The quarry is situated in SARDINIA (Italy) in the town of VILLANOVA TULO.
It has a surface are of 240 hectares and its main activity is the extraction of Montmorillonite for industrial use.
Its most important characteristic is the presence of very pure montmorillonite ( more than 85% of the total mineral ).
There are even some seams to be found with a purity of up to 85 %.
Firstly the products destined for the pharmaceutical industry or similar uses are detected in the quarry by series of core boring, thus allowing us to determine the seams which meet the desired norms.
The core boring is carried out at one metre intervals over a length of face of generally 25 metres, for an extraction of 250 tonnes. The average height is 3 to 4 metres, the thickness 2 to 3 metres.
The mineral is extracted by means of digging and the required quantity is immediately taken away and stored under shelter.
On extraction the clay comes in the form of semi-humid blocks ( 25% on average ), sized between 2 and 30 cm.
It has to be crushed in order to be dried properly.
Drying takes place in a rotational tempered steel dryer heated by gaz.
There is a simultaneous current of air so that the temperature does not surpass 90°C.
The material is then ground on Forplex equipment, comprising an F3 grinder and an SD3 dynamic selector. The latter machine has a speed variation which enables different granulometric sizes, that is :
77µ, 45µ, 20µ.
We can add besides that the drying process we have developed guarantees the bacteriological cleanliness of the clay we treat.
There are 3 types of control at this stage to select the area of extraction.
- X diffraction to identify the clay which is to be treated.
- Capacity for ionic exchange to check the richness in montmorillonite
- Level of lead and heavy metals
- A bacteriological control of each batch
- A physico-chemical control
Our technical sheets take into account all these analyses and naturally a product which does not comply with our demands is rejected.