METHOD FOR OPENCAST MINING OF SOLID ORES AND MINERALS

摘要

By the method, costs of blast materials are reduced and facilities are created for optimum energy saturation of the rock massif thus avoiding the inclusion of sterile zones in the contour of the field of blasting. By the method, the contour of the field of blasting is determined and it is divided in at least two sectors of blasting (2 & 10), each of which contains at least one blast-hole line (4 & 11). The positioning of the blast holes in the lines is made in such a way that the distance between the front (11) and rear (12) drilled line is 1,31 times greater than the distance a1 between the border contour (3) and the curvilinear blast-hole line (4). After the blast-holes are determined, they are drilled at a slope of 75° from the horizontal line. Their factual parameters are measured, the quantity of blast materials is calculated, the blast-holes are charged with the explosive and a tamping is placed. In the direction from the end to the interior of the field of blasting, first of all the blast-holes of the curvilinear sector (2) are blasted by different time feeding the blast pulse to the charges, and then - the blast-holes positioned at least in one drilling line from the rectalinear sector(10).