Hydraulic fill at Osborne mine.

Osborne copper-gold mine in Queensland commenced hydraulic backfilling of three stopes in April 1999. Two of these stopes experienced barricade failure in July 1999 and January 2000. A comparison of the barricade designs with best practice showed that the Osborne fill system had more water to drain from a smaller area along longer paths, a lower quality of fill drainage properties and a larger face area for barricades of the same thickness. It was thought that damage from underground activities might also have reduced the ultimate strength of the barricades. The process for determining fill specifications and designing barricades was improved and design for a fill trial is almost complete. An issue highlighted by the review process was that the hydraulic fill system must be fully integrated with mine planning.
Osborne copper-gold mine in Queensland commenced hydraulic backfilling of three stopes in April 1999. Two of these stopes experienced barricade failure in July 1999 and January 2000. A comparison of the barricade designs with best practice showed that the Osborne fill system had more water to drain from a smaller area along longer paths, a lower quality of fill drainage properties and a larger face area for barricades of the same thickness. It was thought that damage from underground activities might also have reduced the ultimate strength of the barricades. The process for determining fill specifications and designing barricades was improved and design for a fill trial is almost complete. An issue highlighted by the review process was that the hydraulic fill system must be fully integrated with mine planning.