Spent potlining (SPL) contains water-soluble fluorides and cyanides, and so is a hazardous waste which cannot be be safely left in landfills. Currently the industry generates more than 1.5 million tonnes of SPL every year.
The refractory-rich cut II can be used as a valuable additive in the cement industry, in producing ceramic tiles, in lime kilns, as road pavement additive or as potline electrolyte additive.
The carbon-rich cut I can be used as a carbon-containing concentrate in the production of cathode blocks, in ramming pastes, as well as in raw materials for prebaked anode manufacture. This carbon-rich part can serve as fuel for the manufacture of cement clinker or in energy generation, can help in the recovery of fluorides such as aluminium fluoride, or can be used in the manufacture of rock wool, in selective steel manufacture, or in the pig iron industry.