Expandable graphite is manufactured by treating large and particularly extra-large flake graphite concentrates with an intercalation agent that penetrates between the many layers of each individual flake. It can be sold as is or heated, which causes the intercalation agent to expand, splitting the flakes apart and increasing the volume by hundreds of times. The expanded graphite is then pressed into self-binding sheets or foils. These products are used for thermal management in consumer electronics as every smart phone, tablet and flat panel television, as well as solar panels, requires a sheet of graphite foil to keep it cool and dust free. The product is also used for gasket products in the automotive, petroleum, chemical and nuclear industries as graphite does not rust, corrode or react with acids, in conductive plates for fuel cells and flow batteries, and in fire retardants. The latter market is expected to grow rapidly as the use of brominated flame retardants is phased out or banned. Expandable graphite is principally made from plus-50-mesh extra-large flake, which sells for approximately $1,750 (U.S.) per tonne, while expandable graphite can sell for up to $3,000 (U.S.) per tonne.