”Rock Poppers” are 12-13mm diameter cartridges, drilled with an electric combi-hammer drill, using 14-16mm diameter drill bits about 400mm long. A useful application for this combination, which is light and allows access into tight areas such as crusher jaws. Oversize stuck in the crusher jaws is a costly hold-up, easily solved in situ by a trained operator an electric drill and Nonex rock poppers, which are kept on site for that express purpose.

Mining in Environmentally Sensitive Areas

Drilling & Blasting with conventional explosives in open cast mines and quarries is a global standard. It is cost effective, because large diameter holes are drilled to depths of 10-20 metres; the pit is cleared of plant and personnel, the bench fired. The blasted rock is then recovered by load and haul and delivered to the tip.

The recurring events are shockwave caused by detonation, vibrations which are transmitted through rock, air blast overpressure with loud noise, and impressive fly rock. All these recurring events are unacceptable in environmentally sensitive areas. Villages tend to spring up close to the mine’s working area, roads service the villages. Houses, swimming pools and most installations are subject to damage caused by transmitted vibrations. Social pressure results in new regulations requiring new, more expensive mining methodologies.

Shockwave and Vibrations

Global studies on the effect of vibrations on adjacent structures are naturally based upon conventional detonating explosives. Fundamentally detonation (commonly known as an ‘explosion’) breaks rock ‘on compression’, the rock is crushed. Nonex technology (expanding gasses confined in a drill hole by stemming) breaks rock ‘on tensile’, which is like breaking a stick by bending it over one’s knee. It requires a lot more energy to break rock on compression than to break on tensile. These studies on vibrations are based upon the effects produced by conventional explosives and measured using vibration monitors, expressed in PPV’s (velocity in mm’s/sec) and frequencies (Hz). These vibration monitors indicate that a Nonex initiation produces far lower PPV’s at a given distance than explosives at a significantly higher frequency. Scientists have correlated events created by explosives and damage caused to adjacent structures at given distances, and published these tables. Previously, Nxco engineers tried to extrapolate Nonex results from these ‘explosive’ based tables.

Working with vibration monitors, Nonex contractors clearly established that a Nonex initiation has little if any impact on adjacent structures, that the PPV’s which are registered and at above 40Hz frequency are not damaging. What is registered is the rock breaking on tensile. The only potential damage which seems possible is when the rock underneath the structure breaks on tensile, the resulting movement will impact upon the other. (for example, a wall built without a foundation directly onto a rock which is then broken using Nonex). Non-explosive technology is relatively new, occupies a niche market, which has not yet been thoroughly researched by scientists. What we say is based upon experience contracting with Nonex and using vibration monitors. It is a valid conclusion that extrapolations based upon ‘explosive’ tables are invalid and negatively so for non-explosive technology.

Rock Excavation in Urban Areas

Regulations and restrictions pertaining to the application of conventional explosives are becoming more stringent worldwide. In built-up areas, damage to property caused by shock wave and vibrations imposes the high cost of house by house surveys to establish before and after condition of the houses and swimming pools. The risk of terrorist activity, ATM bombings using stolen explosives imposes added restrictions on transport and storage. These factors are creating unprecedented demand for Nonex technology .

Regulatory Acceptance

It is right and proper that municipal and consulting engineer authorities should do due diligence on permitting the application of non-explosive rock breaking cartridges in sensitive built-up areas. However, it is unnecessary for every authority to arbitrarily reinvent the proverbial wheel. Nxco Mining Technologies designed, developed and had all the relevant UN tests done, conform today with all international standards, which are available for scrutiny and verification. The product is rated UN 1,4S for dangerous goods, the same as for small arms ammunition and fireworks.

It is approved by most airlines for transportation globally in passenger aircraft, which means the airlines have already done their due diligence. Nonex cartridge technology is inherently safe, uses propellant which produces high volumes of expanding gas when initiated electrically, so when confined in a snug-fitting drill hole and stemmed effectively, the build-up of pressure breaks the rock or concrete on tensile. When the rock is breached to atmosphere the process ceases as the energy dissipates.. The technology only produces power when confined, so initiation in the open does no harm

Public Reaction

It is understandable that the general public are nervous about conventional explosives; it makes loud bangs, rock and/or shrapnel and glass fly with lethal consequences, car bombs are horrendous events, shock waves and vibrations damage structures including home and swimming pool. Unscrupulous homeowners blame all structural damage like cracks on ‘blasting’, so all-told it is a messy business.

The application of non-explosive technology overcomes all these nasty symptoms associated with violent reactions, shock wave, air blast, and dangerous vibrations. Experienced contractors additionally use effective covering methodology, cover with conveyor belt mats and up to two meters of earth cover on top. Initiation produces a low rumble and a heave in the earth cover as some rock particles penetrate to the surface. Subdued noise and strict fly rock control eliminates the perception and emotional response to loud noise and shocks.

The technology is of no value to terrorists and ATM bombers simply because it is ineffective .unless used as designed. The perpetrators understand this too.

Vibration monitors, appropriately placed, provide an objective record of what shocks, noise level and vibrations were activated by the Nonex initiation, which block unscrupulous household claims.