activated bleaching earths are produced from clays which generally contain high proportions of montmorillonites through acid activation. clays exhibiting high natural bleaching power are not suitable for activation, and most clay used for activated clay manufacture is poor in natural bleaching ability.

Bleaching clays normally contain 10–18% moisture. If the clay is completely dried prior to use, its structure collapses, causing reduction in the bleaching power because of decreased surface area. In addition to these, adsorptive capacity of acid activated clay is reduced if clay is added to hot oil. This is because the moisture in the clay is driven off too rapidly causing collapse of the clay structure. The acid activated earth should be added to dry, refined oil at 80°C under vacuum conditions and then rapidly brought up to working temperature and held at that temperature for enough time to provide maximal bleach.

Dear Mr Raghdmuhi,

Thank you so much for your reply.my question is that, if we find a clay mine  and we have doubt if it is good for bleaching clay production how we should test the samples to be confident this mine is suitable.

Best Regards

M A Pazokian

dear Mr. Pazokian

Try read the attached file for big beatification, dont hesitate for any information you want

best regards