18-04-2011, 03:50 PM
Presented by
Sharana basava
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Recycling of steel and glass from demolished structure
Introduction
Metals are able to be recycled with steel being one of the most recycled materials in the world.
The most commonly recycled items are construction materials, cans, automobiles, appliances, and containers.
Steel does not lose any of its inherent physical properties during the recycling process.
glass can also be recycled most effectively.
History
The recycling process has been carried around thousands of years.
It was very common occurrence in ancient times to melt down metal items that had served their purpose, after melting down new items like house hold items made.
In world war it is major part of war to organize metal drives & that are recycled.
Benefits
The benefits are in two ways;
1. Environmental benefits.
2. Economical benefits
Environmental benefits
Saving in virgin(new) materials 90%
Reduction in water use 40%
Reduction in water pollution 76%
Reduction in air pollution 86%
Reduction in mining wastes 97%
Reduction in consumer waste generated 105%
Saving in energy 74%.
Economical benefits
Direct & indirect employment to lakhs of peoples involved in recycling industry.
Recycling sectors must be supported & promoted so that white goods are disposed of in safe manner.
Recycled facilities must be set up & supported by the government .
India is on the path to the one of the largest recycled materials generators over next decades.
Process of steel recycling
The major steps involved in process of recycling are;
1. Collection and transportation.
2. Separation and filtering.
3. Re-making.
Collection and transportation
First step is to collect scrap steel which is transported by truck, train etc to processing unit.
Checking hazardous wastes.
And laid over conveyer belt.
Separation and filtration
Conveyer belt feeds the scrap steel into a series of grinders & cutters and made small pieces .
Ferrous & non-ferrous materials are separated.
Re-making
Ferrous materials like iron & steel are melted down & reforged into new steel.
Chemicals used in recycling of steel
Commonly used chemicals in process of recycling of steel are;
1. Oxygen and calcium fluoride.
2. Sulfuric acid.
Ammonia and caustic soda(NaOH)
Facts about steel recycling
A steel frame for a 2000 sq. ft. two story house is equivalent to the material of about six recycled cars, a comparable wooden frame would take over 40 trees to produce.
Recycling of steel saves 74% of energy, enough to power 18 million houses of any city.
All steel cans are 100% recyclable.
Recycling 1kg of steel keeps 2kg of green house gases out of atmosphere.
For every ton of steel recycled approximately 1.5 ton iron ore. 0.5 ton of coal, and 50 kgs of limestone are saved.