In this context intensive grouting of old mine works and backfills including mine roadways, drifts and vertical mine connections were done over more than 10 years.
For the purpose of monitoring stress deformation changes in rocks and backfills in the deepest parts of the mine during flooding up to the XIth level, measurement probes, i.
In the most recent period, measurements were performed twice a year in order to determine whether there are any stress changes in consolidated backfills in the broader area, where extensive mining works were performed in the past.
Although mining works were continuously accompanied by backfilling of dug out areas during the mine's entire operation, the backfills were so deformable that they were unable to prevent surface subsidence.
This offers great potential for backfill surface tailings disposal.
Placing waste back underground as backfill cannot be used to dispose of all the tailings produced, and some surface disposal is usually still required.
The use of tailings in backfill has many potential advantages for underground mines, such as:
Backfill will normally be prepared on surface and there are four main methods used to transport the fill underground.
Underground paste backfill has become well established in the Canadian mining industry over the last several years as a proven, cost-effective, high quality alternative to rock fill and hydraulic slurry backfill.
Golder Associates has been a leader in implementation of paste technology as a preferred solution to backfill placement and surface waste disposal.
Significant cost savings in the development of a paste backfill solution can be achieved through the design of an automated plant to be controlled from the mill control room.
The control equipment displayed in the control room allows the operator to monitor backfill flow on a continual basis thereby minimising the potential for failures associated with the flow.