Tuesday, July 9, 2019

"The Ultra-Pure, Super-Secret Sand That Makes Your Phone Possible"

An excerpt from the book The World in a Grain: The Story of Sand and How It Transformed Civilization (from 2018):

Spruce Pine is not a wealthy place. Its downtown consists of a somnambulant train station across the street from a couple of blocks of two‑story brick buildings, including a long‑closed movie theater and several empty storefronts.


Spruce Pine, it turns out, is the source of the purest natural quartz—a species of pristine sand—ever found on Earth. This ultra‑elite deposit of silicon dioxide particles plays a key role in manufacturing the silicon used to make computer chips. In fact, there’s an excellent chance the chip that makes your laptop or cell phone work was made using sand from this obscure Appalachian backwater. “It’s a billion‑dollar industry here,” Glover says with a hooting laugh. “Can’t tell by driving through here. You’d never know it.”


Working with researchers at North Carolina State University’s Minerals Research Laboratory in nearby Asheville, the TVA scientists developed a much faster and more efficient method to separate out minerals, called froth flotation.


Terrified of the water surrounding them, the mica grains will frantically grab hold of the air bubbles and be carried up to the top of the tank, forming a froth on the water’s surface.
*Previously: "In India, sand is now almost as valuable as gold"