BLENDING RATIO OPTIMIZATION OF DIRTY COAL WITH CHANCE-CONSTRAINED PROGRAMMING (CCP) AND DISCRETE-EVENT SIMULATION OF OPERATIONAL UNIT IN COAL PROCESSING PLANT PT X

• Main Author: Widiapsari Nuraini, Hana
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/47250
• Institution: Institut Teknologi Bandung

PT X is a coal company who works on coal mining and processing raw coal into coal product in Coal Processing Plant (CPP). In CPP, the company operates washing process to reduce ash content of the coal. Washing process for coal with high ash content will make lower yield thus adding cost component of production. The company needs to maintain the yield value above target yield. Coal blending process before washing helps on lowering ash content of the coal input of washing. The company had difficulties on determining the blending ratio because of the uncertainty of the raw coal’s quality from the mine even though it had already been forecasted before. This blending ratio is used on operating the rehandling process in CPP. The purpose of this research is to get optimum blending ratio for Medium Dirty (MD) coal and High Dirty (HD) coal for washing plant’s input and getting alternative solution for operational in CPP. This research used Chance-Constrained Programming (CCP) to get the blending ratio and discrete-event simulation to get the alternative solution for operating the unit. CCP model can be used for blending cases where the qualities of the materials are not known by exact but have known probabilistic distribution. The CCP model in this research will maximize the using of HD coal while fulfilling the constraint of target quality and coal availability. This ratio then used as the input for rehandling operation simulation in CPP. This simulation is covering from the arrival of truck with coal load from the pit until the After-Wash (AW) and Clean Product (CP) coal produced by the plant. The optimum blending ratio for MD:HD if the coal status in ROM not considered is 1:1.38~1.87 for regular HD coal and 1:3.97~5.32 for HD coal from C4_1 seam. This ratio still can fulfill the target yield of 67%. If the coal status in ROM is considered, the yield can only reach 64% with MD:HD ratio 1:1.56 for regular HD coal and 1:3.19~3.70 for HD coal from C4_1 seam. Simulation of CPP operational unit shows that cutting work hour below 12 hours will have a drastic effect. Adding trucks will have more effect to the production of CPP rather than adding wheel loader. Adding two truck units will adding production 9000 ton per month.