Separation method of components in asbestos tailings

Abstract

The invention relates to a method for separating components in asbestos tailings. The method comprises the following steps: injecting hydrochloric acid into asbestos tailing powder to be treated to obtain an acid-soluble solution; carrying out filter pressing treatment on the acid-soluble solution to obtain a first filter cake, adding the first filter cake into a first container, and marking the first filter cake as acid-soluble filter residues; carrying out alkali dissolution treatment on the acid dissolution filter residues to obtain an alkali dissolution solution; carrying out filter pressing on the alkali solution to obtain a first filtrate and a second filter cake; adding the first filtrate into a second container and marking the first filtrate as an alkali-soluble filtrate; putting the second filter cake into a third container and marking the second filter cake as alkali-soluble filter residues; carrying out acid regulation treatment on the alkali-soluble filtrate to obtain a first alkali-soluble solution; carrying out filter pressing on the first alkali solution to obtain a third filter cake, and separating a silicon product from the third filter cake; sequentially carrying out alkali dissolution treatment and acid adjustment treatment on the alkali dissolution filter residues to obtain a second alkali dissolution solution; and carrying out filter pressing treatment on the second alkali solution to obtain a fourth filter cake, and separating a silicon product from the fourth filter cake, thereby ensuring the high purity (99.9%) of the silicon product and the utilization rate of more than 95% of tailings.

Description

Technical Field

[0001] The invention belongs to the technical field of asbestos tailings, and in particular relates to a method for separating components in asbestos tailings. Background Art

[0002] Asbestos tailings are rich in chemical components such as silicon, magnesium, and iron, and have significant recycling value, especially silicon. However, the comprehensive utilization of asbestos tailings resources is mainly limited to the recovery of asbestos short fibers, and has not been separated from silicon, magnesium, and iron to separate high-purity silicon, magnesium, and iron to improve the utilization value of asbestos tailings.

[0003] For example, in the Chinese patent application document with publication number CN101161591A, the filtering and precipitation step is to add salt and acid to the sodium silicate slurry obtained by reacting the solid residue obtained in the initial precipitation step with caustic soda to obtain silicon dioxide precipitation, and then further add particle barrier or surfactant to obtain white carbon black product. It can be seen that the last filtering and precipitation step is actually for the purpose of obtaining white carbon black product, so as to achieve the recovery of asbestos short fibers, rather than for the purpose of separating silicon with higher value. The purity of silicon is not considered at all. At the same time, the insoluble matter at room temperature (or below 100°C) and normal pressure is not recovered, and the recovery rate is not high. Summary of the invention

[0004] In view of the above technical problems, the present invention provides a method for separating components in asbestos tailings to overcome or alleviate the defects of the prior art.

[0005] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical scheme: A method for separating components in asbestos tailings, comprising: injecting hydrochloric acid into the asbestos tailings powder to be treated to obtain an acid-soluble solution; Performing filter pressing on the acid-soluble solution to obtain a first filter cake, and adding the first filter cake into a first container and marking it as acid-soluble filter residue; Performing alkali dissolution treatment on the acid-soluble filter residue to obtain an alkali-soluble solution; Press-filtering the alkaline solution to obtain a first filtrate and a second filter cake; adding the first filtrate into a second container and labeling it as alkaline filtrate; The second filter cake is placed into a third container and marked as alkali-soluble filter residue; Performing an acid adjustment treatment on the alkaline soluble filtrate to obtain a first alkaline soluble solution; Performing filter press on the first alkaline solution to obtain a third filter cake, so as to separate the silicon product therefrom; The alkali-soluble filter residue is subjected to alkali dissolution treatment and acid adjustment treatment in sequence to obtain a second alkali-soluble solution; Performing filter press treatment on the second alkaline solution to obtain a fourth filter cake, so as to separate the silicon product therefrom; The alkaline filtrate is subjected to an acidification treatment to obtain a first alkaline filtrate, comprising: The solution in the second container was sealed and heated to 180°C for hydrothermal reaction, and stirred for half an hour; continuously adding hydrochloric acid solution into the second container and detecting the pH value of the solution in the second container in real time; When the pH value of the solution in the second container is 10-14, stop adding the hydrochloric acid solution to obtain a first alkali-dissolved impurity-removed filtrate; Adding hydrochloric acid solution to the first alkali-dissolved impurity-removed filtrate again and stirring in real time; When the pH value is close to 3, stop adding the hydrochloric acid solution to obtain the first alkaline solution.

[0006] The beneficial effects of the present invention are: (1) Injecting hydrochloric acid into the asbestos tailings powder is mainly to dissolve some of the metal oxides and silicates in the tailings to form an acid-soluble solution. The selective dissolution of hydrochloric acid can remove some impurities and lay the foundation for subsequent treatment.

[0007] (2) Filtering the acid-soluble solution can further remove soluble impurities in the solution and obtain a relatively pure first filter cake. This step helps to reduce the interference of impurities in subsequent processing.

[0008] (3) Alkali treatment of the acid-soluble residue can dissolve the silicon dioxide product and further precipitate the impurity ions, reduce the soluble impurity components in the residue, and form an alkaline solution. This step helps to further separate silicon from other impurities.

[0009] (4) The alkaline solution is filtered to obtain a first filtrate and a second filter cake. The first filtrate contains dissolved silicates and other soluble components, while the second filter cake mainly contains insoluble impurities. This step further improves the purity of silicon.

[0010] (5) The first filtrate is subjected to an acidification treatment to remove amphoteric hydroxides and further improve the purity of the silicon dioxide product, and then further acidified to promote the precipitation of silicates to form a first alkaline solution. The first alkaline solution is then subjected to filter pressing to obtain a third filter cake, which is rich in high-purity silicon products.

[0011] (6) The second filter cake is subjected to an alkali dissolution treatment and an acid adjustment treatment again to obtain a second alkali solution. This step is to further recover silicon products from the remaining filter residue and improve resource utilization. The second alkali solution is subjected to a filter press treatment to obtain a fourth filter cake, from which a high-purity silicon product can also be separated. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a schematic diagram of a method for separating components in asbestos tailings according to an embodiment of the present invention. DETAILED DESCRIPTION

[0013] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work fall within the scope of protection of the present invention.

[0014] Figure 1 FIG. 1 is a schematic diagram of a method for separating components in asbestos tailings according to an embodiment of the present invention. Figure 1 As shown, the method for separating components in the asbestos tailings comprises: S101, injecting hydrochloric acid into the asbestos tailings powder to be treated to obtain an acid-soluble solution; S102, performing filter press treatment on the acid-soluble solution to obtain a first filter cake, and adding the first filter cake into a first container and marking it as acid-soluble filter residue; S103, performing alkali dissolution treatment on the acid-soluble filter residue to obtain an alkali-soluble solution; S104, performing filter press on the alkaline solution to obtain a first filtrate and a second filter cake; S105, adding the first filtrate into a second container and marking it as alkaline soluble filtrate; S106, placing the second filter cake into a third container and marking it as alkali-soluble filter residue; S107, subjecting the alkaline filtrate to an acid adjustment treatment to obtain a first alkaline filtrate; S108, filtering the first alkaline solution to obtain a third filter cake, so as to separate a silicon product therefrom; S109, sequentially performing alkali dissolution treatment and acid adjustment treatment on the alkali-soluble filter residue to obtain a second alkali-soluble solution; S110, performing filter press treatment on the second alkaline solution to obtain a fourth filter cake, so as to separate a silicon product therefrom.

[0015] In this embodiment, before the acid-soluble filter residue is subjected to alkali dissolution treatment, the acid-soluble filter residue may also be subjected to oxidation treatment.

[0016] The embodiments of the present application have at least the following technical effects: (1) Injecting hydrochloric acid into the asbestos tailings powder is mainly to dissolve some of the metal oxides and silicates in the tailings to form an acid-soluble solution. The selective dissolution of hydrochloric acid can remove some impurities and lay the foundation for subsequent treatment.

[0017] (2) Filter pressing the acid-soluble solution can further remove soluble impurities in the solution and obtain a relatively pure first filter cake (acid-soluble filter residue). This step helps to reduce impurity interference in subsequent treatments.

[0018] (3) Optionally, oxidation treatment of the acid-soluble residue can transform some of its components, making them more difficult to dissolve in the subsequent alkaline treatment and thus not entering the silicon product. The subsequent alkaline treatment further precipitates the impurity ions, reduces the soluble impurity components in the residue, and forms an alkaline solution. This step helps to further separate the silicon from other impurities.

[0019] (4) The alkaline solution is filtered to obtain a first filtrate and a second filter cake. The first filtrate contains dissolved silicates and other soluble components, while the second filter cake mainly contains insoluble impurities. This step further improves the purity of silicon.

[0020] (5) The first filtrate is subjected to an acidification treatment to remove amphoteric hydroxides and further improve the purity of the silicon dioxide product, and then further acidified to promote the precipitation of silicates to form a first alkaline solution. The first alkaline solution is then subjected to filter pressing to obtain a third filter cake, which is rich in high-purity silicon products.

[0021] (6) The second filter cake is subjected to an alkali dissolution treatment and an acid adjustment treatment again to obtain a second alkali solution. This step is to further recover silicon products from the remaining filter residue and improve resource utilization. The second alkali solution is subjected to a filter press treatment to obtain a fourth filter cake, from which a high-purity silicon product can also be separated.

[0022] Optionally, the acid-soluble filter residue is subjected to an alkali-soluble treatment to obtain an alkali-soluble solution, comprising: After controlling the pH value of the solution in the first container to be less than 3, adding a hydrogen peroxide solution (for example, a concentration of less than 30%) or a sodium hypochlorite solution to the first container and performing a real-time pH value detection, stirring and then standing, wherein the amount of the hydrogen peroxide solution or the sodium hypochlorite solution added matches the amount of the divalent iron ions in the first container; After reacting for 10 minutes, a sodium hydroxide solution (e.g., a concentration of 30%-50%) is continuously added to the first container, while the solution in the first container is stirred and the pH value is detected in real time; When the pH value of the solution in the first container is equal to 14, stop adding the sodium hydroxide solution to obtain the alkaline solution.

[0023] Therefore, the above-mentioned specific treatment process of oxidation and alkali dissolution of the acid-soluble filter residue has the following technical advantages: 1. Treatment of interfering impurities in acid-soluble filter residues Oxidation timing of hydrogen peroxide: For some ions with intermediate valence such as divalent iron, their hydroxide KSP is lower than that of high-valence particles, and after oxidation to a high-valence state, it is easier to precipitate and separate from the alkaline solution.

[0024] pH control mechanism of oxidation: When the pH value of the solution in the first container is close to 3, hydrogen peroxide is added dropwise. This is because at this pH value, hydrogen peroxide can effectively oxidize the reducing impurities in the acid-soluble filter residue, such as divalent iron, thereby reducing the content of iron ions in the solution after alkali dissolution. At the same time, the pH is controlled to be less than 3 to prevent trivalent chromium ions from being oxidized to hexavalent chromium and avoid residues in the product silicon dioxide. When sodium hypochlorite is used for oxidation, the pH value does not need to be tested.

[0025] Continuous alkaline dissolution treatment: After the oxidation is completed, a 50% sodium hydroxide solution is continuously added and the pH value of the solution is adjusted to above 14 to ensure that soluble components such as silicates are fully dissolved under strong alkaline conditions. This precise pH control not only increases the reaction rate and reduces the consumption of alkali solution, but also promotes the separation of silicon from other impurities.

[0026] 2. Stirring promotes reaction uniformity Solution stirring: Stirring the solution while adding sodium hydroxide solution can ensure that the components in the solution are evenly mixed and avoid uneven reaction caused by local concentration being too high or too low. This not only improves the reaction efficiency, but also helps to generate and remove metal ions in the acid-soluble filter residue.

[0027] 3. Real-time pH detection ensures stable reaction conditions Real-time monitoring of pH value: By real-time monitoring of the pH value of the solution in the first container, the amount of sodium hydroxide solution added can be adjusted in time to ensure that the reaction conditions are always kept within the optimal range. This dynamic control mechanism helps to reduce the adverse effects of pH fluctuations on the reaction process and improve the stability and controllability of the reaction.

[0028] 4. Improve the purity and yield of silicon products Comprehensive benefits: The comprehensive application of the above technical steps effectively removes most of the impurities in the acid-soluble filter residue and improves the purity of target products such as silicates. At the same time, the yield and quality stability of silicon products are ensured by precisely controlling the reaction conditions.

[0029] Economic benefits: High-purity silicon products have higher market value and wider application prospects, which can bring greater economic benefits to enterprises. In addition, by precisely controlling the reaction conditions, the consumption of raw materials and the generation of waste can be reduced, further reducing production costs and environmental burdens.

[0030] 5. Environmental protection and sustainability Reduce pollution: This technical solution achieves effective recovery and reuse of silicon resources in asbestos tailings through a sophisticated chemical treatment process, reducing the pollution of tailings to the environment. At the same time, by precisely controlling the reaction conditions, the generation and emission of harmful by-products are avoided.

[0031] Optionally, the second filter cake is washed with distilled water.

[0032] Optionally, the acidification treatment of the alkaline soluble filtrate to obtain a first alkaline soluble solution comprises: The solution in the second container is sealed and heated to 180° C. for hydrothermal reaction, and stirred for half an hour; Continuously adding hydrochloric acid solution (e.g., with a concentration of 31%) into the second container and detecting the pH value of the solution in the second container in real time; When the pH value of the solution in the second container is 10-14, stop adding the hydrochloric acid solution to obtain a first alkali-dissolved impurity-removed filtrate; Adding hydrochloric acid solution (e.g., 31% concentration) to the first alkali-dissolved impurity-removed filtrate again and stirring in real time; When the pH value is close to 3, stop adding the hydrochloric acid solution to obtain the first alkaline solution.

[0033] Stopping the addition of hydrochloric acid solution when the pH value of the solution in the second container is 10-14 is determined according to the control point of impurities.

[0034] To this end, the specific process of acidifying the alkaline soluble filtrate to obtain the first alkaline soluble solution has the following technical advantages: 1. Improve the purity of silicon products Acid adjustment and impurity removal: In the technical solution, the second container is first subjected to a hydrothermal reaction in order to promote the reaction of sodium titanate and aluminum ions therein to generate complex ions and reduce titanium dioxide impurities in the silicon product; then, a hydrochloric acid solution is continuously added to the second container, and the pH value of the solution is detected in real time. Stop adding hydrochloric acid when the pH value is 10-14, in order to further remove amphoteric hydroxide impurities, thereby removing amphoteric hydroxide impurities, and removing them from the solution to ultimately improve the purity of silicon dioxide. In addition, adding hydrochloric acid to the acid-soluble filtrate to adjust the pH value can not only remove amphoteric hydroxide impurities, but also optimize the precipitation conditions of silicates. When the pH value is 10-14, the solubility of silicates will decrease, making it easier to precipitate from the solution, which helps to increase the yield of silicon dioxide and improve production efficiency. Then, add the hydrochloric acid solution again and stir in real time, and stop adding when the pH value is close to 3, rather than when the pH value is lower, thereby ensuring that the silicic acid crystal dispersion state is better, in order to ensure the yield of silicon dioxide, it is beneficial to obtain micron-sized silicon dioxide.

[0035] 2. Precise control of pH value Precise pH control can effectively further remove impurities, improve the purity of silica, and prevent entrainment due to excessive precipitation; accurate control can be achieved through dropwise addition to ensure the accuracy of impurity removal and improve product yield; precise control of pH can prevent target products such as silicates from producing excessive salt under over-acidic or over-alkaline conditions, which will affect product purity; at the same time, by controlling the rate of change and endpoint of pH, the final form of silica can be controlled.

[0036] 3. Improve reaction efficiency and controllability Real-time stirring: Real-time stirring while adding the hydrochloric acid solution can ensure that the components in the solution are evenly mixed, avoiding uneven reactions caused by local concentrations that are too high or too low. This improves the reaction efficiency and ensures the uniformity and controllability of the acid treatment, while controlling the macroscopic morphology of the silica formed.

[0037] Dynamic adjustment: By real-time detection of pH value and dynamic adjustment of the amount of hydrochloric acid solution added, it is possible to ensure that the reaction conditions are always kept within the optimal range, reducing the adverse effects of pH fluctuations on the reaction process.

[0038] 4. Environmental protection and sustainability Reduce waste emissions: Accurate acid treatment can reduce unnecessary chemical consumption and waste generation, reducing pollution to the environment.

[0039] Resource recycling: Through effective acid treatment, the yield and purity of silicon products can be improved, thereby achieving resource recycling and sustainable development.

[0040] Optionally, the filtering the first alkaline solution to obtain a third filter cake to separate a silicon product therefrom comprises: Performing filter press on the first alkaline solution to obtain a third filter cake; The third filter cake is washed with water and then dried, and after drying, a chloride ion titrant (such as silver nitrate solution) is used to titrate the chloride ion content in the third filter cake; When the chloride ion content is ≤0.1%, the third filter cake is further dried and marked as a silicon product after drying.

[0041] To this end, the above-mentioned specific process of filtering the first alkaline solution and subsequently treating it to separate the high-purity silicon product has the following technical advantages: 1. Improve the purity of silicon products Filter pressing separation: By filtering the first alkaline solution, the target product such as silicate can be effectively separated from the impurities in the solution to form a third filter cake. This step is the key to purifying silicon products and can remove most of the impurities dissolved in the solution.

[0042] Water washing: Use high-purity water (or distilled water) to repeatedly wash the third filter cake to reduce the residual sodium chloride impurity and further improve the product purity of silicon dioxide.

[0043] Chloride ion detection and control: After further washing and drying the third filter cake, the chloride ion content in the third filter cake is titrated with a chloride ion titrant. Chloride ion is one of the common impurities, and its content directly affects the purity of the silicon product. By setting the standard of chloride ion content ≤ 0.1%, it can be ensured that the final silicon product has a high purity. This step reflects the strict control of product quality and helps to improve the market competitiveness of the product.

[0044] 2. Ensure stable product quality Standardized processing flow: The technical plan specifies in detail the entire processing flow from filtration, water washing, chloride ion detection, to drying and marking as silicon products. This standardized processing flow helps reduce human operation errors and ensures that the processing process of each batch of silicon products is consistent, thereby obtaining products with stable quality.

[0045] 3. Improve production efficiency and economic benefits Efficient separation: As an efficient solid-liquid separation technology, filter pressing can quickly separate silicon products from solutions and improve production efficiency. At the same time, it can also further improve separation efficiency and filter cake quality.

[0046] Reduce costs: High-purity water (or distilled water) is used to clean silicon dioxide. Wastewater, as a good electrolytic raw material, enters the electrolytic wastewater treatment process during industrialization to achieve resource recycling, which can reduce the additional processing costs and resource waste caused by excessive impurities in the subsequent processing process. In addition, high-purity silicon products usually have higher market value and broad application prospects, which can bring greater economic benefits to enterprises.

[0047] Optionally, when a 31% hydrochloric acid solution is continuously added to the second container, the reaction temperature is AMB and the reaction time is less than 1 h; The third filter cake is washed with water and then placed in an oven and dried at 200° C. for 3 h; To this end, combined with the specific operating conditions provided in the technical solution, the following technical benefits are achieved: 1. Precise reaction temperature and time control Reaction temperature is AMB (room temperature or close to room temperature): Reduced energy consumption: Carrying out reactions at close to room temperature can reduce the energy consumption required for heating or cooling, thereby reducing production costs.

[0048] Improve safety: High temperature reactions may pose safety risks, such as increased risk of flammable and explosive substances. Carrying out reactions at close to room temperature helps improve the safety of operations.

[0049] Control the morphology of the reaction products: Too high a temperature may also lead to violent and uneven reactions, resulting in excessive local crystallization and affecting the final morphology of the product.

[0050] Reaction time is less than 1h: Reduce impurity generation: Long reaction time may lead to more side reactions and generate unnecessary impurities. Shortening the reaction time helps reduce the generation of impurities and improve the purity of the product.

[0051] 2. Optimization of drying conditions Drying temperature is 200℃: Efficient moisture removal: Higher drying temperature helps to quickly remove moisture from the filter cake and improve drying efficiency.

[0052] Maintain product stability: Appropriate drying temperature can prevent the product from decomposing or denaturing at high temperatures, thereby maintaining the stability and activity of the product.

[0053] Optionally, a sixth filtrate is obtained when the first alkaline solution is subjected to filter pressing, and the sixth filtrate is added to a ninth container and marked as the first post-silicon precipitation filtrate; When the second alkaline solution is subjected to pressure filtration, a seventh filtrate is obtained, which is added to a tenth container and marked as the second filtrate after silicon precipitation.

[0054] To this end, when the first alkaline solution and the second alkaline solution are subjected to filter pressing treatment, the sixth filtrate and the seventh filtrate are obtained respectively, and they are marked as the first filtrate after silicon precipitation and the second filtrate after silicon precipitation, respectively, which has the following technical advantages: 1. Maximize resource utilization Reduce waste: Through filter press treatment, not only can the silicon product be separated from the solid phase, but it can also be recycled in the liquid phase (high brine), reducing the waste of water resources and salt resources in the liquid phase.

[0055] Subsequent processing potential: The collected filtrate can be further utilized by electrolysis to regenerate hydrochloric acid and sodium hydroxide solution, which can be returned to the front end to maximize the utilization of resources.

[0056] 2. Environmentally friendly Reducing wastewater discharge: Effectively treating the filtrate before discharging or reusing it can significantly reduce the amount of wastewater discharged and the concentration of pollutants therein, thereby reducing the negative impact on the environment.

[0057] 3. Product Quality Control Purity assurance: Removing impurities and incompletely reacted raw materials through filter pressing helps to improve the purity of silicon products and ensure product quality.

[0058] Optionally, the alkali-soluble filter residue is subjected to alkali dissolution treatment and acid adjustment treatment in sequence to obtain a second alkali-soluble solution, comprising: After placing the alkali-soluble filter residue in the third container in a high-temperature and high-pressure reactor, continuously adding a sodium hydroxide solution (e.g., a concentration of 50%) into the high-temperature and high-pressure reactor to react with the alkali-soluble filter residue at a high temperature and high pressure to obtain a dissolved solution; The dissolved solution is filtered to separate the high-temperature filtrate and the high-temperature filter residue; The high temperature post-filtrate solution is charged into a fourth container; Continuously adding hydrochloric acid solution (e.g., with a concentration of 31%) into the fourth container and performing real-time detection of the pH value of the solution in the fourth container; When the pH value of the solution in the fourth container is 10-14, stop adding the hydrochloric acid solution to obtain a second alkali-dissolved impurity-removed filtrate; Adding hydrochloric acid solution (e.g., with a concentration of 31%) to the second alkaline-dissolved impurity-removed filtrate again and stirring in real time; When the pH value is close to 3, stop adding the hydrochloric acid solution to obtain a second alkaline solution.

[0059] To this end, the specific process of sequentially performing alkali dissolution treatment and acid adjustment treatment on the alkali-soluble filter residue to obtain the second alkali-soluble solution has the following technical advantages: 1. Improve resource utilization Deep extraction: By performing a secondary alkali treatment on the alkali-soluble filter residue, other forms of valuable components can be further extracted to avoid waste of resources. This deep extraction technology helps to maximize the use of raw materials and improve the economic benefits of the enterprise.

[0060] 2. Optimize reaction conditions High temperature and high pressure reaction: Alkali dissolution treatment in a high temperature and high pressure reactor can dissolve the ferrosilicon components that are insoluble at room temperature, accelerate the reaction rate, further extract the remaining alkali-soluble components, and improve the reaction yield. High temperature and high pressure conditions help break the chemical bonds in the raw materials, allowing more target products such as silicates to dissolve into the solution, thereby increasing the yield of the product.

[0061] 3. Accurate pH control Acid adjustment in stages: Similar to the treatment of the first alkaline solution, the pH value of the solution can be more accurately controlled by acid adjustment in stages. First, stop adding hydrochloric acid when the pH value is 10-14 to preliminarily adjust the acidity of the solution; then, continue to add hydrochloric acid and stir in real time until the pH value is close to 3 to ensure that the final second alkaline solution has a suitable acidity. Its technical principles and advantages are exactly the same as the first alkaline solution treatment process.

[0062] The second alkaline solution is subjected to filter pressing to obtain a fourth filter cake to separate the silicon product therefrom, and the principle and process are the same as those for separating the silicon product from the second filter cake.

[0063] acid dissolving the high-temperature filter residue to obtain a second acid-dissolved solution; Performing filter press treatment on the second acid-soluble solution to obtain a fifth filter cake and a second acid-soluble filtrate; The method further comprises: adding the second filtrate and the second acid-soluble filtrate to a fifth container and labeling it as the acid-soluble filtrate; continuously adding sodium hydroxide solution into the fifth container; Performing real-time detection on the pH value of the solution in the fifth container; When the pH value of the liquid in the fifth container is 4-7, stop adding the sodium hydroxide solution, wait for the precipitate to completely turn reddish brown, and then add a hydrogen peroxide solution or a sodium hypochlorite solution to the fifth container to obtain an iron precipitation solution; Performing filter pressing on the iron precipitation liquid to obtain a third filtrate and a fifth filter cake; Add the third filtrate into a sixth container and mark it as the filtrate after iron precipitation; The fifth filter cake is washed with pure water and then the chloride ion content in the fifth filter cake is titrated with a chloride ion titrant; When the chloride ion content is ≤1%, the fifth filter cake is dried and marked as an iron product after drying.

[0064] In the above steps, when the pH value of the liquid in the fifth container is 4-7, the addition of the sodium hydroxide solution is stopped, and after filtering the liquid in the fifth container to extract the filter residue, a hydrogen peroxide solution or a sodium hypochlorite solution is added to the fifth container to obtain an iron precipitation liquid; In the above steps, by first adding the sodium hydroxide solution to the fifth container and then adding the hydrogen peroxide solution or the sodium hypochlorite solution to the fifth container, the pH value can be accurately adjusted to 4-7. When the pH value is 4-7, the addition of the sodium hydroxide solution is stopped, so that part of the ferrous hydroxide in the liquid is first precipitated and naturally oxidized quickly, thereby reducing the consumption of the oxidant.

[0065] In combination with the technical solution, the filter press treatment of the acid-soluble solution and the subsequent series of steps have the following technical advantages: 1. Maximize the use of resources Filtrate recovery: The second filtrate obtained by filter pressing the acid-soluble solution is not directly discarded, but is collected and marked as acid-soluble filtrate for subsequent iron recovery. This step effectively avoids the waste of valuable components that may be contained in the filtrate.

[0066] Iron recovery: Sodium hydroxide solution is added to the acid-soluble filtrate to adjust the pH value, and hydrogen peroxide or sodium hypochlorite solution is added to obtain iron precipitation liquid, and then the iron product is obtained by filter pressing. This process realizes the efficient recovery of iron elements in the acid-soluble filtrate and improves the utilization rate of resources.

[0067] Oxidant consumption control: By adjusting the order of adding oxidants, by first precipitating part of the ferrous hydroxide, and taking advantage of the fact that ferrous oxide is easily oxidized in the air, allowing it to oxidize naturally before adding oxidants to oxidize the ferrous ions, the consumption of oxidants is greatly reduced.

[0068] 2. Improve product purity and quality Precise pH control: In the process of adjusting the pH value of the acid-soluble filtrate, real-time detection is used to ensure that the pH value is within the range of 4-7, providing the best conditions for the precipitation of iron. This step helps to reduce the co-precipitation of impurities, improve the purity of the final iron product, and maximize the yield.

[0069] Chloride ion content control: The iron product obtained by filtration after iron precipitation is washed and tested for chloride ion content, and a qualified standard of ≤1% is set. This step ensures that the iron product meets the quality requirements of specific application areas and improves the market competitiveness of the product.

[0070] 3. Environmental protection and sustainability Resource recycling: By recovering the iron element and other possible valuable components in the filtrate, resource recycling is achieved.

[0071] On the basis of completing the iron precipitation as mentioned above, in order to improve the waste utilization rate, the following steps can be performed to separate the magnesium product from the filtrate after iron precipitation, so as to achieve full utilization of the tailings, as follows: Optionally, the method further comprises: Continuously adding sodium hydroxide solution into the sixth container and detecting the pH value of the solution in the sixth container in real time; When the pH value of the solution in the sixth container is 7-9, stop adding the sodium hydroxide solution to obtain a crude magnesium precipitation solution; The magnesium precipitation crude liquid is subjected to pressure filtration to obtain a fourth filtrate and a sixth filter cake; Add the fourth filtrate into a seventh container and mark it as impurity-removed magnesium filtrate; The sixth filter cake is washed with distilled water and then the chloride ion content in the sixth filter cake is titrated with a chloride ion titrant; When the chloride ion content is ≤1%, drying the sixth filter cake and marking it as a magnesium impurity product after drying; Continuously adding sodium hydroxide solution into the seventh container, and detecting the pH value of the solution in the seventh container in real time; When the pH value of the solution in the seventh container is 12-14, stop adding the sodium hydroxide solution to obtain a magnesium precipitation solution; Performing filter pressing on the magnesium precipitation solution to obtain a fifth filtrate and a seventh filter cake; Add the fifth filtrate into an eighth container and mark it as magnesium precipitation filtrate; The seventh filter cake is washed with distilled water and then the chloride ion content in the seventh filter cake is titrated with a chloride ion titrant; When the chloride ion content is ≤1%, the seventh filter cake is dried and marked as a magnesium product after drying.

[0072] Therefore, the above-mentioned specific treatment process of the magnesium precipitation crude liquid in the sixth container has the following technical advantages: 1. Treatment of magnesium precipitation crude solution Precise pH control: Sodium hydroxide solution is continuously added to the sixth container, and the pH value of the solution is detected in real time. When the pH value reaches 7-9, the addition is stopped. This step precisely controls the alkaline environment of the solution, providing suitable conditions for the precipitation of magnesium ions. Precise pH control helps reduce the co-precipitation of impurities and improves the purity of magnesium products.

[0073] Solid-liquid separation: The crude magnesium precipitate is subjected to filter pressing to obtain the fourth filtrate and the sixth filter cake. The solid-liquid separation process is efficient and thorough, which helps to effectively separate magnesium ions from other soluble components and facilitates subsequent processing.

[0074] 2. Preparation of Magnesium Impurity Products Chloride ion content control: After washing the sixth filter cake with distilled water, the chloride ion content in the sixth filter cake is titrated with a chloride ion titrant. When the chloride ion content is ≤1%, the filter cake is dried and marked as a magnesium impurity product. This step ensures that the chloride ion content of the magnesium impurity product meets specific requirements and improves the quality and market adaptability of the product.

[0075] Resource recycling: Through water washing and drying treatment, not only the attachments on the surface of the magnesium impurities are removed, but also the sodium chloride component is retained, providing favorable conditions for the subsequent recycling of sodium chloride.

[0076] 3. Preparation of magnesium precipitation solution and purification of magnesium products Deep impurity removal: Continue to add sodium hydroxide solution to the seventh container, adjust the pH value of the solution to 12-14, and obtain magnesium precipitation solution. This step further increases the alkalinity of the solution, promotes the precipitation of magnesium ions, and helps to deeply remove other impurities such as calcium in the solution.

[0077] Efficient solid-liquid separation: The magnesium precipitation liquid is subjected to filter pressing to obtain the fifth filtrate and the seventh filter cake. The efficient solid-liquid separation process ensures the purity and yield of the magnesium product.

[0078] Strict quality control: After washing the seventh filter cake with distilled water, the chloride ion content in the seventh filter cake is titrated with a chloride ion titrant. When the chloride ion content is ≤1%, the filter cake is dried and marked as a magnesium product. This step ensures that the chloride ion content of the final magnesium product meets strict quality standards.

[0079] Optionally, the sodium hydroxide solution continuously added to the fifth container has a concentration of 50%; Add 1 L of hydrogen peroxide solution or sodium hypochlorite solution to the fifth container, the corresponding oxidation temperature is AMB, and the corresponding reaction time is 0.5 h; After adding hydrogen peroxide solution or sodium hypochlorite solution into the fifth container, let it stand for 30 minutes to obtain iron precipitation liquid; The reaction time of the sodium hydroxide solution and the second filtrate is 1h, and the oxidation temperature is AMB; The fifth filter cake is repeatedly washed with pure water for 5 to 20 times; When the fifth filter cake is dried, the fifth filter cake is placed in a crucible and sent into a muffle furnace, kept at a high temperature of more than 300° C. for drying for 0.5-3 hours, and weighed after drying. After weighing, it is marked as an iron product and packed into a product sealing bag.

[0080] 1. Oxidation treatment of hydrogen peroxide / sodium hypochlorite solution Adding an appropriate amount of oxidant: Add 1L of hydrogen peroxide solution or sodium hypochlorite solution to the fifth container to narrow the precipitation range of iron element and improve the purity of iron hydroxide.

[0081] By first precipitating and then adding the oxidant, the instability of ferrous hydroxide is utilized to greatly reduce the consumption of oxidation.

[0082] 2. Treatment of iron precipitation liquid and product purification Filter pressing separation: The iron precipitate liquid is subjected to filter pressing treatment to obtain the third filtrate and the fifth filter cake. The filter pressing process is efficient and thorough, which helps to effectively separate the precipitated iron from other soluble components.

[0083] Repeated washing with pure water: The fifth filter cake is repeatedly washed with pure water. This step effectively removes soluble impurities and residual oxidants attached to the surface of the filter cake, further improving the purity of the product.

[0084] Optionally, the sodium hydroxide solution continuously added to the seventh container has a concentration of 50%, a reaction temperature of AMB, and a reaction time of 1 h; The volume of the seventh container is 5L; The sixth filter cake is repeatedly washed with distilled water and then titrated with a chloride ion titrant; When the sixth filter cake is dried, the sixth filter cake is placed in a beaker and sent into a muffle furnace, and dried at 400° C. for 3 hours.

[0085] Optionally, the method further comprises: after screening out large particles of stone in the asbestos tailings, weighing 1 kg and placing it in a 5L container to serve as the asbestos tailings to be treated.

[0086] Optionally, when injecting hydrochloric acid into the asbestos tailings powder to be treated to obtain an acid-soluble solution, the particle size of the asbestos tailings powder to be treated is maintained at 100-300 mesh, and 2.5L of a hydrochloric acid solution with a concentration of more than 31% is slowly added to a 5L container, and the temperature is maintained at 50-80°C, and stirring is stopped after 1 hour to obtain the acid-soluble solution.

[0087] To this end, in the above-mentioned technical solution of injecting hydrochloric acid into the asbestos tailings powder to be treated to obtain an acid-soluble solution, by controlling the particle size of the asbestos tailings powder to be treated, the concentration of the hydrochloric acid solution, the amount added, the reaction temperature and the stirring time and other key parameters, the following technical benefits can be brought about: 1. Improve reaction efficiency Particle size control: Maintaining the particle size of the asbestos tailings powder to be treated at 100-300 mesh helps to increase the specific surface area of ​​the powder and increase the contact area with the hydrochloric acid solution, thereby improving the reaction rate and yield.

[0088] 2. Optimize reaction conditions Temperature control: Maintain the reaction temperature at 50-80°C. This temperature range not only ensures the full reaction of hydrochloric acid with the soluble components in the asbestos tailings powder, but also avoids the volatilization of hydrochloric acid caused by excessively high temperature.

[0089] Stirring time: Stop stirring after 1 hour. This time setting ensures that the reaction proceeds fully while avoiding unnecessary energy consumption and time waste.

[0090] 3. Improve product quality Improve purity: By controlling the reaction conditions, magnesium, iron, silicon and other components in asbestos tailings can be leached more effectively, providing high-quality acid-soluble solution for subsequent product purification and separation.

[0091] Reduce impurities: Appropriate reaction conditions can help reduce the generation and introduction of impurities and improve the purity of the final product.

[0092] Optionally, when a sodium hydroxide solution with a concentration of 50% is continuously added to the first container, the reaction temperature is 70° C. and the reaction time is 1 hour.

[0093] The reaction equations implemented in the above steps are as follows: (1) Acid dissolution (Mg∙Fe)SiO3+HCl → MgCl2+FeCl2+ FeCl 3+ SiO2↓+H2O (2) Iron H2O2+2FeCl2+2HCl→2FeCl3+2H2O FeCl3+3NaOH→Fe(OH)3↓+3NaCl (3) Magnesium deposition MgCl2+2NaOH→ Mg(OH)2↓+2NaCl (4) Alkaline dissolution of filter residue SiO2+NaOH→ Na2SiO3+H2O (5) Acid adjustment Na2SiO3+2HCl→H2SiO3+2NaCl, H2SiO3→SiO2↓+H2O As can be seen from the above reaction formula, a large amount of sodium chloride solution will be produced when iron and magnesium are precipitated. Therefore, the sodium chloride solution is sent to the salting process of the chlor-alkali device to generate hydrochloric acid and sodium hydroxide solution through electrolysis and then recycled to the front end for use. The reaction formula is as follows: (6) The sodium chloride solution produced in the above process is sent to the salting process of the chlor-alkali unit to generate hydrochloric acid and sodium hydroxide solution through electrolysis and then recycled to the front end for use. The electrolysis reaction is as follows: 2NaCl+2H2O→2NaOH+H2+Cl2 (7) The reaction equation of the acid production process is as follows:

[0094] The detailed principles of the above reaction formulas are all prior art and will not be described in detail here.

[0095] In the above embodiment, the reason why hydrochloric acid is easy to add is that a large amount of waste salt will be generated in the above process. In order to achieve "squeezing out and eating up", the waste salt (such as the above sodium chloride solution) will be further electrolyzed to obtain hydrochloric acid and sodium hydroxide for recycling, realizing the recycling of by-products, reducing production costs, and achieving no wastewater discharge. However, if sulfuric acid solution is added, since sulfate ions (SO4²⁻) are not as easy to separate from waste salts and regenerate sulfuric acid as chloride ions (Cl⁻) during the electrolysis process, the waste salt cannot be effectively electrolyzed, and a large amount of untreatable wastewater will eventually be generated, affecting the feasibility of the project. In addition, trace amounts of barium and lead in the raw materials are easily soluble or slightly soluble in hydrochloric acid, but difficult to dissolve in sulfuric acid, which affects the disposal depth of the tailings and may also affect the quality and purity of the final product. Therefore, it is more appropriate to choose hydrochloric acid rather than sulfuric acid as the leaching agent.

[0096] Based on the above solution of the present application, the analysis results in a specific scenario are shown in Table 1:

[0097] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for separating components in asbestos tailings, characterized in that: include: injecting hydrochloric acid into the asbestos tailings powder to be treated to obtain an acid-soluble solution; Performing filter pressing on the acid-soluble solution to obtain a first filter cake, and adding the first filter cake into a first container and marking it as acid-soluble filter residue; Performing alkali dissolution treatment on the acid-soluble filter residue to obtain an alkali-soluble solution; Press-filtering the alkaline solution to obtain a first filtrate and a second filter cake; adding the first filtrate into a second container and labeling it as alkaline filtrate; The second filter cake is placed into a third container and marked as alkali-soluble filter residue; Performing an acid adjustment treatment on the alkaline soluble filtrate to obtain a first alkaline soluble solution; Performing filter press on the first alkaline solution to obtain a third filter cake, so as to separate the silicon product therefrom; The alkali-soluble filter residue is subjected to alkali dissolution treatment and acid adjustment treatment in sequence to obtain a second alkali-soluble solution; The second alkaline solution is subjected to filter pressing to obtain a fourth filter cake to separate the silicon product therefrom; wherein the alkaline filtrate is subjected to acid adjustment to obtain a first alkaline solution, comprising: The solution in the second container is sealed and heated to 180° C. for hydrothermal reaction, and stirred for half an hour; continuously adding hydrochloric acid solution into the second container and detecting the pH value of the solution in the second container in real time; When the pH value of the solution in the second container is 10-14, stop adding the hydrochloric acid solution to obtain a first alkali-dissolved impurity-removed filtrate; Adding hydrochloric acid solution to the first alkali-dissolved impurity-removed filtrate again and stirring in real time; When the pH value is close to 3, stop adding the hydrochloric acid solution to obtain the first alkaline solution.

2. The method according to claim 1, characterized in that: The step of subjecting the acid-soluble filter residue to an alkali-soluble treatment to obtain an alkali-soluble solution comprises: Controlling the pH value of the solution in the first container to be less than 3, dripping a hydrogen peroxide solution or adding a sodium hypochlorite solution into the first container, stirring and then standing, wherein the amount of the hydrogen peroxide solution or the sodium hypochlorite solution added matches the amount of the divalent iron ions in the first container; After reacting for 10 minutes, continuously adding sodium hydroxide solution into the first container, stirring the solution in the first container and detecting the pH value in real time; When the pH value of the solution in the first container is equal to 14, stop adding the sodium hydroxide solution to obtain the alkaline solution.

3. The method according to claim 2, characterized in that The method of filtering the first alkaline solution to obtain a third filter cake to separate the silicon product comprises: Performing filter press on the first alkaline solution to obtain a third filter cake; The third filter cake is washed with water and then dried, and after drying, a chloride ion titrant is used to titrate the chloride ion content of the third filter cake; When the chloride ion content is ≤0.1%, the third filter cake is further dried and marked as a silicon product after drying.

4. The method according to claim 3, characterized in that: When a 31% hydrochloric acid solution is continuously added to the second container, the reaction temperature is AMB and the reaction time is less than 1 hour; The third filter cake was washed with water and then placed in an oven and dried at 200° C. for 3 hours.

5. The method according to claim 4, characterized in that A sixth filtrate is obtained when the first alkaline solution is filtered, and the sixth filtrate is added to a ninth container and marked as the first post-silicon precipitation filtrate; When the second alkaline solution is subjected to pressure filtration, a seventh filtrate is obtained, which is added to a tenth container and marked as the second filtrate after silicon precipitation.

6. The method according to claim 5, characterized in that The step of sequentially subjecting the alkali-soluble filter residue to alkali-dissolution treatment and acid-adjustment treatment to obtain a second alkali-soluble solution comprises: After the alkali-soluble filter residue in the third container is placed in a high-temperature and high-pressure reactor, a sodium hydroxide solution is continuously added to the high-temperature and high-pressure reactor to react with the alkali-soluble filter residue at a high temperature and high pressure to obtain a dissolved solution; The dissolved solution is filtered to separate the high-temperature filtrate and the high-temperature filter residue; The high temperature post-filtrate is placed in a fourth container; Continuously adding hydrochloric acid solution into the fourth container and detecting the pH value of the solution in the fourth container in real time; When the pH value of the solution in the fourth container is 10-14, stop adding the hydrochloric acid solution to obtain a second alkali-dissolved impurity-removed filtrate; Adding hydrochloric acid solution to the second alkali-dissolved impurity-removed filtrate again and stirring in real time; When the pH value is close to 3, stop adding the hydrochloric acid solution to obtain a second alkaline solution.

7. The method according to claim 6, characterized in that The high temperature and high pressure reactor was set to a reaction temperature of 215° C. and a pressure of 2.0 MPag, and the high temperature and high pressure reactor was opened after 2 hours to charge the dissolved solution into the fourth container.

8. The method according to claim 7, characterized in that The method further comprises: washing the fourth filter cake with water and then placing it in an oven, drying it at 200° C. for 3 hours; performing filter pressing on the acid-soluble solution to obtain a second filtrate; The method further comprises: acid dissolving the high-temperature filter residue to obtain a second acid-dissolved solution; Performing filter press treatment on the second acid-soluble solution to obtain a fifth filter cake and a second acid-soluble filtrate; adding the second filtrate and the second acid-soluble solution into a fifth container and labeling it as acid-soluble filtrate; continuously adding sodium hydroxide solution into the fifth container; Performing real-time detection on the pH value of the solution in the fifth container; When the pH value of the liquid in the fifth container is 4-7, stop adding the sodium hydroxide solution, wait for the precipitate to completely turn reddish brown, and then add a hydrogen peroxide solution or a sodium hypochlorite solution to the fifth container to obtain an iron precipitation solution; Performing filter pressing on the iron precipitation liquid to obtain a third filtrate and a fifth filter cake; Add the third filtrate into a sixth container and mark it as the filtrate after iron precipitation; The fifth filter cake is washed with pure water and then the chloride ion content in the fifth filter cake is titrated with a chloride ion titrant; When the chloride ion content is ≤1%, the fifth filter cake is dried and marked as an iron product after drying.

9. The method according to claim 8, characterized in that The method further comprises: Continuously adding sodium hydroxide solution into the sixth container and detecting the pH value of the solution in the sixth container in real time; When the pH value of the solution in the sixth container is 7-9, stop adding the sodium hydroxide solution to obtain a crude magnesium precipitation solution; The magnesium precipitation crude liquid is subjected to pressure filtration to obtain a fourth filtrate and a sixth filter cake; Add the fourth filtrate into a seventh container and mark it as impurity-removed magnesium filtrate; The sixth filter cake is washed with distilled water and then the chloride ion content in the sixth filter cake is titrated with a chloride ion titrant; When the chloride ion content is ≤1%, drying the sixth filter cake and marking it as a magnesium impurity product after drying; Continuously adding sodium hydroxide solution into the seventh container, and detecting the pH value of the solution in the seventh container in real time; When the pH value of the solution in the seventh container is 12-14, stop adding the sodium hydroxide solution to obtain a magnesium precipitation solution; Performing filter pressing on the magnesium precipitation solution to obtain a fifth filtrate and a seventh filter cake; Add the fifth filtrate into an eighth container and mark it as magnesium precipitation filtrate; The seventh filter cake is washed with distilled water and then the chloride ion content in the seventh filter cake is titrated with a chloride ion titrant; When the chloride ion content is ≤1%, the seventh filter cake is dried and marked as a magnesium product after drying.

10. The method according to claim 9, characterized in that The sodium hydroxide solution is continuously added to the fifth container, and the concentration thereof is 10%-50%; Add 1 L of hydrogen peroxide solution or sodium hypochlorite solution to the fifth container, the corresponding oxidation temperature is AMB, and the corresponding reaction time is 0.5 h; After adding hydrogen peroxide solution or sodium hypochlorite solution into the fifth container, let it stand for 30 minutes to obtain iron precipitation liquid; The reaction time of the sodium hydroxide solution and the second filtrate is 1h, and the oxidation temperature is AMB; The fifth filter cake is repeatedly washed with pure water for 5 to 20 times; When the fifth filter cake is dried, the fifth filter cake is placed in a crucible and sent into a muffle furnace, kept at a high temperature of more than 300° C. for drying for 0.5-3 hours, and weighed after drying. After weighing, it is marked as an iron product and packed into a product sealing bag.

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