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ORIGIN
The quarry is situated
in SARDINIA 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
97%, 98% even 99%.
EXTRACTION
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.
TREATMENT
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 100°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.
CONTROLS
IN THE QUARRY
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
AFTER TREATMENT
The same analyses are
conducted in 10 tonnes lots with in addition
:
- A bacteriological
control of each lot
- A physico-chemical control to check the
granulometric conformity, the pH and so
on.
Our technical
sheets take into account all these analyses
and naturally a product which does not comply
with our demands is rejected.
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