Improved understanding of sublevel blasting – Determination of the extent of the compacted zone, its properties and the effects on caving

LKAB Contact    LTU Contact Daniel Johansson
Posted in Sustainable mining

Background and Main objective

Sub-level caving (SLC) is characterized by complex processes involving several distinct mechanisms related to blasting and geomechanical conditions affecting the cavability of the blasted and waste material lying in front of a production ring.

This study will investigate the gravity flow mechanisms and the influence of the caved waste rock on the blasting performance with respect to fragmentation in SLC. Additionally, it will show potential sources of disturbances in the flow of caved rock, causing hang-ups and irregular caving geometries.

By means of these tests it will be possible to estimate:

  • The extent of the compaction zone within the caved waste rock masses
  • The changes in properties of the caved rock and
  • The influence of the caved waste rock on the cavability of the broken material.

Potential outcome

The mechanisms behind the caving process of the blasted rock mass and the interaction between the caved waste rock and the blasted material will be identified. These results will improve the gravity flow models, improve the ore flow and decrease dilution.