| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 214111 | International Journal of Mineral Processing | 2012 | 7 Pages |
Partially Laterised Khondalite (PLK) rocks are the waste materials generated during mining of bauxite. These PLK rocks even though contain > 40% of Al2O3 are not suitable for metallurgical industries due to the presence of reactive silica. The rock is not directly suitable for value addition as it contains major discoloring element (iron oxide) as impurity which renders it unsuitable for use as a filler material. Physical methods such as magnetic separation, flotation, scrubbing etc. are not fully successful for removal of iron from PLK rocks. Acid leaching techniques are the only alternative method to minimize iron content in the PLK rocks. Present investigation is to get superfine particles from PLK rocks by stage crushing followed by classification using hydrocyclone. These superfine particles are subjected to hydrochloric acid leaching to remove the iron content and the final product is suitable for industries. First order reaction kinetics is found to be fit for the experimental results. The apparent activation energy for F1 model is 48.8 kJ/mol and for R3 model is 71.1 kJ/mol, which is much less compared to leaching of iron from bauxite. The brightness of the product is 80% which is desirable for filler industries. Ceramic properties of the product are compared with the Indian Standard and are found suitable for ceramic industries.
Graphical abstractPartially Laterised Khondalite rocks (Bauxite mining waste) contain reactive silica (kaolinite) which is not suitable for metallurgical industry. These rocks also contain iron as a coloring material which prevents its suitability for filler industries. This can be used as a filler/ceramic industry by reducing the iron content using acid leaching process.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Partially Laterised Khondalite rocks are bauxite mining waste. ► PLK rocks contain iron as discoloring element not suitable for filler industries. ► The rate of iron oxide dissolution followed first order reaction mechanism. ► The brightness of the product is 80.07% with activation energy of 16.2 kJ/mol. ► This product is suitable for ceramic industries making insulators, cups and plates.
