Lithium adsorption from natural brine using surface-modified manganese oxide adsorbents

• Published in: Materials letters Vol. 251; pp. 214 - 217
• Main Authors: Ohashi, Fumihiko, Tai, Yutaka
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.09.2019; Elsevier BV
• Subjects: Adsorbents; Aluminum; Chemical synthesis; Composite materials; Crystal structure; Heat treatment; Inductively coupled plasma; Lithium; Lithium ions; Manganese; Manganese oxides; Materials science; Metal oxides; Nickel; Organic chemistry; Saline water; Spinel; Sulfuric acid; Transmission electron microscopy; Lithium; Composite materials; Spinel; Crystal structure; Manganese
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2019.05.064

•Metal-oxide coated spinel-type manganese oxides as a Li ion sieve were synthesized.•Li adsorption capacity and acidic durability were higher than that of uncoated spinel.•Lower Mn dissolution should be caused by substituting Mn(III) by other elements. A series of surface-modified lithium ion adsorbents was synthesized in a pH-controlled solution using impregnation method; different oligomeric metal-hydroxide precursors were added on the surface of a spinel-type manganese oxide (Li1.33Mn1.67O4), which was then heat treated. X-ray diffractometry indicated that the crystal structure of spinel was maintained after heating. Transmission electron microscopy revealed that their surfaces were partially covered with metal-oxide layers of 10–20 nm thickness. Loaded metal-oxide contents in mass % were 7.1 of Al and 11.8 of Ni, respectively. The effect of metal-oxide species on chemical stability of the resulting materials in 0.25 mol dm−3 H2SO4 solution was investigated by inductively-coupled plasma spectrometry. Metal-oxide coated Li1.33Mn1.67O4 showed lower manganese dissolution and higher lithium extraction, compared with that of the raw Li1.33Mn1.67O4.