The Boger Slump Test is a simple, yet effective method used to assess the yield stress and flow behaviour of paste materials and high-density slurries.
In this video, a cylinder-shaped mould is filled with a sample of paste material. Once the mould is carefully lifted, the paste begins to slump under its own weight. The degree to which the paste flattens out—or maintains its shape—provides valuable insight into the material’s yield stress. A material with high yield stress will retain its cylindrical shape with minimal slump, while one with lower yield stress will spread out more significantly.
This test is especially useful during paste recipe development, as it helps engineers gauge whether the paste will be pumpable. By visually observing the slump characteristics, engineers can make informed adjustments to solids concentration to ensure reliable transport to the underground workings.
The Boger Slump Test is a quick and low-cost tool that complements more advanced rheological testing methods, offering immediate, practical feedback in the lab or on site.
