Recycling is the process of collecting, separating, processing and selling recyclable materials to convert them into new products. Recycling, recovery and reprocessing of waste materials for use in new products. The basic stages of recycling are the collection of waste materials, processing or manufacturing them into new products and the purchase of those products, which can then be recycled. Typical materials that are recycled include scrap iron and steel, aluminum cans, glass bottles, paper, wood, and plastics.
Materials reused in recycling serve as substitutes for raw materials obtained from increasingly scarce natural resources such as oil, natural gas, coal, minerals and trees. Recycling can help reduce the amounts of solid waste deposited in landfills, which have become increasingly expensive. Recycling also reduces air, water and land pollution as a result of waste disposal. The recycling of metals such as iron means that these materials can be reused, saving energy and reducing the impact on the environment, since fewer mines and quarries are needed to extract finite reserves of metallic minerals.
Internal recycling is the reuse in a manufacturing process of materials that are a waste product of that process. An example of external recycling is the collection of old newspapers and magazines for pulping and manufacturing them into new paper products. We can recycle paper and cardboard, plastic food packaging, glass, metal packaging, cardboard packaging and food waste. Recycling is economically attractive when the cost of reprocessing waste or recycled materials is lower than the cost of treating and disposing of materials or of processing new raw materials.
In addition to preventing waste from ending up in landfills, recycling brings many benefits to society and the environment. Waste incineration plants use catalysts to prevent pollutants and emissions from being released into the atmosphere, making this recycling method environmentally friendly. Another form of internal recycling is observed in the distillation industry, in which, after distillation, used cereal puree is dried and transformed into edible feed for livestock. Mechanical recycling transforms waste materials into new products without changing their chemical composition.
External recycling consists of recovering materials from a product that has worn out or has become obsolete. Despite its significant benefits, waste recycling is not a perfect solution to pollution and landfill problems. Aluminum cans and glass bottles are other examples of everyday objects that are externally recycled on a large scale.