Corrosion and its effect on wire rope used in underground coal mines

R. P. Singh, Mousumi Mallick, M. K. Verma

Industries in India play an important role in the economic growth of country. These industries face challenging conditions in effective corrosion estimation, prevention and control. The corrosion cost in any developing country is predicted by 5% of the GDP which is significant to all countries. In this paper brief information about corrosion and its types has been given. The effects of corrosion in our daily lives are both direct where corrosion affects the useful service lives of our possessions, and indirect where in producers and suppliers of goods and services incur corrosion costs, which they pass on to consumers. Corrosion poses a serious threat to mining industries as well. Wire rope which is an intricate device made up of a number of precise moving parts used in underground mines. The amount of corroded metal is a function of the surface which oxygen can attack. Steel wire ropes have an exposed surface about 16 times larger than a steel bar of the same diameter and will therefore corrode correspondingly faster. Here in this paper, how corrosion can seriously shorten wire rope life, both by metal loss and by formation of corrosion pits in the wires has been described. Static ropes (suspension ropes or rope sections lying over a saddle or an equalizer sheave) are more likely to corrode faster than running ropes/ winding ropes. This has been illustrated with failure analysis of two different types of wire ropes used in coal mines, one guide rope which is static in nature and one winding rope which is a moving rope. From the two case studies it is found that the static guide rope used in coal mines has been failed due to excessive corrosion resulted in high reduction in diameter.