The four barges were each carrying approximately 7200t of coal from its Alam Duta Kalimantan mine and were sold to an Indonesian trading group.

Orpheus has a 50% stake in the ADK mine which is located in the province of South Kalimantan.

The mine has been in production since April 2011 and has shipped 95,000t of coal over the last three months.

The product from ADK is low in ash and sulphur, with product specification reaching 5500-5300 kilocalories per kilogram.

The SDK port is located about 15km from the ADK coal mine and 10km down the coast from the PCMU port, which provides additional available capacity for Orpheus coal exports.

Orpheus executive chairman Wayne Mitchell said the shipping of coal from ADK was a significant milestone for the company.

“We are delighted that the joint venture has been able to progress so quickly into coal exports since we first announced Orpheus had secured a 50% equity interest in the ADK coal project in March 2012,” he said.

The company plans to increase its export tonnage through SSDK port over the coming months.

Orpheus is a subsidiary of Australian explorer Coalworks and has projects in both Indonesia and Australia.