Abstract: The quantitative analysis of mineral experiments with Czech FEI company MLA650F mineral liberation analyzer, use the MLA original sample method and MLA heavy mineral method to analyze the mineral composition in the southwest and southeast of Mu Us Sandy Land in Shaanxi Province and Inner Mongolia Autonomous Region, China. Results show that MLA650F have good repeatability and high accuracy, and the mineral types measured are richer than those measured using the optical microscope. However, unlike the optical microscope, it cannot directly provide the original color, shape, transparency, luster, surface fracture, and other characteristics of the mineral. Although the individual mineral content and the mineral analysis index measured by QEMSCAN and optical microscope have some differences, the mineral change trend is basically the same. It is concluded that the main light minerals in Mu Us Sandy Land are quartz-feldspar and the heavy minerals are hornblende-garnet. In addition, QEMSCAN and optical microscope show similar change trend of mineral analysis indexes of the same sample. The original sample method of MLA is consistent with the Q/TF and ATi indexes of the optical microscope and with the CIA indexes of chemical weathering. Results showed that the weathering in the southwest of Mu Us Sandy Land was stronger than that in the southeast. Although both QEMSCAN and optical microscope can reflect the sedimentary environment, in practice, it should be noted that the data used should be established in the same measurement system, and the experimental data measured by different laboratories or experimental methods should be carefully quoted.

Key words: QEMSCAN, mineral analysis, Mu Us Sandy Land