Minerals are the main composition of soils. Soil minerals, especially secondary minerals, determine physical and chemical properties of soils. In this study, the X-ray diffraction ray experiments were carried out to study the mineral composition of eleven different color soft rocks and sands. The study found that the soft rock in Mu Us Sandy Land is mainly composed of quartz, potassium feldspar, plagioclase, calcite, montmorillonite, illite and kaolinite. The soft rock has various color types, such as yellow, grayish white, purple, grayish green. Different color soft rocks have different mineral composition. The grayish white soft rock has the lowest secondary mineral, accounting for only 5.4%; the light brown soft rock has the highest secondary mineral, up to 59%. The sands are composed of quartz, potassium feldspar, plagioclase, calcite, hornblende, montmorillonite, illite, of which the original mineral accounted for 93.5%, and the secondary mineral accounted for 6.5%.
The X-ray diffraction method and gas adsorption method were used to investigate the mineral composition and special surface area of different soft rocks, sands, and composed soil. The results showed that (1) Montmorillonite, kaolinite, potash feldspar, calcite, quartz, plagioclase and illite, constitute the soft rock. Quartz, potash feldspar, plagioclase, calcite, montmorillonite, illite, and kaolinite constitute the soft rock in the Mu Us sandy land. There are several types of soft rocks, and there are some differences in the mineral composition of different types. The highest primary mineral content is 94.6% and the lowest 41%; the secondary mineral content is the highest 59% and the lowest is 5.4; (2) The special surface area of different types of soft rock is quite different, and the special surface area is up to 17.14 m2g−1, the lowest is 3.12 m2g−1, and the average content is 9.98 m2g−1. The cation exchange capacity is up to 7.25 cmol(+)/kg, and the lowest is 3.36 cmol(+)/kg; (3) The fitting formula of secondary minerals and specific decomposition of arsenic sandstone, aeolian sandy soil and composite soil is y = 2.423e0.0871x, and the correlation coefficient R2 = 0.8258. The fitting formula for the exchange capacity of secondary minerals and cations is y = 3.105e0.0348x, and the correlation coefficient R2 = 0.9235.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.