Vein VN_10 is one of the main targeted veins in the current infill drill program and is exposed in a new development drift
in the lowest section of the North Ramp.
Stope areas 3 and 4 are located along the eastern half of the development drift
, with cumulative assay results for both stope drifts as follows:
The company has established a 166 feet development drift
that will serve as the main haulage for future mining activities at the Mineral Hill Gold Mine.
The majority of the drilling will be conducted from sites on the hanging-wall development drift
at the 1,270-m level and from the footwall ramp below the 1,150-m level.
"We have a huge development drift
in the very bottom of the mine on the main decline drift and at the brow of that drift there is water coming out that just runs down the ramp.
The test drive on five level commenced in May this year: the MM130 is excavating a development drift
some 300 m long on the straight and level and will then drive a curve with a 20 m centreline radius and finally an 8|degrees~ decline.
Most of McArthur River's pumping capacity is located 530 meters below the surface, just below the development drift
, where the water entered the mine.
This allowed the mining of a partial parallel development drift
which could be varied in width to follow exactly the limits of the hanging wall The initial drift was supported with a line of timbers.
Hecla will spend about $6.6 million to drive 6,500 ft of decline and development drift
into the Golden Promise mine.
Based on operational experience an optimum airflow is considered to be 1.5-3.0 m/s in working stoppings and 0.4-0.6 m/s in development drifts
. In the main ventilation drifts, airflow should not exceed 6-8 m/s .
"For RMR's from about 35-60 (Fair Rock) most characteristic of rock surrounding the ore and in development drifts
, shotcrete can be thought of as acting as an arch," the report stated.
Each of them is organized with parallel development drifts
, following the dip of the gypsum beds, from which the exploitation drifts reach out with a steady angle, following the strike of gypsum strata (Fornaro et al.