A method for preparing a ceramic shell of a buried copper / saturated copper sulfate reference electrode
By optimizing the manufacturing process of the ceramic shell, the porosity and contact problems of traditional buried reference electrodes were solved, achieving a long electrode life and improved accuracy and stability of potential measurement.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CNNC NUCLEAR POWER OPERATION MANAGEMENT CO LTD
- Filing Date
- 2022-12-20
- Publication Date
- 2026-06-09
AI Technical Summary
Traditional buried reference electrodes have high porosity in their ceramic shells, leading to the loss of copper sulfate solution and the infiltration of soil ions. This affects the electrode's lifespan and potential accuracy, and poor contact between the electrode and the soil results in poor ion exchange.
A porous ceramic slurry is formed by mixing raw talc powder, sodium feldspar powder and polyvinyl alcohol binder in a specific ratio. After molding and high-temperature firing, a ceramic shell with suitable pore size is made, and a circular unglazed area is designed at the bottom to ensure effective contact with the soil.
It extends the lifespan of the reference electrode, improves the accuracy and stability of potential measurement, and ensures unobstructed ion exchange channels by optimizing pore size and porosity to control electrolyte permeation.
Smart Images
Figure CN118221453B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of cathode protection reference electrode technology, specifically relating to a method for preparing a ceramic shell for a buried copper / saturated copper sulfate reference electrode. Background Technology
[0002] In power energy, petrochemical, and municipal facilities, there are a large number of buried metal objects. Therefore, impressed current cathodic protection systems are commonly used to polarize and protect these buried metal objects. During the operation and management of cathodic protection systems, it is essential to monitor the protection potential of the protected object throughout the entire process. The protection potential is a crucial parameter for determining the effectiveness and degree of protection of the cathodic protection system. Long-life buried copper / saturated copper sulfate reference electrodes are typically used to monitor the protection potential, and these electrodes are permanently or permanently buried in the soil near the protected buried metal object. Traditional buried reference electrodes are generally housed in unglazed ceramic containers. Due to the high porosity of ceramics, the copper sulfate solution inside the container always leaks out at some rate, and some ions in the soil (such as harmful Cl-) can seep into the container, contaminating the copper sulfate solution. Therefore, the long lifespan of the buried reference electrode cannot be guaranteed, and the accuracy and stability of the reference electrode potential are also affected.
[0003] In addition, traditional buried reference electrodes typically use a sealed cylindrical body on the side of the electrode body, and ion exchange occurs between the reference electrode and the soil through a flat or conical micro-permeable end. However, due to the shaking of the electrode body, gaps may exist between it and the soil contact surface, which can lead to obstruction of the ion exchange channel and a shift in the test potential. Summary of the Invention
[0004] The technical problem to be solved by the present invention is to address the above-mentioned deficiencies in the prior art by providing a method for preparing a buried copper / saturated copper sulfate reference electrode ceramic shell, thereby solving the problem of potential inaccuracy caused by the reference electrode body being suspended in contact with the soil.
[0005] To solve the above problems, the technical solution of the present invention is as follows: a method for preparing a buried copper / saturated copper sulfate reference electrode ceramic shell, the method comprising the following steps:
[0006] Step S1: Pre-calcining raw talc powder to form calcined talc powder;
[0007] Step S2: Add raw talc powder, sodium feldspar powder, and polyvinyl alcohol binder to calcined talc powder and mix to form a ceramic slurry;
[0008] Step S3: Place the ceramic slurry into the mold and apply a molding pressure of 20-25 MPa to form a ceramic green body;
[0009] Step S4: Firing the ceramic green body into porous ceramic by holding it at 1280-1300℃ for 10-30 minutes.
[0010] The pre-firing temperature in step S1 is 1250℃.
[0011] In step S2, the proportion of calcined talc is 88%, the proportion of raw talc is 6%, the proportion of albite powder is 6%, and the proportion of polyvinyl alcohol binder is 4-5% of the total mass fraction of calcined talc, raw talc, and albite powder.
[0012] The fabricated porous ceramics have pore sizes of 522–576 nm and porosity of 17.4–20.4%.
[0013] The ceramic shell has a columnar structure, with a glaze layer on the outer wall and a recess at the bottom. The outer edge of the recess has a circular unglazed area.
[0014] The significant advantages of this invention are as follows: A method for preparing a buried copper / saturated copper sulfate reference electrode ceramic shell, by providing production process parameters and optimizing suitable pore size and porosity parameters, effectively slows down the electrolyte permeation rate; furthermore, a circular unglazed area at the bottom of the tank allows for ion exchange with the external soil medium, and the concave bottom structure design ensures that the micro-permeation tip of the reference electrode ceramic maintains effective contact with the soil at any angle, solving the problem of potential inaccuracy caused by the reference electrode body being suspended in contact with the soil. This effectively extends the service life of the buried reference electrode and improves the accuracy and stability of the measured potential. Attached Figure Description
[0015] Figure 1 A front view of the ceramic housing structure of a buried copper / saturated copper sulfate reference electrode;
[0016] Figure 2 A bottom view of a buried copper / saturated copper sulfate reference electrode ceramic shell structure;
[0017] Figure 3 To obtain a scanning electron microscope image of the ceramic shell using the method described in this invention;
[0018] In the diagram: 1. Ceramic jar body; 2. Copper rod electrode; 3. Ceramic jar lid; 4. Glaze layer; 5. Unglazed circular area; 6. Supersaturated copper sulfate solution; 7. Wing nut. Detailed Implementation
[0019] The technical solutions of the invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without creative effort are within the scope of the invention.
[0020] In the description of this invention, it should be noted that the use of terms such as "above" to indicate orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings and is only for the purpose of facilitating and simplifying the description. It does not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.
[0021] In the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0022] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connection," "setting," "installation," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0023] like Figure 1-2 As shown, a buried copper / saturated copper sulfate reference electrode ceramic housing includes a ceramic tank 1, a copper rod electrode 2, and a ceramic tank lid 3.
[0024] The outer side of the ceramic jar 1 is covered with a continuous and smooth glaze layer 4; the bottom of the ceramic jar is concave inward, and the outer edge of the concave bottom is provided with a circular unglazed area 5, through which ion exchange occurs with the soil, and the concave area is covered with glaze layer 4; the internal space of the ceramic jar 1 is filled with supersaturated copper sulfate solution 6; the copper rod electrode 2 is vertically inserted into the supersaturated copper sulfate solution 6, fixed and sealed at the central circular hole of the ceramic jar lid 3; the copper rod electrode 2 is fixed to the ceramic jar lid 3 by a wing nut 7.
[0025] The ceramic jar 1 has dimensions of φ50mm×160mm, is cylindrical, has a wall thickness of 4mm, and a glaze layer 4 thickness of 0.5mm. The copper rod electrode is a solid straight T2 copper rod, and its length is 4 / 5 of the length of the ceramic jar.
[0026] A method for preparing a buried copper / saturated copper sulfate reference electrode ceramic shell, the method comprising the following steps:
[0027] Step S1: Pre-calcining raw talc powder to form calcined talc powder.
[0028] The pre-firing temperature is 1250℃;
[0029] Step S2: Add raw talc powder, sodium feldspar powder, and polyvinyl alcohol binder to calcined talc powder and mix to form a ceramic slurry;
[0030] The proportion of calcined talc is 88%, the proportion of raw talc is 6%, the proportion of albite powder is 6%, and the proportion of polyvinyl alcohol binder is 4-5% of the total mass fraction of calcined talc, raw talc, and albite powder.
[0031] Step S3: Place the ceramic slurry into the mold and apply a molding pressure of 20-25 MPa to form a ceramic green body;
[0032] Step S4: Firing the ceramic green body into porous ceramic by holding it at 1280-1300℃ for 10-30 minutes;
[0033] The fabricated porous ceramics have pore sizes of 522–576 nm and porosity of 17.4–20.4%.
[0034] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.
Claims
1. A method for preparing a ceramic shell for a buried copper / saturated copper sulfate reference electrode, characterized in that: The method includes the following steps: Step S1: Pre-calcining raw talc powder to form calcined talc powder; Step S2: Add raw talc powder, sodium feldspar powder, and polyvinyl alcohol binder to calcined talc powder and mix to form a ceramic slurry; Step S3: Place the ceramic slurry into the mold and apply a molding pressure of 20~25MPa to form a ceramic green body; Step S4: Firing the ceramic green body into porous ceramic by holding it at 1280~1300℃ for 10~30 minutes; The pre-firing temperature in step S1 is 1250℃; In step S2, the proportion of calcined talc is 88%, the proportion of raw talc is 6%, the proportion of albite powder is 6%, and the proportion of polyvinyl alcohol binder is 4-5% of the total mass fraction of calcined talc, raw talc, and albite powder. The fabricated porous ceramics have pore sizes of 522~576 nm and porosity of 17.4~20.4%. The ceramic shell has a columnar structure, with a glaze layer (4) on the outer wall and a depression at the bottom. The outer edge of the depression has a circular unglazed area (5).