Patent ID: 7297315
Filing Date: 2007-11-20
Classification: B01J,C22B,Y02P

Abstract:
1. A method of recovering a cleaning agent, the cleaning agent having been used for removing, through contact with a harmful gas, a phosphine contained as a harmful component in the harmful gas, to sorb the phosphine into the cleaning agent during the course of cleaning the harmful gas, and being at least one species selected from the group consisting of a cleaning agent containing copper oxide as a copper component thereof, a cleaning agent containing basic copper carbonate as a copper component thereof, and a cleaning agent containing copper hydroxide as a copper component thereof, the method comprising: immersing the cleaning agent in an acidic solution, to thereby dissolve the cleaning agent, forming a resultant solution; adding to the resultant solution a precipitant for phosphorus, to thereby cause a phosphorus compound to precipitate; separating the phosphorus compound that has precipitated, leaving a solution from which the phosphorus compound has been removed; adding a precipitant for copper to the solution from which the phosphorus compound has been removed, to thereby cause a copper compound to precipitate; and recovering the copper component of the cleaning agent.