Terraflow: A cost-effective alternative binder in backfill application
CIM MEMO 2011
Robert Gustas, Ike Isagon, Drew Marr, Roger Santerre,
Binder is a major component of operating costs in backfill operations. With over two and a half million tons of backfill placed underground in Vale’s underground mining operations in Sudbury, ON, the application of a more cost-effective binder product becomes critical. Terraflow binder, a blend of blast furnace slag, Portland cement and cement kiln dust (CKD), offers a more compatible replacement to achieve cost reduction and sustain viable backfilling operations, without compromising safety. A partial replacement of Portland cement in the current binder blend is the key to a lower unit cost. Alpena CKD is normally used in roadbed stabilization projects.
Intensive laboratory testworks were conducted in the past to try various binder types and recipes. These test works involved both the short and long term fill strength values of the new binder, using the current binder as a base case. The testworks involved different fill materials currently in use at Vale’s operating mines in Sudbury, ON. The positive test results from Terraflow led to field trial proposals which were presented to the mines for scoping and approval. A few mines were selected for field trial based on fill material type and availability of stopes suitable for fill performance evaluation. Field procedures, risk assessments and management of change (MOC) were performed at all participating mine sites. Final evaluation of the fill performance requires compilation and analysis of data from extensive field sampling and testing program, laser survey (cms) of exposed stopes, dilution due to fill, and cost-effectiveness.