Alternative mining pilot tests in narrow veins: The Company is currently carrying out pilot testing of mining methods for narrow veins, using the
sublevel stoping and conventional mining cut and fill methods, in order to determine the optimal mining method for these types of structures.
AMEC believes the preferred concept for mining the Blue River Deposit is by underground methods using variations of
sublevel stoping under a conceptual scenario that considers mining and processing at a rate of 7,500 tonnes per day.
The Kvannevann iron oxide mine in Northern Norway is currently using
sublevel stoping system (SLS) to extract the hematite / magnetite ore.
After modifying the mining sequence at Turmalina, while maintaining the
sublevel stoping mining method, dilution has diminished significantly and run-of-mine grades are in-line with the mine plan.
Chanda and Katongal note that with VCR, "improvements in grade factors, recoveries and control of dilution are clearly evident compared to conventional
sublevel stoping previously employed.
Sublevel stoping was reviewed by E Villaescusa, [28] considering the factors controlling stope wall behaviour such as excavation geometry, rockmass strength, induced stress, ground support, blast damage and drill drive layout.
Other mining method names are merely variations or closer definition of others (
Sublevel Stoping is typically Blasthole carried out with more than one drill drift per level interval and Sublevel Retreat simply defines the direction of the mining).