The Department of Resources Engineering under National Cheng Kung University in southern Taiwan has developed a method to separate high-purity silicon and silicon carbide from silicon slurry, a waste from making crystalline silicon solar cells.

Researchers from the department said the recycled materials from the new method is beginning to be used by steel plants.

Recycling service providers usually separate such silicon slurry into liquid and solid-state slurry and extract ethylene glycol from the former for sale and bury the latter.

The researchers said their method can separate high-purity silicon and silicon carbide using physical and chemical processes.

Silicon slurry from solar cell production contains many waste materials and therefore needs advanced purifying and extracting technologies to recover silicon and silicon carbide, whereas that from semiconductor production contains fewer wastes and the recovering process is relatively simple, the department indicated.