Patent ID: 8308843

Claim:
A method using pyrolysis for recycling a used printed circuit board, comprising the following steps: Step 1: dipping a used printed circuit board into melted nitrate in a reactor to start a pyrolysis process and chemical reactions, wherein water is introduced in the reactor for cooling the used printed circuit board and melted nitrate to stabilize the pyrolysis process and to maintain a positive pressure with moisture generated by heating the water, thereby removing oxygen and forcibly discharging pyrolysis gas out of the reactor; Step 2: using a room temperature condensing/compressing and recycling system to condense the pyrolysis gas to sort out fuel and gas for recycling; Step 3: separating out the melted nitrate after the pyrolysis process by using water; wherein nitrate and halide are sorted out based on their different densities and melting points; Step 4: separating salt and carbon residue in carbon film generated in the pyrolysis process by using water Step 5: separating glass fiber and metals, wherein if solder mask copper foil is not melted, then the solder mask copper foil is separated from the used printed circuit board by applying an external force or through chemical reduction.