Industrial Ramie Growing on Reclaimed Ion-Adsorption Rare Earth Elements Mine Tailings in Southern China: Defibration and Fibers Quality

Abstract

Ramie plants (Boehmeria nivea) have been cultivated on ion-adsorption rare earth elements (REEs) mine tailings and showed a low ability to accumulate REEs, especially in the stems (ΣREE\u2009=\u200924\u2009±\u200917\xa0mg\xa0kg−1) with higher concentration in leaves and roots (ΣREE\u2009=\u200957 to 66\xa0mg\xa0kg−1). Ramie individual fibers were isolated using three degumming processes: a traditional alkali treatment (AT), a steam explosion (SE) treatment after a neutral (SEN) or after a basic (SEB) impregnation. Cellulose-rich (>\u200980%) fine fibers with very low amounts of non-cellulosic sugars (<\u20095%), low REE concentrations (ΣREE ≈ 4–6\xa0mg\xa0kg−1) and a high mechanical strength (tensile strength ≈ 260–540 cN/fiber, breaking point ≈ 20–50 cN/fiber) have been produced. However, SE degumming resulted in more degraded fibers with cracks slightly affecting their tensile properties.