Analysis of Quarterly Production Scheduling Using Ore Blending Strategy Case Study Pit 7A and 15 Block a Tayan Bauxite Mine, PT ANT AM (Persero) Tbk.

摘要

Tayan Bauxite Mine is one of the mining projects in West Kalimantan developed by Antam. Overall amount of resource owned by this mine is 50.25 million wmt of washed bauxite (WBx). In block A, total WBx resource contained is 26.75 million wmt, with average grade of 48.14% Al_2O_3 and 3.23% R-SiO_2. Starting from 2014, this mine will be projected to supply Chemical Grade Alumina (CGA) plant. To fulfill the needs of plant, 850,000 wmt of WBx supply is required annually, with minimum 46% Al_2O_3 and maximum 3.6% R-SiO_2. This tonnage is approximately equivalent to 1,700,000 tonnes of crude bauxite (CBx) mined from the mine front. Based on block model data, pit limit 7A and 15 are carried out to determine the potencies of both pits to meet production target. From pit 7A, 1,655,428 wmt of WBx can be obtained, with average grade of 50.05% Al_2O_3 and 2.35% R-SiO_2. While from pit 15, there are 872,646 wmt of WBx, with average grade of 38.40% Al_2O_3 and 6.35% R-SiO_2. Then, quarterly production scheduling is carried out to produce the mine boundary for each quarter, which is used as guidance in mining operation. After mining and washing process, stockpile management and ore blending strategy are carried out so that the plant target can be achieved. From the ore blending strategy result, the average tonnage ratio obtained of pit 7A to pit 15 is 2.31 :1. By using the ore blending strategy, Antam can apply conservation by optimizing marginal grade reserve so it can be fully utilized.