STEEP MINERAL DEPOSIT DEVELOPMENT METHOD Russian patent published in 2006 - IPC E21C41/00 E21C41/26 

FIELD: mining, particularly methods of underground or surface mining.

SUBSTANCE: method involves excavating deposit up to design depth by opened method; cutting ore located under pit bottom in top-down direction by opencast-underground mining method, which is changed for underground-opencast mining method with opened excavated space and with ore movement via ore pass located in deposit center. During opencast-underground mining ore is developed within the limits of rock contour and then ore is cut along with forming platforms and faces having angles of inclination of not more than extreme ore shifting angles. During underground-opencast mining radial blind drifts are created in prepared sublevels and blind drifts are connected with working horizons by cross headings. Ore is cut from the blind drifts by blasting thereof so that inclined platforms for ore delivery to ore pass are created. Angles α of platform inclinations obey the following condition: φ≤α≤γ, where φ is angle of natural rock debris slope, γ is maximal angle of ore face shifting.

EFFECT: possibility to cut ore deposit located below design pit bottom mark up to lower level of explored reserves and increased working safety.

2 cl, 2 dwg