SENSE [37] developed a hydrometallurgical process for CIS waste treatment. Solid wastes mainly including CIS-coated glass plates and grinding dusts from the edge grinding of the CIS modules were first homogenized and brought to a suitable grain size by milling and screening. Then the materials were dissolved in an oxidizing acid. The solution was filtered and the insoluble fractions in it were removed. In a first liquid–liquid extraction step, the indium from the solution was transferred into an organic solution while the other metals remained in the inorganic solu- tion, which could be treated further to recover the gallium and the selenium. In the stripping step (re-extraction), the indium was transferred again into an inorganic acid solution, and then were either precipitated as a fairly pure indium hydroxide or directly deposited as metal by electroplating.