A slurry pipeline is a specially engineered pipeline used to move ores, such as coal or iron, or mining waste, called tailings, over long distances. A mixture of the ore concentrate and water, called slurry, is pumped to its destination and the water is filtered out. Due to the abrasive properties of slurry, the pipelines can be lined with high-density polyethylene (HDPE), or manufactured completely from HDPE Pipe, although this requires a very thick pipe wall.[1] Slurry pipelines are used as an alternative to railroad transportation when mines are located in remote, inaccessible areas.
Canadian researchers at the University of Alberta are investigating the use of slurry pipelines to move agricultural and forestry wastes from dispersed sources to centralized biofuel plants. Over distances of 100 kilometres pipeline transport of biomass can be viable provided it is used in processes that can accept very wet feedstocks such as hydrothermal liquefaction or ethanol fermentation. Compared to an equivalently sized oil pipeline, a biomass slurry pipeline would carry around 8% of the energy.[2]