Evaluation of Potash Dissolution by Inflow Brine Using Acoustic Emission
CIM MineSpace 2001
Fulchand Fulchand Shende, Euler De Souza,
Around the world many potash mines suffer from brine inflow problems. The presence of brine in underground excavations may induce structural and stability problems. A study has been carried out to simulate the effect of brine on the performance of pillar support. The testing program consisted of loading potash specimens of 8.25 cm diameter and 15.1 cm long in a creep frame, and simulating inflows by continuously pumping brine into an experimental cell. Brine temperatures ranged between 20° and 60° and load conditions varied from unloaded to 50% of the unconfined compressive strength (UCS) of the rock. Specimens were fitted with acoustic emission transducers to monitor energy emissions during an eight-hour test duration. Samples of brine, collected at regular intervals, were analyzed using atomic absorption techniques to provide K+ and Na+ concentration data necessary for an accurate assessment of the dissolution process. Test results indicated that dissolution rates are highly dependent on brine temperature and load conditions. Loads approaching 50% UCS tend to generate very high rates of energy emissions, often leading to the failure of the simulated pillars. This study demonstrated that acoustic emission can be effectively used for predicting the performance of pillars when exposed to inflow brine.
Brine inflow, Acoustic Emission, Dissolution, Creep, Potash