From Unofficial Stationeers Wiki
Reagent Mix is mixture of different materials.
Obtain: You can get Reagent Mix from recycling items at kit recycle.
Reagent Mix can be used on Centrifuge, you can extract ores from reagent mix.
- NOTE*** - Steel cannot be reclaimed from the Recycler and Centrifuge. It will continue to reprocess the Reagent Mix. Also note, if you have chutes designed as part of your recycler/centrifuge process, introducing steel reagent mix will cause your chutes to clog. You will need to disassemble your centrifuge to get the unprocessed reagent out of the centrifuge.