SAFE AND ECO-FRIENDLY DETERMINATION OF LITHIUM IN SILICATE ORES USING SINTERING AND INDUCTIVELY COUPLED PLASMA OPTICAL EMISSION SPECTROMETRY.

We developed new methodologies for the quantitative determination of lithium in lithium-bearing silicate minerals and clays. This research describes direct analysis of Li in powder using an atomic-emission complex for spectrum analysis "PGS-DDP-BAES" and sintering as a sample preparation technique followed by ICP-OES analysis. A new atomicemission complex for spectrum analysis could be used to efficiently overcome the complex matrix effects, and thus allows for the direct quantitative determination of lithium in solid samples (ores, clays). The relative standard deviation is up to 7.0%. For the extraction of Li from silicate ores and clays by sintering various parameters including sintering temperature, reaction time and additives were studied. The results indicate that the optimal temperature for sintering with NH₄ Cl and CaCO₃ is at around 900°C. Optimum conditions for lithium extraction were found to be 300 °C (30 min) and 900 °C (60 min), at mass ratios of an ore : NH₄Cl :CaCO₃ of 1 : 1 : 8. In these conditions a lithium extraction degree of 92% is reached. Relative standard deviations for the method with sintering and ICP-OES analysis vary in the interval from 1.7 to 2.2%. [ABSTRACT FROM AUTHOR]