QUARRY BLASTING

Varistem® stemming plugs are the ultimate blaster’s tool in terms of its versatility and ability to be applied towards specific environmental and/or productivity goals.
The core principle behind Varistem® technology is the ability to contain the blast shockwave better and longer, resulting in more of the chemical energy from blasting going into the rock mass and less energy escaping into the surrounding environment.

Generally speaking, quarries worldwide use the Varistem® stemming plugs to improve fragmentation and mitigate and reduce common blast-related environmental factors like flyrock, noise, airblast/overpressure, and vibration.

The most common blast-induced productivity-related problems quarries face are poor fragmentation, production of oversized boulders, and poor particle size distribution (e.g., excessive fines). In many cases, oversize originates from the stemming/capping layer.

Varistem® addresses this problem by improving energy retention and, in doing so, energy distribution throughout the blast bench.

The most common blast-induced environmental-related problems that quarries face are excessive noise, vibration and airblast/overpressure levels. Varistem® has a proven track record of significantly reducing noise and airblast/overpressure levels, allowing quarries to remain legally compliant while still enjoying productivity improvements.

SEE HOW VARISTEM® HAS HELPED QUARRIES

80% Reduction in flyrock distance

Varistem helped a coal mine minimise fyrock, noise and airblast, leading to improved retention of blast energy.

87% Improvement in cast

A coal mine saw a vast refinement in cast gain in a split blast test, showing Varistem's effectiveness.

14%+ Crusher throughput

Varistem plugs improved fragmentation, loading, haul cycle times, and crusher throughput.

+$10M per year in value

A manganese mine saw huge gains in both lumpy and low grade manganese, from Varistem.

$1.45M savings p/a

An iron ore mine saw a reduction in waste blasts by using Varistem, saving millions each year.

8% Gain in loading rates

A metalliferous mine saw the immediate impact of Varistem with improved fragmentation.

We work on a coal mine in South-Africa with many challenges. Our most important priority is keeping our surrounding community safe, and fully comply with the law regarding flyrock and airblast. We finally found support from the ERG Team that is assisting us with the Varistem product, approved by the DMRE. Since trailing these plugs, we saw a significant difference in our blast quality and our ability to control accountability in the way we can now manage the final stemming and having that confidence in a product that works. Excellent service and products.

I worked for Overlooked Group at Dorstfontein East Coal Mine and have recently undergone an exercise using Varistem product as an addition to blasting application to reduce noise/airblast and to improve explosives energy retention in the blast block. The product showed immediate improvement of air blast up to 12% without changing any other blast parameters. Blast performance also improved as a result of good energy retention and produced better cast performance, fragmentation and as a result we could reduce powder factors with by almost 15% and still achieve similar results.

I work for Mota-Engil Guinea as a drill and blasting Manager. I recently used Varistem® Blasting Plugs from ERG Industrial for improving blast efficiency in our mining operations. The experience lead to significant improvements in rock fragmentation and operational cost savings. Exceeded our expectations

Any mining operation can benefit from the innovative products ERG Industrial offers, such as the Varistem plugs. ERG Industrial is a pleasure to deal with and will optimise blasting practices in a mine through a structured consultative approach

I have used ERG Industrial's Varistem Blasting Plugs on my quarry. Gomes Sand has seen significant improvements in the end result of the lasted product after implementing this product.

QUARRY BLASTING FAQs

Can Varistem® be used for airdecking?

Yes, Varistem® can be used for airdecking and can support the weight of the stemming column on top of the plug.

Do I have to airdeck with Varistem®?

No, you do not need to airdeck with Varistem®. The conventional application for Varistem® is to install the plug in the hole in direct contact with the explosives, and then add stemming on top. In cases with a history of oversize in the stemming layer, we recommend the airdeck application. However, whether airdecked or not, the Varistem® plugs will still contain the same amount of energy.

Can Varistem® be used in buffer and pre-split holes or only production holes?

Yes. We recommend a slightly modified application as compared to production holes. Typically buffer holes are charged less than production holes. We recommend airdecking in buffer holes. For pre-split holes, we recommend a specialist application that aims to create “semi-confinement” – enough to reduce airblast and noise levels, but not enough to send excess energy into the high walls (defeating the purpose of pre-splitting). Typical pre-splitting recommendations include installing the Varistem® at 1m from the hole collar and stemming with fine drill cuttings.

How long does it take to install Varistem® in a hole?

Application and depth-dependent, but typically takes between 8 – 14 seconds per hole.