The designs of submersible hammers and dampers protected by patents for reducing the vibration of the drilling rig of roller drill machines are proposed. The variants of modernizing drilling rigs for drilling hard rocks and faces of complex structures are considered. Particular attention is paid to the joint work of submersible shockers and pneumatic shock absorbers, the preferred schemes for the arrangement of these devices by drilling rigs are indicated. The results of experimental tests of machines with pneumatic hammers are presented to determine the vibration performance and drilling speeds. The pneumatic hammer allows increasing the speed of drilling process to the intensification of the destruction of the plain face by the shock load and the cleavage of the protrusions of the unevenness of the face, the better fitting of the bit to the face and the release of the blades or the bit pins from the drill bit. The choice of a particular type of damper or shock absorber depends on its design scheme and the possibility of changing the design of the drill string. With the complexity of installing a damping device in the mast (with significant dimensions of shock absorbers and drilling of strong heterogeneous rocks), it is advisable to use a set of tools to reduce hydraulic pulsations in the mains and cylinders of the hydraulic system by installing chokes in the oil plants and pneumatic shock absorbers. It is proposed to use the device for the development of pneumatic hammers by a patent-pending drilling method with a hollow piston filled with magnetically active heavy liquid, which will allow controlling the frequency and size of the shock pulses and partially compensating for the drill string fluctuations arising from the uneven immersion of the bit in the array. It is noted that the proposed solutions increase the drilling speed by an average of 15%.

The results of experiments on determination of the cylindrical part mass loss of the cone-shaped strikers made of 38XM (AISI P20), У8 (AISI W1-A), and X12MФA (AISI D2) steels, which have been subjected to heat treatment applied by the striking tools manufacturers, and additional cold treatment, with their friction and abrasive wear on granite, are presented. It was found that the strikers made of steel X12MФA with all types of heat treatment show the greatest wear resistance under the wear conditions (static conditions), while the strikers made of 38XM have the lowest wear resistance. Cryogenic treatment and, to a lesser extent, cold treatment increase the wear resistance of all materials. The comparison of set values of wear resistance Ist and hardness HV of the strikers, as well as the analysis of their microstructure allows to conclude that wear resistance of a tool depends not only on its hardness, but also on the type, volume, shape of carbides forming the structure of material used for tool manufacturing. For this reason, after the cryogenic treatment, the tool made of X12MФA steel shows the greatest wear resistance, because its material has the highest content of carbon (~1.5%) and alloying elements (~13%), which provides up to 10.8% increase in the number of fine carbide particles in its structure, that ensure wear resistance increase, after the cold treatment. The results obtained for Ist are compared with the earlier obtained data on wear resistance of the same striker at striking upon granite (in dynamic conditions). The conclusion about similarity of the wear mechanisms of the analyzed strikers in dynamic and static conditions is made.

The article describes the current situation in the global uranium concentrate market, explains the reasons for the formation of an excess amount of finished goods and the subsequent decreasein prices. The authorsevaluated the prospects of using market mechanisms to improve the financial results of Russian uranium mining enterprises. The location of the main mining centers in comparison with the centers of consumption of finished goods, pricing for the products of uranium mining companies, the dynamics of price changes over the past 20 years, the influence of non-market factors on the supply of finished products are analyzed.This study led to the conclusion that the expectation of changes in the market situation is not viable in a long term. The authors outlined the direction to improve the profitability of mining enterprises by introducing technological changes aimed at reducing the cost of the final product.