Abstract

In the process of extraction of the piece stone and in the destruction of concrete and brick buildings in dense urban areas, the issue of safety and efficiency of work is very important. For reducing the percussive action during blasting operations, various methods and means are used. Currently, when extracting block stone, the substances are used that can create pressure in the hole due to the combustion reaction in the deflagration mode. The article is devoted to the research and development of gas-generating compositions based on the sodium nitrate to improve safety during the destruction of artificial objects. Sodium nitrate was chosen as an oxidizer, this is primarily due to the low cost of sodium nitrate, low sensitivity to mechanical and detonation effects, and a significantly lower content of harmful compounds in the combustion products compared to analogues. Magnesium and carbon (from a gas mask and walnut) were used as fuel. Tests for the flammability of mixtures and thermodynamic calculations of combustion parameters were carried out to determine the optimal ratio of the initial components. It was established that a sufficiently high efficiency and uniformity of combustion are observed at a ratio of the initial components of 60 % — NaNO3, 20 % — Mg, 20 % — C. X-ray phase analysis of solid combustion products was carried out. It is shown that the main products are magnesium oxide and sodium carbonate. Field experiments on the destruction of concrete blocks were carried out. The performed studies and field tests showed high efficiency and safety of the use of the developed gas generator composition for the destruction of artificial objects, which can be used for the directed destruction of artificial objects or rocks of medium strength with a coefficient of 8 on the scale of the professor MM. Protodyakonov. The destruction of the concrete block occurred without the scattering of individual stone fragments, the formation and propagation of a shock air wave.

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