Details

Autor(en) / Beteiligte

• Gu, Donglei
• Sun, Wenjun
• Han, Guofei
• Cui, Qun
• Wang, Haiyan

Titel

Lithium ion sieve synthesized via an improved solid state method and adsorption performance for West Taijinar Salt Lake brine

Ist Teil von

• Chemical engineering journal (Lausanne, Switzerland : 1996), 2018-10, Vol.350, p.474-483

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2018

Link zum Volltext

Quelle

ScienceDirect Journals (5 years ago - present)

Beschreibungen/Notizen

• C2H3LiO2·2H2O was firstly used as the lithium resource to synthesize precursor Li2TiO3. Melting of C2H3LiO2·2H2O (at 66 °C) during the early calcination stage can form liquid–solid phase and remarkably improve mixing of C2H3LiO2·2H2O and TiO2. Besides, huge heat and gases released during the reaction of dehydrated C2H3LiO2·2H2O and TiO2 (between 380 °C and 515 °C) accelerates the nucleation process and effectively inhibited agglomeration, which leads to a smaller particle size of Li2TiO3 (∼70 nm). Subsequently, Adsorption rate constant of obtained lithium ion sieve H2TiO3 reaches 0.0508 g/(mg·h). Seperation factor α (Li/Mg) reaches 5441.17, and lithium ion uptake of synthesized H2TiO3 could remain around 24.5 vmg/g after five adsorption–desorption cycles, meaning better adsorption selectivity and stability of lithium ion for West Taijinar Salt Lake brine. [Display omitted] •C2H3LiO2·2H2O and TiO2 were firstly applied to synthesize lithium adsorbent via solid state method.•Reaction mechanism between C2H3LiO2·2H2O and TiO2 was analyzed.•Seperation factor α (Li/Mg) in West Taijinar Lake reaches 5441.17.•Adsorption uptake remains 24.5 mg/g after 5 cycles in West Taijinar Salt Lake brine. Monoclinic β-Li2TiO3 (LTO) is regarded as a lithium adsorbent precursor. In order to inhibit agglomeration during solid state reaction, C2H3LiO2·2H2O instead of Li2CO3 was firstly used as the lithium resource to synthesize LTO. Lithium ion sieve H2TiO3 (HTO) was then obtained by acid treatment of LTO. Physicochemical properties of obtained LTO and HTO were characterized via powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and particle size distribution analysis (PSD). Lithium adsorption selectivity and stability of prepared HTO for West Taijinar Salt Lake were investigated. Solid state reaction mechanism of C2H3LiO2·2H2O and TiO2 was investigated by TG-DTA analysis. Results show that melting of C2H3LiO2·2H2O (at 64.5 °C) during the early calcination stage could form liquid–solid phase and remarkably improve mixing of C2H3LiO2·2H2O and TiO2. Compared to Li2CO3 used as the lithium resource, huge heat and gases released during the reaction of dehydrated C2H3LiO2·2H2O and TiO2 (between 380 °C and 515 °C) accelerate the nucleation process and effectively inhibits agglomeration, which leads to a smaller particle size (∼70 nm). It is shown that lithium uptake and adsorption rate were improved because of easier mass transfer during the ion-exchange process. Lithium adsorption behavior could be well described by the Langmuir isotherm and pseudo-second-order kinetic model. Seperation factor α (Li/Mg) of obtained HTO in West Taijinar Salt Lake brine reached 5441.17, meaning remarkable lithium adsorption selectivity in real lake brine. Besides, adsorption uptake remained 24.5 mg/g after 5 cycles in West Taijinar Salt Lake brine, which indicates obtained HTO has good stability.