La-containing magnetic zeolite synthesized from gangue by ball-milling method

Lanthanum-containing magnetic zeolite (LMZ) was fabricated from coal gangue by an energetic ball-milling method followed by hydrothermal process. Careful morphological, structural, and magnetic investigations show that the LMZ sample has a typical NaA zeolite structure with an diameter of 150–800 nm. La3+ ions and Fe3O4 evenly distribute in the LMZ particles. LMZ has a SBET of 47.88 m2/g, more than 9 times larger than that of the precursor zeolite. The phosphorus adsorption of LMZ is 8 times higher than that of the precursor zeolite. The maximum phosphorus adsorption is tested as 44.64 mg/g, much higher than those of the reported lanthanum composite and zeolite. The specific magnetism of LMZ is measured as 25.6 emu/g and more than 99.6% LMZ particles can be magnetically separated from water efficiently. LMZ could be reused for tens of times after proper chemical treatment. The phosphorus adsorption mechanism is discussed.