Device for producing nano C-S-H based on narrow-gap electrolytic cell and preparation method

Abstract

The invention discloses a device for producing nano C-S-H based on a narrow-gap electrolytic bath and a preparation method.The device comprises an electrolytic bath assembly, the electrolytic bath assembly comprises an acid reaction liquid bin, an alkaline reaction liquid bin, a separation membrane and a bipolar plate, and the acid reaction liquid bin and the alkaline reaction liquid bin are separated through the separation membrane; the two bipolar plates are used for clamping and fixing the reaction liquid bin and the separation membrane; the at least two electrolytic cell assemblies are connected in series; the electrolysis assembly provides electric energy for the electrolytic tank assembly; the acid liquor tank is connected with each acid reaction liquid bin; the alkali liquor pool is connected with each alkaline reaction liquid bin; electrolyte in the precipitation reaction tank, the acid liquor tank and the alkali liquor tank flows to the precipitation reaction tank. According to the device, the contact area of the acidic electrolyte and the alkaline electrolyte is increased through the plurality of electrolytic bath assemblies connected in series, and the distance between the acidic reaction liquid bin and the alkaline reaction liquid bin is closer so as to improve the electrolytic efficiency; in addition, the requirement for the purity of calcium minerals and siliceous minerals is not high, and dependence on high-purity raw materials is avoided.

Description

Technical Field

[0001] The present invention relates to the field of electrochemical technology, and in particular to a device and a preparation method for producing nano CSH based on a narrow gap electrolytic cell. Background Art

[0002] CSH, or calcium silicate hydrate, is a non-stoichiometric compound composed of CaO-SiO2-H2O. CSH formed at room temperature is usually amorphous, and the gel particle size is nanometer-sized. At present, there are also electrochemical methods for obtaining CSH on the market. The specific process is to apply direct current to the aqueous solution to obtain hydrogen ions and hydroxide ions, produce local acidity and alkalinity, and the acidic liquid produced at the anode can fully dissolve calcium carbonate to generate Ca 2+ , and then react with the alkaline liquid produced at the cathode, and CSH crystals are obtained after subsequent solid phase precipitation and drying.

[0003] However, since the hydrogen ions and hydroxide ions in the solution are only enriched on the electrode surface, the reaction area accounts for a small proportion, and increasing the effective reaction area requires a larger electrode surface and current. Moreover, since the raw materials react in situ in the electrode compartment, it is inevitable that the electrode spacing increases and the current efficiency decreases. The reaction area can only be increased by increasing the electrode plate area, resulting in an increase in the volume of the equipment. In addition, current research mainly uses pure CaCO3 to participate in the dissolution precipitation reaction, and the output gas is pure CO2, H2 and O2. However, in industrial applications, it is foreseeable that low-grade raw materials with high impurity content will be used for production. If it contains a small amount of chlorine, fluorine or other organic impurities, an oxidation reaction will occur under the action of a large current, which will not only corrode the electrode, but may also produce toxic or polluted gases, causing serious environmental damage. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a device for producing nano-CSH based on a narrow gap electrolytic cell, which can improve the electrolysis efficiency and get rid of the dependence on high-purity raw materials.

[0005] The present invention also provides a method for preparing a device for producing nano-CSH based on the narrow gap electrolytic cell.

[0006] According to the first aspect of the present invention, a device for producing nano-CSH based on a narrow gap electrolytic cell comprises:

[0007] An electrolytic cell assembly, comprising an acidic reaction liquid tank, an alkaline reaction liquid tank, a separator membrane and a bipolar plate, wherein the acidic reaction liquid tank and the alkaline reaction liquid tank are both provided with cavities and the separator membrane separates the cavities of the two, the acidic reaction liquid tank, the alkaline reaction liquid tank and the separator membrane together constitute an assembly, the number of the bipolar plates is two and they clamp and fix the assembly together; the number of the electrolytic cell assemblies is at least two and they are arranged in series with each other;

[0008] An electrolytic assembly, comprising an anode electrode and a cathode electrode, wherein the anode electrode and the cathode electrode are respectively arranged at two ends of the electrolytic cell assembly;

[0009] An acid liquid tank connected to each of the acidic reaction liquid tanks;

[0010] An alkaline solution tank connected to each of the alkaline reaction liquid tanks;

[0011] The precipitation reaction tank is connected to the acid tank and the alkali tank, and the electrolytes in the acid tank and the alkali tank are both circulated to the precipitation reaction tank.

[0012] The device for producing nano-CSH based on a narrow gap electrolytic cell according to an embodiment of the present invention has at least the following beneficial effects: the contact area between the acidic electrolyte and the alkaline electrolyte is increased by a plurality of electrolytic cell components arranged in series, and the distance between the acidic reaction liquid tank and the alkaline reaction liquid tank is closer, which reduces the movement distance of ions during the electrolysis process, thereby improving the electrolysis efficiency; in addition, an acidic solution and an alkaline solution are obtained by electrolysis to dissolve calcium minerals and silicon minerals respectively, and the purity requirements for calcium minerals and silicon minerals are not high, thereby getting rid of the dependence on high-purity raw materials.

[0013] According to some embodiments of the present invention, the acidic reaction liquid tank and the alkaline reaction liquid tank are both provided with a liquid inlet and a liquid outlet connected to their respective cavities, the liquid inlet is connected to the precipitation reaction tank, the liquid outlet of the acidic reaction liquid tank is connected to the acid liquid tank, and the liquid outlet of the alkaline reaction liquid tank is connected to the alkaline liquid tank.

[0014] According to some embodiments of the present invention, the liquid inlet is arranged at the bottom of the cavity, and the liquid outlet is arranged at the top of the cavity.

[0015] According to some embodiments of the present invention, the apparatus for producing nano-CSH based on a narrow gap electrolytic cell further includes a drying box, into which the solid phase material in the precipitation reaction tank is discharged, and the drying box is used to dry the solid phase material to obtain CSH crystals.

[0016] According to some embodiments of the present invention, the electrolytic assembly further comprises a sealing plate, which is installed on the outside of the anode electrode and the cathode electrode to provide insulation and prevent leakage of the electrolyte.

[0017] According to some embodiments of the present invention, the surfaces of the anode electrode and the cathode electrode are both provided with a titanium mesh plated with PbO2.

[0018] According to some embodiments of the present invention, the separation membrane is specifically a porous PTEF membrane, which can prevent the flow of hydroxide ions and hydrogen ions.

[0019] According to some embodiments of the present invention, the surface of the bipolar plate is plated with a PbO2 titanium plate.

[0020] According to some embodiments of the present invention, the surface of the bipolar plate is provided with a concave-convex pattern.

[0021] A preparation method according to an embodiment of the second aspect of the present invention is carried out using the above-mentioned device for producing nano-CSH based on a narrow gap electrolytic cell, comprising the following steps:

[0022] Connecting the anode electrode and the cathode electrode to a constant current DC power supply, and waiting for the pH of the liquid in the acidic reaction liquid tank to be less than 2, and the pH of the liquid in the alkaline reaction liquid tank to be greater than 12;

[0023] The electrolyte in each of the acidic reaction liquid tanks is led out to the acid liquid tank, and the electrolyte in each of the alkaline reaction liquid tanks is led out to the alkaline liquid tank;

[0024] Adding calcium raw materials into the acid solution pool, adding silicon raw materials into the alkali solution pool, and stirring and dissolving them;

[0025] After the raw materials are fully dissolved in the acid solution pool and the alkali solution pool, they are allowed to settle, and the supernatant is sent to the precipitation reaction pool;

[0026] The reaction liquid generates flocculated emulsion after sufficient reaction and aging in the precipitation reaction tank, and solid-liquid separation is performed, and the solid phase material is filtered and dried to obtain CSH crystals.

[0027] The preparation method according to the embodiment of the present invention has at least the following beneficial effects: the device for producing nano-CSH based on a narrow gap electrolytic cell can improve the preparation efficiency of CSH and reduce the requirement for raw material purity.

[0028] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0030] Figure 1 This is a schematic diagram of the connection of a device for producing nano-CSH based on a narrow gap electrolytic cell according to an embodiment of the first aspect of the present invention;

[0031] Figure 2 This is a disassembled diagram of an electrolytic cell assembly 100 in a device for producing nano-CSH based on a narrow gap electrolytic cell according to an embodiment of the first aspect of the present invention;

[0032] Figure 3 It is a cross-sectional view of an acidic reaction liquid tank 110 and an alkaline reaction liquid tank 120 in a device for producing nano-CSH based on a narrow gap electrolytic cell according to an embodiment of the first aspect of the present invention.

[0033] Figure numerals: 100 - electrolytic cell assembly, 110 - acidic reaction liquid tank, 120 - alkaline reaction liquid tank, 130 - separation membrane, 140 - bipolar plate, 150 - liquid inlet, 160 - liquid outlet, 210 - anode electrode, 220 - cathode electrode, 230 - sealing plate, 300 - acid liquid tank, 400 - alkaline liquid tank, 500 - precipitation reaction tank, 600 - drying oven. DETAILED DESCRIPTION

[0034] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0035] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0036] In the description of the present invention, "several" means more than one, "many" means more than two, "greater than", "less than", "exceed", etc. are understood to exclude the number itself, and "above", "below", "within", etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0037] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0038] In the description of the present invention, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0039] CSH, or calcium silicate hydrate, is a non-stoichiometric compound composed of CaO-SiO2-H2O. CSH formed at room temperature is usually amorphous, and the gel particle size is nanometer-sized. At present, there are also electrochemical methods for obtaining CSH on the market. The specific process is to apply direct current to the aqueous solution to obtain hydrogen ions and hydroxide ions, produce local acidity and alkalinity, and the acidic liquid produced at the anode can fully dissolve calcium carbonate to generate Ca 2+ , and then react with the alkaline liquid produced at the cathode, and CSH crystals are obtained after subsequent solid phase precipitation and drying.

[0040] However, since the hydrogen ions and hydroxide ions in the solution are only enriched on the electrode surface, the reaction area accounts for a small proportion, and increasing the effective reaction area requires a larger electrode surface and current. Moreover, since the raw materials react in situ in the electrode compartment, it is inevitable that the electrode spacing increases and the current efficiency decreases. The reaction area can only be increased by increasing the electrode plate area, resulting in an increase in the volume of the equipment. In addition, current research mainly uses pure CaCO3 to participate in the dissolution precipitation reaction, and the output gas is pure CO2, H2 and O2. However, in industrial applications, it is foreseeable that low-grade raw materials with high impurity content will be used for production. If it contains a small amount of chlorine, fluorine or other organic impurities, an oxidation reaction will occur under the action of a large current, which will not only corrode the electrode, but may also produce toxic or polluted gases, causing serious environmental damage.

[0041] In this regard, the present application proposes a device for producing nano-CSH based on a narrow gap electrolytic cell. By using a plurality of electrolytic cell assemblies 100 arranged in series, the contact area between the acidic electrolyte and the alkaline electrolyte is increased, and the distance between the acidic reaction liquid tank 110 and the alkaline reaction liquid tank 120 is closer, which reduces the movement distance of ions during the electrolysis process, thereby improving the electrolysis efficiency. In addition, an acidic solution and an alkaline solution are obtained by electrolysis to dissolve calcium minerals and silica minerals respectively, and the purity requirements for calcium minerals and silica minerals are not high, thereby getting rid of the dependence on high-purity raw materials.

[0042] In addition, the present application also proposes a preparation method for the device for producing nano-CSH using the above-mentioned narrow gap electrolytic cell, which can improve the preparation efficiency of CSH and reduce the requirements for raw material purity.

[0043] Reference Figure 1 , the device for producing nano-CSH based on a narrow gap electrolytic cell in the embodiment of the first aspect of the present application includes an electrolytic cell assembly 100, an electrolytic assembly, an acidic liquid pool 300, an alkaline liquid pool 400 and a precipitation reaction pool 500. Among them, the electrolytic cell assembly 100 is used to electrolyze the electrolyte and obtain an acidic electrolyte and an alkaline electrolyte respectively, in preparation for the subsequent dissolution of the calcium raw material and the silicon raw material. The electrolytic assembly is used to provide electrical energy to ensure the smooth progress of the electrolysis work. The acidic liquid pool 300 is used to load the acidic electrolyte flowing out of the electrolytic cell assembly 100, and complete the dissolution reaction of the calcium raw material therein. The alkaline liquid pool 400 is used to load the alkaline electrolyte flowing out of the electrolytic cell assembly 100, and complete the dissolution reaction of the silicon raw material therein. The precipitation reaction pool 500 is used to mix the products after the reaction in the acidic liquid pool 300 and the alkaline liquid pool 400, and after mixing and natural sedimentation, filter to obtain the solid phase material therein, and obtain CSH crystals after subsequent drying.

[0044] Specifically, refer to Figure 2 , the electrolytic cell assembly 100 includes an acidic reaction liquid tank 110, an alkaline reaction liquid tank 120, a separator 130 and a bipolar plate 140. Among them, the acidic reaction liquid tank 110 and the alkaline reaction liquid tank 120 are both provided with cavities and the separator 130 separates the cavities of the two. The separator 130 enables water molecules in the two cavities to pass through, but isolates the flow of hydrogen ions and hydroxide ions, thereby avoiding acid-base neutralization of the two cavities. The acidic reaction liquid tank 110, the alkaline reaction liquid tank 120 and the separator 130 together constitute an assembly, and the number of bipolar plates 140 is two and they jointly clamp and fix the assembly. It is worth noting that there are at least two electrolytic cell assemblies 100 and they are arranged in series with each other.

[0045] The electrolytic assembly includes an anode electrode 210 and a cathode electrode 220 , which are respectively disposed at two ends of the electrolytic cell assembly 100 , and are used to guide current to the electrolytic cell assembly 100 to complete the electrolysis work.

[0046] The acid solution pool 300 is connected to each acidic reaction liquid tank 110 to carry the acidic electrolyte flowing out therefrom; the alkaline solution pool 400 is connected to each alkaline reaction liquid tank 120 to carry the alkaline electrolyte flowing out therefrom.

[0047] The precipitation reaction tank 500 is connected to the acid tank 300 and the alkali tank 400 . The electrolytes in the acid tank 300 and the alkali tank 400 flow to the precipitation reaction tank 500 , and are mixed and naturally settled in the precipitation reaction tank 500 .

[0048] When the anode electrode 210 and the cathode electrode 220 are electrically connected to a DC power source, a potential difference is generated at both ends of the electrolytic cell assembly 100. In the electrolytic cell assembly 100, the reaction liquid tank near the high potential end is the acidic reaction liquid tank 110, and the reaction liquid tank near the low potential end is the alkaline reaction liquid tank 120. Two or more electrolytic cell assemblies 100 work together for electrolysis. Compared with conventional electrolysis devices, the distance between the acidic reaction liquid tank 110 and the alkaline reaction liquid tank 120 becomes shorter, and the movement path of ions during the electrolysis process is shorter, thereby improving the electrolysis efficiency.

[0049] Further, refer to Figure 3 The acidic reaction liquid tank 110 and the alkaline reaction liquid tank 120 are both provided with a liquid inlet 150 and a liquid outlet 160 connected to their respective cavities. The liquid inlet 150 is connected to the precipitation reaction tank 500, the liquid outlet 160 of the acidic reaction liquid tank 110 is connected to the acidic liquid tank, and the liquid outlet 160 of the alkaline reaction liquid tank 120 is connected to the alkaline liquid tank. Thus, the supernatant liquid after natural sedimentation in the precipitation reaction tank 500 can flow back to each acidic reaction liquid tank 110 and alkaline reaction liquid tank 120 through the liquid inlet 150, so as to realize the recycling of the liquid after sedimentation and reduce the consumption of raw materials.

[0050] Furthermore, the liquid inlet 150 is arranged at the bottom of the cavity, and the liquid outlet 160 is arranged at the top of the cavity, so that the electrolyte enters from the bottom of the cavity and flows out from the liquid outlet 160 at the top after being fully electrolyzed.

[0051] Furthermore, the apparatus for producing nano-CSH based on a narrow gap electrolytic cell further includes a drying box 600 , into which the solid phase material in the precipitation reaction tank 500 is discharged, and the drying box 600 is used to dry the solid phase material to obtain CSH crystals.

[0052] Furthermore, the electrolytic assembly further includes a sealing plate 230 , which is installed outside the anode electrode 210 and the cathode electrode 220 to provide insulation and prevent leakage of the electrolyte.

[0053] Specifically, the acidic reaction liquid tank 110 and the alkaline reaction liquid tank 120 are both filled with 1M sodium nitrate solution as electrolyte.

[0054] Specifically, the material of the anode electrode 210 and the cathode electrode 220 is resistant to oxidation and corrosion and has a certain catalytic effect on the electrolysis of water to produce hydrogen, and a titanium mesh plated with PbO2 is provided on the surface.

[0055] Specifically, the separator 130 is a porous PTEF membrane, which can prevent the flow of hydroxide ions and hydrogen ions, maintain the local acid-base environment in the reaction liquid chambers on both sides, and transmit water and electrolyte ions to promote the electrolysis reaction.

[0056] Specifically, the surface of the bipolar plate 140 is plated with a PbO2 titanium plate, and the surface of the bipolar plate 140 is provided with a concave-convex pattern, the function of which is to distinguish the acidic reaction liquid tank 110 from the alkaline reaction liquid tank 120, prevent liquid penetration, reduce liquid convection, increase conductivity, conduct current, and promote uniform distribution of the electric field.

[0057] A preparation method in an embodiment of the second aspect of the present application is carried out using the above-mentioned device for producing nano-CSH based on a narrow gap electrolytic cell, comprising the following steps:

[0058] S100. Connect the anode electrode 210 and the cathode electrode 220 to a constant current DC power supply, and wait for the pH of the liquid in the acidic reaction liquid tank 110 to be less than 2, and the pH of the liquid in the alkaline reaction liquid tank 120 to be greater than 12;

[0059] S200. The electrolyte in each acidic reaction liquid tank 110 is led to the acid liquid tank 300, and the electrolyte in each alkaline reaction liquid tank 120 is led to the alkaline liquid tank 400;

[0060] S300. Add the calcium raw material to the acid solution pool 300, add the silicon raw material to the alkali solution pool 400, and stir and dissolve;

[0061] S400. The raw material is fully dissolved in the acid tank 300 and the alkali tank 400 and then allowed to settle, and the supernatant is sent to the precipitation reaction tank 500;

[0062] S500. After the reaction liquid is fully reacted and aged in the precipitation reaction tank 500, a flocculated emulsion is generated, and solid-liquid separation is performed, and the solid phase material is filtered and dried to obtain CSH crystals.

[0063] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the purpose of the present invention. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

Claims

1. A device for producing nano-CSH based on a narrow gap electrolytic cell, characterized in that: include: An electrolytic cell assembly, comprising an acidic reaction liquid tank, an alkaline reaction liquid tank, a separator and a bipolar plate, wherein the acidic reaction liquid tank and the alkaline reaction liquid tank are both provided with cavities and the separator separates the cavities of the two, the acidic reaction liquid tank, the alkaline reaction liquid tank and the separator together constitute an assembly, the number of the bipolar plates is two and they clamp and fix the assembly together; the number of the electrolytic cell assemblies is at least two and they are arranged in series with each other; An electrolytic assembly, comprising an anode electrode and a cathode electrode, wherein the anode electrode and the cathode electrode are respectively arranged at two ends of the electrolytic cell assembly; An acid liquid tank connected to each of the acidic reaction liquid tanks; An alkaline solution tank connected to each of the alkaline reaction liquid tanks; The precipitation reaction tank is connected to the acid tank and the alkali tank, and the electrolytes in the acid tank and the alkali tank are both circulated to the precipitation reaction tank.

2. The device for producing nano-CSH based on a narrow gap electrolytic cell according to claim 1, characterized in that: The acidic reaction liquid tank and the alkaline reaction liquid tank are both provided with a liquid inlet and a liquid outlet connected to their respective cavities, the liquid inlet is connected to the precipitation reaction tank, the liquid outlet of the acidic reaction liquid tank is connected to the acid tank, and the liquid outlet of the alkaline reaction liquid tank is connected to the alkaline tank.

3. The device for producing nano-CSH based on a narrow gap electrolytic cell according to claim 2, characterized in that: The liquid inlet is arranged at the bottom of the cavity, and the liquid outlet is arranged at the top of the cavity.

4. The device for producing nano-CSH based on a narrow gap electrolytic cell according to claim 1, characterized in that: The apparatus for producing nano-CSH based on a narrow gap electrolytic cell further includes a drying box, into which the solid phase material in the precipitation reaction tank is discharged, and the drying box is used to dry the solid phase material to obtain CSH crystals.

5. The device for producing nano-CSH based on a narrow gap electrolytic cell according to claim 1, characterized in that: The electrolytic assembly also includes a sealing plate, which is installed on the outside of the anode electrode and the cathode electrode to provide insulation and prevent leakage of the electrolyte.

6. The device for producing nano-CSH based on a narrow gap electrolytic cell according to claim 1, characterized in that: The surfaces of the anode electrode and the cathode electrode are both provided with a titanium mesh plated with PbO2.

7. The device for producing nano-CSH based on a narrow gap electrolytic cell according to claim 1, characterized in that: The separation membrane is specifically a porous PTEF membrane, which can prevent the flow of hydroxide ions and hydrogen ions.

8. The device for producing nano-CSH based on a narrow gap electrolytic cell according to claim 1, characterized in that: The surface of the bipolar plate is plated with a PbO2 titanium plate.

9. The device for producing nano-CSH based on a narrow gap electrolytic cell according to claim 8, characterized in that: The surface of the bipolar plate is provided with a concave-convex pattern.

10. A method for preparing a device for producing nano-CSH based on a narrow gap electrolytic cell according to any one of claims 1 to 9, characterized in that: include: Connecting the anode electrode and the cathode electrode to a constant current DC power supply, and waiting for the pH of the liquid in the acidic reaction liquid tank to be less than 2, and the pH of the liquid in the alkaline reaction liquid tank to be greater than 12; The electrolyte in each of the acidic reaction liquid tanks is led out to the acid liquid tank, and the electrolyte in each of the alkaline reaction liquid tanks is led out to the alkaline liquid tank; Adding calcium raw materials into the acid solution pool, adding silicon raw materials into the alkali solution pool, and stirring and dissolving them; After the raw materials are fully dissolved in the acid solution pool and the alkali solution pool, they are allowed to settle, and the supernatant is sent to the precipitation reaction pool; The reaction liquid generates flocculated emulsion after sufficient reaction and aging in the precipitation reaction tank, and solid-liquid separation is performed, and the solid phase material is filtered and dried to obtain CSH crystals.

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