Material World: The Six Raw Materials That Shape Modern Civilization

by Ed Conway

As you read this, the cells of a chloralkali plant somewhere not too far from you will be humming away, turning salty water into a cocktail of chemicals. Here is caustic soda, without which there would be no paper—since we use the corrosive chemical to pulp wood into fibre. Here is hydrogen chloride, without which there would be no solar panels or silicon chips (remember the part it plays in the Siemens process). Here is chlorine to purify our water…If much of what makes us human is our determination to turn one substance into another, then salt is among our most important tools. Somewhere near that electrolysis plant is another factory turning brine into soda ash, to be used as a flux to turn sand into glass. Elsewhere, an artisan is marinating cheese in a brine solution to turn it hard and salty. And a chef is sprinkling food with flakes evaporated from seawater, much as the people did on the clifftop at Boulby thousands of years ago.