The invention discloses a method for recovering valuable metals from a waste
printed circuit board. The method comprises the following steps: sorting and crushing the
printed circuit board, evenly mixing
powder containing multiple
metal parts with a fluxing agent, and
smelting at low temperature for 1-3.5h; adding hot water into
smelting products for leaching; evaporating and concentrating filtrate after
filtration, and then returning
evaporation mother liquor to the water leaching process step; using solution after leaching for swirl electrodeposition of
metal silver, and adding 5-25% of HNO3 into filter residue for leaching; filtering the solution after electrodeposition, and adding 1-5 times of the weight of
aqua regia into the filter residue for leaching; using the solution after leaching by the
aqua regia for the swirl electrodeposition of gold, adding saturated NH4Cl into the solution after the electrodeposition for reaction, then filtering, using
ammonium chloroplatinate for refining the filter residue, obtaining
sponge platinum, adding methanoic acid into the solution after
precipitation, and carrying out reaction for obtaining crude
palladium powder. The method can extract
copper,
nickel, silver, gold,
platinum,
palladium and other main products and other by-products, realize the maximization of reutilization of value
metal resources in the waste
printed circuit board and solve the environmental
pollution problem; and the adoption of the swirl
electrolysis technology can realize low
energy consumption, low
reagent consumption, short process flow and simple operation.