Selective underground mining of complex structured ore bodies of Kryvyi Rih Iron Ore Basin

Selective mining of complex structured ore bodies will enable
increased iron content in the mined ore mass in underground mining at
Kryvyi Rih iron ore basin applying the existing mining systems. The
article determines the way the grade changes in a mine block of a complex
structured ore body when applying bulk and selective mining as well as
factors influencing indices of extracting ore mass from the block. The
investigation results prove that it is reasonable to mine complex structured
ore deposits with barren inclusions applying selective mining if the iron
content in the block varies from 64 to 67% and horizontal thickness of the
barren inclusion makes 4 – 12 m. At that, the thickness ratio should not
exceed 0.3. Stoping methods should be applied to receive high indices of
ore mass extraction. There is determined an ore/barren inclusion-to-ore
body thickness ratio considering the dilution factor that confirms
practicability of selective mining of complex structured ore bodies.
Selective mining of complex structured ore deposits of Kryvyi Rih iron ore
basin applying open stoping enables increasing the mined ore mass quality
without considerable capital and operating costs and, consequently, staying
on the market and enhancing the environmental situation in the region.