Method of placer mining by directional well drilling

The study aims at justifying the method for the development of placers by directed drilling of wells. A description is given of the opening of the site, the receding and oncoming scheme of the digging excavation, drilling and expansion of the wells, the main hydraulic unit with remote control. The physics-mechanical substantiation of technological parameters is given: hydro-jet erosion, the shape and size of the cleaning chambers, the adaptation of hydrotransport calculation methods. With jetting, the required flow rate and pressure of water to break rocks is based on the laws of soil mechanics. The parameters of the clearing space and the shape of the chambers are taken in accordance with the magnitude of the vault of natural equilibrium. As a determining factor in the calculation of gravity hydrotransport, the consistency of the pulp is adopted with observance of the condition necessary for the bearing capacity. To adapt the methodology for calculating the hydraulic lifting of pulp to the conditions of well development, the coefficient of dilution is taken as the main design parameter. Modeling of jetting jet in the laboratory conditions was carried out, dependences of decrease in axial pressure were obtained at removal of the face from the nozzle