OPTIMISATION OF THE RECOVERY OF LITHIUM OXIDE USING FROTH FLOTATION FROM MICA

Abstract

Recently the rise of hybrid and electric vehicles have surged the demand for lithium metal which is the main component of their batteries. The need to phase out fossil fuels and conserve the environment has driven the growth in lithium ion technology. In the UK lithium deposits have been discovered at Cornwall. Lithium is found as lithium oxide in ratios with rubidium oxide available in some of the mica minerals. The mineral bearing rock is classified as Zinnwaldite ore that is also found in continental Europe. This is the major ore containing lithium oxide; however, smaller quantities arise from muscovite mineral. The zinnwaldite ore has however been found to possess high iron content and relatively low Li2O content. This thesis performs grinding test, flotation and lithium recovery from the ore found in Cornwall. The results obtained indicated that the dosage of the collector used has greater impact than the effect of pH. The results also indicate that the higher pH has higher recoveries. The P-XRD data analysis indicated that the main elements in the ore were; aluminum at 1.017%, silicon at 7.23%, potassium at 2.54%, iron at 1.04%, and rubidium at 0.11%, calcium at 0.134% and titanium. However, the bulk of the material was found to be gangue of about 87% which could not be separated into its constituent minerals. In the P-XRD analysis, lithium was not detected since it does not detect low atomic elements like lithium. However, in the recorded weight of rubidium, some of it is lithium hence other methods can be used to determine the percentage of lithium present in the rubidium. Based on the studies in this research, the optimum flotation results was at PH 3.5 with a Flotigam 7100 concentration of 28.75ml and 76.5ml of flotigam 7550 which achieved recoveries of 85% during condition 1, 80% during condition 3 and 100% during condition 3. This test reveals the optimum dosage and pH combination that can be applied in treating this ore from South West England.