What miracles have not been prepared on Earth for man! For example, an amazing sight - white sand. From afar, you won’t understand right away: whether it’s snowdrifts in the middle of summer, or mountains of granulated sugar, or maybe table salt or another chemical? And only approaching, taking in the palm of your hand and waking through your fingers, you understand that this is white sand, a photo of which is given in this article. And it consists of quartz - a mineral common on Earth. Quartz is included in the mineral composition of oligomictic and polymictic sands, which compose desert dunes, dunes of coasts, shallows of water bodies.
Natural white sand
Deposits of quartz sand are found in river valleys. White river sand is the purest, usually it does not contain pollutants, as well as mountain quartz sand, weathered vein outcrops. It is likely to find nuggets of precious metals or their minerals in deposits of natural quartz sand. There is white sand buried under the strata of other sedimentary rocks and mined by a quarry method. It usually contains contaminants in the form of admixtures of clays, sandy loams, loams, polymictic sands, which are found in the thickness of quartz sand in the form of interlayers and lenses.
Creation of nature and human hands
White sand, consisting of 90-95% of quartz, is not so common and is very much appreciated as a raw material for many industries. The lack of natural sand can be compensated for - to obtain artificial quartz sand using crushing and screening equipment. For the production of sand, monolithic blocks of milk-white quartz are used, crushing them and sifting the destroyed rock, they obtain sand with specific and necessary particle sizes (fractions). Artificial sand differs from natural sand in exceptional monominerality, acute-angle sand grains.
Where is quartz sand used?
White sand is used to make glass. Such requirements are imposed on it: it consists of 95% quartz, must be medium-grained (diameter of grains of sand 0.25-0.5 mm), without an admixture of substances insoluble in glass mass, without harmful admixtures of minerals containing iron, chromium, and titanium (they color the glass and increase its light absorption). Good glass sand is considered to be one that is 98.5% quartz and contains no more than 0.1% iron oxide.
Quartz glass is needed for the manufacture of chemical glassware, in instrumentation - it withstands significant temperature extremes. For molds and cores in the foundry of ferrous and non-ferrous metals, quartz sand is also used, which is called molding sand in metallurgy. The quality of this sand is determined by its
particle size distribution and the shape of particles that affect gas permeability, and the amount of impurities that reduce the refractoriness of sand. It is necessary that in the sands there are no minerals with a high content of sulfur and phosphorus, which are harmful to metal casting. Quartz sand is used to produce
grinding wheels and “sandpaper” - for this sand is melted with graphite and carborundum is obtained, which is inferior in hardness only to diamond. Exceptional dirt capacity (sorption capacity) of quartz sand is used in filters to purify water from iron and manganese oxides. This sand is used in construction for plastering surfaces and for the production of finishing panels,
concrete blocks. Use in landscaping. And even coffee, warmed up in a marmit filled with white quartz sand, will delight you with its aromatic taste.