The 15,000ha BBM project is in Central Kalimantan and has a JORC resource of 77 million tons comprised of 70Mt inferred and 7Mt indicated.

The Indonesia-focused explorer said the potential additional seams, the ‘KLM’ seams are the uppermost in the package of thirteen seams which have been mapped to date.

The company has drilled 18 bore holes along the KLM seams and tested four of the core samples received.

“These laboratory results on initial the cores conducted in Australia by ALS confirm that the coal seams in the far Eastern portion of BBM continue to produce a premium coking coal and a welcome addition to the existing premium metallurgical coal at the BBM project,” Cokal executive director Pat Hanna said.

“All of the core samples which have intersected the seam have demonstrated excellent coking potential with Crucible Swell Numbers of 9 even on the raw coal results.”

Hanna said that although the initial analytical results of the raw coal samples indicated a range of ash of 12.6%-16.5%, the washed coal results indicated high yields of 80%-90% and ash results from 4%-5%, achieved using a relatively high separation density of 1.6. In-situ ash is generally related to the presence of thin stone bands, he said.

“We are currently testing large diameter cores (150mm diameter) to determine the possibility of easily separating the stone bands from the coal using a simple in-pit screening process.”

Cokal is completing definitive studies and obtaining the necessary approvals for BBM, with the aim of starting construction in October and first production in H1 2014.

“We continue to receive strong interest from some of the world steel industry’s biggest participants,” the company said in the announcement Monday.

“They are motivated to support the potential for a new metallurgical coal basin which allows them to diversify their current raw material supply away from the existing limited geographic locations which are dominated by the majors.”

Cokal has interests in five projects in Central Kalimantan and one project in West Kalimantan, all prospective for metallurgical coal.