Pengaruh Penambahan NaOH dan Ca(OH)2 Terhadap Penurunan Kadar Logam Berat (Fe) di Kolong Tambang 23 Desa Kimhin Kecamatan Sungailiat: The effect of the addition NaOH and Ca(OH)2 at reduced levels of heavy metal (Fe) in Tambang 23 Kimhin Village of Sungailiat Subdistrict. mineral. 2020;2(2):56-61. doi:10.33019/mineral.v2i2.1552