Flotation separation of Cd, Co, Cr, Cu, Ni and Tl from calcium minerals and their determination by inductively coupled plasma-atomic emission spectrometry

The method of inductively coupled plasma-atomic spectrometry (ICP-AES), is developed for determination of Cd, Co, Cr, Cu, Ni and Tl in traces in calcite and gypsum. The interferences of Ca as matrix element on Co, Cr, Cu, Ni and Tl intensities during their ICP-AES determination are investigated. The results reveal that Ca does not interfere on intensities of Cr, but tends to decrease the intensity of the other elements. To eliminate those matrix interferences of Ca on trace elements intensities a flotation separation method is proposed. Lead(II) hexamethylenedithiocarbamate, Pb(HMDTC)2, is applied as a collector for flotation of trace elements from acidic solutions of mineral samples. The most suitable concentrations of calcite and gypsum solutions for flotation are ascertained. The detection limits of ICP-AES method following flotation of elements present in calcite and gypsum as impurities are determined: 0.022 and 0.061 μg·g-1 for Cd, 0.071 and 0.042 μg·g-1 for Co, 0.026 and 0.132 μg·g-1 for Cr, 0.164 and 0.149 μg·g-1 for Cu, 0.289 and 0.095 μg·g-1 for Ni and 0.645 and 0.7666 μg·g-1 for Tl, respectively. (Original)