The RockLock stemming plug creates energy confinement and reduces stemming ejection to offer more reliable blasting results. By improving confinement, it improves fragmentation, enables explosives to be loaded higher in the borehole in cap-rock applications and greatly reduces fly rock occurrences for a higher degree of safety. Offering reliable blast performance, the device also reduces air overpressures and delivers more predictable results in decking applications.
Constructed of high tensile strength pliable plastic, the spherical stemming plugs require no accessories, such as loading poles, for use in the field. The sphere is partially filled with stemming material and dropped into the borehole. Upon blast detonation, the pliable RockLock flexes to create a frictional gas-permeable seal that prevents stemming ejection. Its design absorbs and equalizes the pressure field across the borehole.
They are available in a range of diameters from 1.5 to 9.25 inches. To choose the right RockLock for the application, blast technicians select a stemming plug size that is 90% the borehole diameter. For optimum results, the hole is filled with stemming material to a depth of 1.5 times the borehole diameter prior to placement of the partially filled RockLock. The hole is then completely filled with stemming material.
The device is field-proven to better contain the explosive gasses generated by a production blast. For pennies per ton, the stemming plug more effectively improves blast performance, muckpile uniformity and overall operational safety than by using stemming material alone.