Method for removing silica gel from high-silicon acidic solution
By using freeze-dried algae as a desilication agent, the problem of difficult filtration of silica gel during the acid leaching process of metal silicate minerals has been solved, achieving efficient silica gel removal and valuable metal recovery, with environmental and economic advantages.
Patent Information
- Application Number
- CN202510904016.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-01
- Publication Date
- 2025-11-07
AI Technical Summary
In existing technologies, silica gel in the acidic solution generated during the acid leaching process of metal silicate minerals is difficult to filter, which leads to difficulties in sedimentation and filtration operations. Furthermore, the silica gel carries away valuable metals, resulting in low yields. Traditional activated carbon adsorption methods are also inefficient.
Freeze-dried algae are used as desilication agents. They react with silica gel in a highly silicic acid solution, utilizing the physical structure and surface chemical properties of the algae to form hydrogen bonds or electrostatic adsorption. Combined with the action of natural flocculants, this achieves efficient removal of silica gel.
It achieves a silica gel removal rate of over 93%. The algae desiliconizing agent is environmentally friendly, low in cost, suitable for strongly acidic environments, requires no additional pH adjustment, and the waste is easy to treat or utilize.
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Figure CN120903444A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the technical field of hydrometallurgy, and particularly relates to a method for efficiently removing silica gel from an acid leaching solution of metal silicate minerals. BACKGROUND
[0002] In the acid leaching process of metal silicate minerals such as copper slag and oxidized lead-zinc ore, an acid solution containing silica gel is often produced. The acid solution usually contains silica gel that is difficult to filter, and the silica gel is composed of a multi-cavity network of colloidal particles with a size of 0.001-0.1 μm, which brings great difficulty to the settling and filtering operations. In addition, the gel material in the solution also causes a high water content in the slag, thereby taking away the valuable metals in the solution and causing a low yield of valuable metals. Therefore, the acid solution needs to be desilicated, but the traditional desilication method mainly uses activated carbon adsorption, and the activated carbon has a low adsorption capacity for colloidal silica. Therefore, it is urgent to develop a high-efficiency and low-cost silica gel removal technology. SUMMARY
[0003] The technical problem to be solved by the present application is to overcome the deficiencies and defects mentioned in the above background, and to provide a method for removing silica gel from a high-silicon acid solution.
[0004] To solve the above technical problems, the technical solution provided by the present application is as follows: A method for removing silica gel from a high-silicon acid solution, comprising the following steps: A frozen and dried algal desilication agent is added to the high-silicon acid solution, and stirring is performed at a temperature of 20-90℃ for 0.5-3 hours to carry out a desilication reaction. After the reaction is completed, the precipitate and the supernatant are separated by solid-liquid separation to achieve the removal of silica gel. The addition amount of the algal desilication agent is 20-60wt% of the mass of silicon in the high-silicon acid solution.
[0005] In the above method for removing silica gel from a high-silicon acid solution, preferably, the algal desilication agent is selected from at least one of spirulina, green algae, Microcystis aeruginosa and Volvox.
[0006] In the above method for removing silica gel from a high-silicon acid solution, preferably, the temperature of the desilication reaction is 40-70℃, and the reaction time is 1-2 hours.
[0007] In the above method for removing silica gel from a high-silicon acid solution, preferably, the solid-liquid separation is performed by any one of vacuum filtration, centrifugal separation, gravity settling and pressure filtration.
[0008] In the above method for removing silica gel from a high-silicon acid solution, preferably, the high-silicon acid solution is obtained by mixing and slurrying a metal silicate mineral with water, adding concentrated sulfuric acid to perform a curing reaction, and then water leaching.
[0009] Preferably, the metal silicate mineral is selected from at least one of copper smelting slag and oxidized lead-zinc ore.
[0010] Preferably, the amount of concentrated sulfuric acid is 150-200wt% of the mass of the metal silicate mineral.
[0011] Preferably, the temperature of the ripening reaction is 150-250℃, and the reaction time is 0.5-1 hour.
[0012] Preferably, in the water immersion process, the leaching temperature is 50-70℃, and the liquid-solid ratio is (5-10):1, the ratio unit being mL / g.
[0013] Preferably, the silicon content in the high-silicon acidic solution is 10-40 g / L, and the pH is -2-7.
[0014] Compared with the prior art, the present application has the following beneficial effects: (1) The present application uses freeze-dried algae as a desilication agent, which can achieve excellent desilication effect in a high-acid solution, mainly due to its unique physical structure and surface chemical properties. After freeze-drying treatment, the surface of the algae is rich in hydrophilic functional groups such as carboxyl and hydroxyl groups, which can form hydrogen bonds or electrostatic adsorption with the silanol groups on the surface of the silica particles, thereby effectively capturing silica particles. At the same time, the porous three-dimensional structure formed by the algae helps to adsorb and fix colloidal particles, promoting the aggregation and sedimentation of particles. The natural macromolecules in the cell wall of the algae, such as polysaccharides and proteins, can also act as natural flocculants under acidic conditions, further enhancing the desilication efficiency. Compared with traditional inorganic filter aids, the present application uses algae as a desilication agent, which has the advantages of being green, environmentally friendly, widely available, low in processing cost, easy to operate, suitable for strong acidic environments, and not requiring additional pH adjustment for use. In addition, the algae desilication agent can be adjusted according to different needs, and the waste after sedimentation is easy to handle or resource utilization, which has good application prospect and industrial promotion value.
[0015] (2) The process for removing silica gel from a high-silicon acidic solution of the present application can achieve a desilication rate of more than 93%. BRIEF DESCRIPTION OF DRAWINGS
[0016] In order to make the technical solutions in the embodiments of the present application or the prior art clearer, the accompanying drawings needed in the embodiments or prior art description will be briefly introduced. Obviously, the accompanying drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0017] Figure 1 is a process flow diagram of the present application for removing silica gel from an acid leaching solution of metal silicate minerals. DETAILED DESCRIPTION
[0018] In order to facilitate the understanding of the present application, the present application will be described more fully and completely by reference to the accompanying drawings and preferred embodiments. However, the scope of protection of the present application is not limited to the following specific embodiments.
[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The technical terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present application.
[0020] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present application can be purchased from the market or can be prepared by existing methods.
[0021] The main chemical components of the copper smelting slag used in the following examples and comparative examples are shown in Table 1, and the main chemical components of the high-silicon lead-zinc oxide ore are shown in Table 2.
[0022] Table 1 Main chemical components of copper smelting slag
[0023] Table 2 Main chemical components of high-silicon lead-zinc oxide ore
[0024] Example 1 The method for efficiently removing silica gel from an acid leaching solution of metal silicate minerals in this embodiment has a process flow diagram as shown in Figure 1 The method comprises the following steps: (1) 20 g of copper smelting slag was mixed with 12 g of water to form a slurry, and then 40 g of concentrated H2SO4 (98%) was added and stirred rapidly to uniformity. Subsequently, the mixture was placed in a muffle furnace and allowed to mature at 200°C for 0.5 h. After the reaction was completed, the material was added to 100 mL of water and stirred at 60°C for 1 h to obtain a high-silicon acidic solution, which had a chemical composition including Al: 0.22 g / L, Ca: 0.20 g / L, Co: 0.12 g / L, Cr: 0.06 g / L, Cu: 0.84 g / L, Fe: 86.08 g / L, Mg: 0.29 g / L, Mn: 0.06 g / L, Ni: 0.04 g / L, Pb: 0.02 g / L, Si: 20.69 g / L, Zn: 1.45 g / L, and pH ≈ 0.
[0025] (2) The spirulina was frozen at -40°C for 96 h, and then the frozen spirulina was added to the high-silicon acidic solution as a desilication agent to perform a desilication reaction. The amount of the desilication agent added was 40 wt% of the mass of silicon in the high-silicon acidic solution, and the desilication reaction was performed at 60°C while stirring for 1 h.
[0026] (3) The high-silicon acidic solution after the reaction of step (2) was poured into a Buchner funnel, and vacuum filtration was performed to separate the precipitate and the supernatant at a filtration speed of 0.62 m 3 / (m 2 h). The supernatant was a high-iron solution, which had a chemical composition including Al: 0.21 g / L, Ca: 0.18 g / L, Co: 0.11 g / L, Cr: 0.06 g / L, Cu: 0.80 g / L, Fe: 81.77 g / L, Mg: 0.28 g / L, Mn: 0.05 g / L, Ni: 0.04 g / L, Pb: 0.02 g / L, Si: 1.03 g / L, and Zn: 1.38 g / L.
[0027] The silicon removal rate in this embodiment was 95%.
[0028] Example 2: The method for efficiently removing silica gel from a metal silicate mineral acid leaching solution in this embodiment is shown in the process flow diagram as Figure 1 follows, which includes the following steps: (1) The high-silicon acidic solution was prepared as in Example 1.
[0029] (2) The Microcystis aeruginosa was frozen at -40°C for 96 h, and then the frozen Microcystis aeruginosa was added to the high-silicon acidic solution as a desilication agent to perform a desilication reaction. The amount of the desilication agent added was 50 wt% of the mass of silicon in the high-silicon acidic solution, and the desilication reaction was performed at 70°C while stirring for 1 h.
[0030] (3) The high-silicon acid solution after the reaction of step (2) is poured into a Buchner funnel, and vacuum filtration is used to separate the precipitate and the supernatant, the filtration speed is 0.61 m 3 / (m 2 h), and the supernatant is an iron-rich solution, the chemical composition of which includes Al: 0.22 g / L, Ca: 0.18 g / L, Co: 0.11 g / L, Cr: 0.06 g / L, Cu: 0.80 g / L, Fe: 82.64 g / L, Mg: 0.28 g / L, Mn: 0.05 g / L, Ni: 0.04 g / L, Pb: 0.02 g / L, Si: 1.24 g / L, and Zn: 1.39 g / L.
[0031] The silicon removal rate in this embodiment is 94%.
[0032] Example 3: The method for efficiently removing silica gel from the acid leaching solution of metal silicate minerals in this embodiment has a process flowchart as shown in Figure 1 , and includes the following steps: (1) The preparation of the high-silicon acid solution is the same as in Example 1.
[0033] (2) The botryococcus is frozen at -40°C for 96 hours, and then the frozen botryococcus is added to the high-silicon acid solution as a desiliconizing agent to perform a desiliconization reaction, wherein the addition amount of the desiliconizing agent is 55wt% of the mass of silicon elements in the high-silicon acid solution, the desiliconization reaction temperature is 60°C, and stirring is maintained during the desiliconization process for 2h.
[0034] (3) The high-silicon acid solution after the reaction of step (2) is poured into a Buchner funnel, and vacuum filtration is used to separate the precipitate and the supernatant, the filtration speed is 0.59 m 3 / (m 2 h), and the supernatant is an iron-rich solution, the chemical composition of which includes Al: 0.22 g / L, Ca: 0.17 g / L, Co: 0.11 g / L, Cr: 0.06 g / L, Cu: 0.80 g / L, Fe: 81.64 g / L, Mg: 0.28 g / L, Mn: 0.05 g / L, Ni: 0.04 g / L, Pb: 0.02 g / L, Si: 1.23 g / L, and Zn: 1.23 g / L.
[0035] The silicon removal rate in this embodiment is 94%.
[0036] Example 4: The method for efficiently removing silica gel from the acid leaching solution of metal silicate minerals in this embodiment has a process flowchart as shown in Figure 1 , and includes the following steps: (1) The preparation of the high-silicon acid solution is the same as in Example 1.
[0037] (2) The green algae is frozen at -40°C for 96 hours, and then the frozen green algae is added into the high-silicon acidic solution as a desilication agent to perform a desilication reaction, wherein the addition amount of the desilication agent is 40wt% of the mass of silicon in the high-silicon acidic solution, the desilication reaction temperature is 60°C, and stirring is maintained for 2h during the desilication process.
[0038] (3) The high-silicon acidic solution after the reaction in step (2) is poured into a Buchner funnel, vacuum filtration is used to separate the precipitate and the supernatant, the filtration speed is 0.65m 3 / (m 2 h), and the supernatant is a rich-iron solution, and the chemical composition of the rich-iron solution is Al: 0.21 g / L, Ca: 0.16 g / L, Co: 0.11 g / L, Cr: 0.06 g / L, Cu: 0.80 g / L, Fe: 83.45 g / L, Mg: 0.28 g / L, Mn: 0.05 g / L, Ni: 0.04 g / L, Pb: 0.02 g / L, Si: 1.03 g / L, and Zn: 1.38 g / L.
[0039] The silicon removal rate in this embodiment is 95%.
[0040] Example 5: The method for efficiently removing silica gel from a metal silicate mineral acid leaching solution in this embodiment has a process flowchart as shown in Figure 1 , and includes the following steps: (1) The preparation of the high-silicon acidic solution is the same as in Example 1.
[0041] (2) The green algae and Microcystis aeruginosa are frozen at -40°C for 96 hours, and then the frozen green algae and Microcystis aeruginosa are added into the high-silicon acidic solution as desilication agents to perform a desilication reaction, wherein the addition amount of the green algae is 20wt% of the mass of silicon in the high-silicon acidic solution, the addition amount of the Microcystis aeruginosa is 25wt% of the mass of silicon in the high-silicon acidic solution, the desilication reaction temperature is 60°C, and stirring is maintained for 2h during the desilication process.
[0042] (3) The high-silicon acidic solution after the reaction in step (2) is poured into a Buchner funnel, vacuum filtration is used to separate the precipitate and the supernatant, the filtration speed is 0.69m 3 / (m 2• h), the supernatant is a rich iron solution, and the chemical composition is Al: 0.21 g / L, Ca: 0.16 g / L, Co: 0.11 g / L, Cr: 0.06 g / L, Cu: 0.80 g / L, Fe: 83.45 g / L, Mg: 0.28 g / L, Mn: 0.05 g / L, Ni: 0.04 g / L, Pb: 0.02 g / L, Si: 0.83 g / L, Zn: 1.19 g / L.
[0043] The silicon removal rate in this embodiment is 96%.
[0044] Example 6: The method for efficiently removing silica gel from an acid leaching solution of metal silicate minerals in this embodiment has a process flowchart as shown in Figure 1 The method comprises the following steps: (1) 20 g of high-silicon lead-zinc oxide ore is slurried with 12 g of water, and then 40 g of concentrated H2SO4 (98%) is added and stirred uniformly. Subsequently, the mixture is placed in a muffle furnace and incubated at 200°C for 0.5 h. After the reaction is completed, the material is added to 100 mL of water and stirred at 60°C for 1 h to obtain a high-silicon acid solution, which has a chemical composition of Al: 8.09 g / L, Ca: 0.74 g / L, Fe: 5.39 g / L, Mg: 1.37 g / L, Mn: 0.25 g / L, Si: 18.41 g / L, Pb: 0.98 g / L, Zn: 45.39 g / L, and pH ≈ -0.2.
[0045] (2) The spirulina is frozen at -40°C for 96 hours, and then the frozen spirulina is added as a desilication agent to the high-silicon acid solution for desilication reaction. The addition amount of the desilication agent is 40 wt% of the mass of silicon in the high-silicon acid solution, and the desilication reaction is carried out at a temperature of 50°C while stirring for 1 h.
[0046] (3) The high-silicon acid solution after the reaction in step (2) is poured into a Buchner funnel, and vacuum filtration is used to separate the precipitate and the supernatant, with a filtration speed of 0.63 m 3 / (m 2 • h), the chemical composition of the supernatant is Al: 7.28 g / L, Ca: 0.66 g / L, Fe: 4.85 g / L, Mg: 1.23 g / L, Mn: 0.22 g / L, Si: 1.29 g / L, Pb: 0.87 g / L, Zn: 40.85 g / L.
[0047] The silicon removal rate in this embodiment is 93%.
[0048] Example 7: The method for efficiently removing silica gel from a metal silicate mineral acid leaching solution, a process flow chart of which is shown in Figure 1 , includes the following steps: (1) Preparation of high-silicic acid solution is the same as in Example 6.
[0049] (2) Freeze the spirulina and Microcystis aeruginosa at -40°C for 96 hours, then add the frozen spirulina and Microcystis aeruginosa as desilication agents to the high-silicic acid solution for desilication reaction, wherein the addition amount of spirulina is 20wt% of the mass of silicon in the high-silicic acid solution, the addition amount of Microcystis aeruginosa is 20wt% of the mass of silicon in the high-silicic acid solution, the desilication reaction temperature is 70°C, and stirring is maintained for 1h during the desilication process.
[0050] (3) Pour the high-silicic acid solution after reaction in step (2) into a Buchner funnel, separate the precipitate and supernatant using vacuum filtration, the filtration speed is 0.68 m 3 / (m 2 h), and the chemical composition of the supernatant is Al: 6.96 g / L, Ca: 0.72 g / L, Fe: 4.12 g / L, Mg: 1.13 g / L, Mn: 0.22 g / L, Si: 0.74 g / L, Pb: 0.75 g / L, and Zn: 41.23 g / L.
[0051] The silicon removal rate in this example is 96%.
[0052] Comparative Example 1: The difference between this comparative example and Example 6 is that in step (2), spirulina is replaced with an equal amount of activated carbon as a desilication agent, and other processes and parameters are exactly the same as in Example 6. The chemical composition of the supernatant is Al: 6.34 g / L, Ca: 0.61 g / L, Fe: 3.95 g / L, Mg: 0.96 g / L, Mn: 0.19 g / L, Si: 2.76 g / L, Pb: 0.61 g / L, and Zn: 40.12 g / L.
[0053] The silicon removal rate in this comparative example is 85%.
Claims
1. A method for removing silica gel from a high-silica acidic solution, characterized by, The method comprises the following steps: The desilication reaction is carried out by adding the freeze-dried algal desilication agent to the high-silicon acidic solution and stirring at a temperature of 20-90℃ for 0.5-3 hours, and then separating the precipitate from the supernatant to remove the silica gel, wherein the addition amount of the algal desilication agent is 20-60wt% of the mass of silicon in the high-silicon acidic solution.
2. The method of removing silica gel from a high-silica acid solution of claim 1, wherein, The algal desilication agent is at least one selected from the group consisting of spirulina, green algae, Microcystis aeruginosa and Volvox.
3. The method of removing silica gel from a high-silica acid solution of claim 1, wherein, The temperature of the desilication reaction is 40-70℃, and the reaction time is 1-2 hours.
4. The method of claim 1 wherein the silica gel is removed from the high-silica acidic solution by, The solid-liquid separation is performed by any one of vacuum filtration, centrifugal separation, gravity sedimentation and pressure filtration.
5. The method of claim 1 wherein the silica gel is removed from the high-silica acidic solution by, The high-silicon acidic solution is obtained by mixing a metal silicate mineral with water, adding concentrated sulfuric acid for a curing reaction, and then water immersion.
6. The method of removing silica gel from a high-silica acid solution of claim 5, wherein, The metal silicate mineral is at least one selected from the group consisting of copper smelting slag and lead-zinc oxide ore.
7. The method of removing silica gel from a high-silica acid solution of claim 5, wherein, The amount of the concentrated sulfuric acid is 150-200wt% of the mass of the metal silicate mineral.
8. The method of removing silica gel from a high-silica acid solution of claim 5, wherein, The temperature of the curing reaction is 150-250℃, and the reaction time is 0.5-1 hour.
9. The method for removing silica gel from a high-silica acidic solution according to claim 5, characterized by, In the water immersion process, the leaching temperature is 50-70℃, and the liquid-solid ratio is (5-10):1, the ratio unit being mL / g.
10. The method of removing silica gel from a high-silica acid solution of claim 5, wherein, The silicon content in the high-silicon acidic solution is 10-40 g / L, and the pH is -2-7.