Case Study: Effect of Stemming Length on Blast Fragmentation – Part 2 This part of this article evaluates a granite quarry blast introduced in Part 1 of my post (https://lnkd.in/efKgchFt), which consisted of two sections designed with different stemming lengths. The decision to adjust the stemming length was driven by the need for improved confinement, aiming to reduce excessive energy venting and mitigate poor fragmentation caused by energy loss. The first image illustrates the division of the blast: one section with a 1.8 m stemming length and the other with a 2.0 m stemming length. Each blast hole was drilled on a 2.7 m × 2.3 m pattern, and the stemming material used had a D80 size of 22 mm. Results show that while the 2.0 m stemming zone provided better confinement, it produced coarser fragments due to pre-existing geological fractures. These fracture observations and their influence on fragmentation were discussed in detail in the referenced article available here: https://lnkd.in/e7ytv28B The second application of the adjusted stemming length demonstrated both strong confinement and improved fragmentation. WipFrag was used to analyze each section independently, as shown in the attached images. The yellow pocket is the Quarry crusher compatibility, design on WipFrag for this quarry KPI sizes.