REPLACEMENT TIME DETERMINATION METHOD OF ION EXCHANGE RESIN

摘要

PROBLEM TO BE SOLVED: To provide a replacement time determination method of ion exchange resin which can easily and securely determine replacement time of the ion exchange resin without surface analysis of the resin before and after adsorption.SOLUTION: There is used a precious metal recovery system including an adsorption unit formed by connecting in series at least two resin tubes filled with the ion exchange resin. The replacement time determination method of ion exchange resin includes the steps of: flowing precious metal dissolving liquid through a first resin tube and a second resin tube connected with one another of the at least two resin tubes in this order to absorb the precious metal; and determining a time point at which the ion exchange resin in the vicinity of an inlet port of the second resin tube for the precious metal dissolving liquid begins to be colored, as replacement time of the ion exchange resin of the first resin tube.