The treatment of metal extraction in waste electrical appliances requires a systematic and safe method. The following are step-by-step guidance recommendations： ###1. Preliminary preparation 1. **Safety protection** -Equipment: cut-resistant gloves, goggles, N95 mask, dust-proof apron -Environment: Operate in an outdoor ventilated place, away from fire sources and children's activity areas 2. **Tool preparation** -Basic tools: multifunctional screwdriver set, wire cutters, crowbars, hammers -Sorting tools: powerful magnets (identification of ferromagnetic metals), digital multimeters (detection of charged components) -Containers: fireproof metal barrels (storage of combustibles), sealed plastic boxes (storage of hazardous substances) ###2. Precise classification and disassembly 1. **Classification and treatment of electrical appliances** -Give priority to high-value equipment: air conditioners (copper pipes), desktop computers (gold fingers), microwave ovens (transformers) -Distinguish hazardous components: CRT display (leaded glass), lithium battery pack (fire risk), mercury-containing components 2. **Disassembly process optimization** -Modular disassembly: keep the complete wiring harness (such as the engine wiring harness), and remove the cooling module as a whole -Non-destructive disassembly: use a hot air gun (120℃) to soften the plastic buckle and remove the circuit board completely -Magnetic sorting: use neodymium iron boron magnets to quickly separate steel components ###3. Metal extraction technology 1. **Mechanical separation method** -Wire processing: use wire strippers to process the insulation layer in batches, and the copper wire is wound into bundles -Crushing and screening: the aluminum shell is treated with hydraulic shears, and the metal debris is graded by screens of different meshes. -Gravity sorting: self-made inclined shaker (wooden board + motor), using density difference to separate metals 2. **Metallurgical purification (professional guidance required)** -Aluminum recycling: build a simple reflective furnace (refractory brick structure) with a melting temperature of 660℃ -Precious metal extraction: it is only recommended to treat gold-plated parts and use 50% nitric acid to selectively dissolve the base metal -Electrolytic refining: copper sheet as anode, copper sulfate electrolyte, 12V DC power supply ###4. Handling of special components 1. **Circuit board processing** -Precious metal enrichment area: CPU slot, memory bar, gold finger, relay contact -Sub-board technique: Use a jig saw to cut the epoxy resin substrate, retaining the metal contacts 2. **Handling of hazardous substances** -Electrolyte collection: neutralize battery leakage with lime -Lead-containing components: individually sealed and stored, marked with the "Pb" logo ###5. Efficiency improvement strategy 1. **Establish a classification system** -Set up five categories: precious metals/copper and aluminum/steel/hazardous materials/non-metals -Color-coded containers: red (dangerous), yellow (copper), blue (aluminum) 2. **Batch processing** -Centralized processing of the same type of components (such as batch disassembly of motors) -Establish a standard operating process (SOP) and record the time-consuming of each link 3. **Resource integration** - Form a collaborative group of 3 people: disassembly/sorting/storage division of labor -Develop simple fixtures: such as circuit board holders, wire harness winders ###6. Compliance and benefits 1. **Legal compliance** - Check the local "Catalogue of Waste Electrical and Electronic Products Disposal" -More than 500 kg/month, you need to apply for a temporary disposal permit 2. **Economic analysis** -Cost accounting: tool input/time cost/energy consumption -Revenue comparison: direct sale of the whole machine vs The price of metal after disassembly 3. **Environmentally friendly disposal** -Plastic treatment: contact the local recycled plastic factory (it needs to reach a minimum output of 5 tons) -Professional recycling: parts with a gold content of >100g are recommended to be entrusted to a licensed company ### Advanced suggestions： 1. Learn the basics of metal materials science and master the identification of common alloy grades 2. Invest in a small metal analyzer (second-hand equipment for XRF spectrometer is about 20,000 yuan) 3. Join the community of disassembly enthusiasts and share resource information Note: When the processing capacity exceeds 200kg/month, it is recommended to register a micro-recycling enterprise and apply for environmental protection qualifications. Remember, the safety margin is always higher than the economic benefits, and complex components (such as the disassembly of lithium battery packs) are recommended to be handled by professionals.