Arsenic(V) removal from enargite leach solutions by precipitation of magnesium ammonium arsenate

ABSTRACT

This study investigated a potential method for the removal of arsenic from enargite leach solution containing 5.86 g/L As(V) by precipitation of magnesium ammonium arsenate (MAA). The experimental results showed the As(V) concentration can be reduced to 1.8 mg/L under the optimum conditions. The molar ratio NH₄/Mg/As in precipitates formed at different pH values was checked by wet chemical analysis, indicating that some of by-products such as Mg₃(AsO₄)₂, Mg(OH)₂, and MgHAsO₄ will be formed at the solution pH above or below pH 9.5. Notably, this study indicated MAA has a better ability for arsenic removal than magnesium arsenate. The precipitates also were characterized by XRD and SEM.

KEYWORDS:

• Arsenic removal
• precipitation
• magnesium ammonium arsenate
• magnesium arsenate

Acknowledgments

This research was supported by National Natural Science Foundation of China (NSFC. 51204207) and the Independent Research-innovation Program of Central South University of China (2012zzts370). The authors are grateful for this support.

Additional information

Funding

This work was supported by the the Independent Research-innovation Program of Central South University of China [2012zzts370];National Natural Science Foundation of China [51204207].