Trace and major minerals of (natural and manufactured) sand: the importance of manufactured sand for construction purposes and the preservation of rivers

One of the key activities and major occupations in various districts of India focusses on developing the infrastructure by building construction with a variety of materials such as sand, among others. The demand for sand, which is naturally available from rivers or artificially granulated by industries, is increasing because of the growing urbanization in India. This has put a lot of pressure on unsustainable riverine resources, and on the environment itself, on account of numerous factors. Properties of both kinds of sands and their minerals were determined by environmental magnetism (e.g.,: mass-specific susceptibility χ, anhysteretic ratio χ_ARM/χ, etc.), Fourier transform infrared spectroscopy, the Extinction coefficient and the Crystallinity index. We identified trace minerals (magnetite, hematite, etc.) and major minerals (e.g.,: quartz, feldspar, kaolinite, etc.) present in natural river and manufactured sand (M-Sand). The mineralogical characterization suggested that the grain size separation is meaningless for manufactured sand, and quartz is a major mineral for river sand (the Extinction coefficient ranges from 3.86–234). Content of magnetic minerals for manufactured sand (mean [s.d.] value of χ = 736 [386] × 10^–8 m³ kg⁻¹) is higher than for river sand (χ = 105 [122] × 10^–8 m³ kg⁻¹). Such high values of χ seem to be more favorable for properties of concretes, and hence they lead to a better replacement product. These results make M-Sand a suitable alternative for replacing traditional river sand and for preserving natural rivers.