Pot scrap is the leftover result of the CZ method for growing silicon ingots. A quartz crucible is used during this process and once an ingot has been fully grown and cooled the end result will leave behind silicon pot scrap. This pot scrap has a small percentage of quartz from the crucible still attached. After chipping off the quartz the remaining silicon can be remelted resulting in lower grade silicon.
Crucible ready pot scrap can be chemically doped and mixed with virgin polysilicon allowing the ingot process to continue once again.
Because silicon pot scrap is the end result of a manufacturing process, it is often times overlooked and disregarded as waste and usually disposed of into landfills. Silrec pioneered the recycling of Semiconductor grade silicon pot scrap through a process of chipping off the excess quartz, leaving a maximum of 1% residual quartz on one plane of a single piece. This enables a low cost method of reusing material which would have otherwise been thrown away.