Abstract: A model of the slurry concentration in a stirred vessel was proposed to explore the quantitative relationship between AE (acoustic emission) energy, stirring rate, and slurry concentration, by using wavelet transform.It was based on the mechanism that AE signals with different frequencies were emitted when solid and liquid impacted the wall.The system of water and sands was used as an example and was investigated in the slurry concentration range from 0 to 0.4 g·ml^-1 and at the stirring rates from 350 to 550 r·min^-1 in a stirred vessel.AE signals were analyzed by using 8 scales wavelet transform when the stirring rate was greater than 350 r·min^-1.It was found that the sum of the AE energy in the 4th, 5th, 6th frequency ranges was proportional to the slurry concentration, and to the 3rd power of the stirring rate.Based on these experimental data, the model parameters were estimated.The average absolute relative error between the calculated values and the actual values of the slurry concentration was 7.62 %.Therefore, this model could predict the slurry concentration with fairly good accuracy.