A solid waste-based multilayer electrode and its application

Abstract

The present invention discloses a solid waste-based multilayer electrode, which consists of a conductive material layer and a solid waste base layer located on both sides of the conductive material layer; the present invention adopts solid waste and conductive material to be contacted and hot-pressed layer by layer, and releases electrons to the solid waste layer by virtue of the conductive properties of the conductive material, and the conductive particles in the solid waste are transferred to the electrons, thereby realizing uniform release of electrons; the present invention reduces the preparation cost of the electrode, realizes the resource utilization of solid waste, and increases the service life of the electrode; reduces the cost of using electrodes in fields such as electric-assisted fermentation and electric-assisted wastewater treatment, and improves the efficiency of electrode use.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrode preparation, and in particular relates to a solid waste-based multilayer electrode and applications thereof. Background Art

[0002] With the continuous development of industrialization, the electrode industry has become a strategic industry worldwide. However, the existing electrode preparation technology currently faces a shortage of raw materials and high preparation costs. The increasing demand for electrodes and the high cost of electrode raw materials have led to the depletion of many electrode raw materials. Reducing electrode preparation costs and improving electrode production efficiency have become hot topics of concern worldwide. The pollution problem of bulk solid waste is becoming increasingly serious. So-called solid waste is simply material that cannot be used in existing production technologies. Most solid waste contains trace amounts of rare and precious heavy metal elements, which are, to a certain extent, good raw materials for electrode preparation. In view of the single nature of existing bulk solid waste treatment technologies, combined with the unique properties of bulk solid waste, the cost of electrode preparation can be reduced and its efficiency improved. Using solid waste to prepare electrodes provides a development direction for the high-value-added resource utilization of solid waste, while also greatly improving electrode utilization efficiency and reducing electrode production costs.

[0003] Hebei Shuntian Electrode Co., Ltd. has proposed an enhanced composite graphite electrode shell and electrode, application number 201320287766.3. The electrode shell contains carbon fiber, which doubles the shell's compressive strength and prevents cracking due to thermal stress. This utility model utilizes the surface skin effect principle of current conductors, resulting in an electrode with excellent conductivity, reduced energy consumption, and lowered manufacturing costs. Its structure is simple and convenient, and its operation is safe and reliable. Permelek Electrode Co., Ltd. provides a method for manufacturing electrodes for electrolysis, application number 201480004945.9. This method can appropriately adjust the amount of electrode catalytic components to the desired amount, enabling the economical and efficient manufacture of high-performance electrolysis electrodes without compromising electrode performance. A method for manufacturing an electrolytic electrode comprises the following steps of forming an electrode catalyst layer: applying a coating liquid containing a starting material of an electrocatalytic component to the surface of a conductive electrode substrate having multiple pores, such as a porous mesh, followed by drying and calcining to form electrode catalyst layers on the front and back sides of the substrate. In this manufacturing method, the substrate comprises at least one metal selected from the group consisting of Ti, Ta, Nb, Zr, and Ni, or an alloy thereof, and the electrode catalyst component comprises at least one selected from the group consisting of Pt, Ir, Ru, Pd, Os, and oxides thereof. In the electrode catalyst layer forming step, the substrate is preheated at least once to a temperature higher than room temperature immediately before application of the coating liquid, and the temperature is then changed again to adjust the amount of the electrode catalyst component attached to the back side of the substrate. Although existing electrode manufacturing technology has advanced rapidly, manufacturing costs remain high. Summary of the Invention

[0004] In response to the technical problems of high production cost, strong corrosion and poor performance of existing electrodes, the present invention provides a solid waste-based multilayer electrode. This method adopts solid waste and conductive materials to contact and hot-press molding layer by layer. The conductive properties of the conductive material are used to release electrons to the solid waste layer. The conductive particles in the solid waste are transferred to the electrons to achieve uniform release of electrons. This method reduces the preparation cost of the electrode, realizes the resource utilization of solid waste, and enhances the service life of the electrode. It also reduces the cost of electrode use in the fields of electro-assisted fermentation and electro-assisted catalysis, and improves the efficiency of electrode use.

[0005] The solid waste-based multilayer electrode of the present invention is composed of a conductive material layer and a solid waste base layer located on both sides of the conductive material layer. The solid waste base layer is obtained by pressing the solid waste using hot pressing contact molding, and then a layer of conductive material is laid on the solid waste base layer. The conductive material layer is then formed by hot pressing contact molding. A layer of solid waste is laid on the conductive material layer and pressed using hot pressing contact molding to finally obtain the solid waste-based multilayer electrode.

[0006] The conductive material is selected from graphite powder, platinum powder, carbon fiber powder, and copper powder, has a particle size of less than 100 μm, and a moisture content of 4% to 10%.

[0007] The solid waste is selected from iron tailings, antimony tailings, phosphorus tailings, mud phosphorus, lead-zinc tailings, titanium tailings, and tin tailings, with a particle size distribution of 10-100 μm and a moisture content of 4%-10%.

[0008] The solid waste base layers on both sides of the conductive material layer are the same type of solid waste or different types of solid waste.

[0009] The pressing pressure is 2.3-400 MPa, the pressing temperature is room temperature-700° C., and the holding time is 8-300 s.

[0010] The solid waste-based multilayer electrode of the present invention is used in electric-assisted fermentation and electrocatalysis, and the conductive material layer is connected to a power source when in use.

[0011] Advantages and technical effects of the method of the present invention:

[0012] 1. This method reduces the cost of electrode preparation, realizes the resource utilization of solid waste, and increases the service life of the electrode. It also reduces the cost of electrode use in fields such as electro-assisted fermentation and electro-assisted catalysis, improves the efficiency of electrode use, and provides a new idea for solid waste treatment.

[0013] 2. This method is simple to operate, low in cost and highly feasible. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the structure of the solid waste-based multilayer electrode of the present invention;

[0015] Figure 2 Schematic diagram of the solid waste-based multilayer electrode structure;

[0016] Figure 3 It is a schematic diagram of the structure of the bracket part;

[0017] In the figure: 1-solid waste base layer I; 2-conductive material layer; 3-solid waste base layer II; 4-good electrical conductor; 5-cathode wire; 6-anode wire; 7-insulating stabilizing rod; 8-insulating bracket. DETAILED DESCRIPTION

[0018] The technical solutions of the present invention are further described below with reference to specific embodiments, but the protection scope of the present invention is not limited to the above contents;

[0019] like Figure 1-3 As shown, the device used for the solid waste-based multilayer electrode in the following embodiments includes an insulating bracket 8, an insulating stabilizing rod 7, 8 solid waste-based multilayer electrodes, a cathode wire 5, and an anode wire 6; the 8 solid waste-based multilayer electrodes are mounted on the insulating bracket 8 via 3 insulating stabilizing rods 7, the cathode wire 5 and the anode wire 6 are arranged on the top of the insulating bracket 8 and are respectively connected to the positive and negative poles of the power supply, wherein 4 solid waste-based multilayer electrodes are respectively connected to the cathode wire 5 via a good conductor 4, serving as negative electrodes; the other 4 solid waste-based multilayer electrodes are respectively connected to the anode wire 6 via a good conductor, serving as positive electrodes, and the negative electrodes and the positive electrodes are alternately arranged; the solid waste-based multilayer electrode is composed of a conductive material layer 2, a solid waste base layer I1 and a solid waste base layer II3 located on both sides of the conductive material layer 2, and a good conductor 4 is connected to the conductive material layer;

[0020] Example 1: The iron tailings-based multilayer electrode of this embodiment consists of a graphite conductive material layer and an iron tailings-based layer located on both sides of the conductive material layer;

[0021] Iron tailings mainly come from tailings produced after iron ore beneficiation and low-grade ore left after mining. Its particle size distribution is 10~20μm, the moisture content is 5%, and the graphite powder particle size is less than 100μm;

[0022] During the preparation, iron tailings with a particle size of 10-20 μm are evenly spread with a thickness of 4 cm in a steel mold, and pressed into an iron tailing base layer at a pressure of 15 MPa on a hot press contact molding machine at room temperature and a holding time of 10 seconds; a layer of graphite powder is spread with a thickness of 2 cm on the surface of the iron tailing base layer, and pressed into a conductive material layer at a pressure of 15 MPa on a hot press contact molding machine at room temperature and a holding time of 10 seconds; a layer of iron tailings is spread with a thickness of 4 cm on the conductive material layer, and pressed into an iron tailing base layer at a pressure of 15 MPa at room temperature and a holding time of 10 seconds;

[0023] The above-mentioned iron tailings-based multilayer electrode was applied to the fermentation experiment of pig manure (water content of 45%) and sludge (water content of 96.95%). The power supply supplied 0.8V DC to the iron tailings-based multilayer electrode through the good conductor 4. The device with the iron tailings-based multilayer electrode was placed in the reaction vessel and pig manure and sludge (mixed in a volume ratio of 1:9.5) were injected until the device was covered. The spacing between the multilayer solid waste electrodes was adjusted to 8cm according to the fermentation conductivity so that the current was between 20~40mA. At the same time, a device containing livestock and poultry manure digestion sludge without the iron tailings-based multilayer electrode was used as a control. The results showed that compared with the control, the average daily methane production of the reactor of the device with the iron tailings-based multilayer electrode increased by 9.2%, and the fermentation cycle was shortened by 20%.

[0024] Example 2: The lead-zinc tailings-based multilayer electrode of this embodiment consists of a copper conductive material layer and a lead-zinc tailings-based layer located on both sides of the conductive material layer;

[0025] Lead-zinc tailings mainly come from the tailings produced after lead-zinc ore beneficiation and the low-grade ore left after mining. Its particle size distribution is 20-50μm, the moisture content is 10%, and the copper powder particle size is less than 100μm.

[0026] During the preparation, lead-zinc tailings with a particle size of 20 to 50 μm are evenly spread to a thickness of 3 cm in a steel mold, and pressed into a lead-zinc tailings base layer on a hot press contact molding machine at a pressure of 40 MPa, a temperature of 300°C, and a holding time of 25 seconds; a layer of copper powder is spread to a thickness of 2 cm on the surface of the lead-zinc tailings base layer, and pressed into a conductive material layer on a hot press contact molding machine at a pressure of 40 MPa, a temperature of 300°C, and a holding time of 25 seconds; a layer of lead-zinc tailings is spread to a thickness of 3 cm on the conductive material layer, and pressed into a lead-zinc tailings base layer under a pressure of 40 MPa, a temperature of 300°C, and a holding time of 25 seconds;

[0027] The above-mentioned lead-zinc tailings-based multilayer electrode was applied to the treatment of blister manure piggery wastewater with a COD of 21600 mg / L and an NH3-N of 461.07 mg / L. The power supply supplied 1.2V DC to the iron tailings-based multilayer electrode through a good conductor 4. The device containing the lead-zinc tailings-based multilayer electrode was placed in the SBR and injected with blister manure piggery wastewater until the device was submerged. The spacing between the multilayer solid waste electrodes was adjusted to 15 cm according to the fermentation conductivity so that the current was between 30 and 80 mA. At the same time, the SRB containing blister manure piggery wastewater without the lead-zinc tailings-based multilayer electrode was used as a control. The results showed that compared with the control, after 16 hours of continuous operation of the reactor containing the lead-zinc tailings-based multilayer electrode, the COD in the aquaculture wastewater was 2365 mg / L, the degradation rate was increased by 10.5%, and the removal rate of ammonia nitrogen was 50.48 mg / L, increased by 22.3%.

[0028] Example 3: The antimony-iron tailings multilayer electrode of this embodiment is composed of a carbon fiber conductive material layer and an antimony tailings base layer and an iron tailings base layer located on both sides of the conductive material layer;

[0029] Antimony tailings mainly come from the tailings produced after antimony ore beneficiation and the low-grade ore left after mining. Its particle size distribution is 50~100μm, the moisture content is 8%, and the particle size of carbon fiber powder is less than 100μm.

[0030] During the preparation, antimony tailings with a particle size of 50-100 μm are evenly spread with a thickness of 5 cm in a steel mold, and pressed into an antimony tailing base layer on a hot press contact molding machine at a pressure of 50 MPa, a temperature of 210°C, and a holding time of 45 seconds; a layer of carbon fiber powder is spread on the surface of the antimony tailing base layer with a thickness of 3 cm, and pressed into a conductive material layer on a hot press contact molding machine at a pressure of 50 MPa, a temperature of 210°C, and a holding time of 45 seconds; a layer of iron tailings powder (10-20 μm) is spread on the conductive material layer with a thickness of 5 cm, and pressed into an iron tailing base layer under a pressure of 50 MPa, a temperature of 210°C, and a holding time of 45 seconds;

[0031] The above-mentioned antimony-iron tailings-based multilayer electrode was applied to the catalytic degradation of dye wastewater. The power supply supplied 3V DC to the antimony-iron tailings-based multilayer electrode through a good conductor 4. The device containing the antimony-iron tailings-based multilayer electrode was placed in a reaction tank and simulated printing and dyeing wastewater (300 mg / L azo dye Acid Orange 7, pH 5.5-6.5) was injected until the device was submerged. The spacing between the multilayer solid waste electrodes was adjusted to 12 cm according to the fermentation conductivity so that the current was between 120 and 180 mA. At the same time, the reaction tank of the device without the antimony-iron tailings-based multilayer electrode was used as a control. The results showed that compared with the control, the reduction rate of azo dye Acid Orange 7 was 92% after the device was continuously operated for 7 hours, and the treatment effect remained basically unchanged with the extension of continuous use time.

Claims

1. A solid waste-based multilayer electrode, characterized in that: It consists of a conductive material layer and a solid waste base layer located on both sides of the conductive material layer; A solid waste base layer is obtained by pressing solid waste using hot press contact molding, and then a layer of conductive material is laid on the solid waste base layer, and then hot press contact molding is used to form a conductive material layer, and then a layer of solid waste is laid on the conductive material layer, and hot press contact molding is used to finally obtain a solid waste-based multilayer electrode; The solid waste is selected from iron tailings, antimony tailings, phosphate tailings, mud phosphorus, lead-zinc tailings, titanium tailings, and tin tailings, with a particle size distribution of 10~100μm and a moisture content of 4%~10%.

2. The solid waste-based multilayer electrode according to claim 1, characterized in that: The conductive material is selected from graphite powder, platinum powder, carbon fiber powder, and copper powder, with a particle size of less than 100 μm and a moisture content of 4% to 10%.

3. The solid waste-based multilayer electrode according to claim 1, characterized in that: The solid waste base layers on both sides of the conductive material layer are the same type of solid waste or different types of solid waste.

4. The solid waste-based multilayer electrode according to claim 1 is used in electric-assisted fermentation and electrocatalysis.

Images