Flotation as a random process, in which the random variable representing the number of particles raised to the froth layer during a fixed time t depends on time, is a stochastic process. As a result of turbulence of the medium in the flotation chamber, apart from the process of particles adhesion to bubbles, a reverse process occurs whose intensity depends on the ash content. This is the process of detachment the particles from bubbles. Such a situation is described best by the stochastic process of birth and death. The paper briefly presents the assumption and differential equation of the model as well as its solution in the form of the equation of flotation kinetics. The authors have presented the interpretation of equation parameters. According to the empirical dependences of recovery of floating particles in the froth product on time for several coal samples, differing by the ash content, the following parameters of the kinetics equation were calculated: the resultant adhesion rate constant and permanent adhesion rate constants. The resultant adhesion rate constant, being the sum of permanent adhesion and detachment rate constants, is independent on the ash content whereas the permanent adhesion rate constant decreases with the increase of ash content.