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What is Glass Recycling?

When it comes to glass recycling, a common question is, “Is glass recyclable?” & “How is Glass Recycled?”. Yes, glass is 100% recyclable. It can be recycled any number of times without losing its purity and quality.

Glass is a wonderful substance. It can be recycled over and over again. The good thing about glass recycling is that the glass retains its quality. Cullet, better known as domestic glass, is the most common glass. Imagine how many bottles of soda, juice, and glass jars are used daily. If we were to simply throw them away, the environment would suffer greatly. It is therefore important that the culture of recycling be kept alive.

Cullet is easy to recycle. It has an unlimited life. It can be melted and recycled endlessly to make quality new glass products. The glass manufacturers mix cullet—a granular material made by crushing bottles and jars — with limestone, sand, and other raw materials, and melt the glass to manufacture new glass containers.

According to Glass Packing Institute, 10 million metric tons of glass are disposed of every year in the US, and yet only 33% of waste glass gets recycled, which pales when compared with the 90% recycling rate in Switzerland, Germany, and other European countries.

This post contains information on what types of glasses can be recycled and what are non-recyclable. The complete glass recycling process is explained here, along with other essential details like the price of recycling glass, the end product of glass recycling, and relevant FAQs.

But before we dive into the glass recycling process, let us first know what type of glass can be recycled.

What Type of Glasses Can be Recycled?

woman-recycling-glass-garbage

Almost all glasses which are sold as food packaging can be recycled. Some of the examples are as follows:

  • Glass containers
  • Food storage glass containers
  • Mason glass jars
  • Glass bottles of alcoholic drinks, soft drinks, etc.

What Type of Glasses Can’t Be Recycled?

Following are the types of glasses that can’t be recycled:

  • Computer monitors, phone screens
  • Ceramics, Pyrex, or other heat-resistant glass
  • Safety glass, car windshields
  • Broken glass
  • Light bulbs
  • Ceramics, pyrex, decorative glass
  • Plate glass: windows, sliding doors (can be recycled separately)
  • Art glass and leaded crystal
  • Mirrors
  • Drinking or wine glasses and plates

How Is Glass Recycled?

Following is the step-by-step process of glass recycling:

Glass recycling process

Credit: Glass Container Recycling Loop

  1. Collection and Transportation:

    Glass is collected from all the glass drop-off bins and transported to the recycling center. Before going to the next step, all the glasses are checked for contamination and hazardous material.

  2. Sorting:

    The sorting stations carefully sort the glass waste. The first 2 stations sort the material unfit for recycling, usually light bulbs, cardboard, window frames, mirrors, aluminum cans, etc. The proceeding stations sort the non-brown glass to process separately.

  3. Breaking:

    Hammers break the glass into crude particles for further processing by spinning quickly around the axle in the glass recycling container. This machine uses water mist to control airborne particles.

  4. Trommel:

    The broken glass particles pass through a revolving screen to get further sorted. In this stage of the glass recycling process, paper labels are detached here and collected in a paper recycle bin. Other unfit items which can’t be shattered, like caps and lids, are also collected to recycle separately.

  5. Bed Drier Fluidization:

    Glass particles go through the drier where the air is heated to 190 degrees F. This process burns sugar and bacteria and loosens the glue. These residues float at the top and get sucked out via a vacuum system.

  6. Primary Screening:

    The glass recycling machine now screens the size of the particles for different purposes. It also produces the size grades for other customers.

  7. Pulverization:

    Bigger glass particles are sent through the pulverizer. It also uses hammers to break the particles into smaller sizes further. All particles recirculate before ultimately being screened.

  8. Secondary Rotary Screening:

    After primary screening and pulverization, particles are passed through secondary screening. Here they are separated into 4 size grades according to different end markets. Those sizes are 12 to 20 mesh, 20 to 40 mesh, 40 to 70 mesh, and 70 mesh and smaller.

  9. The Final Product – Cullet:

    The final product of the process of recycling glass is known as the cullet. They may look like pebbles, sand, or powder according to their grade (size).

glass-cullet-glass-recycling

Recycling glass is simple and, as most families go through several glass jars and bottles in a week, an act of recycling can be very beneficial, accompanied by several advantages and, of course, disadvantages.

How Does Recycling Glass Help the Environment?

By simply recycling glass, we can:

  • reduce non-renewable fossil fuel usage
  • reduce the emissions of process CO2 from carbonate raw materials such as limestone.

Learn More: All About Glass Recycling Machine

Pros and Cons of Glass Recycling

Advantages of Glass Recycling

  1. Recycling of Glass Saves Energy

    The recycled glass melts at a lower temperature than its raw material components. The amount of energy required to make glass from scratch is 40% more than that needed to recycle it. If recycling is done on a large scale, maximum profit is achieved. Research has shown that recycling a glass bottle can produce enough energy to light up a normal bulb for 4 hours.

  2. Recycling of Glass Reduces Industrial Pollution

    The levels of pollutants that are released daily into the air around the world are very alarming. Recycled glass reduces the emissions of air and water pollution by around 20% and 40% respectively. Reducing industrial pollution benefits not only the environment but also the entire ecosystem.

  3. Glass Recycling Pays

    Some countries have capitalized on the financial gains that can be had from recycling glass. In America for instance, some states have recycling programs that offer cash incentives for most recycled glass products.

  4. Recycling of Glass Conserves Natural Resources

    Recycling glass saves on the need to obtain more raw materials to make new glass. Industrialized nations with strong economies are aware that their economies grow more when monies do not have to be earmarked for tree planting or purchasing fossil fuels. By recycling glass, they save the natural resources that they already have.

  5. Recycling of Glass Conserves the Landscape

    The aesthetic value of the environment is greatly improved through glass recycling. Many people tend to litter parks and parking lots with glass and other packaging. Due to the inorganic nature of glass, it will never decay. Recycling glass is very simple, and you can start the process by dropping the glass you have into recycling bins.

  6. Recycling of Glass Is Good for the Environment

    A glass bottle sent to a landfill can take up to a million years to break down. On the other hand, a glass bottle from your kitchen takes as little as 30 days to leave your recycling bin and appear on a store shelf as a new glass product.

  7. Recycling of Glass Is Sustainable

    Since glass containers are 100% recyclable, they can be recycled endlessly with no loss of quality or purity.

Disadvantages of Glass Recycling

  1. Not All Glass Can Be Recycled

    Even though glass items can be recycled, there are a few exceptions. For example, glass from light bulbs and window panes cannot be recycled because they contain ceramics and other impurities that would contaminate the entire recycling process.

  2. Glass Recycling Creates Unemployment

    It has been argued that glass bottle recycling has a significant impact on employment within the glass manufacturing industry. Millions of individuals who would have otherwise been gainfully employed providing manpower to create new glass items lose out on this opportunity as fewer people are needed to work in glass recycling plants.

  3. High Costs Associated With Glass Recycling

    For glass to be properly recycled, it has to be separated by color. This process is quite a labor intensive and rather complicated. Recycling in most countries is also done overseas due to a lack of proper facilities locally, making it very costly.

  4. Glass Is Becoming the Contaminant 

    Glass is increasingly becoming a contaminant in a single recycling stream. The broken glass can contaminate other recyclables like paper and cardboard, lowering their value.

  5. Broken Glass Is Difficult to Sort 

    Broken glass is difficult to sort, and if it’s broken down too finely, it may become too difficult to reprocess. When it is too difficult or expensive to separate the glass, the recyclers send the entire stream to the landfill. According to Recycle Across America, more than 28 billion glass bottles and jars end up in landfills every year.

What Products Are Obtained From Glass Recycling?

The glass cullet is used to manufacture many products. Some of them are as follows:

  • Adsorbents
  • Abrasives
  • Ammunitions
  • Containers
  • Hydroponic rooting
  • Additive/flux – metal foundry
  • Binder/flux – brick and ceramic
  • Filtration medium
  • Fiberglass
  • Filler – paint, and plastic

How Productive is Glass Recycling?

Glass recycling is a highly productive exercise for the environment. A significant amount of natural resources are protected by recycling glass. When 10% cullet is used in manufacturing, you save 2.3% on energy costs.

How is Recycling Glass Better Than Making Glass From New Raw Material?

In every way, recycling glass is better than letting it go in landfills and using the space which can be filled with other non-recyclable materials. Many energy resources are also exhausted in making glass from new raw materials.

On the other hand, the cullet is broken down to the required size and melted, preventing energy expense. By saving energy, related air and water pollution also gets reduced.

FAQs:

  1. Can All Glasses Be Recycled?

    No. Some glasses can’t be recycled. You will learn about them in the upcoming section.

  2. How much is glass recycling worth?

    On average, you can earn 0.10 USD/LB from recycling glass. It may vary according to the state from where you are operating.

  3. How much does recycling glass conserve energy?

    You can operate a 100-watt light bulb for 4 hours by saving energy by recycling one glass bottle. One notable fact is that 1 glass bottle takes 1 million years to break down at the landfill.

  4. Can you recycle broken glass?

    No, broken glasses can’t be recycled. They need to be treated as junk.

  5. How is recycled glass used?

    Glass can be recycled infinite times. Therefore, many products can be manufactured using recycled glass. Some of the prominent examples are:

    • Fiberglass
    • Foam aggregate
    • Ground cover
    • Countertops
    • Containers

  6. What will be the effects on the environment if the glass is not recycled?

    If glass recycling is not done, the landfills will be full of glass trash, and many energy resources will be exhausted in making new glass. Eventually, air and water pollution will also increase. So not recycling the glass is certainly not good for the environment.

  7. Can you Recycle Colored Glass?

    Yes, colored glass can be recycled, but with limitations. Common colors like green, amber, and clear are usually accepted. Less common colors might require a special recycling center

  8. Can frosted glass be recycled?

    Generally not. Frosted glass often has a coating that can contaminate the recycling stream. There might be exceptions for frosted glass treated with sandblasting, which is a non-chemical technique. It’s always best to check with your local recycling program for frosted glass

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