METHOD FOR OPEN PIT MINERAL MINING Russian patent published in 2006 - IPC E21C41/26 

FIELD: mining, particularly to develop steep and inclined ore bodies.

SUBSTANCE: method involves separating stages and dividing open-pit field into penetration and production horizons; excavating ore and removing capping by bench movement; employing temporarily inactive wall parts; constructing descents and haulage benches, conveying semi-trenches; delivering ore and cut capping to day surface; dividing capping rock in transversal section in hanging and laying wall into inclined layers, wherein angle of temporary inactive wall slope parts of layers to be excavated is different in upper, central and lower zones and the angle is increased in dependence of different speed of horizontal and vertical bench movement in upper and lower horizons; forming temporary (intermediate) dumps, permanent and additional in deposit sides; conveying rock along the descents directed towards the second and the third excavation stage pit contour with the use of cyclic vehicle means and then with the use of continuously acting vehicles, wherein trenches with conveyers are directed so that conveyor lifting means may be extended or cascade system may be created if ore body thickness varies or ore body inclination angle changes. Conveyer lifting means are formed in ore production zone when cyclic acting means reach extreme transportation level, which puts the system out of optimal operation area. Conveyer lifting means path is selected to elongate the conveyer lifting means or to provide their operation along with vertical lifting means to deliver ore to transfer point on day surface. The last lifting means is constructed at high depth so that composite transport level does not project outwards optimal system operation area. At final pit development stage design wall angles are adjusted, the last layers are cut and the wall angle magnitudes are brought to extreme stability-varied final magnitudes.

EFFECT: increased efficiency of capping and ore extraction, reduced current stripping ratio, decreased stripping volume in sides during sloping thereof under steep angles and increased operational safety.

6 dwg, 1 ex