This paper presents a new approach to planning experiments for hydrometallurgical processing of gold from waste printed circuit boards of cell phones by aqueous thiourea solution with and without ultrasound exposure. It is established that the use of the probabilistic-deterministic approach to the planning of experiments significantly reduces the consumption of resources and energy by reducing the number of experiments. It is shown that the models obtained using the probabilistic-deterministic approach of Malyshev V.P. allow forecasting the gold extraction from the electronic waste with sufficient accuracy. Obtained the values of gold recovery under the optimal conditions calculated by simulation which were 84.66% without ultrasound and 91.46% with ultrasound, respectively. The experimental gold recovery under optimal conditions was 79.6% without ultrasound and 88.2% with ultrasound. The correlation coefficient of the ultrasonic leaching model was R = 0.87, with a significance of the correlation coefficient tR = 12.34 > 2. The correlation coefficient of the leaching model without ultrasound was R = 0.86; the significance of the correlation coefficient tR = 11.5 > 2. Evaluating the influence of each factor individually and in aggregate to find the optimal process parameters, we built a mathematical model of the dependence of leaching and the degree of extraction of gold from e-waste.