Anglo American chief executive Mark Cutifani and Metallurgical Coal chief executive Seamus French turned the first sod on the project Thursday.
The expansion plan is expected to extend the life of the Trend operation by 16 years, the company said.
Anglo American expects the second phase of the project to be permitted by the end of the year and to complete the Roman expansion by the first quarter of 2014.
The Trend mine produces premium hard coking coal, which is used to make steel.
The company has said the combined Trend and Roman operation is will employ up to about 450 people full time.