Abstract

Based on earlier hydrotransport research by English and Russian researchers, a special test stand has been designed and constructed to obtain data to determine hydraulic drag, pipe wear, and comminution of particles. These data are intended for design and separate-effects operating information. This information will be used to supplement data developed by the Hydrotransport Research Facility located at the Pittsburgh Mining Operations, Pittsburgh, Pennsylvania. This report describes the equipment as designed, explains how the hydraulic drag is calculated using test-stand data, and presents some preliminary tests results using water. Tests using water are continuing to further substantiate the system and later, tests will be started using slurries. Document type: Report

Abstract

Redwood is used as an impact energy-absorbing material in the plutonium air transportable (PAT) package. To function properly the redwood must retain its properties over a wide temperature range. Since data were not available, an experimental program was conducted on 3-inch cubes of redwood over the temperature range of -40 to 230/sup 0/F (-40 to 110/sup 0/C). The specific energy, average crushing stress, and percent compression at bottoming are presented for the 22 specimens tested. Average values show an approximately 10% decrease in the specific energy and average crushing stress for a temperature rise from 70 to 230/sup 0/F (21 to 110/sup 0/C); and an approximate 30% increase in these quantities for a decrease from 70 to -40/sup 0/F (21 to -40/sup 0/C). 10 figs. Document type: Report

Abstract

The minerals processing and aggregate industry have relied on steady-state population and mass balance simulators for decades. However, accurately modeling new processes remains a critical challenge that hinders innovation and decision-making in the industry. In recent years, time-dynamic simulators have been developed, which offer more accurate predictions of process variability and performance, as well as the ability to introduce regulators and control algorithms. Yet, these still require simplified process models of each unit in the system. The development of high-performance discrete element method (DEM) solvers with advanced particle physics models presents a new opportunity to model complete comminution and classification processes. In this paper, we discuss the potential, challenges, and current limitations of using DEM for advanced dynamic process and equipment evaluation, exemplified by a coarse comminution crushing and screening case. We demonstrate the methodology using a GPU polyhedral DEM implementation with a boundary-volume hierarchy (BVH) collision search algorithm. The results show that the scale of a full-scale two-stage crushing process is possible to simulate. The transition from algebraic process models to DEM would make a significant advancement, bridging the current gap between overly simplified generalized process models and specific equipment design. This approach offers exciting opportunities for the mineral processing and aggregate industry to develop more innovative and efficient circuits.