Near-wall samples were collected from the top, side, and bottom of a horizontal pipeline flow loop for two broad, bimodal slurries: fine (d50 = 0.18 mm) and medium (d50 = 0.43 mm) sand representing 94% of solids, and 6% rock with d50 = 5.1 mm. Samples were less representative as median particle size increased. Samples from the pipe invert were denser and contained larger particles than samples from the pipe top. Two models were tested to predict vertical variations in concentration and particle size. The modified Karabelas model predicted local median particle size within ~ 25% in all trials. SRC PipeFlow M1.0 predicted local median particle size within ~ 4% for medium sand slurry at the pipe invert.
Slurry transport is used extensively to deliver mined ore and tailings in Alberta's oil sands mining industry in western Canada. Processing of silica-based solids in this industry at one time resulted in severe equipment wear with maintenance costs estimated to be on the order of $1 billion per year [1]. Thanks to efforts by the Materials and Reliability in Oil Sands (MARIOS) program managed by InnoTech Alberta and by many others, several wear-resistant materials and strategies have been evaluated and implemented in oil sands slurry applications, resulting in significant savings [2] [3] [4]. However, the wear resistance of some materials appears to decrease significantly with increasing average particle size [3]. While pipeline material selection remains the preferred strategy to increase reliability, further improvements are possible through optimized pipeline operation and a better understanding of the effects of particle size distribution (PSD) on material wear. Such improvements would also extend to other industries such as hard rock mining and dredging.
