Removal of Mica from Jamuna river sand

Abstract

A sample of Jamuna river sand assaying 84.00% SiO2, 6.83% Al2O3, 2.28% Fe2O3, 0.39% TiO2, 1.5% CaO, 1.18% MgO, 1.64% alkali chlorides and 2.38% loss on ignition, was received from the National Building Organization, Ministry of Works, Housing and rehabilitation, New Delhi, for removal of its mica, so as to make it suitable for use in building industry. The sand as received consisted of quartz, feldspars, amphiboles, pyroxenes and micaceous minerals. The flaky micaceous minerals, which constitute about 5% by weight of sand, consisted of muscovite, biotite, sericite and chlorite in order of abundance. Opaque minerals were present in traces. Except flotation, no other method was found suitable for separation of mica from sand. Cationic flotation of the sand employing Aeromine 3037 as collector and lead nitrates as activator for mica, at pH 3.0 yielded a sand tailing containing 1.3% mica in it. Flotation of the washed sand under the same conditions yielded a tailing containing only 0.2% by wt. of micaceous minerals and rejecting almost all of them in the float. The application of this process on industrial scale will depend upon economic which can be determined only after large scale tests including pilot plant scale trials.