Yakutniproalmaz Institute, ALROSA Co. (Yakutsk, Russia):

Kul’minsky A. S., Deputy Chief Engineer on Mining, e-mail: KulmiskyAS@alrosa.ru
Tishkov M. V., Senior Researcher, Candidate of Engineering Sciences

Currently, deep reserves of Internatsionalnaya kimberlite pipe are extracted using downward multislice room-and-pillar method with solidifying backfilling. Structural elements of the mining method are stope drifts, crossdrifts and stoping bands. The mechanized stoping uses selective heading machine with swept executive element equipped with cutting head. Due to design features of the executive element, ore is irretrievably lost at the roof and floor of every cut and production layer, since rectangular cross-sections of roadways have rounded corners, so called “baseshoes,” where ore loss reaches 4 thousand tonnes a year, which is 1% of the annual mine output. Aimed at the ore loss minimization, special mechanical device has been designed—side cutter that is mounted and bolted on the both sides of executive element of heading machine. The additional cutters are employed directly at each stage of preparing a mined-out stope for backfilling with sand and concrete solidifying mixture. Mounting of the cutters is done by the heading machine operator and a mechanic within 30 min. Overall labor intensity of assembly of the additional cutters (twice a month) is 24 man hours per year. With the mounted cutters, the ore mining technology has been improved and the permanent ore loss has been reduced by 70% (2800 t/yr) in the Internatsionalny Mine.