In a process for beneficiating phosphate rock a slurry is provided having 30% to 70% by weight of a liquid phase and having a solid phase comprising clay, sand, and phosphate rock. In the process, the slurry is exposed to ultrasonic energy released from a sonotrode located within the slurry. The slurry may be exposed to the ultrasonic energy for less than 10 seconds. The ultrasonic energy may be produced by a piezoceramic transducer to have a resonance frequency within the range of from 16 kHz to 100 kHz. The ultrasonic energy may have an intensity within the range of from 0.0001 W/cm.sup.3 to about 1000 W/cm.sup.3. The ultrasonic energy may create cavitational forces within the slurry. After exposure to ultrasonic energy, clay and sand are separated from the phosphate rock, perhaps using an air flotation process and a cycloning process.