Search

Recovery of lithium from lithium-rich electrolytes has attracted worldwide attention because of issues related to the electrolytic production of aluminum and its environmental impacts. Lithium carbonate preparation from a lithium-rich electrolyte by H 2 SO 4 leaching, followed by removal of impurities and lithium precipitation with Na 2 CO 3 was investigated. About 98% Li leaching efficiency was achieved in 1 h using 6% H 2 SO 4 at 80 °C while maintaining a liquid-to- solid ratio of 2:1. Li 2 SO 4 in the resulting leach solution was sequentially purified by NaOH addition to an end pH of 11 and then addition of 3 g/L ethylenediaminetetraacetic acid. Li 2 CO 3 of 99.5% purity was then obtained by precipitation with addition of 290 g/L Na 2 CO 3 at 95 °C for 50 min. This research is expected to improve understanding of requirements for the stable operation of electrolytic aluminum production and to potentially design processes for recycling of industrial lithium-rich electrolytes with high viability. • An effective method for recycling lithium-rich electrolyte was developed to prepare lithium carbonate. • Up to 98% Li was extracted using 6% H 2 SO 4 at 80 °C. • The recovery of lithium was over 84% under the optimized conditions. • A high purity of 99.5% Li 2 CO 3 could be finally obtained by NaOH purification and EDTA deeply purification. [ABSTRACT FROM AUTHOR]

Lithium extraction from hard-rock ores has regained importance due to the increased demand for this metal to supply the growing battery market. Therefore, several studies have been focused on the lithium extraction from ores, however, leaching and purification steps are sparsely studied. Thus, the objective of this study was to evaluate the main factors affecting the water leaching step and the subsequent purification operations for lithium recovery from a lepidolite concentrate, which was processed by mechanical activation and sulphuric acid digestion. In the leaching step, among the variables studied, only one, the leaching temperature, showed a significant effect on the lithium extraction, taking into account the range of values tested. Thus, the recommended operating value for the leaching time and the L/S ratio is the minimum, while for the leaching temperature is 50°C. After optimizing the leaching operation, the purification of the leachate, by neutralization, was thoroughly performed by efficient removal of impurities (Fe, Al, Mn and Ca), allowing to obtain lithium carbonate as final product, as well as other relevant by-products, such as rubidium and potassium alums. [ABSTRACT FROM AUTHOR]

In this study, an integrated process was developed to separate and simultaneously recover both magnesium and lithium from brines. This technology includes production of magnesium-aluminum-carbonate-layered double hydroxide materials (MgAlCO 3 -LDHs), removal of boron, CO 3 2– , and SO 4 2 − , and precipitation of lithium carbonate. Factors such as water addition ratio, Mg 2 + /Al 3 + mole ratio, and lithium loss rate were investigated during MgAlCO 3 -LDHs production. The effects of lithium concentration and CO 3 2 − /2Li + mole ratio on lithium carbonate precipitation were also studied. It was found magnesium and lithium had been effectively separated after MgAlCO 3 -LDHs production. The magnesium content in brine displayed a notable decrease from 117 g/L to less than 0.02 g/L with a lithium yield more than 95.0%. To concentrate lithium and precipitate lithium carbonate, 96.46% of boron, 99.2% of the CO 3 2 − , and 99.56% of the SO 4 2 − impurities were removed from the brine by adsorption, acidification, and precipitation, respectively. The lithium yield was more than 91% when lithium concentration in brine approximated 27 g/L and the CO 3 2 − /2Li + mole ratio was 1.2. The purity of this product was 99.70%. Overall, this study provides an interesting vision for future integrated utilization of magnesium and lithium resources from salt lake brines with high Mg/Li ratio. [ABSTRACT FROM AUTHOR]

To supplement the increasing demand for lithium (Li) resources dictated by the growing market for lithium-ion batteries (LIBs), this study aimed to secure lithium carbonate (Li 2 CO 3) using a waste box sagger generated from the process of manufacturing cathode materials for LIBs. Lithium was recovered through sulfation and subsequent wet conversion into high-purity Li 2 CO 3. Lithium extractability (93%) from the waste box sagger powder was determined by the sulfation reaction using 5 M sulfuric acid (H 2 SO 4) and distilled water (H 2 O) leaching of the resultant. The precipitation efficiency (85%) of Li into lithium phosphate (Li 3 PO 4) in extracted Li solution was established using a sodium hydroxide (NaOH) and phosphoric acid (H 3 PO 4) mixture. The maximum conversion efficiency (99%) of Li 3 PO 4 to lithium chloride (LiCl) solution was calculated using a reflux method with calcium chloride (CaCl 2) solution at a solid (g)/liquid (L) ratio of 100. The highest Li+ concentration reached 50,800 mg/L at a solid/liquid ratio of 400 and Cl/Li molar ratio of 0.95 in the range of tested conditions. Finally, high-purity Li 2 CO 3 (99.8% in metal basis) was produced from the obtained Li solution through purification using NaOH, followed by carbonation using sodium carbonate (Na 2 CO 3). The proposed method demonstrates the feasibility of securing a Li resource by recycling waste box sagger instead of disposing them as a designated waste. [Display omitted] • Li contained in waste box sagger was recovered as Li 2 CO 3. • Integrated sulfation/wet conversion resulted in high Li recovery efficiency (>90%). • High conversion efficiency (>99%) of Li 3 PO 4 to Li solution was achieved. • No-acid leaching was applied to prepare a concentrated Li solution from Li 3 PO 4. [ABSTRACT FROM AUTHOR]

A novel process for extracting lithium from carbonate subtype and sulfate type salt-lakes of Tibet by making full use of local resources and energy was developed. In this research, we extract lithium from carbonate subtype and sulfate type salt-lakes of Tibet through following three steps: carbonate enriched brine was prepared via freezing and evaporating of carbonate type brine (CO 3 2 − content is 60.76 g/L); lithium enriched brine was obtained by mixing sulfate-type brine and frozen carbonate-type brine (Li + content is 12.56 g/L); and lithium carbonate with a purity of 97.49% and a lithium yield of 54.85% was precipitated by mixing the lithium enriched brine and carbonate enriched brine. [ABSTRACT FROM AUTHOR]

In this study lithium was extracted from β-spodumene with hydrofluoric acid leaching. The operating parameters studied were: solid–liquid ratio, stirring speed, particle size, temperature, reaction time and HF concentration. Reagents and products were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), atomic absorption spectroscopy (AAS), scanning electronic microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The lithium extraction efficiency of 90% could be reached with solid–liquid ratio, 1.82% ( w/v ); temperature, 75 °C; HF concentration, 7% ( v/v ); stirring speed, 330 rpm and reaction time, 20 min. Al and Si can be precipitated as Na3AlF6 and Na2SiF6 with a recovery of 92%. Lithium carbonate was separated from leach liquor by carbonatation and crystallization during water evaporation, with recovery values of 90%, approximately. [ABSTRACT FROM AUTHOR]

The recovery of lithium compounds from various Li resources is attracting attention due to the increased demand in the Li-ion battery (LIB) industry. This study aimed to secure lithium carbonate (Li 2 CO 3) using the waste Li solution generated from the cathode manufacturing process. The effects of initial Li+ concentration, solution pH, and applied phosphate compounds were examined on converting Li-ion into lithium phosphate (Li 3 PO 4) by a precipitation method. Li 2 CO 3 was then obtained from Li 3 PO 4 by reflux and subsequent carbonation methods, in which a concentrated Li solution was produced from Li 3 PO 4 by reaction with metal chloride solutions. Among the tested metal chlorides (AlCl 3 , MgCl 2 , and CaCl 2), CaCl 2 showed the best performance to produce a concentrated Li solution. The highest conversion efficiency (97%) from Li 3 PO 4 to Li solution was observed at 80 °C, and the highest Li concentration (55,900 mg/L) was obtained at a solid(g)/liquid(L) ratio of 500 by reflux reaction. High purity Li 2 CO 3 was produced from the obtained Li solution by purification using sodium hydroxide, and its carbonation using sodium carbonate in turn. The proposed method shows an alternative way to secure Li 2 CO 3 from waste Li solution, in which no acid leaching of Li 3 PO 4 is required to prepare concentrated Li solution to be used Li 2 CO 3 production. • Precipitation-reflux method was applied to Li recovery from waste Li solution. • Reflux reaction of Li 3 PO 4 into LiCl solution showed 97% of conversion efficiency. • Li concentration in solution by reflux method reached approximately 55,900 mg/L. • This approach can alternate for acid leaching process of Li 3 PO 4 into Li solution. [ABSTRACT FROM AUTHOR]

This study describes a hydrometallurgical process to investigate the recovery of lithium from seawater using devised total process including an adsorption process with manganese oxide adsorbent and a precipitation process. First, precipitation experiments on Ca(OH)2, Mg(OH)2, and Mn(OH)2 from CaCl2, MgCl2, and MgCl2 in NaOH-H2O solutions were carried out under various conditions of reaction temperature (25–90°C), NaOH concentration (7–14 pH), and initial amount of CaCl2, MgCl2, and MnCl2 (10 and 100mmol/dm3). The obtained results showed that there was a need to divide the precipitation process into two steps based on the precipitation characteristics of the target elements in NaOH (or HCl)-H2O solutions. These two steps consist of a first stage with precipitation of Ca(OH)2, Mg(OH)2, and Mn(OH)2 by NaOH and a second stage with Li2CO3 recovery by neutralization using HCl, carbonation using Na2CO3, and concentration using evaporation. Chemical modeling with OLI-Systems® software was used to interpret the precipitation behavior of target elements in the first and second stages; it was compared with available experimental data and good agreement was found. On the basis of the above data, it was possible to separate Ca, Mg, and Mn under pH values ranging from 11.5 to 12.5 in the first stage after the process of seawater adsorption with manganese oxide adsorbent and to recover crystalline Li2CO3 with high purity (over 99%) carbonated by Na2CO3 in the second stage, involving neutralization by adjusting the pH value in the range of 6–8 and evaporation at 100°C to obtain the product with high yield. [ABSTRACT FROM AUTHOR]

Abstract: A hydrometallurgical process was developed to recover lithium from a brine collected from Salar de Uyuni, Bolivia, which contains saturated levels of Na, Cl and sulphate, low Li (0.7–0.9g/L Li) and high Mg (15–18g/LMg). Unlike other commercial salar brines currently being processed, the high levels of magnesium and sulphate in Uyuni brine would create difficulties during processing if conventional techniques were used. A two-stage precipitation was therefore first adopted in the process using lime to remove Mg and sulphate as Mg(OH)2 and gypsum (CaSO4.2H2O). Boron (at 0.8g/L in the raw brine), a valuable metal yet deleterious impurity in lithium products, could also be mostly recovered from the brine by adsorption at a pH lower than pH11.3 in this first stage. The residual Mg and Ca (including that added from lime) which were subsequently precipitated as Ca–Mg oxalate could be roasted to make dolime (CaO∙MgO) for re-use in the first stage of precipitation. Evaporation of the treated brine up to 30 folds would produce 20g/L Li liquors. The salt produced during evaporation was a mixture of NaCl and KCl, containing acceptable levels of sulphate, Mg, Ca, etc. The final precipitation of lithium at 80–90°C produced a high purity (99.55%) and well crystalline lithium carbonate. [Copyright &y& Elsevier]

Abstract: Li1.6Mn1.6O4 was prepared by calcinating orthorhombic LiMnO2 at 410°C, which was synthesized using a hydrothermal reaction with LiOH and Mn2O3 as the starting reagents. After the Li1.6Mn1.6O4 had been leached with diluted hydrochloric acid, an ion-sieve for lithium (H1.6Mn1.6O4) was obtained. The pickling reaction reached balance quickly, the ratio of extracted lithium was above 90% and the loss ratio of dissolved Mn was under 2.5%. Physical analysis showed that the basic microstructure and surface topography of the materials remained unchanged in the process of pickling and adsorption. The chemical stability of the materials was sufficiently high. The adsorption capacity rose sharply when the pH value was greater than 11; a buffer system was essential to increase the adsorption capacity in weak acidic solution. The adsorption reaction could reach balance quickly in brine because of an increase in temperature; the maximum uptake of lithium from brine was 27.15mg/g at 50°C. Dissolved Mn did not affect the adsorption capacity. The adsorption rate of lithium from brine was over 99% under certain conditions in brine. Circulation tests showed that the adsorption capacity decreased as the number of cycles increased. The adsorption and desorption capacity were still more than 20mg/g after 10cycles. Larger separation coefficients indicated that high concentrations of Mg2+, Na+, and K+ in brine had a slight adverse effect on lithium recovery using an ion-sieve, and the final lithium carbonate of reagent grade was obtained by a series of steps. [Copyright &y& Elsevier]

Abstract: Preparation of lithium carbonate from spodumene concentrate was carried out by a sodium carbonate autoclave process. The effects of different operation conditions including liquid-to-solid ratio, Na/Li ratio, agitation speed, reaction temperature and reaction time on the lithium carbonate conversion efficiencies were initially investigated. The results show that the conversion efficiency is not less than 94% under the optimal conditions. The purity of the obtained lithium carbonate can reaches up to 99.6%, which is higher than that obtained by sulfuric acid method. [Copyright &y& Elsevier]

Abstract: In this study, Li2CO3 was extracted from a zinnwaldite concentrate with 1.21% Li and 0.84% Rb prepared from zinnwaldite wastes (0.21% Li, 0.20% Rb). These wastes originated from dressing of Sn–W ores, which were mined in the Czech Republic in the past. Processing of the zinnwaldite concentrate consisted of roasting the concentrate with CaCO3 followed by water leaching of the resulting calcines. This method made it possible to extract about 90% of Li as well as Rb. Lithium carbonate products were separated from leach liquor using two different procedures. The first one comprised conversion of the original alkaline leach liquor to carbonated solution by CO2 bubbling, solution purification and Li2CO3 crystallization during water evaporation. The second procedure consisted of lithium solvent extraction from the original leach liquor using LIX 54 and TOPO as an extraction agent followed by stripping with diluted H2SO4, solution purification and lithium carbonate precipitation with K2CO3. Water-washed lithium carbonate salts were produced in both procedures and contained almost 99.5% Li2CO3 with the first method providing higher yield. Mother liquors after Li2CO3 crystallization and/or inorganic phases after lithium solvent extraction are suitable intermediates for production of rubidium compounds, such as Rb2CO3, Rb2SO4 or RbOH. [Copyright &y& Elsevier]

Ongoing research to develop a new generation of materials to achieve a more reliable and higher energy density lithium-ion batteries has attracted working groups attention worldwide in academia and industry. Products like lithium carbonate or lithium hydroxide are fundamental as the main feedstock for future materials. Recently, metal-atom substituted cathode materials with various metals has proved to improve the life-time, stability and performance of cathodes and consequently of the batteries. In this regard, this publication describes an approach to remove calcium impurities from industrial Lithium-rich brines with oxalic acid. Moreover, the present magnesium is reduced by the precipitation of magnesium hydroxide in a controlled manner in order to obtain a Lithium-enriched brine with a well-defined magnesium concentration in the absence of calcium. Finally, a process is presented to produce high purity lithium carbonate with controlled concentrations of magnesium between 1% to 3% as magnesium hydroxide. The magnesium hydroxide containing lithium carbonate is produced in a co-precipitation step, where initially the magnesium hydroxide is precipitated and subsequently the lithium carbonate is precipitated in a one-pot process. • Up to 90% removal of initial Ca from three Li-rich brines with varying Ca concentrations. • Control of Mg concentration in solution to yield lithium carbonate with defined Mg content. • Li 2 CO 3 with Mg concentrations from 1% to 3% was obtained in excellent yields >85%. [ABSTRACT FROM AUTHOR]

A hydrometallurgical process was developed to extract lithium from a spent lithium-containing aluminum electrolyte, reduce the stacking of spent aluminum electrolyte, and recover the valuable elements. In this study, we extracted lithium from an electrolyte using the following three steps: 1) leaching with HNO 3 − Al(NO 3) 3 , 2) neutralizing the leachate obtained in the first step, and 3) precipitating the lithium carbonate. A lithium extraction efficiency of 88.0% could be achieved after a leaching time of 6 h, at a leaching temperature of 80 °C and an Al/F molar ratio of 1:6. During the process of neutralization, Al3+ and F− was precipitated as Al 2 ((OH) 0.46 F 0.54) 6 (H 2 O). The obtained Li 2 CO 3 with a high purity of 98.8%. Unlabelled Image • Li 2 CO 3 was recovered from lithium-containing aluminum electrolytes with aluminum hydroxyfluoride hydrate byproduct. • The process involved leaching, neutralization, and precipitation • Most suitable leaching time, temperature, Al/F molar ratio were 6 h, 80 °C, 1:6. [ABSTRACT FROM AUTHOR]

Lithium carbonate precipitation from a Li 2 SO 4 solution in a stirred crystallizer in semi-batch processes was investigated and compared using a heterogeneous CO 2 reaction and homogeneous Na 2 CO 3 reaction. Nucleation and crystal growth were successfully monitored by an inline Particle Track based on the focused beam reflectance measurement technique. The results obtained indicate that the particle size decreased with an increase in mixing speed for both precipitation processes. However, the CO 2 feed rate in the heterogeneous reaction and the pumping rate of Na 2 CO 3 in the homogeneous reaction did not have a significant impact on the particle size distribution. Temperature and the final pH play critical roles in precipitation when using CO 2 as a reactant. High alkaline conditions are needed to induce heterogeneous precipitation. The lithium recovery with homogeneous precipitation was higher than with heterogeneous precipitation, probably due to the gas-liquid mass transfer phenomena of absorption influencing carbon dioxide conversion to carbonate ions in heterogeneous precipitation. Agglomerates of leaf-shaped primary crystals were mainly obtained. • Heterogeneous and homogeneous precipitation of Li 2 CO 3 were studied and compared. • Particle size decreased with the increase of mixing intensity. • Temperature and final pH play important roles in heterogeneous precipitation. • Homogeneous precipitation resulted in higher recovery efficiency of lithium. [ABSTRACT FROM AUTHOR]

In this work, membrane electrolysis technology is used to conduct the basic research on directly preparing lithium carbonate powders with lithium chloride solution, mainly exploring the influence of electrolyte concentrations, electrolyte temperature, current density and carbon dioxide flowrate on the physical phase, micro morphology and particle size of lithium carbonate. By comparing the results of XRD analysis and SEM micromorphology, it was found that the products with higher diffraction peak representing crystal plane (−110) had mostly lamellar planar structure, while the products with higher peak representing crystal plane (002) had mostly rod-like line type structure. Under the conditions of higher anolyte concentration, lower catholyte concentration, lower temperature and lower current density, is beneficial to obtain single crystal structure with small size, but the cross growth of numerous monocrystalline will increase the final crystal size. Besides, the smallest size product was obtained under the conditions of anolyte with LiCl concentration of 300 g/L, catholyte with LiCl concentration of 50 g/L, electrolyte temperature of 50 °C, current density of 100 mA/cm2 and carbon dioxide flowrate of 1.0 L/min. The experimental results show that it has great potential and space to research on the direct preparation of lithium carbonate by membrane electrolysis. • Membrane electrolysis is used to conduct basic research on directly preparing Li 2 CO 3. • The influence of 5 factors on the physical chemical characteristics of Li 2 CO 3 were studied. • Two crystal types corresponded to (002) and (−110) crystal planes with higher XRD peaks. • Experimental parameters for obtaining the minimum particle size of Li 2 CO 3 were obtained. [ABSTRACT FROM AUTHOR]