Field Studies

STUDY 1 by MREL

MREL (Mining Resource Engineering Ltd) tested stemming movement and ejection velocity. The longer time to stemming movement and the lower stemming ejection velocity means more blast energy is retained in the bore hole. Energy is directed into the rock, and not lost into the air. There is better fragmentation, less flyrock, and a reduction in noise. Using VARI-STEM® with standard rock stemming, stemming movement was slowed 100% and stemming ejection velocity was reduced 44%.

STUDY 2 by DBA CONSULTING

DBA (Douglas Bartley) Consulting extended the MREL tests to provide quantifiable data on VARI-STEM® performance in Increasing Rock Fragmentation, Improving Crusher Throughput and Blast Control.

The study revealed our plugs slowed stemming movement 130% directing the blast energy into the rock, not up the bore hole. The plugs also decreased the mean average rock size in the post blast muck pile by 27%, which resulted in a 3% (25 - tons/hour) increase of limestone through the primary crusher. (Please note, these performance improvements were achieved even after the quarry switched over to an electronic initiation system to eliminate timing inaccuracy.)

DBA did a computer analysis of "every truckload" of rock taken to the primary crusher. This was a 100% muck pile study, and did not rely on carefully selected, biased photos of a muck pile. It is also more reliable than "eye balling" the surface of the muck pile.

The DBA Study confirmed our VARI-STEM® Plugs effectively contained expanding gases approximately 3 times longer than bore holes stemmed with crushed stone only.

View the complete DBA study showing Blast Data and Timed Photos.

STUDY 3 Stemming Performance Study

DBA Consulting conducted this study to quantify the effectiveness of VARI-STEM® using Different Types of Top Stemming Material.

The primary result of the test was that VARI-STEM plugged holes all yielded retention times at least 2 times longer than non-plugged holes. The average retention time for crushed stone stemmed (non-plugged) holes was 39 ms, for VARI-STEM with crushed stone 120 ms, and for VARI-STEM with sand drill cuttings (fines) 145 ms. This test indicates our plugs with sand drill cuttings out performed crushed stone stemming alone. (Because these results may be a site-specific occurrence, MOCAP hopes to expand upon this study with further testing in the future.)

Just think of the potential cost savings! Quarries, contractors and blasters could potentially eliminate, or at least reduce, the volume and expense of crushed stone stemming, allowing them to use less expensive drill cuttings for stemming.

View the complete Stemming Performance study showing Timed Photos and a Photo of the Resulting Energy Trough.