Extracting rare metals from waste electrical appliances is a highly technical task that requires professional knowledge and equipment to ensure safety and environmental protection. The following are step-by-step guidance and suggestions, but please note that **For non-professionals, it is recommended to hand over waste electrical appliances to qualified recycling companies for disposal** to avoid health and environmental risks. --- ### **1. Classification and identification** First of all, clarify the types of rare metals contained in waste electrical appliances (common target metals)： -**Gold (Au)**: Circuit board, CPU, memory bar contacts. -**Silver (Ag)**: switches, relays, conductive coatings. -**Palladium (Pd), platinum (Pt)**: catalyst, electrode. -**Copper (Cu), aluminum (Al)**: wire, radiator. -**Rare earth elements**: Magnets (such as neodymium iron boron), phosphors (old displays). **Tool preparation**: Multimeter (detecting conductivity), magnet (distinguishing ferromagnetic materials), magnifying glass or microscope (observing circuit board details). --- ### **2. Safe disassembly** -**Protective equipment**: Wear anti-cut gloves, goggles, and N95 masks (to prevent dust) and operate in a well-ventilated area. -**Disassembly steps**： -Remove the plastic shell (can be recycled separately). -Separate circuit boards, batteries, wires, magnetic components, etc. -Note: ** Lithium batteries need to be handled separately** (piercing or short circuit may cause fire). --- ### **3. Metal enrichment and preliminary treatment** ####**Circuit board processing (including gold, silver, and palladium)** -**Mechanical separation**: Use pliers or a hot air gun (above 300°C) to remove chips, capacitors and other components. -**Acid leaching method (extreme caution is required)**： -**Gold removal**: Dissolve the base metal (copper, nickel) with dilute nitric acid (HNO₃), dissolve the remaining gold layer with aqua regia (hydrochloric acid + nitric acid, 3:1), and finally use a reducing agent (such as sodium sulfite) to precipitate the gold powder. -**Risk**: Strong acids can easily corrode the skin and produce toxic gases (such as nitrogen dioxide). It needs to be operated in a fume hood. ####**Wire treatment (copper, aluminum)** -Peel off the insulating layer (wire stripper or incineration method can be used, the latter is highly polluting and is not recommended). -It is more economical to sell bare copper wire directly. ####**Magnet (Neodymium iron boron)** -After crushing with a hammer, use a strong magnet to adsorb and separate the rare earth powder (further chemical purification is required). --- ### **4. Chemical purification (for professionals only)** -**Electrolysis method**: Suitable for the purification of copper and silver (requires an electrolytic cell and a DC power supply). -**Pyrometallurgy**: High-temperature smelting (refractory crucible and high-temperature furnace are required), suitable for batch processing but high pollution. -**Environmentally friendly alternative**: Biological leaching (dissolving metals with microorganisms, but low efficiency). --- ### **5. Sales channels** -**Unpurified waste**: Sold directly to electronic waste recyclers (the price is lower but it is easier). -**Purified metal**： -**Gold, silver, and palladium**: Precious metal refineries (component test reports are required). -**Copper, aluminum**: Local metal recycling station. -**Rare earth powder**: specialized chemical or magnetic material enterprises (a certain scale is required). --- ###**Important Notes** 1. **Legal compliance**： -Many countries/regions require a license for the treatment of electronic waste (such as China's "Administrative Measures for the Qualification and Licensing of Waste Electrical and Electronic Products"). -It is forbidden to dump acid or incinerate at will (violations of environmental laws may face high fines). 2. **Health risks**： -Strong acid, lead, mercury, cadmium and other toxic substances need professional protection. -Long-term exposure to e-waste may cause heavy metal poisoning. 3. **Economic assessment**： -The cost of small-scale extraction may be higher than the price of the metal (especially the gold content<0.1% of the circuit board). --- ###**Suggest an alternative** -**Formal recycling**: Contact the local environmental protection department or large recycling companies (such as Grammy, Umicore). -**Public welfare treatment**: Some manufacturers (such as Apple and Dell) provide trade-in or free recycling services. For further guidance, it is recommended to refer to the "Electronic Waste Resource Technology Manual" or consult a metallurgical engineer. Safety first!