Sodium chloride, an essential ingredient in any kitchen, and in many industrial processes, it can be obtained by exploiting sea water or exploiting rock-salt, resulting from the disappearance of ancient oceans and existing in the underground, as in the Campina de Cima mine exploited by CUF in Loulé.
Historically, salt, a substance essential to life, has also had a significant importance, to the point where it originated the word "salary". 6,000 years ago, in present day Romania and in China, there were already salt producers. Later on, Egyptians, Hebrews, Romans, Hittites, and others, commercialised salt all around the world.
Nowadays, from the annual production of 200 million tons, only 6% is meant for human consumption.
Other applications are countless: from the direct application in tasks like defrosting roads, to indirect uses like agriculture, paper manufacture, and soap or detergent production.
In indirect uses, all begins with chemistry, with the use (still) on a large scale in manufacturing sodium hydroxide, chlorine, hydrogen and hydrochloric acid, through the chloralkali electrolysis process.