â€œThis year, we will have 10 [quarries] in operation at one time,â€ said Yvan Grise, CGA, President and General Manager of Polycor's quarry division. â€œWe will quarry two to three years at each quarry to extract material.â€ Grise explained that skilled quarry workers are transported around to different sites depending on the needs of each quarry.
The quarry is comprised of a series of vertical joints, which are sometimes very tight and other times are between 20 and 50 feet apart. To cut the blocks, six Pellegrini wire saws are on site. The diamond wire used in the saws comes from Diamant Boart and Tyrolit Vincent. â€œCambrian Black can't fracture, so that's why we use diamond wire there,â€ said Grise, adding that this method is preferable over using explosives. â€œBlasting opens the cracks more and creates microfissures.â€
At the time of Stone World's visit, Polycor was working nine levels to get full production at its Cambrian Black site. â€œThe secret is to keep all levels ready,â€ said Grise, explaining that when a problem occurs on one level, they can move to the next one. As a result, production is never impeded.
With 20 workers on the Cambrian Black site, the quarry yields approximately 500 cubic meters per month and 5,000 cubic meters per year. The workers complete 80 hours in seven days and then have seven days off in remote locations, according to the quarry General Manager. Shipments are scheduled to correspond to when the workers are on site.
Improving productivity has always been a priority for Polycor, and investments in fixed assets are planned in order to provide subsidiaries with state-of-the-art production means. This policy has meant investments exceeding $8 million for each fiscal year ending in January 2004.
Cambrian Black graniteAbsorption by weight: 0.101%
Density: 179 pounds/cubic foot
Compressive strength: 22,122 psi (153 Mpa)
Modulus of rupture: 1,868 psi (12.92 Mpa)
Annual production: 5,000 cubic meters and up
Reserves: Over 100 years
Quarry operating since: 1980