Glass recycling

Glass recycling is the processing of waste glass into usable products. Glass waste should be separated by chemical composition, and then, depending on the end use and local processing capabilities, might also have to be separated into different colors. Many recyclers collect different colors of glass separately since glass retains its color after recycling. The most common types used for consumer containers are colorless glass, green glass, and brown/amber glass. Glass is ideal for recycling since none of the material is degraded by normal use.

Glass makes up a large component of household and industrial waste due to its weight and density. The glass component in municipal waste is usually made up of bottles, broken glassware, light bulbs and other items. Adding to this waste is the fact that many manual methods of creating glass objects have a defect rate of around forty percent. Glass recycling uses less energy than manufacturing glass from sand, lime and soda.

Every metric ton (1,000 kg) of waste glass recycled into new items saves 315 kilograms (694 lb) of carbon dioxide from being released into the atmosphere during the creation of new glass. Glass that is crushed and ready to be remelted is called cullet.

Many collection points have separate bins for clear, green and amber. Glass reprocessors that intend to make glass containers require separation by color, because glass tends to retain its color after recycling. If the recycled glass is intended for other products, or if the glass reprocessor uses newer optical sorting equipment, separation by color at the collection point may not be required. Heat-resistant glass like Pyrex or borosilicate glass should not be disposed of in the glass container as even a single piece of such material will alter the viscosity of the fluid in the furnace at remelt.

When glass is used for new container manufacturing, it is virtually infinitely recyclable. The processing and use of recycled glass in manufacturing conserves raw materials, and reduces energy consumption. That which is not recycled, but crushed, reduces the volume of waste sent to landfills.

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