Speaking at the 5th annual Australian Longwall mining conference in Yeppoon in March, Joy Mining Machinery (China) general manager, Paul Freeman presented the paper on behalf of vice general engineer, Madame Gong.
The Shenhua Group is one of China’s major longwall mining companies and through subsidiary Shendong Coal Corporation, operates the Daliuta 1 and 2, Bulainta and Yu Jia Liang longwall mines. Mines operating with continuous miners include Shangwan, Dahaize, Halagou, Sun Jia Guo and Wulan Mulan.
During calendar (or fiscal?) 2001, Shendong produced 37.9 million tonnes of coal and production for 2002 is planned to increase to 47 Mt.
Daliuta #1 was the first modern mine to be opened in 1995. In 2001 this mine produced an extraordinary 9.35 Mt raw coal, (7.73Mt longwall coal), with average productivity of 114.22t/man shift. Best monthly record for the year was 1.02Mt and best daily record is 42,800t. The most recently opened mine, Yujialiang, produced 6.8 Mt in 2001 and production for 2002 is forecast at 10Mt.
The focus of the Shenhua paper was on the rapid longwall face moves the company has perfected using auxiliary multiple entry technology. This involves two entries developed parallel to the longwall face in advance. A number of cross roadways are then developed at 30m intervals to form access roads to the face salvage line. Roof supports are turned and removed through the cross cuts improving the efficiency, speed and safety of salvage operations.
Since the company began using this approach in 1997, 18 face moves have been completed, for an average of 8 days. In September last year, Yujialiang mine took only 6 days and 23 hours to complete its first face move since longwalling began in January 2001.
No equipment was preinstalled during the move so all shields, AFC, stageloader, shearer, etc were moved 5km to the next face. The moving equipment consisted of six heavy transporters (Domino, DBT and Eimco vehicles) and ten Chinese light vehicles.
