Derin Ötektik Çözücüler Kullanılarak Lityum İçeren Borlu Atıklardan Lityum Ekstraksiyonunun İncelenmesi

Abstract

Lithium is an element that is found in limited places in the world and is widely used today, especially in lithium-ion batteries, due to its chemical properties. The global importance of lithium has increased both the studies on the development of existing production techniques and the research on the recovery of lithium from wastes such as battery waste and lithium-containing boron waste. In this thesis study, the use of environmentally friendly and cost-effective deep eutectic solvents (DES), instead of petrochemical solvents, was investigated in the extraction of lithium(I) ions in boron waste obtained from Eti Maden in Eskişehir Kırka. In the first part of the studies, the structure of boron waste was examined using FTIR, XRD, TGA and SEM/EDS and it is determined that boron waste contains a smectite type lithium clay structure and its main components consist of dolomite and tincalconite. In the extraction studies carried out in the batch stirred system, firstly, H2SO4 solutions of different concentrations were used as reference solvents, and lithium(I) extraction from boron waste was examined as a function of the solid (amount of boron waste)/liquid (solvent volume) ratio and temperature. Then, the extraction of lithium(I) from boron waste was investigated by preparing various types of DES consisting of choline chloride as a hydrogen bond acceptor and urea/ethylene glycol/lactic acid/p-toluene sulfonic acid as a hydrogen bond donor. Finally, the appropriate DES type was determined and the effects of solid/liquid ratio, temperature and mixing speed on lithium(I) extraction were examined. The results showed that lithium(I) extraction at high temperatures and mixing speeds using DES, which is prepared from choline chloride, pure water and p-toluene sulfonic acid in a ratio of 1:2:1 (mol/mol/mol), provides lithium(I) extraction at higher speed and efficiency than H2SO4 solution. While 68,8 mg/L lithium(I) was extracted into 1,63 M H2SO4 solution at 20 g/L solid/liquid ratio, 100°C temperature and 200 rpm stirring speed; this value was increased approximately 6 times and 374,9 mg/L lithium(I) was extracted into DES at the same solid/liquid ratio, at 120°C temperature and 400 rpm stirring speed. Lithium(I) extraction behavior in both solvents was described by a second-order kinetic model. When the results were examined in terms of lithium (I) selectivity, it was seen that, in addition to lithium (I) ions; potassium(I), sodium(I), calcium(II) and magnesium(II) ions also passed into the 1,63 M H2SO4 solvent and DES prepared from choline chloride, pure water, and p-toluene sulfonic acid in a 1:2:1 (mol/mol/mol) ratio at much higher concentrations