Kyanite Natural Mineral Resources In Nigeria And Its Deposits
Kyanite is one of the natural mineral resources in Nigeria, West Africa, it is a blue-green crystalline mineral which contains aluminium silicate and is mostly found in metamorphic rocks, sedimentary rock or aluminium-rich metamorphic pegmatites.
Kyanite can be found in; Kaduna and Niger states.
Kyanite is mostly formed during sedimentary rocks metamorphism mainly from the pressure alteration of clay minerals which at the time is very high. It is literally found in specific metamorphosed areas like in gneisses and schists and less often in eclogite or even in quartzite, it is also associated most times with other metamorphic minerals like staurolite, garnet, and corundum.
To extract Kyanite from its relative ore such as quartzite rock which is likely to contain other impurities such as rutile, mica, clays, iron oxides and other minerals, the rock is first mined and then crushed into smaller sizes.
The grounded homogeneous ore which constitutes of many minerals is fed into a processing plant and at this stage, it is allowed to go through many processes such as;
- It is first subjected to wet rod milling where the particles of the ore are further reduced into smaller or fine particles.
- The wet fine particles now in form of a slurry is fed into a hydro-cyclone to separate the clay from the slurry.
- It is then next sent to the hydrosizer which is a density separator and classifies the slurry ore particles according to its density (weight).
- To further get a better result of about (90 - 92)% Kyanite, it is fed into a spiral separator which sorts the slurry components or particles by density.
- To make the wet concentrate more dry by dewatering, it is subjected to gravity after which is the further dried and properly roasted as this will ultimately convert the 95% of the iron oxide impurities to a form where it can be removed by using magnetic separation leaving the Kyanite.
Kyanite has a relatively high strength and hardness which is dependent on its crystallographic direction and most time are also referred to as Cyanite, Disthene, or Rhaeticite.
Uses of Kyanite
- Aluminium silicate, used in heat-resistant ceramics.
- It is the basic material used in ceramic and refractory products.
- It is also used in electronics, electrical insulators, and abrasives.
- It is also used in a semiprecious gemstone.
- It is used in porcelain dishwares and plumbing fixtures.
- It’s used in the manufacturing of refractory products mortars, bricks.
- Also used in the production of kiln furniture used in high-temperature furnaces.
- It is used in porcelain such as white porcelain insulator on a spark plug, bathroom fixtures, sinks, and dentures.
- It is used in railroad and automotive industries as a heat resistance.
- Calcined kyanite like Mullite is used to make clutch facings and brake shoes.