How to reduce the output of fines rate during block stone extraction by drilling and blasting?

At many quarries for the extraction of building stone there is a problem of increased output of fines after all stages of crushing and grinding, which leads to a decrease in the economic performance of mining enterprises. The fine fraction is formed by the crushing / grinding of prefractured rock mass. Reducing the intensity and size of the prefracture zones will lead to a solution to the problem at hand. It was established that the greatest influence on the shape and duration of the blast pulse is exerted by the velocity of explosive detonation. As the detonation velocity decreases, the peak pressure of the head part of the pulse decreases, and the duration of its rise increases, while a low-amplitude pulse of long duration contributes to better crushing of a rock mass with the least effect of prefracture. Using explosives with a reduced detonation velocity allows reducing the “surplus” impact on a rock mass and thus reducing the intensity of prefracture in the zone of controlled crushing during a blast. This is because the individual pieces will be weakened to a lesser extent after a blast and as a result, the yield of undersize when crushing rock into crushed stone will be reduced.

For more information, see the article:

📌 Khokhlov S.V., Vinogradov Yu.I., Makkoev V.A., Abiyev Z.A. Effect of explosive detonation velocity on the degree of rock pre-fracturing during blasting. Mining Science and Technology (Russia). 2024;9(2):85-96. https://doi.org/10.17073/2500-0632-2023-11-177

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