2012 Wyoming Statutes
TITLE 30 - MINES AND MINERALS
CHAPTER 2 - MINING OPERATIONS
30-2-607. Only permissible explosives or blasting devices to be used; requirements as to use.

(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.