Application Report - Block quarrying in the Natural
Stone Industry
Marble - dimensionally
accurate marble blocks
The Job: Marble cutting in Eichstätt, Germany. Eichstätt
marble possesses a compressive strength of 1400 kp/cm2. The dimensions
of the blocks produced range from
0.6 m to 1.5 m in height,
4 m - 12 m in length and
1 m - 2.5 m in width.
The requirements: Material wastage was to be minimal when the raw
blocks underwent further processing. This was possible thanks to the
particularly small-diameter wedge set of the splitters. The marble
cutter could examine the structure of the rock in advance to determine
the course of the split which the splitters would produce. The multiple
splitting cylinders were lined up in a row to produce a long straight
split with no hairline cracks. Hairline cracks often become a problem
when blasting methods are used to split marble.
The solution: First, holes are drilled at intervals of 24 - 40
cm. For the production of blocks, it is advisable to drill right through
the rock stratum, thereby benefiting the vertical course of the split
and preventing it from spreading laterally further down. The intervals
between drill-holes and the number of splitting cylinders used depend
on the length of the blocks and the hardness and homogeneity of the
rock. After the blocks have been split by several C 4 splitting cylinders,
a C 10 S cylinder was used to overcome the natural integrity of the
blocks. They can then easily be lifted out with a large wheelloader.
By using hydraulic rock and concrete splitters, the Eichstätt
marble quarries have more than tripled their production of blocks
while costs could be reduced. The wellbeing of the workers has also
improved markedly.