pre-neutralized solution.

[0036] Specifically, the beryllium glass leachate, heated to a preset temperature, undergoes a pre-neutralization reaction treatment to neutralize the beryllium glass. + Al³ + Almost no precipitation, only a small amount of Fe³ + A slight hydrolysis precipitation occurs, thereby reducing the acidity of the solution, adjusting the solution state, stabilizing subsequent process parameters, and reducing subsequent beryllium loss.

[0037] As a preferred embodiment of the present invention, the beryllium glass leachate is prepared by successively melting beryl and alkaline flux and water quenching to obtain beryllium glass, and then successively ball milling, grading, sulfuric acid aging and water leaching of the beryllium glass; wherein, the initial sulfuric acid concentration of the system in the sulfuric acid aging stage is ≥150g / L.

[0038] Specifically, the beryllium glass leachate is prepared by melting beryl and alkaline flux at a high temperature of 1500-1700℃ and quenching it in water to obtain beryllium glass, which is then ball-milled, graded, aged in sulfuric acid, and leached in water. It is an acidic solution rich in beryllium, iron, and aluminum, with an initial sulfuric acid concentration ≥150g / L, high acidity, and high impurity content.

[0039] It should be noted that this invention does not impose any particular limitation on the source of the beryllium glass leachate; any beryllium glass leachate prepared by any existing process can be applied to the purification method provided by this invention. The preparation process of the beryllium glass leachate given above is only a preferred embodiment of this invention and is provided as an example only. It is not intended to limit the acquisition method of the beryllium glass leachate. Those skilled in the art can flexibly select beryllium glass leachates obtained by other conventional preparation processes according to actual production conditions, and all such leachates fall within the protection scope of this invention.

[0040] In a preferred embodiment of the present invention, during the process of heating the beryllium glass leaching solution to a preset temperature and adding alkaline calcium-based slurry for pre-neutralization reaction to obtain the pre-neutralized solution, The preset temperature is 80–95℃; The alkaline calcium-based slurry is a calcium carbonate slurry or a calcium hydroxide slurry with a mass fraction of 10% to 30%. At the end of the pre-neutralization reaction, the pH of the beryllium glass leachate was 1.8–2.0.

[0041] Specifically, the preset temperature is preferably, but not limited to, 80–95°C. When the pH of the beryllium glass leaching solution is 1.8–2.0, Be² + Al³ + Almost no precipitation, only a small amount of Fe³ + Slight hydrolysis and precipitation occur. The alkaline calcium-based slurry is preferably, but not limited to, a calcium carbonate slurry or a calcium hydroxide slurry with a mass fraction of 10% to 30%, which will not introduce other impurities.

[0042] Step S2: Perform a first liquid-solid separation treatment on the pre-neutralized liquid to obtain the pre-neutralized liquid and filter residue.

[0043] Specifically, the pre-neutralized feed solution undergoes liquid-solid separation to remove a small amount of precipitated iron slag, yielding a pre-neutralized liquid. At this point, the Be, Fe, and Al contents in the feed solution are basically the same as those in the mother liquor (beryllium glass leaching solution), with only a significant reduction in acidity, providing a stable feed solution for subsequent deep iron and aluminum removal.

[0044] As a preferred embodiment of the present invention, the first liquid-solid separation process is filtration or pressure filtration.

[0045] It should be noted that the first liquid-solid separation process is preferably, but not limited to, filtration or pressure filtration.

[0046] Step S3: The pre-neutralized solution is subjected to deep iron and aluminum removal treatment according to either the first or second depth iron and aluminum removal route to obtain a beryllium-containing leachate and an iron and aluminum-containing leachate residue, thereby completing the purification of the beryllium glass leachate; wherein, The first deep iron and aluminum removal route includes: adding a first neutralizing agent to the pre-neutralized liquid to neutralize the pre-neutralized liquid, performing a second liquid-solid separation treatment on the neutralized slurry obtained from the neutralization reaction treatment, and performing a first pressure leaching treatment on the neutralized residue obtained from the second liquid-solid separation treatment after adding water and sulfuric acid to adjust the slurry, to obtain a beryllium-containing leaching solution and an iron and aluminum-containing leaching residue. The second deep iron and aluminum removal route includes: adding an oxidant and a second neutralizer to the pre-neutralized liquid to perform an oxidation-neutralization reaction treatment on the pre-neutralized liquid, and performing a second pressure leaching treatment on the oxidation-neutralized slurry obtained from the oxidation-neutralization treatment to obtain a beryllium-containing leaching solution and an iron-aluminum-containing leaching residue.

[0047] Specifically, the deep iron and aluminum removal process can flexibly adopt either a first-depth iron and aluminum removal route or a second-depth iron and aluminum removal route. The first-depth iron and aluminum removal route has high removal efficiency and strong adaptability; the second-depth iron and aluminum removal route has a shorter process flow and lower beryllium loss. Regardless of whether it is the first-depth or second-depth iron and aluminum removal route, no NH4 is introduced throughout the entire process. + F - Cl - Impurity ions such as iron and aluminum can be efficiently removed under mild conditions, thereby significantly improving beryllium recovery rate and product purity.

[0048] In a preferred embodiment of the present invention, the pre-neutralized liquid is subjected to deep iron and aluminum removal treatment according to either a first-depth iron and aluminum removal route or a second-depth iron and aluminum removal route to obtain a beryllium-containing leachate and an iron and aluminum-containing leachate residue, thereby completing the purification process of the beryllium glass leachate. When the mass ratio of iron to beryllium in the pre-neutralized liquid is greater than or equal to 0.5, the pre-neutralized liquid is subjected to deep iron and aluminum removal treatment according to the first deep iron and aluminum removal route. When the mass ratio of iron to beryllium in the pre-neutralized liquid is less than 0.5, the pre-neutralized liquid is subjected to deep iron and aluminum removal treatment according to the second deep iron and aluminum removal route.

[0049] Specifically, based on the iron to beryllium mass ratio in the pre-neutralized solution, the process can flexibly adopt either a first-depth iron-aluminum removal route or a second-depth iron-aluminum removal route. The iron to beryllium mass ratio in the pre-neutralized solution is only used as a preferred reference indicator and is not the sole or mandatory standard for route selection. The first-depth iron-aluminum removal route (precipitation and pressure leaching) is the preferred option when the iron to beryllium mass ratio is ≥0.5, offering high iron-aluminum removal efficiency and strong adaptability. The second-depth iron-aluminum removal route (oxidation and direct pressure leaching) is the preferred option when the iron to beryllium mass ratio is <0.5, resulting in a shorter process and lower beryllium loss.

[0050] In a preferred embodiment of the present invention, during the process of adding a first neutralizing agent to the pre-neutralized liquid to perform a neutralization reaction, The first neutralizing agent is a sodium carbonate solution with a mass fraction of 10% to 30% or a sodium bicarbonate solution with a mass fraction of 10% to 30%. At the end of the neutralization reaction, the pH of the pre-neutralized solution is ≥7.5; The neutralization reaction time is 2 to 5 hours.

[0051] Specifically, the first neutralizing agent is preferably, but not limited to, a sodium carbonate solution or a sodium bicarbonate solution with a mass fraction of 10% to 30%. Ammonia water can also be used, but when ammonia water is used, it should only be used temporarily to avoid the introduction of NH4 through long-term use. + The core pH range remains unchanged. Add the first neutralizing agent to the pre-neutralized solution, controlling the endpoint pH to ≥ 7.5, so that the Be² in the solution remains constant. + The beryllium hydroxide is completely precipitated, while iron and aluminum co-precipitate and enter the neutralization residue.

[0052] As a preferred embodiment of the present invention, during the second liquid-solid separation process of the neutralized slurry obtained from the neutralization reaction treatment... The second liquid-solid separation process is filtration or pressure filtration; The neutralized liquid obtained from the second liquid-solid separation process is used to prepare the first neutralizing agent.

[0053] Specifically, the neutralized slurry undergoes a second liquid-solid separation process to obtain a neutralized liquid and a neutralized residue. The neutralized liquid can be returned to prepare the first neutralizing agent for recycling. The neutralized residue is enriched with beryllium, iron, and aluminum, and serves as a raw material for pressure leaching. It should be noted that the second liquid-solid separation process is preferably, but not limited to, filtration or pressure filtration.

[0054] In a preferred embodiment of the present invention, after the neutralized residue obtained from the second liquid-solid separation treatment is slurried with water and sulfuric acid, it undergoes a first pressure leaching treatment to obtain a beryllium-containing leachate and an iron-aluminum-containing leaching residue. The mass ratio of sulfuric acid to neutralization residue is 100–1200 kg / t; The liquid phase composed of water and sulfuric acid has a liquid-to-solid mass ratio of 6 to 8:1 with the neutralization residue. The first pressure leaching treatment is carried out in a pressure vessel at a temperature of 180–250°C for 1–2 hours.

[0055] Specifically, the neutralized residue is mixed with water and sulfuric acid to form a slurry, controlling the acid-to-ore ratio at 100–1200 kg / t and the liquid-to-solid ratio at 6–8:1. The mixture is reacted in a pressure vessel for 1–2 hours at a temperature of 180–250°C. After leaching, the liquid and solids are separated. The leachate contains a high concentration of beryllium and low impurities, and directly enters the subsequent beryllium extraction process. The leaching residue is mainly composed of iron and aluminum, containing trace amounts of beryllium, and can be used as a secondary resource for beryllium recovery, or solidified for use as a building material. Preferably, monovalent metal salts such as sodium and potassium salts can be added during the first pressure leaching process to better enhance the aluminum removal effect.

[0056] In a preferred embodiment of the present invention, during the process of adding an oxidant and a second neutralizing agent to the pre-neutralized liquid to perform an oxidative neutralization reaction, The oxidant is hydrogen peroxide or oxygen; wherein, when the oxidant is hydrogen peroxide, 2-5g of hydrogen peroxide is added per liter of pre-neutralized solution, and the mass concentration of hydrogen peroxide is 30%; when the oxidant is oxygen, the oxygen flow rate is 200-1000mL / min based on the pre-neutralized solution, and the purity of oxygen is 100%. The second neutralizing agent is a sodium carbonate solution with a mass fraction of 10% to 30% or a sodium bicarbonate solution with a mass fraction of 10% to 30%. At the endpoint of the oxidation-neutralization reaction, the pH of the pre-neutralized solution was 3.0–3.2. The oxidation-neutralization reaction takes 2–4 hours.

[0057] Specifically, an oxidant (hydrogen peroxide or oxygen) and a second neutralizing agent are simultaneously added to the pre-neutralized solution, controlling the endpoint pH to 3.0–3.2 and the reaction time to 2–4 h; the Fe²⁺ in the solution is then removed. + Completely oxidized to Fe³ + And some iron is initially precipitated under these conditions, Be² + It produces almost no precipitation and has extremely low beryllium loss.

[0058] It should be noted that the second neutralizing agent is preferably, but not limited to, a sodium carbonate solution or a sodium bicarbonate solution with a mass fraction of 10% to 30%.

[0059] In a preferred embodiment of the present invention, during the second pressure leaching treatment of the oxidized and neutralized slurry obtained from the oxidation and neutralization treatment to obtain a beryllium-containing leachate and an iron-aluminum-containing leaching residue... The second pressure leaching treatment is carried out in a pressure vessel at a temperature of 180–250°C for 1–2 hours.

[0060] Specifically, the slurry after oxidation and neutralization is not subjected to liquid-solid separation and is directly fed into a pressure vessel without the need for additional acid or water; the temperature is controlled at 180–250℃ and the reaction time is 1–2 h to allow residual Fe³⁺ to be absorbed.+ Al³ + Deep hydrolysis produces stable hydroxide precipitates, Be² + It remains stable in the solution; after leaching, the liquid and solid separate, the leachate has very low impurities and enters the subsequent beryllium extraction process; the leaching residue contains a small amount of beryllium and can be extracted again or solidified.

[0061] It should be noted that in this embodiment, the first liquid-solid separation treatment, the second liquid-solid separation treatment, the first pressure leaching treatment, the second pressure leaching treatment, the first deep iron and aluminum removal route, and the second deep iron and aluminum removal route are merely naming conventions used to distinguish different operation steps. These ordinal numbers do not represent a unique and fixed sequential execution order between the processes. They are only used to distinguish and limit the operating conditions and processing objects at different stages of the process flow. They do not constitute additional restrictions on the technical characteristics, reaction mechanism, or material ratio of the process itself, but only serve as a distinguishing identifier.

[0062] The purification method for beryllium glass leachate provided by this invention involves first performing a pre-neutralization reaction on the beryllium glass leachate to reduce its acidity, adjust its state, and stabilize subsequent process parameters to reduce subsequent beryllium loss. A first liquid-solid separation process removes a small amount of precipitated iron slag, resulting in a pre-neutralized liquid with significantly reduced acidity, providing a stable feed solution for subsequent deep iron and aluminum removal. The method flexibly employs either a first or second deep iron and aluminum removal route for deep iron and aluminum removal treatment, and regardless of the route, no NH4 is introduced throughout the entire process. + F - Cl - Impurity ions such as iron and aluminum can be efficiently removed under mild conditions, thereby significantly improving beryllium recovery rate and product purity. It has the advantages of wide process control window, mild conditions, short process, high beryllium recovery rate, good iron and aluminum removal effect, easy wastewater treatment, and strong industrial implementation. It can effectively solve the problems of introducing impurities, strict control, complex process, and large beryllium loss in existing technologies.

[0063] In summary, the present invention has the following advantages: 1. No impurities introduced, low environmental pressure: No impurity ions such as ammonia nitrogen, fluorine, and chlorine are introduced throughout the process. The wastewater is a low-salt sulfuric acid system, which is easy to treat and recycle. There is no highly polluting hazardous waste, and the environmental protection cost is greatly reduced.

[0064] 2. Wide process window and strong stability: High tolerance for fluctuations in parameters such as temperature, pH, and reagent dosage; mild operating conditions; low difficulty in industrial control; and stable product quality.

[0065] 3. High beryllium recovery rate and excellent resource utilization: The beryllium recovery rate can reach 90%, which is much higher than the 73% to 79% of existing processes, and can significantly improve resource utilization and economic benefits.

[0066] 4. Thorough removal of iron and aluminum, high product purity: both iron and aluminum removal rates are >92%, the leachate has low impurities and can be directly used for subsequent deep purification.

[0067] 5. Short process, low energy consumption, and low cost: No need for evaporation and concentration, multi-stage extraction, reduction and oxidation steps, less equipment investment, reduced energy consumption, and low operating costs.

[0068] 6. Slag resource utilization and simple solid waste disposal: The leaching slag has high iron and aluminum content and low beryllium content. Beryllium can be extracted in a secondary manner or solidified for building materials. There is no difficult hazardous waste disposal.

[0069] To better verify the technical effectiveness of the purification method for beryllium glass leachate provided by this invention, the following specific embodiments were carried out: Example 1: The first-depth iron and aluminum removal route (Fe / Be=0.8) was adopted.

[0070] Raw materials: Beryllium glass leachate, with Be concentration of 4.47 g / L, Fe concentration of 1.26 g / L, Al concentration of 11.46 g / L, and sulfuric acid concentration of 152 g / L.

[0071] Pre-neutralization: Heat to 85℃, add 20% sodium carbonate slurry, adjust pH to 1.8, stir and react for 2 h, and filter to obtain the pre-neutralized liquid (Be 4.11 g / L, Fe 1.15 g / L, Al 9.98 g / L).

[0072] Neutralization: Add 20% sodium carbonate solution to adjust pH to 7.5, stir for 5 h, and filter to obtain neutralization residue (containing 4.15% Be, 1.05% Fe, and 9.19% Al).

[0073] Pressure leaching: The neutralized residue was used to prepare the slurry, with an acid-to-ore ratio of 1109 kg / t and a liquid-to-solid ratio of 11:1. Pressure leaching was carried out for 1 h at a temperature of 250℃. The concentrations of Be in the leachate were 4.98 g / L, Fe 0.13 g / L, and Al 0.89 g / L. The beryllium recovery rate was 90%, and the iron and aluminum removal rates were >92%.

[0074] Example 2: The second-depth iron and aluminum removal route is adopted.

[0075] Raw materials: Beryllium glass leachate, with Be concentration of 4.34 g / L, Fe concentration of 1.27 g / L, Al concentration of 12.76 g / L, and sulfuric acid concentration of 152 g / L.

[0076] Pre-neutralization: Heat to 85℃, add 20% calcium carbonate slurry, adjust pH to 1.8, stir for 2 h, and filter to obtain the pre-neutralized liquid (Be 4.07 g / L, Fe 1.19 g / L, Al 11.98 g / L).

[0077] Oxidation neutralization: Add hydrogen peroxide (2.18 g / L) and 20% sodium carbonate solution, adjust pH to 3.2, react for 4 h, Fe² + Completely oxidized to Fe³ + .

[0078] Pressure leaching: The slurry was directly fed into a pressure vessel at 250℃ for 2 hours; the concentration of Be in the leachate was 2.95 g / L, Fe 0.01 g / L, and Al 0.09 g / L; the beryllium recovery rate was close to 90%, and the iron and aluminum removal rates reached 93% and 98%, respectively.

[0079] As can be seen from the above specific embodiments, the purification method for beryllium glass leachate provided by the present invention first performs a pre-neutralization reaction on the beryllium glass leachate to reduce its acidity, adjust its state, and stabilize subsequent process parameters, thereby reducing subsequent beryllium loss. A small amount of precipitated iron slag is removed through a first liquid-solid separation treatment, resulting in a pre-neutralized liquid with significantly reduced acidity, providing a stable feed solution for subsequent deep iron and aluminum removal. The method flexibly employs either a first or second deep iron and aluminum removal route for deep iron and aluminum removal treatment, and regardless of the route, NH4 is not introduced throughout the entire process. + F - Cl - Impurity ions such as iron and aluminum can be efficiently removed under mild conditions, thereby significantly improving beryllium recovery rate and product purity. It has the advantages of wide process control window, mild conditions, short process, high beryllium recovery rate, good iron and aluminum removal effect, easy wastewater treatment, and strong industrial implementation. It can effectively solve the problems of introducing impurities, strict control, complex process, and large beryllium loss in existing technologies.

[0080] The purification method for beryllium glass leachate according to the present invention has been described above by way of example with reference to the accompanying drawings. However, those skilled in the art should understand that various modifications can be made to the purification method for beryllium glass leachate according to the present invention without departing from the scope of the invention. Therefore, the scope of protection of the present invention should be determined by the contents of the appended claims.

Claims

1. A method for purifying beryllium glass leachate, characterized in that, Includes the following steps: S1. Heat the beryllium glass leaching solution to a preset temperature and add alkaline calcium-based slurry for pre-neutralization reaction to obtain pre-neutralized solution; S2. Perform a first liquid-solid separation treatment on the pre-neutralized liquid to obtain pre-neutralized liquid and filter residue; S3. The pre-neutralized liquid is subjected to deep iron and aluminum removal treatment according to either the first deep iron and aluminum removal route or the second deep iron and aluminum removal route to obtain a beryllium-containing leachate and an iron and aluminum-containing leachate residue, thereby completing the purification of the beryllium glass leachate; wherein, The first deep iron and aluminum removal route includes: adding a first neutralizing agent to the pre-neutralized liquid to perform a neutralization reaction treatment on the pre-neutralized liquid, performing a second liquid-solid separation treatment on the neutralized slurry obtained from the neutralization reaction treatment, and performing a first pressure leaching treatment on the neutralized residue obtained from the second liquid-solid separation treatment after adding water and sulfuric acid to adjust the slurry, to obtain a beryllium-containing leaching solution and an iron and aluminum-containing leaching residue; The second deep iron and aluminum removal route includes: adding an oxidant and a second neutralizer to the pre-neutralized liquid to perform an oxidation-neutralization reaction treatment on the pre-neutralized liquid, and performing a second pressure leaching treatment on the oxidation-neutralized slurry obtained from the oxidation-neutralization treatment to obtain a beryllium-containing leaching solution and an iron-aluminum-containing leaching residue.

2. The purification method for beryllium glass leachate according to claim 1, characterized in that, The beryllium glass leachate is prepared by successively melting beryl and alkaline flux, followed by water quenching to obtain beryllium glass, and then successively ball milling, grading, sulfuric acid aging, and water leaching of the beryllium glass; wherein, the initial sulfuric acid concentration of the system in the sulfuric acid aging stage is ≥150g / L.

3. The purification method for beryllium glass leachate according to claim 1, characterized in that, In the process of heating the beryllium glass leaching solution to a preset temperature and adding alkaline calcium-based slurry for pre-neutralization reaction to obtain the pre-neutralized solution, The preset temperature is 80–95°C; The alkaline calcium-based slurry is a calcium carbonate slurry or a calcium hydroxide slurry with a mass fraction of 10% to 30%. At the end of the pre-neutralization reaction, the pH of the beryllium glass leachate is 1.8 to 2.

0.

4. The purification method for beryllium glass leachate according to claim 1, characterized in that, The first liquid-solid separation process is filtration or pressure filtration.

5. The purification method for beryllium glass leachate according to claim 1, characterized in that, The pre-neutralized liquid is subjected to deep iron and aluminum removal treatment according to either the first or second depth iron and aluminum removal route to obtain a beryllium-containing leachate and an iron and aluminum-containing leachate residue, thereby completing the purification process of the beryllium glass leachate. When the mass ratio of iron to beryllium in the pre-neutralized liquid is greater than or equal to 0.5, the pre-neutralized liquid is subjected to deep iron and aluminum removal treatment according to the first deep iron and aluminum removal route; When the mass ratio of iron to beryllium in the pre-neutralized liquid is less than 0.5, the pre-neutralized liquid is subjected to deep iron and aluminum removal treatment according to the second deep iron and aluminum removal route.

6. The purification method for beryllium glass leachate according to claim 1, characterized in that, During the process of adding a first neutralizing agent to the pre-neutralized liquid to perform a neutralization reaction, The first neutralizing agent is a sodium carbonate solution with a mass fraction of 10% to 30% or a sodium bicarbonate solution with a mass fraction of 10% to 30%. At the endpoint of the neutralization reaction, the pH of the pre-neutralized solution is ≥7.5; The neutralization reaction process takes 2 to 5 hours.

7. The purification method for beryllium glass leachate according to claim 1, characterized in that, During the second liquid-solid separation process of the neutralized slurry obtained from the neutralization reaction, The second liquid-solid separation process is filtration or pressure filtration; The neutralized liquid obtained from the second liquid-solid separation process is used to prepare the first neutralizing agent.

8. The purification method for beryllium glass leachate according to claim 1, characterized in that, In the process of adding water and sulfuric acid to the neutralized residue obtained from the second liquid-solid separation treatment and then subjecting it to a first pressure leaching treatment to obtain a beryllium-containing leachate and an iron-aluminum-containing leaching residue, The mass ratio of sulfuric acid to the neutralization residue is 100–1200 kg / t; The liquid phase composed of water and sulfuric acid has a liquid-solid mass ratio of 6 to 8:1 with respect to the neutralization residue. The first pressure leaching treatment is carried out in a pressure vessel at a temperature of 180–250°C for 1–2 hours.

9. The purification method for beryllium glass leachate according to claim 1, characterized in that, During the process of adding an oxidant and a second neutralizing agent to the pre-neutralized solution to perform an oxidative neutralization reaction, The oxidant is hydrogen peroxide or oxygen; wherein, when the oxidant is hydrogen peroxide, 2-5g of hydrogen peroxide is added per liter of the pre-neutralized solution, and the mass concentration of the hydrogen peroxide is 30%; when the oxidant is oxygen, the oxygen flow rate is 200-1000mL / min based on the pre-neutralized solution, and the purity of the oxygen is 100%. The second neutralizing agent is a sodium carbonate solution with a mass fraction of 10% to 30% or a sodium bicarbonate solution with a mass fraction of 10% to 30%. At the endpoint of the oxidation-neutralization reaction, the pH of the pre-neutralized solution is 3.0–3.

2. The oxidation-neutralization reaction takes 2 to 4 hours.

10. The purification method for beryllium glass leachate according to claim 1, characterized in that, In the process of subjecting the oxidized and neutralized slurry obtained from the aforementioned oxidation and neutralization treatment to a second pressure leaching treatment to obtain a beryllium-containing leaching solution and an iron-aluminum-containing leaching residue. The second pressure leaching treatment is carried out in a pressure vessel at a temperature of 180–250°C for 1–2 hours.

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