
MOCAP
Deutschland Ltd.
Eisenstr. 4
44145 Dortmund
Deutschland
Email
Fon: 0231 4461693
Fax: 0231 4461694
Freefon: 0800 6622733
(aus Deutschland)
Internationale Anrufe:
0049 231 4461693
Skype:
MOCAP.Germany
Patent # 5,936,187
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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%.
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NO PLUG
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COMPETITIVE PLUG
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VARI-STEM® PLUG
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ANFO* Velocity of Detonation
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12,000 ft/sec
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11,983 ft/sec
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12,020 ft/sec
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Time To Stemming Movement
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2.3 msec
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3.0 msec
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5.3 msec
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Stemming Velocity
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1,580 ft/sec
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1,300 ft/sec
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920 ft/sec
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*Similar "ANFO Velocity of Detonation"
shows equal ANFO explosive force occurred in all tests
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.
Stemming Performance Study Video [High Bandwidth Connection]
Stemming Performance Study Video [Low Bandwidth Connection]
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