In order to reduce chemical use, one feasible solution is the reduction of material input of the leaching or etching pro- cess. Therefore some dry- or wet-mechanical processes, such as vacuum blasting of intact modules, attrition and sieving of mate- rial mix and flotation, are suggested to be employed to remove the non-metal materials before the leaching or etching process. Fur- thermore, experiments showed that a multi-step flotation would improve the valuable yield and related enrichment of the semi- conductors. During flotation tellurium and indium from thin-film modules were enriched by the factor three (valuables yield of the flotation of Te 12.2% and of In 35.3%) [59].