In Africa significant Vermiculite deposits exist in Uganda, South Africa and Zimbabwe.
Vermiculite is found in geological areas originated by old volcanic activities. It is formed by weathering or hydrothermal alteration of biotite or phlogopite. Its main components are hydrated silicate of magnesium, aluminium, iron and potassium. Vermiculite is mined open cast.
The rocks containing Vermiculite are first grinded and separated from grit and then sieved into grades each having a specified range of particle sizes. Crude Vermiculite consists of golden/brown/anthracite flakes.
The coarsest grade V-Core processes comprises particles ranging between 8mm and 2.8mm, while the finest grade consists of particles between 0.7mm and 0.25mm in size. The specific application drives the choice of grade.
For example, for protective packaging the exfoliated Large grade and for soil mixes the exfoliated Medium and Fine grade are typically used. V-Core’s boards and bricks are based on the exfoliated smaller Superfine and Micron particle sizes which are readily available.