Changes in the qualitative characteristics of the ice shell of soil-ice bodies in water

Relevance. The Arctic zone of the Russian Federation and its shelf areas are promising sources for replenishing and increasing the country mineral resource base. Known technologies for the development of underwater deposits of solid minerals are currently not widely used in the development of reserves located in the Arctic waters. The authors propose a mining technology, which is based on: a natural phenomenon in the form of ice bodies formed in the seas and lakes located in different points of the Earth; and the difference in the density of water in its liquid and solid aggregate states. The essence of the technology consists in the fact that air with negative temperature is supplied to the underwater face, due to which favourable conditions are created for initiation of water crystallisation around mineral particles, and, consequently, for formation of soil-ice bodies with negative hydraulic size, transporting these particles from the bottom to the water surface. As an advantage over already known technologies, the paper highlights the possibility of excluding from the transport process the soil intake devices characterised by high energy costs or reducing the depth of their operation. Aim. To investigate changes in the qualitative characteristics of the ice shell of the soil-ice body in dynamics, taking into account the impact of the surrounding water temperature. The results obtained will be used for scientific substantiation of parameters and conditions of application of the proposed technology in the northern seas. Methods. Laboratory modelling methods of soil-ice body surfacing processes at different sea water temperatures typical for northern waters. Samples of soil-ice bodies of different masses were used for the experiment; their weight changes were observed during the whole process to determine the impact of temperature conditions on the dynamics of changes in their physical and mechanical properties. Results. The authors have developed a mathematical model describing the specific melting rate of the ice component of soil-ice bodies on the basis of experimental data. Conclusions. The developed mathematical model is necessary for forecasting the speed and duration of soil-ice bodies surfacing under different water area temperature conditions, which in its turn allows expanding the understanding of the efficiency of the proposed technology application in those or other climatic, hydraulic and geological conditions. This makes it possible to assess the competitiveness and practicality of the proposed technology in specific conditions.