Historical studies show air-deck volumes of 10% - 15% can be realized without any major reduction in fragmentation. These studies used air bags for stemming support, which save explosives but do not improve fragmentation. Air-Decking with VARISTEM® achieves up to a 27% fragmentation improvement while also saving on explosives.
The VARISTEM also enables consistent stemming heights when using gas emulsions. Simply reduce the emulsion volume allowing for maximum expansion. Set the Varistem in an air-desk so that stemming heights are consistent in all drill holes. This will eliminate short stemming heights and blow-outs.
Air-Decking with the VARISTEM allows shorter stemming heights, while also reducing ANFO height, to dramatically minimize over-sized cap rock from a common 10% oversized, down to a 2% oversized. Fly Rock and stemming ejection is controlled.
The cost-savings potential of the VARISTEM is clear. The VARISTEM is very low-cost, and will pay for itself many times over.
Please Contact Us for more information about air-decking, and recommendations on how this technique may be applied in your particular situation.