“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 4, no. 2 (August 15, 2018). Accessed April 13, 2026. https://www.journal.ubb.ac.id/index.php/promine/article/view/108.