Method for preparing ceramic particle electrode by using copper-containing sludge

Abstract

The invention relates to a method for preparing a ceramic particle electrode by using copper-containing sludge, which adopts the copper-containing sludge as a raw material, silicate is added as a silicon source, copper and iron elements with high catalytic activity in the copper-containing sludge are utilized, rare earth elements are supplemented to form a catalytic activity center of the particle electrode, and a pore-forming agent is added, so that the particle electrode can form a porous structure; the bonding agent improves the bonding capacity and uniformity of various materials, and finally, ceramization of a base material, conversion of catalytic active elements and formation of a pore channel structure are completed through high-temperature roasting, so that the ceramic particle electrode is obtained. The ceramic particle electrode can construct a novel three-dimensional electrocatalytic oxidation system, is applied to treatment of high-COD and high-ammonia-nitrogen wastewater, realizes resource utilization of copper-containing sludge, achieves the purpose of treating waste with waste, and has a good application prospect.

Description

Technical Field

[0001] The present invention relates to a method for preparing a ceramic particle electrode, in particular to a method for preparing a ceramic particle electrode by utilizing copper-containing sludge. Background Art

[0002] With the booming development of communications electronics, consumer electronics, automotive electronics, industrial control, medical devices, and aerospace, the circuit board industry has entered a period of new development opportunities, and the resulting environmental issues are also receiving increasing attention. Copper-containing wastewater is the primary source of wastewater in the circuit board industry. Treatment of copper-containing wastewater typically involves the addition of ferrous sulfate for chelation breakdown, followed by polyaluminum chloride for flocculation. This produces a certain amount of copper-containing sludge. This copper-containing sludge typically has a moisture content of 60%-80%, a copper content of 4%-20%, an iron content of 2%-8%, and an aluminum content of 4%-10%. It also contains some organic matter or other metallic elements. Copper and iron are important components of catalysts used in advanced oxidation processes for water treatment, while aluminum serves as the primary skeletal element in catalysts.

[0003] Three-dimensional electrolysis technology is an emerging water treatment technology that can effectively electrocatalytically degrade high-concentration organic wastewater. Its principle is based on two-dimensional electrolysis technology, filling particles between the cathode and anode to form a third-dimensional particle electrode. By applying a certain external voltage, these particles are polarized into a large number of microelectrodes, which greatly improves the current efficiency and mass transfer performance of the electrochemical reactor and enhances the treatment effect on wastewater. For example, CN116332327A discloses a method for preparing a ceramic microbial particle electrode for three-dimensional electrocatalysis. By preparing a three-dimensional electrocatalytic ceramic microbial particle electrode, using a combination of clay, zinc oxide and Fe3O4 powder, combined with electrocatalysis and micromagnetic field, it solves the problem of low efficiency in removing difficult-to-degrade pollutants and nitrogen and phosphorus in water bodies, achieves efficient and stable pollutant removal and nitrogen and phosphorus removal, and reduces energy costs. CN108892209A discloses a porous sludge-based particle electrode catalyst doped with copper tailings. By doping copper tailings and a pore-forming agent into a sludge-based particle electrode to form a porous catalyst, the catalyst solves the problems of high cost and poor performance of particle electrodes in three-dimensional electrolysis technology, achieves efficient wastewater treatment and sludge resource utilization, and reduces environmental pollution.

[0004] However, there is no report on the use of copper-containing sludge from circuit boards to prepare ceramic particle electrodes. Copper-containing sludge from circuit boards has not been effectively utilized, which not only wastes resources but also pollutes the environment. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method for preparing ceramic particle electrodes using copper-containing sludge from circuit boards. The obtained ceramic particle electrodes have a porous structure with many catalytic active sites, good uniformity and tightness.

[0006] The technical solution adopted by the present invention to solve the above technical problems is a method for preparing ceramic particle electrodes using copper-containing sludge, comprising the following steps:

[0007] S1. Disperse the copper-containing sludge with water, add 1%-5% of the total weight of copper and iron in the copper-containing sludge with a rare earth metal salt to make it uniformly dispersed; then add 20%-60% of the dry weight of the copper-containing sludge with a silicate, stir thoroughly to dissolve and disperse, and adjust the pH value to 8.5-10.5 to form a first suspension;

[0008] S2. Take a pore-forming agent and a binder and disperse them evenly with water to form a second suspension; wherein the amount of the pore-forming agent is 10%-40% of the total mass of the copper-containing sludge, rare earth metal and silicate, and the amount of the binder is 5%-25% of the total mass of the copper-containing sludge, rare earth metal and silicate;

[0009] S3, mixing the first suspension and the second suspension to form a third suspension;

[0010] S4, drying and cooling the third suspension to obtain a raw material;

[0011] S5. Crushing and granulating the raw material, and calcining at 900-1100° C. to obtain ceramic particle electrodes.

[0012] Further, in step S1, the rare earth metal salt is any one of cerium nitrate, cerium chloride, cerium sulfate, cerium formate, cerium acetate, cerium oxide, lanthanum nitrate, lanthanum chloride, lanthanum sulfate, lanthanum formate, lanthanum acetate, lanthanum oxide, samarium nitrate, samarium chloride, samarium sulfate, samarium acetate, praseodymium nitrate, praseodymium chloride or praseodymium sulfate, lutetium nitrate, lutetium chloride, and lutetium sulfate.

[0013] Furthermore, in step S1, the silicate is one or more of sodium silicate, potassium silicate or ammonium silicate.

[0014] Furthermore, in step S1, the pH value is adjusted by using an inorganic acid; the inorganic acid is one or more of nitric acid, hydrochloric acid, sulfuric acid, formic acid or acetic acid.

[0015] Furthermore, in step S2, the pore-forming agent is one or more of coconut shell activated carbon powder, coal-based activated carbon, wood activated carbon powder or coal powder.

[0016] Furthermore, in step S2, the particle size of the pore-forming agent is 180-200 mesh.

[0017] Furthermore, in step S2, the binder is one or more of carboxymethyl cellulose, sesbania powder, sodium alginate, agar, dextrin or gelatin.

[0018] Furthermore, in step S4, the drying temperature is 90-110°C.

[0019] Furthermore, in step S4, the particle size of the particles after granulation is 5-15 mm.

[0020] Furthermore, in step S4, the calcination temperature is increased at a rate of 5-10°C / min and the calcination time is 2-8h.

[0021] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0022] The method of the present invention adds silicate to the copper-containing sludge in the circuit board industry, adjusts the silicon-aluminum ratio in the copper-containing sludge, ensures the formation of a ceramic matrix after roasting, and improves the physical strength and chemical stability of the ceramic particle electrode; adds rare earth elements and controls the ratio of rare earth elements to copper and iron in the copper-containing sludge, inhibits the agglomeration of copper and iron during the roasting process, provides new catalytic active sites, and improves the catalytic activity of the ceramic particle electrode; adds a pore-forming agent, which will be ablated to form channels when roasted in an air atmosphere, so that the ceramic particle electrode has a porous structure; adds an adhesive, so that the copper-containing sludge, the rare earth elements and the pore-forming agent can be well dispersed, the tightness, bonding strength and uniformity of the combination are improved, and the final ceramic particle electrode has a uniform texture; fully utilizes the copper, iron and aluminum elements in the copper-containing sludge, and improves the utilization value of the copper-containing sludge.

[0023] The ceramic particle electrode prepared by the method of the present invention has the characteristics of high catalytic activity, good physical strength, stable chemical properties, good reusability and low price.

[0024] The ceramic particle electrodes prepared by the method of the present invention are used to construct a three-dimensional electrocatalytic oxidation system, which has the advantages of high treatment efficiency and low unit pollution substrate degradation cost when treating high COD and high ammonia nitrogen wastewater. DETAILED DESCRIPTION

[0025] The present invention is further described below with reference to specific embodiments, wherein the copper-containing sludge from circuit boards is derived from the comprehensive wastewater pretreatment process of a certain circuit board enterprise.

[0026] Example 1:

[0027] The method of preparing ceramic particle electrodes using copper-containing sludge from the circuit board industry in this embodiment includes the following steps:

[0028] (1) Preparation of the first suspension: First, the copper-containing sludge from the circuit board industry was dispersed with 10 times the mass of water; second, cerium (III) nitrate was added in an amount equivalent to 1% of the total mass of copper and iron in the copper-containing sludge, and the mixture was fully stirred to dissolve and disperse; then, sodium silicate was added in an amount equivalent to 20% of the mass of the copper-containing sludge, and the mixture was fully stirred to dissolve and disperse, and the pH value of the suspension was adjusted to 8.5 with 0.1 mol / L nitric acid to form the first suspension;

[0029] (2) Preparation of the second suspension: First, 180-mesh coconut shell activated carbon powder equivalent to 10% of the total mass of the copper-containing sludge, cerium (III) nitrate, and sodium silicate in the first suspension was weighed as a pore-forming agent; secondly, water equivalent to 5 times the mass of the coconut shell activated carbon powder was added for dispersion; then, carboxymethyl cellulose equivalent to 5% of the total mass of the copper-containing sludge, cerium (III) nitrate, sodium silicate, and coconut shell activated carbon powder was added as a binder, and the mixture was fully stirred to dissolve and disperse to form a second suspension;

[0030] (3) Preparation of the third suspension: combining the first suspension and the second suspension, stirring thoroughly to form a third suspension;

[0031] (4) Drying: The third suspension was placed in a 90°C forced air drying oven and dried to constant weight, and then naturally cooled to room temperature to obtain a raw material;

[0032] (5) Grinding, granulating, and roasting: The raw material is crushed and ground to a size of 150 mesh or larger to obtain a raw powder; the raw powder is prepared into 5 mm spherical particles using a disc granulator; the spherical particles are roasted in an air atmosphere at a heating rate of 5 °C / min, a roasting temperature of 900 °C, and roasted for 8 h. The ceramic particle electrode is then naturally cooled to room temperature to obtain a ceramic particle electrode.

[0033] Example 2:

[0034] The method of preparing ceramic particle electrodes using copper-containing sludge from the circuit board industry in this embodiment includes the following steps:

[0035] (1) Preparation of the first suspension: First, the copper-containing sludge from the circuit board industry was dispersed with 12 times the mass of water; second, lanthanum (III) chloride (2% by mass of the total mass of copper and iron in the copper-containing sludge was added, and the mixture was fully stirred to dissolve and disperse; then, potassium silicate (30% by mass of the copper-containing sludge) was added, and the mixture was fully stirred to dissolve and disperse, and the pH value of the suspension was adjusted to 9.0 with 0.5 mol / L sulfuric acid to form the first suspension;

[0036] (2) Preparation of the second suspension: First, 200-mesh coal-based activated carbon powder containing 20% ​​of the total mass of the copper-containing sludge, lanthanum (III) chloride, and potassium silicate in the first suspension was taken as a pore-forming agent; secondly, water was added at a mass ratio of 6 times that of the coal-based activated carbon powder to disperse the mixture; then, 10% of the total mass of the copper-containing sludge, lanthanum (III) chloride, potassium silicate, and coal-based activated carbon powder was added as a binder, and the mixture was fully stirred to dissolve and disperse the mixture to form a second suspension;

[0037] (3) Preparation of the third suspension: combining the first suspension and the second suspension, stirring thoroughly to form a third suspension;

[0038] (4) Drying: Dry the third suspension in a 95°C forced air drying oven to constant weight, and cool naturally to room temperature to obtain a raw material;

[0039] (5) Grinding, granulating, and roasting: The raw material is crushed and ground to a size of 150 mesh or larger to obtain a raw powder; the raw powder is prepared into 8 mm spherical particles using a disc granulator; the spherical particles are roasted in an air atmosphere at a heating rate of 6 °C / min, a roasting temperature of 950 °C, and roasted for 6 h. The ceramic particle electrode is then naturally cooled to room temperature to obtain a ceramic particle electrode.

[0040] Example 3:

[0041] A method for preparing ceramic particle electrodes using copper-containing sludge from the circuit board industry comprises the following steps:

[0042] (1) Preparation of the first suspension: First, the copper-containing sludge from the circuit board industry was dispersed with 15 times the mass of water; second, samarium (III) acetate was added at a concentration of 3% by mass of the total copper and iron in the copper-containing sludge, and the mixture was fully stirred to dissolve and disperse; then, ammonium silicate was added at a concentration of 40% by mass of the copper-containing sludge, and the mixture was fully stirred to dissolve and disperse, and the pH value of the suspension was adjusted to 9.5 with 0.5 mol / L hydrochloric acid to form the first suspension;

[0043] (2) Preparation of the second suspension: First, 200-mesh wood activated carbon powder containing 20% ​​of the total mass of the copper-containing sludge, samarium (III) acetate, and ammonium silicate in the first suspension was taken as a pore-forming agent; secondly, water with a mass ratio of 8 times that of the wood activated carbon powder was added for dispersion; then, sodium alginate containing 15% of the total mass of the copper-containing sludge, samarium (III) acetate, ammonium silicate, and wood activated carbon powder was added as a binder, and the mixture was fully stirred to dissolve and disperse to form a second suspension;

[0044] (3) Preparation of the third suspension: combining the first suspension and the second suspension, stirring thoroughly to form a third suspension;

[0045] (4) Drying: Dry the third suspension in a forced air drying oven at 100° C. to constant weight, and cool naturally to room temperature to obtain a raw material;

[0046] (5) Grinding, granulating, and roasting: The raw material is crushed and ground to a size of 150 mesh or larger to obtain a raw powder; the raw powder is prepared into 10 mm spherical particles using a disc granulator; the spherical particles are roasted in an air atmosphere at a heating rate of 8 °C / min and a roasting temperature of 1000 °C for 6 h, and then naturally cooled to room temperature to obtain a ceramic particle electrode.

[0047] Example 4:

[0048] A method for preparing ceramic particle electrodes using copper-containing sludge from the circuit board industry comprises the following steps:

[0049] (1) Preparation of the first suspension: First, the copper-containing sludge from the circuit board industry was dispersed with 18 times the mass of water; second, praseodymium (III) sulfate was added at a concentration of 4% by mass of the total copper and iron in the copper-containing sludge, and the mixture was fully stirred to dissolve and disperse; then, sodium silicate was added at a concentration of 50% by mass of the copper-containing sludge, and the mixture was fully stirred to dissolve and disperse, and the pH value of the suspension was adjusted to 10.0 with 0.8 mol / L formic acid to form the first suspension;

[0050] (2) Preparation of the second suspension: First, 180-mesh biocarbon powder (35% by weight of the total mass of copper-containing sludge, praseodymium (III) sulfate, and sodium silicate in the first suspension was taken as a pore-forming agent; secondly, water (10 times the mass of the biocarbon powder) was added for dispersion; then, agar (20% by weight of the total mass of copper-containing sludge, praseodymium (III) sulfate, sodium silicate, and biocarbon powder) was added as a binder, and the mixture was fully stirred to dissolve and disperse to form a second suspension;

[0051] (3) Preparation of the third suspension: combining the first suspension and the second suspension, stirring thoroughly to form a third suspension;

[0052] (4) Drying: Dry the third suspension in a forced air drying oven at 105°C to constant weight, and cool naturally to room temperature to obtain a raw material;

[0053] (5) Grinding, granulation, and roasting: The raw material is crushed and ground to a size of 150 mesh or larger to obtain a raw powder; the raw powder is prepared into 12 mm spherical particles using a disc granulator; the spherical particles are roasted in an air atmosphere at a heating rate of 8 °C / min and a roasting temperature of 1100 °C for 4 h, and then naturally cooled to room temperature to obtain a ceramic particle electrode.

[0054] Example 5:

[0055] A method for preparing ceramic particle electrodes using copper-containing sludge from the circuit board industry comprises the following steps:

[0056] (1) Preparation of the first suspension: First, the copper-containing sludge from the circuit board industry was dispersed with 20 times the mass of water; second, lutetium (III) nitrate was added at a concentration of 5% by mass of the total mass of copper and iron in the copper-containing sludge, and the mixture was fully stirred to dissolve and disperse; then, potassium silicate was added at a concentration of 60% by mass of the copper-containing sludge, and the mixture was fully stirred to dissolve and disperse, and the pH value of the suspension was adjusted to 10.5 with 1.0 mol / L acetic acid to form the first suspension;

[0057] (2) Preparation of the second suspension: First, 200-mesh coal powder containing 40% of the total mass of the copper-containing sludge, lutetium (III) nitrate, and potassium silicate in the first suspension was taken as a pore-forming agent; secondly, water with a mass ratio of 10 times that of the coal powder was added for dispersion; then, gelatin containing 25% of the total mass of the copper-containing sludge, lutetium (III) nitrate, potassium silicate, and coal powder was added as a binder, and the mixture was fully stirred to dissolve and disperse to form a second suspension;

[0058] (3) Preparation of the third suspension: combining the first suspension and the second suspension, stirring thoroughly to form a third suspension;

[0059] (4) Drying: Dry the third suspension in a forced air drying oven at 110° C. to constant weight, and cool naturally to room temperature to obtain a raw material;

[0060] (5) Grinding, granulating, and roasting: The raw material is crushed and ground to a size of 150 mesh or larger to obtain a raw powder; the raw powder is prepared into 15 mm spherical particles using a disc granulator; the spherical particles are roasted in an air atmosphere at a heating rate of 10 °C / min and a roasting temperature of 1200 °C for 2 h, and then naturally cooled to room temperature to obtain a ceramic particle electrode.

[0061] Application Example 1 Treatment of Resin Wastewater by a Three-Dimensional Electrocatalytic Oxidation System

[0062] A titanium-based dimensionally stable electrode (Ti / RuO2) was used as the anode and a titanium plate was used as the cathode. The distance between the plates was 10 cm. The ceramic particle electrodes prepared in Examples 1-5 were filled between the anode and cathode plates to construct a three-dimensional electrocatalytic oxidation system. The effective volume was 150 mL. 50 g of the ceramic particle electrodes of the present invention were filled in the system. The system was operated at a current density of 25 mA / cm 2 Under the following conditions, aeration intensity of 50 L / h was used to treat resin wastewater. The initial COD content of this wastewater was 12143.9 mg / L, typical of high-COD wastewater. To better evaluate the catalytic effect of the ceramic particle electrodes of the present invention, a two-dimensional electrocatalytic oxidation system was constructed using the same electrocatalytic oxidation conditions, but without the ceramic particle electrodes. This system was then compared with a three-dimensional electrocatalytic oxidation system. The results are shown in Table 1.

[0063] Table 1 Effect, current efficiency and energy consumption of the wastewater treatment system constructed by using the ceramic particle electrode prepared by the present invention (1)

[0064]

[0065]

[0066] Note: Except for time, current efficiency and energy consumption, other data in the table are COD content in wastewater, in mg / L. Current efficiency and energy consumption are calculated based on 5h data.

[0067] The data in Table 1 demonstrate that the novel three-dimensional electrocatalytic oxidation wastewater treatment system constructed using the ceramic particle electrodes obtained in various embodiments of the present invention exhibits superior degradation efficacy, current efficiency, and energy consumption for high-COD wastewater from the resin industry compared to a two-dimensional electrocatalytic oxidation wastewater treatment system. This demonstrates that the ceramic particle electrodes provided by the present invention possess a superior catalytic effect on COD degradation in wastewater. Furthermore, it was found that the ceramic particle electrode obtained in Example 4 exhibited the highest catalytic effect.

[0068] Application Example 2 Treatment of High Ammonia Nitrogen Wastewater by Three-Dimensional Electrocatalytic Oxidation System

[0069] A titanium-based dimensionally stable electrode (Ti / RuO2) was used as the anode and a titanium plate as the cathode. The distance between the plates was 10 cm. The ceramic particle electrodes prepared in Examples 1-5 were filled between the anode and cathode plates. The current density was 25 mA / cm 2 Under the following conditions, aeration intensity of 50 L / h was used to treat ammonia-nitrogen wastewater. The initial ammonia-nitrogen content in this wastewater was 2185.84 mg / L, typical of high-ammonia-nitrogen wastewater. To better evaluate the catalytic effect of the ceramic particle electrodes, a two-dimensional electrocatalytic oxidation system was constructed using the same electrocatalytic oxidation conditions, but without the ceramic particle electrodes. The results were compared with a three-dimensional electrocatalytic oxidation system. The results are shown in Table 2.

[0070] Table 2 Effect, current efficiency and energy consumption of the wastewater treatment system constructed using the ceramic particle electrode prepared by the present invention (2)

[0071]

[0072]

[0073] Note: Except for time, current efficiency and energy consumption, other data in the table are ammonia nitrogen content in wastewater, in mg / L. Current efficiency and energy consumption are calculated based on 100 min data.

[0074] From the data in Table 2, it can be seen that the new three-dimensional electrocatalytic oxidation wastewater treatment system constructed by using the ceramic particle electrodes obtained in each embodiment has better degradation effect, current efficiency and energy consumption for high ammonia nitrogen wastewater than the two-dimensional electrocatalytic oxidation system, indicating that the ceramic particle electrode provided by the present invention also has a good catalytic effect on the degradation of ammonia nitrogen. In addition, it can be found that the ceramic particle electrode obtained in Example 4 has the best catalytic effect. The effect of Example 1 is slightly worse than that of other three-dimensional electrocatalytic oxidation systems. The reason is that the amount of pore-forming agent added is small, resulting in underdeveloped pore structure of the particle electrode, and the proportion of rare earth element addition is low. The above reasons reduce the catalytic activity of the particle electrode. The calcination temperature of Example 5 is relatively high, which causes the metal oxide to agglomerate and reduces the number of catalytic active sites of the particle electrode, so the effect is slightly worse than that of Examples 2-4.

[0075] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of protection of the patent. It should be noted that a person of ordinary skill in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A method for preparing ceramic particle electrodes using copper-containing sludge, characterized in that: The following steps are involved: S1. Dispersing the copper-containing sludge with water, adding a rare earth metal salt equivalent to 1%-5% of the total weight of copper and iron in the copper-containing sludge to uniformly disperse it; then adding a silicate equivalent to 20%-60% of the dry weight of the copper-containing sludge, stirring thoroughly to dissolve and disperse it, and adjusting the pH value to 8.5-10.5 to form a first suspension; S2. Take a pore-forming agent and a binder and disperse them evenly with water to form a second suspension; wherein the amount of the pore-forming agent is 10%-40% of the total mass of the copper-containing sludge, rare earth metal and silicate, and the amount of the binder is 5%-25% of the total mass of the copper-containing sludge, rare earth metal and silicate; S3, mixing the first suspension and the second suspension to form a third suspension; S4, drying and cooling the third suspension to obtain a raw material; S5. Crushing and granulating the raw material, and calcining at 900-1100° C. to obtain ceramic particle electrodes.

2. The method for preparing ceramic particle electrodes using copper-containing sludge according to claim 1, characterized in that: The rare earth metal salt is any one of cerium nitrate, cerium chloride, cerium sulfate, cerium formate, cerium acetate, cerium oxide, lanthanum nitrate, lanthanum chloride, lanthanum sulfate, lanthanum formate, lanthanum acetate, lanthanum oxide, samarium nitrate, samarium chloride, samarium sulfate, samarium acetate, praseodymium nitrate, praseodymium chloride or praseodymium sulfate, lutetium nitrate, lutetium chloride, and lutetium sulfate.

3. The method for preparing ceramic particle electrodes using copper-containing sludge according to claim 1 or 2, characterized in that: The silicate is one or more of sodium silicate, potassium silicate or ammonium silicate.

4. The method for preparing ceramic particle electrodes using copper-containing sludge according to claim 1 or 2, characterized in that: In step S1, the pH value is adjusted by using an inorganic acid; the inorganic acid is one or more of nitric acid, hydrochloric acid, sulfuric acid, formic acid or acetic acid.

5. The method for preparing ceramic particle electrodes using copper-containing sludge according to claim 1 or 2, characterized in that: In step (2), the pore-forming agent is one or more of coconut shell activated carbon powder, coal-based activated carbon, wood activated carbon powder or coal powder.

6. The method for preparing ceramic particle electrodes using copper-containing sludge according to claim 5, characterized in that: The particle size of the pore-forming agent is 180-200 meshes.

7. The method for preparing ceramic particle electrodes using copper-containing sludge according to claim 1 or 2, characterized in that: In step S2, the binder is one or more of carboxymethyl cellulose, sesbania powder, sodium alginate, agar, dextrin or gelatin.

8. The method for preparing ceramic particle electrodes using copper-containing sludge according to claim 1 or 2, characterized in that: The drying temperature is 90-110°C.

9. The method for preparing ceramic particle electrodes using copper-containing sludge according to claim 1 or 2, characterized in that: The particle size of the particles after granulation is 5-15 mm.

10. The method for preparing ceramic particle electrodes using copper-containing sludge according to claim 1 or 2, characterized in that: The heating rate of the calcination is 5-10°C / min, and the calcination time is 2-8h.

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