Status : Verified
| Personal Name | Rosal, Terrence Louis; Tungpalan, Djoan Kate; Mena, Manolo |
|---|---|
| Resource Title | Selective Removal of Arsenic from Enargite-Scorodite Ore via Alkaline Leaching |
| Date Issued | 15 September 2015 |
| Abstract | The increasing complexity of copper ores poses a challenge in processing and production of copper which is further exacerbated by the presence of arsenic. Hydrometallurgical techniques in selectively removing arsenic have shown to be effective and more environmentally benign compared to conventional processes. In this study, alkaline leaching was employed to remove arsenic from copper ores. The ore being studied contained 4% enargite (Cu3AsS4) and 1% scorodite (FeAsO4.2H2O) as the main arsenic minerals and 80% quartz (SiO2) as the main gangue. Additionally, other copper sulfide minerals were in trace amounts which further confirmed the need for removal of arsenic to obtain the valuable copper. Three solvents including Na2S, NaHS and NaClO under alkaline conditions were investigated and showed potential in selective removal of As. Both Na2S and NaHS systems provide a reducing condition to allow S2- from the solvent to be stable and react with enargite to produce thioarsenate (AsS43-) in solution. NaClO leaching provides an oxidizing condition for ClO- to react with enargite and produce arsenate (AsO43-). It was also observed that scorodite was dissolved at alkaline conditions without the addition of a solvent. In Na2S leaching, As dissolution increased with increased temperature and reduced particle size but decreased with increased solvent concentration. For NaHS, As dissolution was favored by high solvent concentration and temperature and reduced particle size. For NaClO, dissolution increased with increased solvent concentration and reduced particle size but decreased with increased temperature due to accelerated decomposition of ClO-. Na2S and NaHS solvents were significantly affected by the particle size of the ore while NaClO was strongly affected by solvent concentration. Leaching using Na2S resulted in the highest As dissolution at 96%, followed by 88% and 85% As using NaHS and NaClO, respectively. Minimal copper dissolution was noted for Na2S and NaHS indic |
| Degree Course | MS Metallurgical Engineering |
| Language | English |
| Keyword | Arsenic Leaching; Enargite; Selective Leaching |
| Material Type | Thesis/Dissertation |
Preliminary Pages
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Category : P - Author wishes to publish the work personally.
Access Permission : Limited Access