“Pengaruh Mineral Sekunder Sulfat Hasil Oksidasi Pirit Terhadap Nilai Total Sulfur Pada Batubara Formasi Haloq Dan Serpih Karbonan Formasi Batuayau Cekungan Kutai Atas: Effect of Secondary Sulphate Mineral Theresults of Oxidation Pyrite Againt Value Total Sulfur In Coal Formation Haloq and Carbonaceous Shale Formation Batuayau On the Kutai Basin”. PROMINE, vol. 4, no. 2, Aug. 2018, https://doi.org/10.33019/promine.v4i2.108.