Abstract
Flotation of coal generally exhibits a maximum around neutral pH. This maximum, despite the marked mineralogical heterogeneity, has been attributed to the isoelectric point of the coal in this pH region. The results obtained in this study demonstrate the important role of multivalent ions in determining the pH dependence of flotation. Ca, Fe, and Al electrolytes are found to depress coal in the pH region of metal hydroxide precipitation. Adsorption tests as a function pH show that coal adsorbs the multivalent ions in a manner similar to oxides. The data obtained are examined in terms of possible surface and bulk precipitation of metal hydroxide species on coal surfaces.
| Original language | English |
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| Journal | Separation Science and Technology |
| Volume | 21 |
| Issue number | 4 , 1986, p.393-402. |
| Publication status | Published - 1986 |