Wind transport of an air-borne dust cloud in the atmospheric boundary layer in the neighborhood area of a surface mine is analyzed by numerical solution of the Navier–Stokes equations in their full form for a compressible liquid and in a subsonic flow approximation. The dust source is a large-scale blast at a total mass of ∼ 100 g of TNT at a depth of 250 m in the pitwall rock mass. The calculations take into account a portion of dust raised above ground surface by blasting. The size of the surface areas of air-borne dust concentrations above maximal allowable values is estimated. The relationship of this size and the wind direction–pitwall angle α is analyzed. The maximal distance between the pitwall and the area of dust concentration above MAV is 3 km. The exposure duration at the fixed point on ground surface is independent of the angle α and ranges from a few minutes at a distance of 500 m from the blast center to a dozen minutes at a distance of 3 km.

Методами численного решения полной системы уравнений Навье - Стокса для сжимаемой жидкости в дозвуковом приближении исследован перенос ветром облака взвешенной пыли в атмосферном пограничном слое территории, прилегающей к горнорудному карьеру. Источник пыли - массовый взрыв с суммарной массой заряда ~ 100 т тротила, расположенный на уступе борта карьера на глубине 250 м. В расчетах учитывается часть пыли источника, поднявшаяся в результате взрыва над дневной поверхностью карьера. Проведены оценки размеров области, где концентрация взвешенной пыли над поверхностью превышает предельно допустимые значения. Исследована зависимость этих размеров от угла α между направлением ветра и бортом карьера. Показано, что максимальное расстояние от борта карьера, на котором концентрация пыли превышает предельно допустимые значения, составляет 3 км. Длительность воздействия в фиксированных точках над поверхностью не зависит от угла α и растет от нескольких минут на расстоянии 500 м от центра взрыва до десятка минут на расстоянии 3 км. Wind transport of an air-borne dust cloud in the atmospheric boundary layer in the neighborhood area of a surface mine is analyzed by numerical solution of the Navier-Stokes equations in their full form for a compressible liquid and in a subsonic flow approximation. The dust source is a large-scale blast at a total mass of ~ 100 g of TNT at a depth of 250 m in the pitwall rock mass. The calculations take into account a portion of dust raised above ground surface by blasting. The size of the surface areas of air-borne dust concentrations above maximal allowable values is estimated. The relationship of this size and the wind direction-pitwall angle α is analyzed. The maximal distance between the pitwall and the area of dust concentration above MAV is 3 km. The exposure duration at the fixed point on ground surface is independent of the angle α and ranges from a few minutes at a distance of 500 m from the blast center to a dozen minutes at a distance of 3 km.

Описывается численная модель для расчета взрывов ВВ в скважинах, которая предусматривает возможность превращения выброшенного из воронки взрыва вещества в дискретные частицы (пыль и камни) и расчета движения этих конденсированных частиц и их взаимодействия с газовым потоком в рамках уравнений движения многофазных сред. Приводятся результаты расчета нескольких взрывов ВВ массой 1000 кг в скважинах глубиной 15 м, демонстрирующие образование и эволюцию газопылевого облака, изменение со временем массы частиц разного размера в воздухе и их распределение по пространству. Проведен численный анализ поведения в поле ветра газопылевого облака после завершения его подъема, и получена в первом приближении зависимость поверхностной концентрации мелкодисперсных частиц от времени на расстояниях до нескольких километров от борта карьера. Согласно расчетам, в условиях рассмотренной задачи превышение предельно допустимой концентрации взвешенных частиц в атмосфере на расстояниях, превышающих 500 м от борта карьера по ветру, достигнуто не будет. A numerical model for calculating explosive detonation in boreholes is described. The model provides for the possibility of converting ejecta from the explosion crater into discrete particles (dust and stones) and calculating the motion of these condensed particles and their interaction with the gas flow within the framework of the equations of motion of multiphase media. The results of the calculation of 1000 kg TNT explosions in several boreholes 15 m deep are presented. These calculations demonstrate the formation and evolution of a gas and dust cloud, the change in the mass of particles of different sizes in the air with time, and their spatial distribution. A numerical analysis of the behavior of a gas and dust cloud in the wind field after completion of its rise was carried out, and the first approximation of dependence of the surface concentration of fine particles on time was obtained at distances up to several kilometers from the quarry wall. According to the calculations, the excess of the maximum permissible concentration of suspended particles in the atmosphere at downwind distances exceeding 500 m from the pit will not be achieved under the conditions of the considered problem.

Here, we present a numerical model for simulating the formation and evolution of the gas and dust cloud that forms after the detonation of high explosive charges in boreholes. This model provides a possible method for converting a substance ejected from an explosion funnel into discrete particles (smaller particles and stones) and calculating the movement of these condensed particles and their interaction with the air–gas flow; this method uses the framework of equations for multiphase media motion. For modeling of borehole explosion, we focused on the parameters of commercial blasting that are carried out at the Lebedinsky open pit. The results of simulating the initial stage of a borehole explosion with a mass of 1000 kg are presented in this paper. These results demonstrate the evolution of a gas and dust cloud, the change in the mass of particles of different sizes in the air over time, and their spatial distribution.

Gas and dust clouding after large-scale blasting at Sitovo Quarry in the Lipetsk Region and the resultant pollution of the neighborhoods of the nearest towns is studied. The concentrations of solid particles less than 2.5  $$\mu$$ m in size are determined in real time using modern equipment. The electronic filming of a large-scale blast and the dust cloud transfer with the wind within the limits of the quarry allowed considering a theoretical partial problem on propagation of fine-dispersion dust from the upper portion of the cloud from a height of 50–100 m to the recording points on ground surface beyond the quarry limits. The methods of computational fluid dynamics are used to model flow at the bottom of the atmospheric boundary layer disturbed by the wind interaction with the quarry topography. It is shown that turbulent diffusion ensures vertical dispersion of micro particles down to the recording points. An explanation is proposed for the revealed non-monotonic maximal concentration of dust over ground surface with an increasing distance from the quarry.

Abstract—Mass industrial explosions on extended benches of open pits are the most effective way to crush rock. Such explosions are accompanied by the rise of a gas and dust cloud. Three-dimensional numerical experiments are used to study the interaction of ascending gas and dust clouds generated by three, five, and multiple linearly arranged explosions in open pit mines. We examine both the initial stage of formation of a hot rarefied dust and gas cloud after the scattering of detonation products and the subsequent rise of thermals caused by buoyancy forces. We have obtained the dependences of the rise altitude and the size of the gas and dust clouds on the distance between adjacent explosions.

The emission of microparticles into the atmosphere during rock mass breaking by blasting in open-pits is one of the factors which determine the ground-level air pollution in the vicinity of the open-pits. The results of instrumental observations over the development of dust and gas clouds occurring from large-scale explosions at the limestone pit in Lipetsk region are presented. A numerical model has been developed to substantiate the function of the boundary layer for the fine dust reaching the monitoring stations.

Pollution of the atmosphere and territories adjacent to opencast mine by mineral particles during explosive breaking of rock mass is one of the factors affecting the environmental situation in the vicinity of quarries and reducing the transparency of the surface layer of the atmosphere. A significant effect of wind on particle transfer begins after the completion of the rise of a dust-gas cloud formed by an explosion on the surface of the earth. Numerical simulation was used to determine the characteristics of a dust cloud starting from the moment of formation of the fireball until the cloud reaches hydrostatic equilibrium. The numerical model was improved in order to calculate the dynamics of the dust cloud for charges with a mass of 1 to 1000 tons of TNT. The fireball parameters were set based on the data of theoretical and experimental studies. Based on numerical calculations, a qualitative and quantitative analysis of the dynamics of the dust-gas cloud for an explosion with a mass of 500 tons of TNT is carried out. The obtained relations allow one to determine the height of the upper edge and the radius of the cap of dust-gas clouds depending on the energy of the explosion with a mass of 1 to 1000 tons of TNT.

The article analyzes statistics on micro-solid emissions in mineral mining and discusses features of micro-emission in atmosphere in large-scale blasting in open pit mines. The gas-dynamic calculations of dust and gas cloud elevation after blasting for localization of solid micro particles and determination of their concentration in the troposphere are presented. The influence of large-scale blasting on regional seismicity is illustrated in terms of the Kuznetsk Coal Basin.

The emission of dust particles into the atmosphere during rock mass breaking by blasting in ore mining open-pits is one of the factors that determine the ground-level air pollution in the vicinity of pits. The data on dust concentration in the cloud, which is extremely difficult to obtain experimentally for large-scale explosions, is required to calculate the dust dispersion in the wind stream. We have elaborated a Eulerian model to simulate the initial stage of dust cloud formation and rising, and a Navier–Stokes model to simulate thermal rising and mixing with the ambient air. The first model is used to describe the dust cloud formation after a 500 t TNT (Trinitrotoluene equivalent) explosion. The second model based on the Large Eddy Simulation (LES) method is used to predict the height of cloud rising, its mass, and the evolution of dust particles size distribution for explosions of 1–1000 t TNT. It was found that the value of the turbulent eddy viscosity coefficient (Smagorinsky coefficient) depends on both the charge mass and the spatial resolution (grid cell size). The values of the Smagorinsky coefficient were found for charges with a mass of 1–1000 t using a specific grid.

One of the hypotheses of mass extinction at the Cretaceous–Paleogene boundary is associated with a sharp increase in the volcanic activity of the Large Igneous Province of Deccan due to the impact of a ten-kilometre asteroid near the Gulf of Mexico [1, 2]. A sudden increase in mantle effective permeability (MEP) initiated by seismic disturbances of the impact was considered in [2] as a cause of the increase in the flow rate of magma. We used an empirical method to estimate the density of seismic energy dissipated in the ground at various distances. The threshold of energy density for increasing the MEP and the energy density released in the province of Deccan after the Chicxulub impact have been revised using this method. It is shown that the threshold values of the energy density can be an order of magnitude higher. At the same time, the use of refined data on seismic efficiency and energy of the Chicxulub impact allows us to increase the density of dissipated energy in the province of Dean also by an order of magnitude. Thus, our analysis supports the idea that the Deccan volcanism could be accelerated by the Chicxulub impact occurred at a distance of about 13,000 km.

In this paper we present the results of numerical modeling of the Chelyabinsk dust train during the first 3 min after the meteoroid entry which are in qualitative agreement with observations. Then we analyze the possibility of plume formation after impacts of small cosmic bodies and make some calculations for the Tunguska event which, unfortunately, cannot be compared directly with observations. We also estimate long-lasting disturbances in the upper atmosphere caused by the plume formation.

The numerical analysis of the propagation of shock waves initiated by either a space body striking the Earth’s surface, or underground explosions, allows us to compare the energies required to attain the same amplitudes of shock waves at impacts and explosions. Proceeding from this and based on the data of seismic efficiency of underground explosions, the authors have estimated the fraction of the kinetic energy of a space body transformed into the energy of seismic disturbances when the body strikes the Earth. This fraction is about 10–3, which is an order of magnitude more than the most common estimates. Space bodies decelerating and collapsing in the atmosphere also generate seismic waves in the ground due to the impact of the air-shock wave on the Earth’s surface. In this case, the seismic efficiency is considerably lower, according to the calculations, it is about 10–5.

Numerical simulation of atmospheric disturbances during the first hours after the Chelyabinsk and Tunguska space body impacts has been carried out. The results of detailed calculations, including the stages of destruction, evaporation and deceleration of the cosmic body, the generation of atmospheric disturbances and their propagation over distances of thousands of kilometers, have been compared with the results of spherical explosions with energy equal to the kinetic energy of meteoroids. It has been shown that in the case of the Chelyabinsk meteorite, an explosive analogy provides acceptable dimensions of the perturbed region and the perturbation amplitude. With a more powerful Tunguska fall, the resulting atmospheric flow is very different from the explosive one; an atmospheric plume emerges that releases matter from the meteoric trace to an altitude of the order of a thousand kilometers.