Evaluation of Bentonite Samples in Kerman Province

Extracted bentonite from different mines has various physical and chemical properties and as a result it would be possible to apply them in various requestes. The main mineral of bentonite is montmorillonite and the amount of montmorillonite, associated minerals and the type of bentonite affect on its properties. In this study, the samples were obtained from active mines and their X-ray diffraction pattern was studied, then the chemical analysis and swelling index investigated. Based on the results the samples 1 and 2 obtained from kheir Abad bentonite mine had relatively high montmorillonite content, while sample 2 was sodium bentonite and sample1 was calcium bentonite. The sample 3 taken from Horjand bentonite mine had relatively high montmorillonite content and qualitative more impurities rather than the other samples and was calcium bentonite. Sample 4 from Tang Ghoohan had relatively high montmorillonite and was calcium bentonite. Cation exchange capacity (CEC) of bentonite samples was determined using copper ethylendiamine complex and methylene blue methods. Copper ethylenediamine complex method in all of the samples was more accurate than methylene blue method. The result showed that methylene blue method was not reliable in determination of CEC of calcium bentonite.