METHOD FOR PREPARING ALKALINE METAL-CONTAINING ETCHING SOLUTIONS

摘要

The present invention relates to a method for preparing alkaline metal-containing etching solutions. This method comprises carrying out a liquid-liquid extraction in which the etching solution represents the heavy phase while an organic solution represents the light phase, and removing the metallic ions from said etching solution. A coalescence separation is carried out during each extraction step. The extraction phase is scrubbed and the alkaline constituent as well as the metallic constituent are recovered from said extraction phase. The alkaline constituent is then removed by a stripping process from the scrubbing liquid containing the same.