§ 30-2-607 — Only permissible explosives or blasting devices to be used; requirements as to use

Wyoming § 30-2-607

• Jurisdiction: Wyoming
• Title 30: Mines and Minerals
• Ch. 2: MINING OPERATIONS
• Art. 6: EXPLOSIVES AND FLAMMABLES

Text

(a) Only permissible explosives or permissible blasting
devices shall be used in all underground coal mines for the
blasting of coal or other blasting operations, except as
otherwise provided by law.
(b) The use of permissible explosives shall comply with
the following:
(i) Fired only with electric detonators of proper
strength;
(ii) Fired with permissible blasting units unless
blasting is done from the surface;
(iii) Boreholes in coal shall not be drilled beyond
the back of the cut, nor into the solid rib, roof or floor;
(iv) Boreholes shall be cleaned and checked to see
that they are placed properly and are of correct depth, in
relation to the cut, before being charged;
(v) To prevent blow-throughs, all portions of the
boreholes where the height of the coal permits, shall have a
burden in all directions of at least eighteen (18) inches before
being fired;
(vi) Boreholes shall be stemmed to the collar with
incombustible material;
(vii) In gassy mines examinations for gas shall be
made immediately before and as soon as practicable after
blasting.
(c) Charges exceeding one and one-half (1 1/2) pounds, but
not exceeding three (3) pounds, shall be used only if boreholes
are six (6) feet or more in depth, and explosives are charged in
a continuous train, with no cartridges deliberately deformed or
crushed, with all cartridges in contact with each other, and
with the end cartridges touching the back of the hole and the
stemming respectively, and Class A or Class B permissible
explosives are used, provided that the three (3) pound limit
shall not apply to solid rock work such as solid rock tunnels,
shafts, etc.
(d) Boreholes shall not be charged while any other work is
being done at the face. A shot shall be fired before any other
work is done, except work necessary to safeguard the employees.
(e) Only wooden tamping bars shall be used when charging
holes.
(f) Leg wires of electric detonators shall be kept shunted
or the ends twisted together until ready to connect to the
firing cable.
(g) Shots shall not be fired from the power or signal
circuit.
(h) Roof and faces of working places shall be tested
immediately before and after blasting.
(j) Ample warning shall be given before shots are fired,
and care shall be taken to ascertain that all persons are in the
clear. Men shall be removed from adjoining working places when
there is danger of a shot blowing through.
(k) Mixed charges shall not be charged or fired in any
borehole.
(m) Adobe (mudcap) or other open, unconfined shots shall
not be fired in any mine.
(n) Blasting cables shall be well insulated, staggered as
to length or kept well separated when attached to the detonator
leg wires, and kept clear of power wires and other possible
sources of stray currents.
(o) Power wires in face regions shall be deenergized
during charging and blasting operations.
(p) Where misfires occur with electric detonators, a
waiting period of at least five (5) minutes shall elapse before
anyone returns to the shot. After such failure, the blasting
cable shall be disconnected from the source of power and the
battery end short-circuited before electric connections are
examined.
(q) Explosives shall be removed by firing a separate
charge at least two (2) feet away from, and parallel to, the
misfired charge or by washing the stemming and the charge from
the borehole with water, or by inserting and firing a new primer
after the stemming has been washed out.