Intercalation experiments for morphological alteration of kaolinite present in iron ore tailings

Abstract

The main aim of this work was to evaluate the use of kaolinite present in iron ore tailings (IOT) in the synthesis of halloysite-like structures. The segregation of kaolinite was performed by acid leaching of the IOT. Three steps were strictly controlled for the efficacy of the synthesis procedure: i) pre-intercalation of the clay mineral using dimethyl sulfoxide; ii) obtaining the methoxy-modified kaolinite; iii) intercalation of the methoxy-kaolinite with suitable organic molecules. The synthesis procedure was performed in one-step and two-step. X-ray diffraction result showed that the product obtained from the IOT was composed essentially of kaolinite. The leaching was efficient in concentrating the kaolinite, considerably increasing the percentage of this clay mineral in the segregated product. Apparently, the contamination of Fe3+ ions did not interfere in the synthesis process. FESEM images indicated the morphological transformation of plate-like kaolinite for kaolinite nanotubes with a halloysite-like structure.