What Does Coal Coke Breeze Mean?
Coal coke breeze is a common backfill material used in cathodic protection. It is a type 1 carbonaceous backfill material. Coal coke breeze backfill has low resistivity and low ash content, and may be treated by the addition of 10% (by weight) commercial grade slaked lime.
The fuel used in the iron ore sintering processes is coke breeze. Its combustion yields high enough amounts of heat which is delivered to the sinter mix.
Corrosionpedia Explains Coal Coke Breeze
In the coal coke production process, during the coke quenching, handling and screening operation, coke breeze is produced. It is either reused on site (such as in the sinter plant) or sold off site as a byproduct. Coal coke breeze is an important carbonaceous backfill material in cathodic protection. Coke breeze offers a backfill solution since it can be compacted by 95% and offers the best conductivity at moisture levels between 5% and 20%. The value of -3+1 mm represents the most favorable particle size for coke breeze.
When impressed current-type cathodic protection systems are used to mitigate corrosion on an underground steel structure, the auxiliary anodes often are surrounded by a carbonaceous backfill. Backfill materials commonly used include coal coke breeze, petroleum coke breeze and natural graphite. Impressed current anodes are supplied with a recommended maximum current density; higher current densities reduce anode life.
Because the purpose of the carbonaceous backfill is to provide an electronic path for current flow, low resistivity, particle size and specific gravity are important backfill properties. Low resistivity favors electronic current flow to the backfill/ground interface. Small particle size and high density favor electronic current flow by improving contact between the anode material and the backfill.