Selectivity of Leaching From Kulonprogo’s Lowgrade Manganese Ore with Organic Acid : Oxalic Acid, Acetic Acid and Citric Acid - Rima Dewi Anggraeni; Agus Prasetya; Rochim Bakti Cahyono (Prosiding Seminar Nasional Teknik Kimia "Kejuangan", 2018)