Flotation behaviour of malachite in mono- and di-valent salt solutions using sodium oleate as a collector
| Autor: | Yosep Han, Hyunjung Kim, Siyoung Q. Choi, Kyuhyeong Park, Junhyun Choi |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
chemistry.chemical_classification
Aqueous solution Chemistry Inorganic chemistry Salt (chemistry) Malachite 02 engineering and technology 021001 nanoscience & nanotechnology Geotechnical Engineering and Engineering Geology 020501 mining & metallurgy Adsorption 0205 materials engineering Geochemistry and Petrology Ionic strength visual_art visual_art.visual_art_medium DLVO theory Surface charge Froth flotation 0210 nano-technology |
| Zdroj: | International Journal of Mineral Processing. 146:38-45 |
| ISSN: | 0301-7516 |
| DOI: | 10.1016/j.minpro.2015.11.011 |
| Popis: | We investigated the influence of a salt solution on the flotation behaviour of synthetic malachite using a sodium oleate as a collector. We found that the floatability of oleate ions-adsorbed synthetic malachite monotonically increases with an increase in the overall ionic strength (IS) range (1–1000 mM) of the monovalent cation (Na + ), while the floatability sharply increases only up to a level of 30 mM of the divalent cation (Ca 2 + ), followed by decreased floatability with further increases in the IS. For a monovalent salt, Na + ions effectively screen a negatively charged bubble surface, reducing the energy barrier for attachment and thus increasing floatability. Moreover, electrophoretic mobility measurements revealed that oleate ions-adsorbed synthetic malachite is negatively charged in a NaCl solution while it is positively charged in a CaCl 2 solution over the entire IS, indicating the specific adsorption of Ca 2 + ions onto the surface of oleate ions-adsorbed synthetic malachite in a CaCl 2 solution. This surface charge reversal in the CaCl 2 solution suggests that electrostatic interaction between positively charged oleate ions-adsorbed synthetic malachite and a negatively charged bubble is attractive, yielding high flotation efficiency. The increased floatability of both the entire IS of NaCl and a low IS of CaCl 2 can be well explained by the extended DLVO theory. At a high IS (100–1000 mM) of CaCl 2 , however, the decreased floatability did not follow the extended DLVO prediction, implying that additional non-DLVO type interactions are likely to be involved. Direct contact angle measurements and an inductively coupled plasma (ICP) analysis with the electrophoretic mobility measurements revealed that this unusual flotation behaviour is likely due to the hydration layer by the hydrated Ca 2 + adsorption onto oleate ions-adsorbed synthetic malachite. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect