Leaching kinetics of a Nigerian complex covellite ore by the ammonia-ammonium sulfate solution
| Autor: | Alafara A. Baba, Ayo F. Balogun, Abdul G. F. Alabi, Rafiu B. Bale, Folahan A. Adekola, Daud T. Olaoluwa |
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| Rok vydání: | 2017 |
| Předmět: |
Ammonium sulfate
General Chemical Engineering Metallurgy chemistry.chemical_element 02 engineering and technology General Chemistry Covellite Hematite 021001 nanoscience & nanotechnology Copper 020501 mining & metallurgy Copper sulfide chemistry.chemical_compound Ammonia 0205 materials engineering chemistry visual_art visual_art.visual_art_medium Leaching (metallurgy) Sulfate 0210 nano-technology Nuclear chemistry |
| Zdroj: | Korean Journal of Chemical Engineering. 34:1133-1140 |
| ISSN: | 1975-7220 0256-1115 |
| Popis: | Hydrometallurgical treatment of copper sulfide ore is increasingly establishing itself as a feasible route for the extraction of copper and recovery of associated precious metals value. This is attributed to the merits of this route, which include suitability for low-grade and complex ores, high recoveries, competitive economics, and other operational features. The leaching kinetics of Nigerian complex covellite ore was investigated in ammonia-ammonium sulfate solution. The concentration of ammonia and ammonium sulfate, the ore particle size, and the temperature were chosen as parameters in the experiments. The results show that temperature, concentration of ammonia-ammonium sulfate has favorable influence on the leaching rate of covellite ores; however, leaching rate decreases with increasing particle size. At optimal conditions (1.75mol/L NH4OH+0.5mol/L (NH4)2SO4, −90+75 μm, 75 °C, with moderate stirring) about 86.2% of copper ore reacted within 120 minutes. The mechanism of the leaching was further established by characterizing the raw ore and the leached residue by EDXRF - chemical composition, SEM - structural morphology and XRD - phase identification studies. From the X-ray diffraction analysis, the partially unreacted Cu and S phases were presumed to be CuO, and the iron present in the CuS phase was mainly converted to hematite (Fe2O3·H2O), as the CuS phase disintegrated and remained in the residue afterward. |
| Databáze: | OpenAIRE |
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