Backfill
In order to reduce the resistance of the earth electrode as much as possible, the anodes are placed in a backfill made of materials that are able to conserve humidity and offer low electrical resistance.
The types of backfill can be inert (typically bentonite mud) or reactive when the material participates in the electrochemical reactions associated with the functionality of the earth electrode (coke).
- Calcined petroleum Coke
- Metallurgical Coke
- Bentonite