Sand is a natural granular material consisting of separate rock and mineral particles. It is determined by size, which is finer than gravel and more rough than mud. Sand can also refer to soil texture class or soil type; ie, soils containing more than 85 percent of sand-sized particles of mass.
The sand composition varies, depending on the source and condition of local rocks, but the most common constituents of sand in inland land and non-tropical coastal settings are silica (silicon dioxide, or SiO 2 ), usually in quartz form. The second most common type of sand is calcium carbonate, for example, aragonite, which has largely been made, over the last half-billion years, by various life forms, such as corals and shells. For example, this is the main form of sand seen in areas where corals have dominated ecosystems for millions of years such as the Caribbean.
Sand is a non-renewable resource during human life span, and sand suitable for making concrete is in great demand.
Video Sand
Composition
The exact definition of sand varies. The Unified Scientific Classification System used in engineering and geology complies with US Standard Sieves, and defines sand as a particle with a diameter between 0.074 and 4.75 millimeters. By another definition, in terms of particle size as used by geologists, sand particles have a diameter ranging from 0.0625 mm (or 1 / 16 mm) up to 2 mm. Individual particles in this size range are called sand grains . Sand grains are between gravel (with particles ranging from 2 mm to 64 mm by the last system, and from 4.75 mm to 75 mm in the previous) and mud (particles smaller than 0.0625 mm to 0.004 mm). The size specification between sand and gravel remained constant for more than a century, but a particle diameter as small as 0.02 mm was considered sand below the Albert Atterberg standard used during the early 20th century. The 1953 engineering standard published by the American Association of State Highways and the Transportation Department regulates the minimum sand sizes at 0.074 mm. The 1938 specification of the US Department of Agriculture is 0.05 mm. Sand feels sandy when rubbed between the fingers. Mud, by comparison, tastes like flour).
ISO 14688 has fine, medium, and rough sand quality ranging from 0.063 mm to 0.2 mm to 0.63 mm to 2.0 mm. In the United States, sand is usually divided into five sub-categories based on size: very fine sand ( 1 / 16 - 1 / 8 diameter mm), fine sand ( 1 / 8 mm - 1 / 4 mm), medium sand ( 1 / 4 Ã, mm - 1 / 2 mm), coarse sand ( 1 / 2 Ã, mm - 1 mm), and very coarse sand (1 mm - 2 mm). This measure is based on the Krumbein phi scale, where is the size? = -log 2 D; D into particle size in mm. On this scale, for sand values? varies from -1 to 4, with the division between sub-categories across numbers.
The most common constituents of sand, in inland land regulation and non-tropical coastal settings, are silica (silicon dioxide, or SiO 2 ), usually in quartz form, which, due to their chemical inaction and loud enough, are the most commonly resistant to weathering minerals.
The mineral sand composition varies widely, depending on the source and local rock conditions. The bright white sand found in tropical and subtropical beach areas is limestone limestone and may contain fragments of corals and shells in addition to other organic or organic fragments of matter, indicating the formation of sand depending on living organisms as well. The gypsum sand dunes of White Sands National Monument in New Mexico are famous for their bright white color. Arkose is sand or sandstone with considerable feldspar content, derived from weathering and erosion of granite rock outcrops (usually nearby). Some of the sand contains magnetite, chlorite, glauconite or gypsum. The rich sand of magnetite is dark to black, like sand derived from volcanic and obsidian basalts. Chloride-glauconite chalk sand is usually green, like sand derived from basaltic (lava) with high olivine content. Many of the sand, especially those found extensively in Southern Europe, have iron impurities in quartz sand crystals, giving a deep yellow color. The sand deposits in some areas contain garnets and other resistant minerals, including some small gems.
Maps Sand
Study
Individual grain studies can reveal much historical information about the origin and type of grain hauling. Quartz sand that has recently weathered from granite or quartz gneiss crystals will become angular. This is called a grus in geology or sharp sand in trading buildings where it is preferred for concrete, and in gardening where it is used as an amendment of soil to loosen the clay. Sand transported remotely by water or wind shall be rounded, with a characteristic pattern of abrasion on the surface of the grain. Desert sand is usually round.
People who collect sand as a hobby are known as arenofil. Organisms that thrive in sandy environments are psammophiles.
Usage
- Agriculture: The ideal sandy soil for plants such as watermelons, peaches and peanuts, and their excellent drainage characteristics make them suitable for intensive dairy farming.
- Aquaria: Sand makes the basic ingredients of a low-cost aquarium that some people think is better than pebbles for home use. It is also a necessity for marine coral tanks, which mimic an environment composed largely of aragonite sand that is crushed from corals and shells.
- Artificial Coral: Geotextile sandbags can serve as a base for new corals.
- An artificial island in the Persian Gulf.
- Beach food: The government moves sand to beaches where tides, storms or deliberate changes on the coastline erode the original sand.
- Bricks: Manufacturers add sand to clay mixtures and other materials for brick making.
- Casks: Rough sand makes up 75% of the ear.
- Concrete: Sand is often a major component of this important construction material.
- Glass: Silica-rich sand is a major component in general eyeglass.
- Cracked hydraulics: Drilling techniques for natural gas, which use spherical silica sand as a "support", material to withstand open cracks caused by the hydraulic fracture process.
- Landscaping: Sand makes small hills and slopes (golf course will be an example).
- Mortar: Sand is mixed with cement stone or Portland cement and lime for use in masonry construction.
- Cat: Mixing the sand with paint produces a textured layer for walls and ceilings or non-slippery floor surfaces.
- Rail: Engine drives and rail operators use sand to increase wheel traction on rails.
- Recreation. Playing with sand is a favorite beach time activity. One of the most loved uses of sand is making the sometimes complicated, sometimes simple structure known as sand castles. Such structures are notorious for their impermanence. Sand is also used in children's games. Special play areas that include significant sand areas, known as sandboxes, are common in many public playgrounds, and even in some single-family homes. The dunes are also popular among climbers, bikers, and beach train drivers.
- Road: Sand increases attraction (and thus traffic safety) in cold or snowy conditions.
- Sand animation: The performance artist drew images in the sand. Animated filmmakers use the same term to describe the use of sand on the windshield or backlight glass.
- Sand Casting: Wetting casters or oil-casting sand, also known as sand casting and then molding it into molds where they pour liquid. This type of sand should be able to withstand high temperatures and pressures, allow gas to escape, have uniform grain size and small and do not react with metals.
- Sand castle: Forming sand into palaces or other miniature buildings is a popular beach activity.
- Sandbag: It protects against floods and gunfire. Cheap bags are easily transported when empty, and unskilled volunteers can quickly fill them with local sand in an emergency.
- Sandblasting: Graded sand serves as an abrasive in cleaning, preparing, and polishing.
- Thermal Weapons: Although not widely used, the sand is used for heating and pouring on attacking troops in classical and medieval periods.
- Water filtration: Filter media using sand to filter water.
- Wu ???: an Islamic procedure for washing body parts.
- Zoanthid "skeleton": Animals in a marine benthic cnidarian order associated with corals and sea anemones, combine the sand into their mesoglea for structural strength, which they need because they lack the true frame.
Resources and environmental issues
Only some sand is suitable for the construction industry, for example to make concrete. Because population growth and towns and construction activities are consequently of great demand for these special types of sand, and natural resources are running low. In 2012, French director Denis Delestrac made a documentary entitled "Sand of War" about the impact of the lack of construction sand. This shows the ecological and economic effects of legal and illegal trades on construction sand.
The use of lots of sand requires a significant dredging industry, increasing environmental awareness of fish thinning, landslides and flooding. Countries such as China, Indonesia, Malaysia and Cambodia banned the export of sand, citing these issues as a major factor. It is estimated that the annual consumption of sand and gravel is 40 billion tons and the sand is a global industry worth US $ 70 billion.
Dangers
Although sand is generally non-toxic, sandblasting activities require precautions. Silica sand bags used for sandblasting now carry a user warning label to use breathing protection to avoid breathing fine dust produced. The safety data sheet for silica sand states that "inhaling excess crystalline silica is a serious health problem".
In areas with high pore water pressure, sand and salt water can form pumice sand, which is a colloidal hydrogel that behaves like a liquid. Quicksand produces a large enough barrier to escape for creatures caught inside, which often die from exposure (not from immersion) as a result.
See also
- Aggregate (geology)
- Beach
- Aggregate construction
- Desert sand (color)
- Drysand is dry
- Energetically modified cement (EMC)
- Heavy mineral sand deposit
- Oil Sand
- Particle size
- Quicksand
- The Rolling River
- Sand Island
- Sand rats
- Sandstone
- Sandstorm
- Sand theft
- Sing sand
- White Sand Monument
References
External links
Media related to Sand in Wikimedia Commons
- Sand Beach: What It Is, Where It's From and How It Happens Here - Beaufort County Library
- Ã, Beach, Chandler B., ed. (1914). "Sand". New Student Reference Work . Chicago: FE Compton and Co.
- Side Effect of Sand Mining
- The World of Walking Out of the Sand - New York Times
- Sand Mining In Indian River Causes Problems - New York Times
- How Sand Demand Kills Rivers In Africa - BBC
- Dubai Sand Import - BBC
Source of the article : Wikipedia
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