The purity of quartz particles obtained by crushing the same quartz is different. Poly (propylene glycol) bis (2aminopropyl ether) (PEA) was used to separate quartz sand particles of different purity by flotation. Through flotation experiments combined with XRD, ICP, FT-IR, and XPS, the collection performance and adsorption principle were studied. Froth flotation results demonstrate that particles with higher purity can be more readily floated. Batch flotation results indicate that the first froth product (F1) has the highest purity and its removal rates of Al, K and Na reached 84.6%, 80.7% and 84.1%. The total impurity content (Al, K, Na) of F1 (448 ppmw), F2 (579 ppmw) and F3 (972 ppmw) is lower than the Feed (2717.4 ppmw) and their mass proportion is greater than 25%. XPS analyses confirm that the impurities are mainly enriched on the fracture surface. Consequently, the crushing-classification mechanism and the PEA adsorption model have been proposed. (C) 2020 Elsevier B.V. All rights reserved.