OJSC «Uralmekhanobr», Yekaterinburg, Russia:

A. V. Kotenkov, Deputy Head of Mining Science Department, gpgr@umbr.ru

The parameters of the stoping space formation are considered in terms of the Ural copper–sulphide ore mining based on the analysis of survey data from 130 mined-out stopes. The ways of increasing stability of the stoping elements are optimized angles of inclination of sidewalls and shapes of minedout stopes. The principle of staggered arrangement of stopes, which allows enlarging mined-out area in stopes in weak ore, is justified. The optimal structure is selected for the stoping system to enhance its efficient and output. The experience of excavating soft ore by diamond-shaped stopes arranged in staggered order, with subsequent backfill at the Aikhal kimberlite deposit is presented. It is revealed that the most difficult stage of transition from slicing to cut & fill stoping is extraction of ore in the zone of transition from trapezoid to diamond-shaped stopes. It is necessary to carry out the fullest possible backfill of these stopes to minimize ore dilution by backfill material. Extraction of ore reserves beneath the transition zone meets no difficulties; the diamond-shaped mined-out area is formed in stopes. It is found that diamond-shaped stopes retain their stability for the entire period of stoping and backfilling. Extraction of kimberlite ore can be carried out effectively and safely by diamond-shaped stopes with calculated parameters. Rocks from drivage are entirely placed at the top of the mined-out diamond-shaped stopes during their backfill (discharge to ground surface is ceased).

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