The study was undertaken to ascertain the effects of holding time during secondary steel making, casting duration, strand loss per heat, and tonnage of steel returned per heat on continuous casting yield (%). A total of 1910 heats, spanning a period of seven years (41 production months) were used for the study. Monthly tonnage of liquid steel produced and cast and the corresponding yield were computed from the casting reports. Also extracted from the casting reports are the average monthly holding time (mins) during secondary steel making, monthly average heat casting duration (minutes), average strand loss per heat and monthly average tonnage of steel returned per heat. A statistical package for social sciences (SPSS) was used to analyse the data obtained. The yield was found to be negatively correlated to steel holding time during secondary steel making (-0.257 mins), strand loss per heat (-0.753 tons), and tonnage of heat returned per heat (-0.944 tons), but positively correlated to casting duration (0.371 mins). The result showed that increase in holding time during secondary steel making, strand loss per heat and tonnage of steel returned per heat decrease the yield of continuous casting process. The model formulated was able to explain 93.4% of the total variation in the observed yield. Efforts should therefore be made to monitor and reduce these parameters that decrease the yield through proper process control, regular checks of the continuous casting machines, replacement of worn out moulds, and in-house training and retraining of casters for optimum process performance.
An Effective Approach for the Scheduling of Refining Process with uncertain iterations in Steel-making and Continuous Casting Process