Arsenic mobilization from sulfidic materials from gold mines in Minas Gerais State

• Published in: Química nova Vol. 31; no. 5; pp. 1127 - 1130
• Main Authors: Andrade, Renato Pereira de, Santana Filho, Salomão, Mello, Jaime Wilson Vargas de, Figueiredo, Bernardino Ribeiro de, Dussin, Tânia Mara
• Format: Journal Article
• Language: English
• Published: Sociedade Brasileira de Química 2008
• Subjects: acid mine drainage; arsenopyrite; contamination
• ISSN: 0100-4042; 1678-7064
• DOI: 10.1590/S0100-40422008000500037

Acid drainage results from exposition of sulfides to the atmosphere. Arsenopyrite is a sulfide that releases arsenic (As) to the environment when oxidized. This work evaluated the As mobility in six sulfidic geomaterials from gold mining areas in Minas Gerais State, Brazil. Grained samples (<2 mm) were periodically leached with distilled water, during 70 days. Results suggested As sorption onto (hydr)oxides formed by oxidation of arsenopyrite. Low pH accelerated the acid generation, dissolving Fe oxihydroxides and releasing As. Presence of carbonates decreased oxidation rates and As release. On the other hand, lime added to a partially oxidized sample increased As mobilization.