Handling rare metals in waste electrical appliances requires careful consideration of safety, environmental protection and legality. The following are step-by-step suggestions： --- ### **1. Identify valuable metals** -**Common metals**: gold (circuit board contacts), silver (conductive layer), palladium (capacitors), platinum (sensors), copper (wires), rare earths (magnets, batteries). -**High-value equipment**: Priority is given to old mobile phones, computers, televisions, hard drives, automobile catalytic converters, etc. --- ### **2. Legality and environmental protection preparation** -**Check regulations**: Confirm local legal requirements for the treatment of electronic waste (e-waste) (for example, the Basel Convention restricts the cross-border transfer of hazardous waste). -**Environmental protection measures**: Avoid incineration, random disposal, and prevent pollution by toxic substances such as lead, mercury, and cadmium. --- ### **3. Spin-off and classification** -**Tool preparation**: Wear gloves, goggles, masks, use screwdrivers, pliers, wire cutters and other tools. -**Spin-off steps**： -Disassemble the shell and separate non-metallic parts such as plastic and glass. -Collect metal-containing components such as circuit boards, wires, batteries, magnetic components, etc. - Categorize and store different metal components (such as copper wires, gold-plated contacts, neodymium magnets). --- ### **4. Metal extraction method (professional conditions required)** -**Physical separation**： -Copper, aluminum, etc. can be sorted by manual stripping or crushing. -Neodymium magnets (hard disk, earphones) can be collected directly. -**Chemical extraction (high risk! Need professional guidance)**： -**Gold extraction**: Dissolve the gold-plated layer of the circuit board with aqua regia (hydrochloric acid + nitric acid), and then use a reducing agent (such as sodium sulfite) to precipitate the gold. -**Silver recovery**: After nitric acid is dissolved, salt is added to precipitate silver chloride, and then reduced to silver powder. -**Rare earth extraction**: High temperature smelting or acid leaching is required, and the process is complex (usually industrial equipment is required). -**Bio-metallurgy (experimental stage)**: The use of microorganisms (such as Thiobacterium ferrous oxide) to dissolve metals is environmentally friendly but inefficient. --- ### **5. Sales channels** -**Direct sale of unprocessed parts**： -Sell the spun-off circuit boards, magnets, etc. to professional recyclers (such as metal recycling companies, electronic waste buyers). -Trade through online platforms (eBay, Alibaba) or local scrap stations. -**Sold after refining**： -Precious metals (gold, silver) need to be purified to more than 99% and sold to precious metal refineries or jewelers. -Rare earth metals need to reach industrial-grade purity, contact a professional metallurgical company. --- ### **6. Alternative: Professional recycling** -**Recommended practice**: Contact a qualified e-waste recycling company (such as ERI in the United States and Grammy in China), they can handle it in compliance and pay reasonable remuneration. -**Public welfare options**: Some brands (such as Apple and Dell) provide trade-in or free recycling services. --- ###**Precautions** -**Safety first**: Chemical reagents (strong acids, cyanides) are corrosive and toxic. They need to be operated in a fume hood and wear protective equipment. -**Economy**: The cost of small-scale extraction may be higher than the benefit, and the input-output ratio needs to be evaluated. -**Environmental responsibility**: Waste liquid and exhaust gas need to be professionally treated and cannot be directly discharged. --- ###**Summary** -**Personal advice**: Unless you have professional knowledge and equipment, give priority to formal recycling channels. If you need to try extraction, it is recommended to start small-scale (such as recycling copper wires and magnets) and learn basic metallurgical knowledge. -**In-depth learning resources**: Refer to books such as "Electronic Waste Recycling Technology" and "Precious Metal Smelting Technology", or participate in related training courses. Processing in a legal and safe manner can not only protect the environment, but also maximize the value of resources.