CN-122012926-A - Method for preparing metal-based functional material based on electronic waste acid leaching-flame spray pyrolysis

CN122012926ACN 122012926 ACN122012926 ACN 122012926ACN-122012926-A

Abstract

The invention relates to a method for preparing metal-based functional materials based on acid leaching-flame spray pyrolysis of electronic wastes, which comprises the steps of firstly, mechanically crushing the electronic wastes to obtain metal-rich powder; the metal-based functional material is synthesized in one step by directly treating the acid solution by flame spray pyrolysis technology, and performing solution atomization, reaction and nucleation growth. Compared with the prior art, the invention eliminates the complicated steps of precipitation, washing, drying and calcining, obviously shortens the process flow, and avoids the use of a large amount of chemical reagents and the discharge of wastewater. In addition, by combining the rapid quenching characteristics of low-cost electronic waste and flame spray pyrolysis, a series of metal-based materials can be prepared, and the method can be applied to various fields such as electrocatalysis, energy storage and the like, and the conversion from low-cost electronic waste to high-value functional materials is realized.

Inventors

WU SHILIANG
XIN ZHIQIANG
XIAO RUI
PAN XIAN
ZHOU XIN
ZHANG ZHIYANG
LIU CHAOYANG
LIU CHANG
LI SHUYU

Assignees

东南大学

Dates

Publication Date: 20260512
Application Date: 20260122

Claims (9)

1. The method for preparing the metal-based functional material based on the acid leaching-flame spray pyrolysis of the electronic waste is characterized by comprising the following steps of: s1, cleaning, disassembling and crushing electronic waste raw materials, and obtaining metal-rich powder by means of physical crushing; S2, dissolving the metal-rich powder obtained in the step S1 in an inorganic acid solution, and filtering and separating to obtain a metal-rich precursor acid solution; s3, treating the metal-rich precursor acid solution obtained in the step S2 by using a flame spray pyrolysis device, placing the metal-rich precursor acid solution in an atomizer, atomizing the metal-rich precursor acid solution by using dispersed gas, and carrying out reaction, nucleation and growth to form particles under high-temperature flame, wherein a Mckenna flat flame burner is adopted as the core of the flame spray pyrolysis device, the burner is connected with three independent gas conveying pipelines, the flow rates of methane, oxygen and nitrogen are respectively controlled to form premixed gas to support flat flame, ignition of the atomized flame is completed, a reaction core area is formed, the flow rate of methane is controlled to be 0.8-2L/min, the flow rate of oxygen is controlled to be 1.5-4L/min, the flow rate of nitrogen is controlled to be 2-4L/min, the flame temperature is 1500-2000K, a circle of protective gas exists at the periphery of the Mckenna flat flame burner, the flow rate of protective gas is controlled to be 4-6L/min, the flow rate of dispersed gas is controlled to be 5-15L/min, and the atomization amount of the metal-rich precursor acid solution is 0.5-5 mL/min; and S4, collecting solid powder generated after the reaction in the step S3 by adopting a collecting device, wherein the solid powder is directly used as the metal-based functional material, and the metal-based functional material is particles with lattice defects or metastable structures.
2. The method for preparing the metal-based functional material based on the acid leaching-flame spray pyrolysis of the electronic waste according to claim 1, wherein the target metal extracted from the electronic waste comprises one or more of copper, nickel, cobalt, tin, gold and silver.
3. The method for preparing the metal-based functional material based on the acid leaching and flame spray pyrolysis of the electronic waste, which is disclosed in claim 1, is characterized in that in the step S1, the electronic waste raw material is crushed into fragments of 0.5-1.5 cm by using a crusher, and the physical crushing mode is multistage crushing by mechanical ball milling, so that the particle size of the powder reaches 80-200 meshes.
4. The method for preparing the metal-based functional material based on the acid leaching-flame spray pyrolysis of electronic waste according to claim 1, wherein the inorganic acid solution in the step S2 comprises one or more of sulfuric acid, nitric acid, hydrochloric acid and aqua regia; the solid-to-liquid ratio of the metal-rich powder to the inorganic acid solution is 1:5-1:20 g/ml.
5. The method for preparing the metal-based functional material based on electronic waste acid leaching-flame spray pyrolysis according to claim 1, wherein the dissolution temperature in the step S2 is 30-80 ℃ and the dissolution time is 4-6 h.
6. The method for preparing the metal-based functional material based on electronic waste acid leaching-flame spray pyrolysis according to claim 1, wherein the total concentration of metal ions in the metal-rich precursor acid solution obtained after filtration and separation in the step S2 is between 0.1 mol/L and 2 mol/L.
7. The method for preparing metal-based functional materials based on acid leaching-flame spray pyrolysis of electronic waste according to claim 1, wherein the dispersion gas in step S3 is one of oxygen or air.
8. The method for preparing the metal-based functional material based on the acid leaching-flame spray pyrolysis of electronic waste according to claim 1, wherein the collecting device in the step S4 comprises an exhaust fan and a stainless steel mesh, the exhaust fan is adopted to adsorb solid powder generated after the reaction on the stainless steel mesh and provide cold air to promote rapid quenching of the powder to form a lattice defect or metastable state structure, then the solid powder is obtained by scraping on the stainless steel mesh, and the air volume of the exhaust fan is 10-20L/min.
9. The method for preparing a metal-based functional material based on acid leaching-flame spray pyrolysis of electronic waste according to claim 1, wherein the metal-based functional material is in the form of a metal oxide, a metal simple substance or a multi-metal composite oxide for use in an energy storage material.

Description

Method for preparing metal-based functional material based on electronic waste acid leaching-flame spray pyrolysis Technical Field The invention relates to the technical field of electronic waste metal recycling and functional material preparation, in particular to a method for preparing a metal-based functional material based on electronic waste acid leaching-flame spray pyrolysis. Background With the iterative upgrade of the global electronic information industry, the amount of electronic waste generated presents an explosive growth trend. The waste printed circuit board, the waste lithium ion battery and various electronic components are rich in nonferrous metals such as copper (Cu), nickel (Ni), cobalt (Co) and the like, and rare noble metals such as gold (Au), silver (Ag) and the like. These metal resources are generally of significantly higher quality than virgin minerals, so electronic waste is regarded as a "municipal mine" of great strategic recovery value. The metal components are efficiently and cleanly recycled, and the method has important significance for relieving resource shortage bottleneck and reducing environmental heavy metal load. Currently, metal recovery techniques for electronic waste are mainly implemented by pyrometallurgy and hydrometallurgy. Among them, hydrometallurgy is the main stream treatment means in the current industry because of its high selective dissolution capacity and recovery rate of metals. However, conventional hydrometallurgical processes have a number of common technical bottlenecks that are difficult to overcome in practical applications. Typical wet recovery processes generally comprise a series of complex operations such as acid leaching, purifying and impurity removing, extracting/precipitating, solid-liquid separation, washing, drying, high-temperature calcining, and the like, so that not only is the process energy consumption high and the waste water and waste gas treatment pressure high, but also when high-added-value functional materials (such as electrocatalyst and energy storage electrode materials) are prepared, the materials are easy to overgrow and seriously agglomerate after subsequent high-temperature treatment, and the severe requirements of the materials on the microcosmic appearance and the crystal structure are difficult to meet. Patent CN201810230086.5 discloses a method for recovering valuable metals from waste circuit boards, which comprises the steps of carrying out detinning treatment and crushing on the waste circuit boards, carrying out magnetic separation and deironing, eddy current separation and deironing to obtain crushed materials, and carrying out a series of steps of pyrolysis, smelting and the like on the materials to obtain the valuable metals. The method still has the defects of complex process and low aging, and is difficult to realize continuous industrial production, particularly in the preparation of functional materials, the materials tend to overgrow and generate serious agglomeration phenomenon due to the treatment of pyrolysis, calcination and the like, and the strict requirements of high-performance electrocatalyst or energy storage electrode materials on microstructures can not be met. The patent with publication number CN119303935A discloses a method for recycling and reutilizing waste circuit boards, which utilizes chemical solvents to dissolve various metal components and adopts an electrolytic method to reduce metal ions, but a great deal of waste water and waste gas are generated in the process, and a series of measures are needed to relieve environmental hazards. In view of the above-mentioned shortcomings of the prior art, flame spray pyrolysis technology is a highly efficient and highly expansive material preparation method that utilizes chemical energy released by combustion to complete atomization, evaporation, reaction, nucleation and growth of a precursor solution in millisecond-scale time. The unique high-temperature transient reaction-rapid quenching process is extremely easy to induce and form metastable state materials with high specific surface area and rich lattice defects. For example, patent invention CN103730704B discloses a method for treating waste secondary batteries, which adopts a mode of burning waste secondary batteries in a rotary kiln in a divided stage, effectively prevents the danger of explosion of the batteries at high temperature, and can produce flue gas with no odor, no malodor and complete burning. However, the application adopts pyrometallurgy, has higher energy consumption, and adopts rotary kiln two-stage combustion equipment with larger occupied area and high manufacturing cost, thereby limiting the large-scale application of the technology. The patent application CN202411247097.6 discloses a method for preparing a catalyst for synthesizing green methanol by flame spray pyrolysis, which comprises the steps of (1) uniformly mixing an organic acid solvent and an alcohol solvent