Corrosion‐erosion behaviour of steel‐1, steel‐2, cast iron and polyurethane lined pipes for handling sand in mines

Abstract

Transportation of solids by slurry pipeline is a rapidly growing field. The pipelines, in the process of transportation undergo severe deterioration externally as well as internally. Corrosion‐erosion, metal damage caused by the combined action of electrocemical corrosion and mechanical erosion, has been studied extensively. In hydraulic transportation of sand, internal wear is caused by combined action of corrosion, associated with the corrosive water, the flow velocity and abrasion due to geometry of the solid particles on the interior pipe wall. Corrosion in slurry pipeline is generally due to the presence of dissolved oxygen in the slurry. The control of corrosion wear in a coal slurry pipeline is reported by Bomberger. The corrosion study by Postlethwaite and Tinkler showed that the presence of solids in commercial concentration increases the rate of corrosion in pipelines. The most common erosion occurred generally is the scratching or grooving of the pipe by the slurry particles. An erosion‐corrosion study in pilot plant slurry transportation in pipeline carrying wide range of water borne solids such as coal, iron ore and sand have shown that the presence of solids increases the chemical corrosion rate, apart from any accompanying erosion. It was also observed that due to severe corrosion‐erosion problem in pipeline, even a pinhole in such a line would be enlarged gradually in a matter of minutes by the out flow of high pressure abrasive slurry. Jacues and Neil had given an account of the causes, control and the economics of internal corrosion of slurry pipelines Zabell et. al. had studied the effect of bacteria using six different processes on corrosion of iron and the steel water pipes. The copper pipe line had been specially studied by Fischer and few others in various environments.