I was trying to figure out how to make a custom case with built-in earbuds, but realized that I don't have time for projects like this.
I had given up on recycling plastic when YouTube recommended this:
They explained that after industrially using sand it becomes unusable and is called "Foundry dust." A lady explained that it is a hazardous material with heavy metals. They combine it with plastic waste in 70/30 ratio to make silica blocks, requiring 300% less energy than standard bricks, and are 2.5 times stronger for the same price.
The only PPE they showed workers wearing while making bricks containing heavy metals were oven mitts.
Here is a video about mixing plastic and foundry ash to make bricks.
Is that the same thing?
This also claims their bricks are 2.5 times stronger, but also 26% lighter.
In the end they say to shove plastic into bottles, call them "Eco-bricks," and build bridges out of them, or something:
I saw one guy wearing a dust mask!
Some Colombians started making bricks with plastic waste, sand, and special sauce, and Unicef called them in 2010, asking them to expand to Ivory Coast, where they have built 300 classrooms. They pay people to collect recyclable plastic and some lady says she is earning 4 times what she used to. Classes are ridiculously overcrowded and the government estimates they need 30,000 more classrooms, which they could make with these techniques.
One city in Ivory Coast produces enough plastic waste to build those 30,000 classrooms in 2 years or less:
This group in the Netherlands tried to figure it out and said that even though plastic is a waste product, it is expensive to collect, so they made hollow bricks. They made them tapered so they wouldn't get stuck in the molds, but figured that fewer people would be interested, so they made something more like legoes, which use more material and are more expensive, but interlock, and are easy do do corners. Their funding ran out, so they published everything necessary to build your own waste plastic bricks:
Bonus: After this young man lost his family in a mudslide caused by deforestation he started making charcoal from coconut husks, which cost vendors to dispose of them.
Of course, there is a secret ingredient.
He charges 4 times as much as wood-based charcoal, but they burn at least 4 times as long, and emit less smoke.
He puts them in plastic containers!