2010-05-07_PERMIT FILE - C2006085 ‎(2)‎

• Permit No: C2006085
• IBM Index Class Name: Permit File
• Doc Date: 5/7/2010
• Section_Exhibit Name: 2.05 Operation and Reclamation Plans
• Media Type: D
• Archive: No

. Development of the coal reserve, starting from the slope and
ventilation shaft sites, will proceed by mining a set of main entries to
the west and concurrent mining of submain entries towards the
mineable limits of the seam. Main and submain entries will provide
long -term access to all areas of the mine, and will be designed and
maintained for their purpose. A typical plan for the design of mains
and submains is illustrated by Figure 2.05.3 -1, Main and Submain
Entry Development. The multiple entry systems depicted on the plan
show the function of individual entries for intake and return airways,
and an entry for coal haulage by conveyor systems. The described
development mining leaves support pillars in place designed to
effectively support the mine openings according to depth of cover and
strength of the coal and the immediate roof and floor strata. The
actual number of entries will vary depending primarily on the area
required to provide sufficient airflow for mine operations.
Mining panels will be developed off the submains, consisting of a set of
five or six entries, to either the limit of mineable coal or the boundary
of adjacent sub -main entries. Panels will access the majority of coal
reserves,- and _will _serve to extract the reserves by retreat mining
methods. The panels will be designed to provide for relatively short-
term access into the mining area and to optimize the recovery of coal
within the boundaries of the panel. Typical plans for development and
pillaring of a panel are shown on Figure 2.05.3 -2, Panel Development
and Retreat Mining. Once a given panel is developed to its designed
limit, additional rows of pillars (rooms) are developed to the side of the
panel to access adjacent reserves from the developed panel.
Generally, only two or three rooms are developed at one time ahead of
a similar number of rows of pillars that are retreat mined. Northfield
will conduct retreat mining by systematically mining as much coal as
safely possible from the pillars, thereby recovering approximately 40
to 50 percent of the coal remaining in support pillars while pillaring the
mine panel. Pillaring will continue through the length of the panel and
stop at a designed location near the entrance to the panel. At this
point, the pillars at the mouth of the panel and adjacent barrier pillars
will be left unmined in order to protect the adjacent main or submain
entries from the increased ground pressure created by the removal of
the panel pillars. Long narrow pillars and relatively large blocks of coal
called barrier pillars will be left unmined in areas such as between
panels, between panels and submains, and in areas where subsidence
control is required. The proposed development and retreat mining
methods will extract approximately 60 percent of the overall in -place
0 coal reserves.
2.05.3 -3 Revised 12/04/09, TR -01