Laboratory evaluation of the filtration behavior of three filters wrapped around drain pipes in fine tailings based on a radial flow test

Installing drain pipes is an effective way to control the height of the saturation line to improve the stability of tailings dams in mine projects. The filtration and clogging behaviors of filters wrapped around drain pipes have a great impact on their drainage capacity. This article presents results from radial filtration tests with drain pipes wrapped by filtration materials in fine-grained tailings. In the tests, three fibrous filters with different production technologies were used under different hydraulic conditions. The test results were interpreted based on the drainage characteristics of the system, the clogging characteristics and mechanism of each filter after testing, and the particle gradation passing through each filter. The results showed that the needle-punched nonwoven geotextiles had good soil retention properties and poor drainage properties, and one denser cake layer was formed upstream as the experiment progressed. For the heat-bonded nonwoven geotextiles with larger apertures and thinner thicknesses, there was a slight degree of clogging and acceptable drainage capacity. Steel wire mesh with a thinner thickness and homogeneous mesh structure seemed to offer the best anti-clogging and drainage performance by retaining coarse particles and washing out fine particles. Thus, it is inferred that drain pipes wrapped with steel wire mesh are a good choice for alleviating the physical clogging problem.