RANCANGAN TEKNIS PENAMBANGAN DAN PENJADWALAN PRODUKSI JANGKA PENDEK (SHORT TERM SCHEDULING) PADA PENAMBANGAN BIJIH NIKEL LATERIT PADA PIT A BLOK ITB PT BOSOWA MINING SITE WAWOHEO KECAMATAN WIWIRANO KABUPATEN KONAWE UTARA PROVINSI SULAWESI TENGGARA

Abstract

Limited Liability Company (Ltd.) Bosowa Mining is one of the national private companies operating in the field of nickel commodity mining industry with an area of permission of mining enterprise (IUP) 1,500 Ha. Currently the company plans to open a new mining land at Pit A Block ITB to maintain production and will be scheduled in an effort to meet the production target when several other blocks have reached the mineout category. The nickel ore production target at the Pit A ITB Block is 70,000 tons/month with the criterion of value cut off grade Ni >1.40% and the company's sales standard is 1.60% Ni. This requires good technical planning and scheduling to reach the desired production target. The mining design is based on pit optimisation using Micromine 2021.5 software with the Lerchs-Grossmann algorithm. Based on the optimized pit shell results, the optimum pit shells were obtained at the sixth pit shell. The mining plan is based on the optimal pit shels with mining geometry is 6 meters bench high, 2 meters berm width, 60° slope angle and 9 meters ramp width. The results of the geotechnical analysis meet the safety factor standard that corresponds to the value of the mining slope SF according to KepMen ESDM No. 1827 K/30/MEM-RI/2018 for single slope, inter-ramp and overall slope conditions. The mining pit limit scheme at Pit A ITB Block produced a total of nickel ore reserves of 639,199 tonnes (1.62% Ni) and overburden/waste of 985,625 tonnes with a stripping ratio of 1.71 : 1. The mine's life is expected ±8 months. The mining sequence design is divided into eight stages that are carried out with a level plan system or follow the level of excavation with the highest elevation of 608 mdpl and the lowest 502 mdpl. Short-term production scheduling is carried out in line with mining sequence division. Production schedules are scheduled to start in January to August.