| 摘要 |
PURPOSE:To carry out the sufficient recovery of valuables such as a pigment or a solvent from a waste ink, by a method wherein a mixed solvent consisting of a solvent inferior to and a solvent superior to pigment dispersibility is added to and mixed in the waste ink and the pigment after solid-liquid separation is dried. CONSTITUTION:A waste ink is introduced into a process 1 at first to remove impurities therein by a filter means or the like and concentrated in a process 2. Subsequently, a solvent good in pigment dispersibility and a solvent bads in pigment dispersbility and having flocculating capacity are added to and mixed in the concentrated ink in a definite ratio in a process 3 to made separability of the pigment particle good as well as to elute a resin or an additive on the surface of the pigment particle into a solvent phase. In the next step, the pigment particle is separated from the solvent by filtration or centrifugal separation in a process 4 and, while dried in a process 5, sent to a re-utilizing process 8 as the recovered pigment. On the other hand, the separated solvent is purified by a distillation method in a process 6 to be sent to a re-utilizing process 9. |
