Metallurgical coal group Cokal has announced an upgrade in JORC-compliant resources for the eastern portion of Bumi Barito Mineral (BBM) Coal Project, comprising 10.5 million measured tonnes, 13.5 million indicated tonnes and 240 million inferred tonnes. The total estimate of 264 million tonnes is a 340% increase on the previous estimate.

Resources at the Central Kalimantan asset include open pit and underground potential while product split of BBM coal is now 90% coking and 10% PCI.

All additional resources have been determined as coking coal from analytical results. Deep stratigraphic boreholes up to 400 metres deep have confirmed the KLM area to consist of the continuation of the J Seam to the east of the J Seam outcrop area. This is due to a synclinal/anticlinal structural feature whereby the J Seam extends from the outcrops down to depths of around 300 metres and then comes back up to the surface in the KLM area in the east.

An economic analysis of the coal resource is under way to determine the ratio of open pit to underground. The roof of the J Seam predominantly consists of a very hard sandstone (up to 95 MPa), while the immediate 1 to 2 metres of roof material is shaley in nature. This combination is ideal for extraction of the deeper J Seam resources using underground methods such as thin-seam longwall mining.

Cokal executive director Pat Hanna says, “This coal resource upgrade is in line with the exploration target previously announced. Further drilling will define additional resources and increase the proportion of measured and indicated resources.” The area covered by the current estimate is 30% of the total area of the BBM Production IUP.

“Cokal is close to completing a definitive feasibility study using the latest coal resources,” CEO Peter Lynch says. “Economic modelling of the DFS results demonstrates a good cashflow in (the) early stage of production; the long term potential will include extraction of a large portion of the resources using efficient underground.”

Cokal is an Australian-listed company seeking to become a global metallurgical coal producer. It has interests in four projects in Central Kalimantan considered prospective for met coal. Cokal has also signed a joint venture to explore for coal in Tanzania with Tanzoz Resource Company.