METHOD FOR OPENCAST STEEP DEPOSIT MINING Russian patent published in 2007 - IPC E21C41/26 

FIELD: mining, particularly opencast mining of mineral deposits in the case of limited vertical ore bodies, for instance kimberlite pipes.

SUBSTANCE: method involves forming pit sides having inclinations less than minimal possible ones to provide pit side stability; preparing rock for further excavation by drilling-and-blasting operations; transporting ore and overburden via main incline by wheeled vehicle; forming transfer point plate at the second stage; excavating up to design depth along with forming pit sides having maximal possible inclinations, which provide pit side stability; cutting main incline from transfer point plate, wherein inclination thereof is increased in longitudinal direction; cutting ore pillars of the first stage; forming pit side having high ledges; forming lower ledge along ore body outline; forming temporary incline in one pit part; transporting ore and overburden to transfer point plate by means of caterpillar vehicle; forming temporary incline to provide pit cutting to design depth and cutting ore pillars under temporary incline.

EFFECT: increased efficiency of deposit excavation due to reduced overburden volume within the bounds of deep limited pits.

3 cl, 1 ex, 1 tbl, 4 dwg