Mathematical model for express evaluation of process of dust air pollution in tailing facility

Abstract

Large areas of land are allocated to the tailings of mining and processing plants. They become sources of intense dust formation after the release of the tail pulp and rapid drying due to the slope height of more than 40 m and high wind flow speeds at these heights. The development of mining and processing plants is impossible without the implementation of ecologically oriented approaches to the management of production and technologies, which involves reducing the intensity of air pollution, the underlying surface. The assessment of the pollution zone is one of the global problems of tailings, since it requires taking into account both physical and natural factors. In this research, a numerical model was developed for the rapid assessment of dust pollution in the air during the removal of dust from the tailings. The numerical model is based on solving the equation of hydrodynamics and the equation of mass transfer by finite difference methods. The Laplace equation is used to find the potential of the air flow velocity, which makes it possible to calculate the velocity field over the entire study area. The solution of the mass transfer equation makes it possible to estimate the dust concentration field, to obtain a visual representation of the concentration in the form of isolines. The study shows that the stability of the calculation is the same when the input parameters of the problem change. The developed model takes into account the geometry of the slopes, the location of the dust source and their type (point or linear), the change in the air flow velocity with height, the presence of screens at the tops of the slopes. Pollution zones correspond to the physics of the process, namely, the formation of a clearly defined halo of pollution from a constantly operating source of pollution is observed, taking into account the influence of the aerodynamics of the air flow on the formation of pollution zones. The obtained results of study can be useful both in assessing dust pollution zones and in determining the geometry of protective equipment, namely the required height of the screens. Reducing the level of dust pollution to standard values is a necessary condition for the environmentally safe living of the population in residential areas. Keywords: tailings storage, dust pollution, mathematical modeling, numerical experiment, pollution concentration.