Mining: Lining of Crusher Chamber Ore Pocket with Rappass

BHP Billiton Olympic Dam Lining of Crusher Chamber Ore Pocket with Rappass

Location: Olympic Dam, South Australia

Olympic Dam is a major gold, copper, silver and uranium producing mine in northern South Australia, some 600km north of Adelaide. It boasts the fourth largest copper deposit globally and the largest known single deposit of uranium in the world. The mine is owned and operated by BHP Billiton. The development includes an underground mine as well as an integrated metallurgical processing plant. The resident workforce reside in the nearby population centre of Roxby Downs, with two major permanent camps accommodating the fly-in / fly-out workforce.

Download PDF

Site

Olympic Dam is a major gold, copper, silver and uranium producing mine in northern South Australia, some 600km north of Adelaide. It boasts the fourth largest copper deposit globally and the largest known single deposit of uranium in the world. The mine is owned and operated by BHP Billiton. The development includes an underground mine as well as an integrated metallurgical processing plant. The resident workforce reside in the nearby population centre of Roxby Downs, with two major permanent camps accommodating the fly-in / fly-out workforce.

Minova were contacted by BHP Billiton in March 2012 to assist during the April Clark Shaft Shutdown.  BHP Billiton were aware of Minova’s range of specialty cementitious products and our capability in applying these products safely and efficiently. The brief was to repair and rehabilitate the badly damaged walls within the ore pocket / chamber below the Clark Crusher.

The walls were very badly damaged as a result of constant impacting from ore dropping into the circular chamber from the crusher some meters above.  As can be seen in the accompanying pictures, the original concrete wall material had been worn away to, and sometimes past, the original steel reinforcement.  In certain areas even the reinforcement had worn away.

Solution

Our experience of similar issues allowed us to quickly organize and implement a solution for the imminent shutdown.

It was decided to utilize the Minova product Rappass in the solution.  Rappass is a special formulation cement product which is engineered to ex-hibit highly performing impact and abrasion resistance.  It has been used in a number of instances where these properties, along with extremely high final strength are required. A few examples are:

  • Draw points
  • Bin liners
  • Ore chutes
  • Ore pass rehabilitation
  • Shaft collar
  • Machinery pads
  • Other areas of high impact and abrasion

Rappass can be manufactured in a pourable grade, as a wet mix shotcrete, or as a dry shotcrete. For the repairs at OD a dry shotcrete mix was chosen. This would allow for high early strength, extremely high final strength, and an ability for high build in a single pass with very little rebound.

For the information of the reader, typical shotcrete will attain UCS of approx 30 - 40MPa after 28 days.

Results

A 2 man crew carried out the application (1 x pump man, 1 x nozzle man), using a Reed pump. Approx. 10 pallets of Rappass were used in the repair.

Including preparation of the area (cleaning of surfaces etc), the application was completed over 2 shifts.  Although it is possible to apply this amount of product within a single shift, some time was lost in lowering the level of remnant ore in the chamber to allow the exposure of further wear.

All feedback from site confirms the application to have been a success, and was carried out safely and efficiently.

Acknowledgements

Appreciation to all at BHP Billiton Olympic Dam, with particular thanks to Wes Thompson and his Fixed Plant Maintenance team, along with all in the Shutdown Planning Department.