S.D Scott has written:

'The system magnetite-fluorapatite-water and its relation to Multi-Minerals Number 6 orebody, Nemegos, Ontario' -- subject(s): Nemegos, Multi-Minerals Ltd

BHP's Cannington mine in Austrlia is largest single silver mine, but also check the San Cristobal mine in Bolivia, and KGHM in Poland. The latter is actually a group of mines, rather than a single orebody.

Overhand cut and fill mining involves excavating a horizontal slice of an orebody, then filling the void with a backfill material - typically mine waste or rejects from the processing plant . After backfilling, another slide is taken on top of the previous one, with the process proceeding until the orebody extraction is complete.

Underhand cut and fill mining also starts with a single horizontal slice, but subsequent slices are removed from below the initial one. In underhand mining, the backfill material usually has cement added to make a low grade concrete roof that is sufficiently strong to safely work under.

I bet they would have loved to have diamond drills, 3-D computer orebody mapping, and the massive haulers used in todays gold mines, not to mention advanced chemical extraction techniques and all the safety advances in use today.

Mining is a huge tech driver; mining companies currently spend billions on R&D. They clearly understand that improving their technology, from bigger loaders to better orebody 3-d mapping, has a massive payoff down the line. That influx of cash is driving research in robotics, computing, chemistry, materials handling, and many other fields.