Executive Summary : | Objective: The main objective of the proposed work is to develop low carbon MgO-C refractory (2-3% carbon) without compromising its chemical and thermo-mechanical properties using different source of nanocarbon. Summary: Presently mining industries are using roof/rock bolts to reinforce mine roofs as a major support to limit the movement and expansion of the rock strata. Since rocks are non-homogeneous, elasto-plastic material, It has always been difficult to predict the behavior of rock under any stress loaded environment. In view of human safety in particular and material safety in general the quality of the rock bolt reinforcement is to be ascertained mandatorily. To carry out this quality assessment ultrasonic guided waves would be very much suitable. As the use of roof bolts as a support system increases, it is very important to check the mechanical integrity of these bolts at a regular interval for safety of the human kind. This test differs from most conventional industrial ultrasonic inspection techniques because for this a guided wave is used, rather than a bulk wave. Further, it is also very important to know the stress pattern generated in a particular bolt during depillaring operation, which may provide significant input for modification of roof bolting system. The development of a suitable rapid underground NDT inspection test for residual length, impending failure, and correctness of bolt length and for the identification of corrosion patches would be very useful to Indian coal mining industry. |