Gem Diamonds reports Indonesian mining ops
Saturday, August 30 2008 - 02:27 AM WIB
Indonesia
BDI Mining was acquired by Gem Diamonds in May 2007. It owns 80% of the Cempaka alluvial diamond mine in South Kalimantan, Indonesia in partnership with PT Aneka Tambang, a company controlled by the Government of Indonesia. The alluvial deposits at the Cempaka Mine are found in the Danau Seran and Cempaka paleochannels.
Minor gold and platinum is present in the diamondiferous gravels in both channels and a precious metal concentrate is recovered as a by-product.
Expansion and Development
Expansion of the plant capacity to 216 000 tpm was completed with the delivery and installation of the 15 tph dense media separation (DMS) plant. The incorporation of the DMS plant will significantly decrease the amount of concentrate reporting to final recovery and reduce the bottle neck previously experienced at the x-ray machine and allow for increased productivity. A grease belt has also been installed to recover any non-fluorescing diamonds
A prefeasibility study into future alternative mining methods has been initiated and the results of this study are expected in 2009.
Gravel mined and treated during months of operation was satisfactory at 183 590 tonnes for January and the targeted production of 220 439 tonnes for February. March 2008 production was below target due to heavy flooding followed by the suspension of mining due to environmental concerns in April 2008 as detailed below.
Waste stripping normalised in H108 from the high levels seen in H107. The target strip ratio for 2008 remains approximately 4.2 times.
Diamond production was lower than in the comparative period despite considerably higher tonnes mined and processed. This is on account of the lower grade of the Cempaka channel mined in the period compared to that of the Danau Seran channel mined in 2007. Work is ongoing to improve the geological understanding of the Cempaka channel and higher grade areas have been targeted for H208.
Operations at the mine were suspended in April 2008 due to concerns raised by the Provincial Government relating to water discharge quality. Construction of approved water treatment facilities was subsequently completed. A revised feasibility study, environmental impact assessment and environmental monitoring and management plan were completed and approved by the authorities post the interim period end.
Rough Diamond Sales
H108
H107 %
Change
Waste mined (tonnes)
2 038 806
1 256 323
62%
Gravel processed (tonnes)
562 148
187 350
200%
Carats produced
6 251
8 441
(26%)
Au/Pt concentrate produced (kg)
4.7
6.03
(22%)
H108
H107 %
Change
Carats sold
21 790
10 411
109%
Total tender value (US$ millions)
6.66
2.27
193%
Achieved US$/ct
305
218
40%