How Does Colored Crushed Glass Sand Work?

What is glass sand?

Glass sand is any glass that is crushed into sand-sized particles. The technical term “cullet” refers to crushed glass at any grain size, from a fine powder to gravel-sized particles. There are a variety of ways to crush glass, ranging from industrial crushers or pulverizers to at-home crushers (Figure 1). There are even handheld crushers available for purchase.

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Glass is originally made from silica sand, which is obtained through mining and dredging. This sand is mixed with sodium carbonate, calcium magnesium carbonate, and limestone (all minerals found naturally in the environment) and melted at extreme temperatures. As the glass cools and solidifies, an amorphous silica structure is produced.

Sand is the second most used resource on Earth, after water, and is considered a nonrenewable, limited resource. Not all sand is the same because it varies by grain size and structure. Therefore, not all sand is suitable to be used for construction, agriculture, or glass manufacturing purposes. Due to a global demand for suitable sand, more sand is now consumed than is naturally produced, which has caused sand shortages in some parts of the world.

Glass is considered 100 percent recyclable and can be endlessly recycled without losing quality. However, only 31 percent of glass is recycled in the U.S. each year. Using waste glass cullet as a substitute for natural sand in glass manufacturing and construction has numerous benefits: it can prevent environmental damage that occurs through the mining and dredging of natural sand, free up landfill space, reduce greenhouse gas emissions, and save energy during the glass manufacturing process.

Is glass sand sharp?

No, glass sand is no sharper than regular sand! Although glass become shards when you drop a glass container, the process of crushing glass helps round out the particles, allowing it to be handled the same way we handle sand (Figure 2). Research at Tulane University shows that recycled glass sand is very similar in roundness to natural dredged sediments after it has been crushed or pulverized.

Is glass sand safe?

Glass sand is biologically inert, meaning that it does not leach any hazardous toxins into the environment above the regulatory thresholds for natural sand. Glass sand is also thought to be safer than natural sand when used for construction purposes such as grinding, crushing, or blasting. This is due to the amorphous silica structure of glass sand, whereas natural sand has a crystalline silica structure that is known to be carcinogenic. Health problems can occur when workers repeatedly inhale crystalline silica sand. To learn more about the health impacts from crystalline versus amorphous, visit the Agency for Toxic Substance and Disease Registry website.

Note: protective eyewear, dust masks, and gloves are recommended when working with glass sand or natural sand.

What are the demonstrated benefits of glass sand?

Chemical and geotechnical research studies have shown the suitability of crushed glass as an alternative to natural silica sand for construction, beach nourishment, and glass manufacturing. In addition, a variety of ecological research has been conducted that demonstrates the suitability of glass sand for plant growth, animal habitation, and human exposure. To learn more about ongoing research assessing the safety and suitability of glass sand in coastal communities, visit the ReCoast website.

Can plants grow in glass sand?

Glass sand has better drainage and compacts less than gardening or fill soil. At the Mississippi State University (MSU) Coastal Research and Extension Center in Biloxi, Mississippi, two outdoor mesocosm experiments were set up to compare coastal marsh plants’ ability to grow in recycled glass sand versus local fill soil (Figure 3). Results from the experiment showed that glass sand can serve as a beneficial addition to rain gardens, restoration sites, or any location where drainage, as opposed to compaction, helps promote plant growth and reduces rainwater surface runoff and flooding.

What can I do with glass sand?

Crushing glass for local uses can reduce glass shipping costs while also saving landfill space and reducing greenhouse gas emissions. Crushed glass can be used locally for various applications, including home gardens, landscaping, swimming pool filtration, sand blasting, and golf course sand traps.

The MSU Extension Service’s Sustainable Communities Program at the Central Mississippi Research and Extension Center is currently performing educational outreach and research on the benefits of increasing community recycling. Identifying ways to recycle glass waste is a top priority of the program because very little glass is recycled in Mississippi. This is primarily due to the lack of availability of local recycling programs and glass manufacturers. However, opportunities still exist to recycle glass locally and educate the public about the benefits of recycling. Figures 4–7 highlight how this is being done by MSU Extension.

Not only can glass be crushed at home or at local businesses, but local municipalities can also purchase glass pulverizers to make glass recycling available to their community. For instance, the Mobile County Commission was recently awarded a grant from the Alabama Department of Environmental Management to purchase a glass pulverizer.

Want to learn more?

The following Louisiana-based companies are pioneering solutions for recycling glass to promote sustainability in their local communities.

• Glass Half Full in New Orleans
  • Founded in , Glass Half Full has expanded their residential and commercial glass recycling program from New Orleans to Baton Rouge, Bay St. Louis, and Birmingham.
  • Visit Glass Half Full’s website to learn about how they expanded from a backyard operation to a successful business to promote glass recycling and more sustainable communities in the Gulf South.
• Backyard Sapphire in Lafayette
  • Founded in , Backyard Sapphire crushes glass into mulch for home garden and yard uses in their community.
  • Backyard Sapphire has partnered with local businesses and organizations to promote community-driven glass recycling efforts in the southern portion of the state.
• Glass Act Recycling in Alexandria
  • Founded in , Glass Act Recycling offers residential glass pickup in Alexandria.
  • The company sells their crushed glass to make a variety of products, including landscaping materials, sandbags, sandblasting materials, glass jewelry, and construction drainage materials.

Links

Andela Products

Backyard Sapphire

Cost Savings. Strategic Materials, Inc

Glass Act Recycling

Glass Filtration Media

Glass Half Full

Glass Cullet

Recycling Glass for Coastal Restoration (ReCoast)

References

Agency for Toxic Substances and Disease Registry (ATSDR). Silica ToxFAQs.

Beiser, V. (). The world in a grain: The story of sand and how it transformed civilization. Penguin.

Commission receives grant to improve the Mobile County Recycling Center. ().

Jani, Y., & Hogland, W. (). Waste glass in the production of cement and concrete – A review. Journal of Environmental Chemical Engineering, 2(3), –.

Makowski, C., Finkl, C. W., & Rusenko, K. (). Using recycled glass cullet for coastal protection: A review of geotechnical, biological, and abiotic analyses. Journal of Coastal Research, -.

If you want to learn more, please visit our website Yuchen Dingsheng.

Makowski, C., Rusenko, K., & Kruempel, C. J. (). Abiotic suitability of recycled glass cullet as an alternative sea turtle nesting substrate. Journal of Coastal Research, 24(3), 771-779.

Peduzzi, P. (). Sand, rarer than one thinks. Environmental Development, 11, 208-218.

Waste 360. Beach in a bottle.

The information given here is for educational purposes only. References to commercial products, trade names, or suppliers are made with the understanding that no endorsement is implied and that no discrimination against other products or suppliers is intended.

Publication (POD-10-24)

Glass is an extremely versatile product, providing many utilities and conveniences in our daily lives. However, when a glass item is no longer needed then it often ends up in landfills, slowly decomposing over the course of millions of years!

• 11 million tons of glass (bottles, windows, industrial, etc.) is used and discarded every year, but only 2-3 million tons is recycled back into bottles.
  • This is a small circular solution for glass recycling.
• Glass started as sand, and all these different types of glass can go back into sand.
  • This is a big circular solution for recycling glass!

Instead of digging big holes or blowing up mountains, turn the waste glass into sand. It is sustainable and always available by simply mining the urban waste stream.

Natural sand, used in various construction applications, is becoming more difficult and more expensive to extract. Turning waste glass back into sand allows glass to be reused and repurposed for construction. This type of circular lifecycle is exactly what our world needs to divert glass from landfill. Fight climate change and preserve the environment by turning glass into sand!

What is the process to make glass sand?

Converting waste glass into sand is a process that involves crushing and pulverizing the glass into fine sand-sized aggregate. Here are some of the common steps involved to turn glass into sand:

1. Collect Glass: Gather the glass you want to convert into sand. This might involve a Material Recovery Facility, community drop-off, or pick-up from local businesses. It can be household glass, and ceramics too! They all can go back to making sand.
2. Sort and Separate Glass: Make sure your glass is free from contaminants like metals, plastics, or other materials that could interfere with the crushing process. Andela’s glass pulverizer systems automatically remove these contaminants for you.
3. Crushing & Pulverizing: Break the glass into smaller pieces using a glass to sand machine. Andela’s glass pulverizers use a flexible impact system that crushes glass into usable aggregate the consistency of fine sand to gravel, eliminating the grinding process typical of other machines.
4. Sifting: If material other than glass (plastic, metal caps, or covers) goes through the pulverizer, then you want to separate it from the glass sand. Andela systems achieve this with a trommel separator and clean-up unit.
5. Cleaning: Simply put the glass sand / aggregates outside and any organics or small bits of paper quickly compost to make a natural sand / aggregate.

What equipment is needed to make glass sand?

To turn glass into sand, all that is needed is an Andela Glass Pulverizer System. Just pick a sized system to meet your processing needs. No need to ship waste glass to another glass processing company. Everyone can make glass sand and use the products in your local community!

Andela glass recycling systems usually consists of a metering surge hopper, glass pulverizer, conveyors, and a trommel separator. Together, all of these components are used to process and pulverize the glass into sand-sized aggregate.

How does a glass pulverizer system work?

There are different types of glass crushers and pulverizers, but they generally operate on similar principles. Here’s how they work:

1. Feeding Mechanism: Glass is fed into the crusher through a metering surge hopper and a conveyor belt. This can be manual or automated, depending on the type and scale of the crusher or pulverizer.
2. Crushing Mechanism: Once inside the pulverizer / crusher, the glass encounters rotating hammers that crush it into smaller pieces. The Andela flexible impactor selectively reduces the glass into sand with rounded edges. The high-speed impact force pulverizes the glass but leaves non-glass residue in its larger form.
3. Size Reduction: Andela machines reduce the glass with the flexible hammers and then the entire mix goes into the trommel screen where it is divided into sand, aggregates, and oversized residue.
4. Collection and Disposal: Glass sand goes into one bunker or bin, glass aggregate into a second bunker or bin, and the residue comes out the end. The residue can be further processed before disposal.

Why are Andela pulverizers the best for making glass sand?

Turning glass into sand is a challenge because the waste glass removed from the recycling or waste stream is not just glass. It is mixed with caps, corks, paper, small metals, and plastics. The Andela Technology with the flexible impactors for crushing and pulverizing glass is specifically designed to process this type of mixture.

You might ask – Why don’t we just use a rock crusher? They make sand that way? Rock crushers grind down all the bigger rocks into smaller particles like gravel and sand. Everything is ground through an internal grate or pinch point, and it must all get small together. If the glass isn’t pre-sorted and cleaned, the metals, plastics, paper, and corks all get ground up and make a contaminated mix of glass aggregate with non-glass residue. Also, this aggregate crusher design will plug up, wear out quickly due to the abrasiveness of glass, and produce a glass aggregate that is too large and sharp, or too fine and dusty.

The Andela Pulverizer systems use a flexible hammer system, to selectively break down the glass into a fine sand and small stone material without sharp edges. It doesn’t break down the caps, corks, paper, plastics or metals. Everything goes directly into the barrel (trommel) screen where the glass sand is separated and cleaned from the larger debris.

How does it do that?? It seems like magic! The Andela pulverizers / crushers with the integrated trommel screens provide a durable, simple solution to making glass sand. There is no need to pre-clean the glass before going into the system. The design does not require a lot of power, is quiet to operate, and doesn’t rely on air collection system to clean the glass.

Andela does not just sell you a crusher but provides complete turn-key systems with all the system components needed to process the waste into the product you need. Just let us know what the glass mix looks like going in, and the size or other specifications for the products coming out, and we can provide one machine, or an entire glass processing plant to make it happen.

What are the uses for crushed glass aggregate and glass sand?

Since there are so many uses and markets for crushed / pulverized glass, we’ve already written extensively on that topic! Please visit the below links to learn more:

Andela Glass Sand & Aggregate Uses

Glass Sand Revolution: Coasts & Marshlands Restored By Pulverized Glass

Green Magic: Andela Glass Sand as a Soil Amendment for Thriving Plants

Discover Great Ideas for Glass Landscaping & Other Outdoor Uses

Crushed Glass Landscaping

Why Sand and Stone is Being Replaced with Glass Aggregate

Get started making your own glass sand with a glass pulverizer from Andela Products!

At Andela Products, we have different system sizes and configurations depending on the type of glass you will be putting into the system, how much you need to process, and what the final product specifications might be for your market.

For more Colored Crushed Glass Sand(es,hi,vi)information, please contact us. We will provide professional answers.