Slurry pipelines find a special place in industrial applications which require transportation of solid particles through a pipeline. Flow-ability of these solid particles is achieved by mixing and suspending them in water or other carrier fluids. Slurry pipelines are characterized with cost effectiveness for long distances, reliability, low maintenance, low air & noise pollution. Importantly it is eco-friendly and does not affect the environment.
Over the past 5 decades, slurry pipelines have proven its effectiveness in cost saving for long distance transportation, safe handling and high reliability. Since the inception of long slurry pipelines in 1957 in Ohio to transport coal, gradually over the period, new technologies in slurry transportation has made it possible to transport minerals and materials over long distances safely and effectively. Many materials such as coal, iron concentrate, phosphate concentrate, copper concentrate, zinc concentrate, lead concentrate, nickel concentrate and limestone have been transported successfully over long distances.
The long distance slurry pipelines have certain disadvantages in terms of high initial capital investment, the carrier fluid availability, and importantly it is feasible in areas wherein rail and road transport is not well developed. Most of the mineral concentrates require a beneficiation step that involves grinding of the ore to a very fine size in order to achieve good recovery. This is a wet process and the size of the product is generally suitable for long-distance pipeline transportation. In particular for coal transportation, the drying cost is add-on cost. These all requirements contribute to the transportation cost and make it uneconomical for short distances. Therefore for slurry pipelines to be economic, the distance of transportation will have to be long.
In recent times, polyethylene pipes have proven to be very cost effective to transport copper, iron ore, phosphates and gold concentrates. They have high resistance to slurry abrasion, prolonged wear life, high ductility and toughness properties. Pumps are developed to handle high pressures of up to 250 bars and facilitated pumping of solid concentration of 60 to 65% weight. Some alternate carrier fluids result in higher concentrate carrying capacity.
Slurry pipelines have proven its high economy and feasibility to operate over long distances. With many developments underway, slurry pipelines will pave way to decrease the load and dependency on rail and roads.