Bioleaching of Cu from enargite using Acidianus brierleyi with concomitant passivation of As
Bioleaching of enargite with thermophilic ironoxidizing archaea, Acidianus brierleyi at 701 for 27 days provided 90. 93％ of Cu recovery and 5. 86％ of As recovery. The preferential dissolution of Cu to As was mainly achieved by the formation of crystalline scorodite ( FeAsO4 *2H2O). Although the chemical valence of As in enargite was confirmed to be As (Ⅲ) , most of dissolved As existed as H3 As O4 in a process of bioleaching of enargite. It indicates As (Ⅲ) released from enargite was immediately oxidized to As (V) in solution by catalytic reaction on the surface of enargite. During the bioleaching of enargite, dissolved Fe(III) was consumed to form precipitations, such as scorodite and jarosite ( (M+ )Fe3(SO4)2(OH)6) as well as an oxidant for enargite. Even after the formation of scorodite completed due to the consumption of Fe (Ⅲ) , As was also passivated in no relation with Fe( Ⅲ) . Co-sorption of Cu( II) and H2 AsO4~ on jarosite led the formation of copper arsenate by seed-forming effect. The subsequent secondary mineral precipitation resulted in the formation of multi-passivation layers consisting of scorodite, potassium jarosite, elemental sulfur and copper arsenate, after most Cu was recovered from enargite by microbially induced leaching.
bioleaching enargite Acidianus brierleyi scorodite TEM
Keiko Sasaki Koichiro Takatsugi Tsuyoshi Hirajima
Department of Earth Resources Engineering, Kyushu University, 744 Motooka, Fukuoka, Japan
国际会议
The 19th International Biohydrometallurgy Symposium(第19届国际生物湿法冶金大会 IBS2011)
长沙
英文
123-125
2011-09-18（万方平台首次上网日期，不代表论文的发表时间）