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Tonnage mined in 2009 totaled 8.2 million tonnes, 8% lower than the previous year’s production of 8.9 million tonnes due to difficult underground conditions and ore handling problems that contributed to lower ore tonnage and grade. This year’s gold grade averaged 0.57 grams per tonne, 11% lower than the average grade of 0.64 grams per tonne in 2008, while the average copper grade of 0.23% is lower by 11% compared to last year’s copper grade of 0.26%.
Development works were focused on the 908 and 782 Meter Levels (ML).
At 908 ML, the projected nine drawpoints to be commissioned for 2009 were completed. Advance drives and support installation for the projected 52 drawpoints for 2010 were also undertaken during the later part of the year.
At 782 ML, 69 drawpoints were commissioned into production, which included the12 drawpoints that were not completed in 2008. The commissioning of eight special drawpoints at the 773 ML and two pillar robbing sites at 782 ML were also completed during the year. Ground stress problems were encountered and mitigated at production lines 8 and 10 and undercut lines 10 and 11. Towards the last quarter of the year, drilling drifts were developed at 840 ML which will serve as additional sources of ore. The area is above the central block of 782 ML from which the Underground Operations plans to extract ore from the 840 ML to 890 ML high grade portion.
Breaker stations at 908 ML and 773 ML were completed to service both production levels. A new twin-shaft sizer was installed at 745 ML feeder belt conveyor 1, the first of its kind in the Philippines, which allows the ore to undergo comminution before it falls to the conveyors. During the year, the installation of the 35 meters sacrificial belt between the loading chutes and the cable hauled conveyor (CHC) was also completed. This sacrificial belt is critical to the operations as it is expected to prolong the life of the conveyor belts of the CHC, which will ensure no major disruption in production.

Section of mining levels - Sto. Tomas II ore body |
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In 2009, the mill produced a total of 62,458 tonnes of concentrate containing 119,171ounces of gold, 33.8 million pounds of copper, and 117,047 ounces of silver. This year’s production is 20% lower than the last year’s production of 77,920 tonnes of concentrate containing 145,003 ounces of gold, 41.2 million pounds of copper, and 136,589 ounces of silver.
The new 50 m3 WEMCO Smart flotation cells.
Total concentrates shipped for the year were 65,059 tonnes containing 125,110 ounces gold, 35.2 million pounds copper, and 121,521 ounces silver.
The mill plant completed last November 2009 the installation of six units of 50 cubic meters WEMCO Smart flotation cells which replaced the old agitair flotation machines. This new technology resulted to additional flotation volume of about 180 cubic meters to the rougher flotation circuit which is expected to improve overall metal recovery.
To improve equipment availability at the dump bin dewatering screens, two units of 5’ x 16’ heavy duty JCI scalper screens were installed as replacement for the phased-out 8’ x 20’ Allis Chalmers screens. By 2010, the plant will replace the remaining two locally fabricated screens with heavy duty scalper screens.
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