A pre-conference workshop on March 20 addressed a range of issues from systems availability to maintenance management. A dominant theme to emerge throughout the conference was the issue of improving utilisation at Australian longwall mines, underpinned by a philosophy of continuous improvement. Joy Mining Machinery’s technical director Brad Neilson spoke on the latter issue at the pre-conference workshop, arguing that a 1% lift in availability (which equates to a 0.3% increase in utlisation) would add $1.2 million to operator’s bottom line.

Underpinning this was a call for maintenance practices to become more predictive, particularly evident among equipment suppliers. Neilson, for example, suggested that both operators and OEMs need to invest more time and effort in the pro-active/predictive phase of the equipment life cycle.

Brian Nicholls of Brian Nicholls Mining suggested that with average utilisation of 45-50% massive revenue gains were possible by seeking continual improvement in systems and equipment. Graeme Baird of utilisation improvement company McAlpine-B endorsed this. Baird argued that Australian mines lagged US counterparts in productivity for two main reasons. “The focus on day-to-day issues eclipses a longer term view of the operation,” he said.

Added to this was a lack of analytical capability to support improvements in utilisation, which require a greater emphasis on predictive rather than reactive maintenance.

Interestingly, an American delegate remarked after Baird’s paper that holding Australian mines to US standards did not make much sense because conditions were so different, and that it might be better to benchmark Australian productivity against Australian mines.

Tom Barczak from US-based National Institute for Occupational Safety and Health (NIOSH) addressed aspects of roof support practices, in particular design issues of three standing roof support applications.

Barczak is an international expert in the design and testing or roof support structures. He looked at how three tailgate support systems were made and what this implied for their application. These were The Can, the Link-N-Lock crib and the Propsetter.

Of great interest was a paper on rapid longwall moves, describing the process in the high production mines of Chinese coal mining company Shenhua. The company operates four modern longwall mines and five continuous miner operations. Total production in 2001 was 37Mt and this is scheduled to rise to 47Mt in 2002. The most productive longwall, Daliuta #1, produced 9.35Mt in 2001, with 7.73Mt off the longwall. (Further details on this paper will be available on ILN on April 1.)

Australian mine profiles included papers from Moranbah North (Steve Rowland, general manager), Kestrel (Dan Teal, general manager), and Metropolitan (Alan Phillips, mine manager).

Colin Merriman, of Joy Mining Machinery, examined the evolution in roof support size. The widest roof support currently available is 2m in width. The next size up for legs would be 450mm bore at a width of 2400mm with a yield density of around 114t/m2.

Also interesting to note was the presence of two papers endorsing thin seam mining methods. DBT’s Harry Martin described the benefits of plow technology in seams measuring under 1.7m in thickness. Plow technology, first installed in Germany is currently enjoying a resurgence, with several systems recently sold into China.

Earl Cook, general manager of Thin Seam Mining, which recently set up a thin seam mining operation at Gibson’s colliery in NSW, described the mining method. Longwall mines with thin seam reserves not amenable to longwalling could benefit from greater utilisation of the resource base. High productivity methods in thin seam mining could be expected to transfer to improvements in roadway development rates he said.

Various papers and issues will be the subject of additional articles over the next month.