Calcined petroleum or metallurgical coke particles tamped or pumped around ICCP anodes. Coke conducts electronically, so much of the current enters the soil from the coke column rather than from the anode itself, which enlarges the effective anode, lowers groundbed resistance and slows anode consumption. Voids, loose packing and contamination all raise resistance.
Pump the coke breeze as slurry from the bottom of the hole, we don't want voids around the anodes.
Also heard as
- coke backfill
- carbonaceous backfill
Related terms
Groundbed
Group of impressed-current anodes buried in backfill that discharges rectifier current into the earth.
Deep anode
Impressed-current groundbed with anodes stacked in a vertical hole drilled tens of metres deep or more.
MMO
Mixed metal oxide anode: titanium coated with precious-metal oxides, the standard long-life ICCP anode.