Once a particular area of an underground mine has been worked out, the empty stopes and tunnels left behind are often filled up by backfilling. This helps to increase the overall stability of the mine and can increase profitability by allowing columns left in place to provide roof support to be mined out and processed for valuable metals and minerals.
One of the more common ways backfilling is practiced, and one that is gaining in popularity, is by pumping or gravity feeding CPB (cemented paste backfill), a thick toothpaste-like mixture, into the stopes and other areas to be filled. As the name indicates, this mix is made up of tailings backfill material, mixed with a hardener (usually cement) and water that is added until the correct consistency is reached.
Barricades are then constructed at stope exits to retain the CPB until it cures and forms a plug. Due to this process, the stability of barricades plays an important role in the overall success of backfill operations.
The failure of a barricade during backfilling and the resultant escape of CPB can have disastrous consequences, including posing a safety hazard for mine personnel, resulting in equipment damage, and causing significant cleanup costs to be incurred.
A practice that is gaining popularity is the insertion of vibrating wire pressure sensors directly into barricades to monitor their stability and integrity as backfilling progresses. This allows barricades to be monitored and action to be taken if excessive pressure within the barricade is detected.
The vibrating wire sensors can then be connected to a wireless node, like the industry-leading wireless VW-RTU, to allow the data to be swiftly and easily sent to mine engineers on the surface where is can be analyzed and acted on.
Contact us to find out more about how the wireless VW-RTU can be used to help monitor backfill barricades.