Ulan No 3 mines the base level 3 metres of the Ulan seam for thermal coal.

The Ulan Seam generally dips uniformly towards the north-east at between one and two degrees, and the seam thickness averages 5 to 7 metres throughout the Ulan Mine Complex. It consists of ten separate plies, which are consolidated into four working sections within the open cut. The working sections are separated by thin claystone horizons.

Ulan Underground uses standard longwall mining methods to mine the lower 3m of the Ulan seam, known as the D Working Section (DWS), for thermal coal. Development of first workings is undertaken using continuous miners and shuttle cars to develop roadways which form the longwall panels.. Access to the mine is via the main and materials drift located adjacent to the Ulan Underground surface facilities. The longwall is approximately 400m wide.

ROM coal is delivered to the HUB Stockpile via conveyors from Ulan No. 3 underground mine.

There is one dedicated reclaim valve for each underground mine and a shared reclaim valve. The reclaim valves deliver coal to the sizing station where it is crushed. The sizing station can send 50mm top size coal to the ROM stockpile, 50mm top size coal to the product stockpiles or 125mm top size coal to the CHPP. From the ROM stockpile there are three reclaim valves that send the coal into a surge bin with two feeders sending coal to the product stockpile. Underground coal can be delivered via the existing open cut conveyor system through a dump hopper surge bin with sizing and trash screen, bypassing the CHPP, to the product coal stockpile at 2000 tonnes per hour.

The CHPP has a flexible raw coal receivals system which allows either individual, or any combination of, direct plant feed, raw coal stockpiling or reclamation from the stockpile by a bucket wheel reclaimer. A coal surge bin distributes between two modules. The CHPP utilises dense medium baths, dense medium cyclones and water washing cyclones to separate rejects from thermal coal. Coarse rejects are trucked from a receivals bin to reject emplacement areas. Tailings are thickened and pumped to the reject emplacement dam within the East Pit.

Product coal is stacked onto product stockpiles and reclaimed by a rail mounted bucket wheel reclaimer to the rail load out bin. Product coal was loaded onto trains at the Rail Load Out area for rail transportation to the Port of Newcastle.