BHP engaged Delta Group to design and deliver a two stage industrial demolition works programme for its Slag Floatation Plant located at their Olympic Dam mine in Roxby Downs, South Australia.

Stage One – Old Gold Room Demolition:

  • Consisting of a steel framed, tin clad shed with an adjoining concrete strong room.
  • Design and Install of Southern wall temporary retention to allow for diversion of existing services prior to demolition of the remaining structure as a part of stage 2.
  • The concrete strong room was demolished first, followed by removal of the exterior tin cladding.
  • A large hopper and sections of the roof frame lifted out by crane.
  • Southern wall retention was installed and remainder of the structure was demolished.

Stage Two – Slag Floats Demolition:

  • Demolition of (previously) retained southern wall of the Old Gold Room, removal of existing hoppers and sump pumps, and demolition of 3 slag floatation rougher cells and associated structures.
  • Hoppers, sump pumps and associated structures removed from beneath the slag flotation cells.
  • Protection of the maintained bund sump pump was also installed, with existing walkways separated and access to top of cells blocked.
  • Separations between the slag rougher cells completed by a combination of excavators fitted with shears and oxy-cutting.
  • Rougher cells were rigged to a 200t mobile crane and lifted out then transported from site for cleaning and further processing
  • Existing cell (support) structures demolished – all C&D waste sent to CWDF for processing, cleaning and categorisation for disposal.

Key Challenges & Outputs:

  • All works undertaken in tight live plant environment, with no downtime to plant operations – specialist zero swing plant purchased to aid and maximise project output
  • Mixture of multiple contaminants and hazardous substances dealt with including, Naturally Occurring Radioactive Material (NORM’s), Xanthate, hydrocarbons, Neutral Pulp and other process contaminants
  • Mixture of shearing and cut and lift methodologies, with sequencing of cell demolition and removal of cell components occurring within a live, fully operational environment. The selected methodology reduced the risk of damage to surrounding plant and hazardous hot works
  • Project completed ahead of time, under budget and without incident – zero LTIs/MTIs
  • 180t of steel of contaminated steel classified, cleaned and sent to approved/licensed landfill and/or recycling facility.