Surface mining & quarrying
Secondary boulder breaking
Secondary rockbreaking in surface mines and quarries occurs where oversize rocks are produced from a primary blast that need to be reduced to a manageable size for loading and crushing. In practice most hard-rock surface mines and quarries would expect to re-blast or break up to 5% of their rock after effective primary blasting.Secondary breaking plays an important role in the surface mining and quarrying process cycle. Many of the factors which are important when considering which method to use for secondary breaking are often not clearly evident and are therefore ignored in the decision making process. The direct cost of secondary breaking per cubic metre is the benchmark for assessing the economics of the various methods.
However, the hidden costs in terms of production delays, the cost of rehandling of oversize material and the cost implications of environmental non-compliance often have a far greater effect on overall costs than the differences in direct costs between the various methods available. The NxbursT™ method for secondary rockbreaking offers surface mines and quarries a safe, low cost, versatile, environmentally sensitive method of secondary breaking, which allows secondary breaking to take place in the pit without having to disrupt the production operation.
Rom pad oversize rockbreaking
Breaking oversize rocks on the ROM pad requires a rockbreaking method that will not disrupt critical haulage operations and will not expose the surrounding infrastructure to damage by fly rock. NxbursT is an ideal tool for oversize rockbreaking on the ROM pad as the charge size can be tailored to the required size of rock. NxbursT™ is available in sizes from 3 grams to 6 grams in the 12mm diameter range, 10 grams in the 13mm diameter range, from 20 grams to 120 grams in the 28mm diameter range, from 20 grams to 250 grams in the 34mm diameter range and from 200 grams to 500 grams in the 60mm diameter range.
Crusher blockages
Freeing a crusher from blockages caused by oversize rocks in the jaws or aperture requires a minimum of energy and a large amount of fl exibility. The NxbursT™ 12mm. RockPopper cartridge is available in charge weights of 3 grams to 6 grams and the 14mm hole can be drilled with a lightweight electrical hand-drill such as a Hilti TE25 Combihammer. The lightweight drill and the small charge weights allow the job to be done safely, quickly and with ergonomic ease. Using NxbursT™ 12mm. RockPoppers to break rocks stuck in the jaws of a crusher ensures that there is no risk of damaging the crusher or any of the mine infrastructure or services. The NxbursT™ 12mm RockPopper splits the rock without fly rock, concussion effects or major noise.
Dimension stone quarrying
NxbursT™ is used to split granite for dimension stone in the quarrying industry. The benefits of using NxbursT™ rather than black powder are that NxbursT™, in contrast to black powder, is waterproof; and is not spark sensitive or impact sensitive, which makes NxbursT™ safer to use, store and transport. Generally, the 28mm range of NxbursT™ cartridges is used in a 32mm diameter hole. Hole spacing between holes is maintained at 40cm but only every second hole is charged using a 60 gram NxbursT™ cartridge. A grooving tool is used in the hole to ensure a clean split.
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Underground - before
Underground - after
