Mineral sands mines are usually open pit mines that can use a range of equipment: trucks and excavators, bulldozers, scrapers, monitors and dredges.
Of all the ore that is excavated, the economic minerals account for about 5% of the volume. Most of the sand is of no economic value and is returned to the mine void.
This means there is no hole left behind as happens with a coal or iron ore mine. Modern mineral sands mines rehabilitate and backfill the mine as it moves through the ore body.
Rehabilitation is a continuous process and can start as soon as the excavated material is returned to the start of the mine pit. Topsoil is replaced and vegetation cover re-seeded or replanted.
Heavy mineral sands are separated from the light sands (mostly quartz and clay) by using gravity processing methods through simple spirals or classifiers.
The mined ore is mixed with water to form a slurry which is pumped to the top of a spiral. As the slurry runs down the spiral, the centrifugal force flings the lighter quartz to the outside edge, leaving the heavy mineral close to the centre of the spiral where it can be collected.
Unlike some other types of mining, no chemicals are used to extract the mineral.
The heavy mineral concentrate or HMC is then stockpiled ready for transport to a port where it is shipped overseas for processing into the final products.
A key element of the Fingerboards mineral sands process is centrifuge equipment. Centrifuges will be used to extract water from fine sand tailings to produce a solid cake. The solid cake will be returned to the mine void as backfill which is part of the rehabilitation process. Water extracted through centrifuge processing will be re-used and recycled.