Preliminary assessment of particle flow code as a tool to assess ore pass safety.
Larson MK; Iverson SR; Stewart BM; Walker K
Int J Rock Mech Min Sci 1998 Jun/Jul; 35(4/5):533
Researchers at the Spokane Research Laboratory of the National Institute for Occupational Safety and Health are investigating the use of the computer program Particle Flow Code in 3 Dimensions (PFC-3D) to simulate the flow and interaction of rock particles in ore passes and determine static and dynamic loads on bins and chute gates. Damping coefficients, contact stiffness, and coefficients of friction must be determined to simulate contact and flow behaviors accurately. Static-compression, double-pendulum, and inclined-plane tests were conducted and angle-of- repose measurements were taken to study these properties in various materials, including samples of ore and waste rock taken from a western U.S. silver mine. From these tests, a methodology was developed for determining the properties of rock particles. These measurements were then used with PFC to simulate double-pendulum tests in the laboratory to validate the ability of the code to simulate particle interaction. To increase the accuracy of predictions of dynamic load, FISH functions were written to (1)reduce the time step during contact of a ball with a target wall and (2)change local damping coefficients of particles during contact to simulate mechanical damping. Using these functions and measured ore particle properties, PFC-3D models of three common ore pass designs were constructed and simulations were run. Results indicated that PFC can be a valuable tool in assessing static and dynamic loads on bins and chutes. Better hazard assessment and design criteria should reduce accidents and fatalities resulting from bin and chute failures and ore pass hang-ups.
Mine-safety; Mining-industry; Mine-workers; Mathematical-models; Accident-prevention; Control-technology;
Author Keywords: ore passes; PFC; property measurement; rock mechanics; particle flow; dynamic load; mechanical damping; chute failure; chute and gate failure
National Institute for Occupational Safety and Health, Spokane Research Laboratory, Spokane, WA 99207
International Journal of Rock Mechanics and Mining Sciences. NARMS '98, Proceedings of the 3rd North American Rock Mechanics Symposium, Paper No. 092, Conference Reference USA-328-2