Klimpel Franziska, Bau Michael, Graupner Torsten
Department of Physics and Earth Sciences, Jacobs University Bremen, Campus Ring 1, 28759, Bremen, Germany.
Bundesanstalt für Geowissenschaften und Rohstoffe, Stilleweg 2, 30655, Hannover, Germany.
Sci Rep. 2021 Mar 5;11(1):5306. doi: 10.1038/s41598-021-84614-x.
Scandium is a critical raw material that is essential for the EU economy because of its potential application in enabling technologies such as fuel cells and lightweight materials. As there is currently no secure supply of Sc, several projects worldwide evaluate potential Sc sources. While elsewhere in Europe emphasis is placed upon secondary resources such as red mud, we investigated the potential of industrial garnet sand and its waste products. Since Sc readily substitutes for Mg and Fe in the crystal lattice of garnet, the garnet minerals almandine and pyrope, in particular, may show high Sc concentrations. Garnet sand, after being used as an abrasive in the cutting and sandblasting industry, is recycled several times before it is finally considered waste which eventually must be disposed of. Extraction of Sc (and rare earth elements, REE) from such garnet sand may generate added value and thereby reduce disposal cost. The studied garnet sands from different mines in Australia, India and the U.S., and industrial garnet sands commercially available in Germany from different suppliers show average Sc concentrations of 93.7 mg/kg and 90.7 mg/kg, respectively, i.e. similar to red mud. Our data also show that "fresh" and recycled garnet sands yield similar Sc concentrations. Within the framework of a minimum-waste approach, it may be feasible to utilize the industrial waste-product "garnet sand" as an unconventional source of Sc and REE, that reduces disposal cost.
钪是一种关键原材料，因其在燃料电池和轻质材料等赋能技术中的潜在应用，对欧盟经济至关重要。由于目前钪没有安全供应，全球多个项目在评估潜在的钪来源。在欧洲其他地方，重点放在赤泥等二次资源上，而我们研究了工业石榴石砂及其废品的潜力。由于钪在石榴石晶格中容易替代镁和铁，尤其是铁铝榴石和镁铝榴石这两种石榴石矿物可能含有高浓度的钪。石榴石砂在切割和喷砂行业用作磨料后，在最终被视为废品并必须处置之前会被多次回收利用。从这种石榴石砂中提取钪（以及稀土元素）可能会产生附加值，从而降低处置成本。我们研究了来自澳大利亚、印度和美国不同矿山的石榴石砂，以及德国市场上不同供应商提供的工业石榴石砂，它们的钪平均浓度分别为93.7毫克/千克和90.7毫克/千克，即与赤泥相似。我们的数据还表明，“新鲜的”和回收的石榴石砂产生的钪浓度相似。在最小化废物方法的框架内，将工业废品“石榴石砂”用作钪和稀土元素的非常规来源并降低处置成本可能是可行的。
