Fly-ash is not categorized as a hazardous waste however it poses two big problems: 鈥?Large areas of land is required for its disposal 鈥?Toxicity associated with heavy metal is leaked into the groundwater.
However Jerry Stackhouse Jersey , Fly ash, which was widely regarded as a water and air pollutant till a decade back, is in fact resourceful and has also proven its worth over a period of time by emerging not only as usable material but also as an environment saviour.
Fly ash is a naturally-cementatious, which means it naturally has a binding property. It is extracted by the precipitators in the smokestacks of coal-burning power plants to reduce pollution. There are near about 130 thermal power plants in the country, the majority of which Bill Laimbeer Jersey , 84% to be exact, runs on coal. These plants use about 500 million tonnes of coal every year and the figure is ever increasing. The coal mined in India has high percentages of ash (35% - 45%) as compared to other coal-rich locations of the world. In addition, the calorific value is also less (3500 - 4000 kcalkg) which results in higher coal requirement for similar amount of energy produced.
Until recent times, the fly-ash produced was just releases into the atmosphere with other flue gases or was dumped in specially constructed ash-ponds or landfills. Still more than 65% of fly-ash all over the world is dumped in land. In India alone, fly ash landfills cover an area of approximate 80 Grant Hill Jersey ,000 acres or to bring it to comparison, half of Mumbai.
That still accounts for only 65% of fly-ash. The rest is however in good hands and gets recycled or reused in many innovative, different and eco-friendly applications, such as 鈥?Admixture in cementconcretemortar 鈥?Lime pozzolana mixture (bricksblocks) 鈥?Cement Industry 鈥?Low lying area fill 鈥?Roads & Embankments 鈥?Dyke Raising 鈥?Brick manufacturing 鈥?Paint industry, agriculture etc.
We will get to more details on these usages below.
Cellular Light Weight Concrete (CLC) Blocks 鈥?These structures or blocks are a modern replacement for conventional brick. They are lighter but stronger and helps in keeping the surroundings cool as well as environment friendly. Fly-ash is a major constituent in manufacturing of these bricks along with cement Christian Laettner Jersey , sand, water and foam.
Polymer Composites 鈥?Fly-ash has also been used in developing composites by a laboratory in Bhopal, Madhya Pradesh. In the structure, fly ash is used as a filler material between threads of jute cloth as reinforcement. After various curing processes at specific temperatures and pressures, the jute cloth is transformed into a laminate which can be added based on the required thickness. This kind of material is a substitute for wood and can be used in a variety of applications like door shutters Joe Smith Jersey , partition panels, flooring tiles, wall panelling, ceiling, etc. One commercial plant is also set-up for the same technology near Chennai.
Portland Pozzolana Cement 鈥?A specific grade of fly-ash can directly be used instead of cement as a blending material in concrete mixtures. Such mixtures have a significant growth in quality and durability properties.
Ready Mixed Concrete 鈥?Fly ash can be used in high quantities in ready mix concrete. Since the ready mix concrete is produced in controlled environments in factories Mateen Cleaves Jersey , it is practical to include fly ash to retain or strengthen the required properties of the concrete which is not as suitable to perform on construction sites.
Sand-Lime-(Gypsum Cement) Bricks Blocks - Fly Ash can also be used in manufacturing of limestone or sand blocks due to its extensive binding properties.
Road Construction 鈥?Roads and highways are one of the most accepting applications for Fly-Ash. That is why, NHAI 鈥?National Highways Authority of India is currently using approximate 10 million cubic metres of fly ash in its projects. 鈥?Fly-Ash can substitute the layer of soil which otherwise is conventionally used. 鈥?No low lying areas are created since no soil excavation is done. 鈥?Cost of excavating the soil and laying it on the roads is completely saved.
Roller compacted concrete 鈥?The hydrophobic properties of fly-ash helps it to be used in construction of various dams through roller compacted concrete techniques. The use of fly-ash lowers the heat, thus allowing thicker placements to occur. Ghatghar Dam Project in India is one such example of its use.
Embankment 鈥?Due to high number of uniform particles present in Fly-ash, it is perfectly engineered to be used in Embankments. Unlike typical soils which were previously used, Fly ash has uniform grain size distribution Dennis Rodman Jersey , compaction characteristics, high shear strength and compressibility, permeability and frost susceptibility.
Asphalt concrete 鈥?Smaller particles of Fly-Ash helps it to entrap between bigger particles of construction aggregate and increases the binding force. High binding force gives asphalt pavements better resistance to stripping.
Agriculture - Fly ash is used as a soil modifier and source of economical plant nutrients, both with or without organic manure bio and chemical fertilizers. It is observed that a Dose of 30 to 50 tonnes per hectare of land increases the growth of grains by 15%, green vegetables by 35% Terry Mills Jersey , and root vegetables by a healthy 50%. Use of Fly-Ash also es crust formation.
All the above mentioned uses and applications of fly ash rendTweet
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