Abstract
We report an experimental study on the flow of spherical particles through a vertical pipe discharged at constant velocity by means of a conveyor belt placed at the bottom. For a pipe diameter 3.67 times the diameter of the particles, we observe the development of hanging arches that stop the flow as they are able to support the weight of the particles above them. We find that the distribution of times that it takes until a stable clog develops, decays exponentially. This is compatible with a clogging probability that remains constant during the discharge. We also observe that the probability of clogging along the pipe decreases with the height, i.e. most of the clogs are developed near the bottom. This spatial dependence may be attributed to different pressure values within the pipe which might also be related to a spontaneous development of an helical structure of the grains inside the pipe.
Highlights
In mining, it is quite frequent that the transport of rocks and ore between different levels is done through underground excavated tubes or ore passes [1]
We start presenting the avalanche duration distribution obtained for the given set of parameters specified above: a 200 cm length and 2.2 cm inner diameter tube full of 0.6 cm diameter glass beads discharged at a constant velocity of 0.215 cm/s
In this work we have shown that spherical beads flowing within a vertical narrow tube are able to display clogging events provided that the tube diameter is small enough in comparison with the particles size
Summary
It is quite frequent that the transport of rocks and ore between different levels is done through underground excavated tubes or ore passes [1] This method has been traditionally employed in underground mining, but nowadays it is becoming extended to open-cast mining. Dust production is considerably reduced when comparing pipe transport with the traditionally implemented strategy of throwing the material from one bench to the other. Other advantages of this pipe transport system are lessening the visual impact of traditional open-cast mines and reducing the noise levels in nearby populated areas. Apart from transport, ore passes serve for low cost storage which is essential to efficient mine operation
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
