BHP posts second straight year of record iron ore production, beats estimates
The world's largest listed miner said iron ore output from Western Australia on a 100% basis was 76.8 million tonnes in the three months to June 30.
In longwall mining, powerful shearing machines drive back and forth across coal faces of up to 400 m in length, producing coal at rates of up to 1 t every second. What makes these impressive coal production rates possible are the massive hydraulic roof supports that shoulder the roof until the shearer has completed its pass. (more…)
