PENENTUAN PERSENTASE DAN NILAI SUSEPTIBILITAS MINERAL MAGNETIK BIJIH BESI YANG BERASAL DARI TIGA LOKASI TAMBANG BIJIH BESI DI SUMATERA BARAT

ABSTRAKTelah dilakukan penelitian untuk menentukan persentase mineral magnetik dan nilai suseptibilitas magnetik dari sampel bijih besi dari tiga lokasi tambang di Sumatera Barat.Tiga lokasi tambang tersebut terletak di Kecamatan Asam Jujuhan Kabupaten Dharmasraya, Kecamatan Sangir Balai Janggo Kabupaten Solok Selatan dan Kecamatan Tigo Lurah Kabupaten Solok.Suseptibilitas magnetik diukur dengan Bartington MS2 Magnetic Susceptibility Meter dengan MS2B dual frequency sensor.Pengukuran suseptibilitas magnetik dilakukan pada 15 arah.Hasil penelitian menunjukkan bahwa nilai rata-rata persentase mineral magnetik bijih besi masing-masing lokasi berturut-turut yaitu 90,8%, 91,6% dan 95,1%. Nilai rata-rata suseptibilitas magnetik masing-masing lokasi berturut-turut didapatkan 1332,6×10-8 m3kg-1, 1339,2×10-8 m3kg-, dan 1347,5×10-8 m3kg-1. Nilai tersebut menunjukkan bahwa mineral magnetik bijih besi dari masing-masing lokasi diperkirakan didominasi oleh mineral ilmenit (FeTiO3) yang bersifat feromagnetik.Nilai koefisien keragaman dari ketiga lokasi tambang berturut-turut yaitu 3,17%, 5,32% dan 4,09% dan dapat disimpulkan bahwa penyimpangan perhitungan nilai suseptibilitas masih relatif kecil.Kata Kunci:Suseptibilitas, anisotopi, magnetik, dan bijih besiAbstractThe research to determine percentage of magnetic mineral and the value of susceptibility magnetic of iron ore from three mine locations in West Sumatera has been done. Those three areas are located in Asam Jujuhan Districts Dharmasraya, Sangir Balai Janggo Districts Solok Selatan and Tigo Lurah Districts Solok. Magnetic susceptibility is measured by using Bartington MS2 Magnetic Susceptibility Meter with MS2B dual frequency sensor, from fifteen different directions of samples. The result of research show that the average percentage of magnetic mineral of iron ore for each location are 90.8%, 9.16% and 95.1%. The average value of magnetic susceptibility are 1332.6×10-8 m3kg-1, 1339.2×10-8m3kg-1, and 1347.5×10-8 m3kg-1.From these values it can be estimated mineral iron ore mineral from each location is dominated by ilmenit mineral (FeTiO3) which are ferromagnetic. Diversity coefficient of three consecutive mine is 3.17%, 5.32% and 4.09% and it can be concluded that the deviation of susceptibility calculation is still relatively small.Keywords: susceptibility, anisotropy, magnetic, and iron or