Alonso Barba was born in the village of Lepe, Huelva, Spain. After studying theology he went to the Americas to work as a parish priest . He spent time touring the province of Charcas in Bolivia, known for its gold, silver and copper mines.

The president of the Audiencia de Charcas, Juan de Lizarazu,, became aware of Barba's knowledge and sought his transfer to the curate of San Bernardo in Potosí, where he asked him for a treaty that systematized the metallurgical processes carried out in the area. Barba's resulting treaty, the Art of Metals, was published in Madrid in 1640. It contained a detailed description of the silver wealth in Bolivia, as well as a fundamental discovery for the exploitation of extracting silver known as the scoop method. The innovation introduced by this method lay in the use of copper scoops instead of iron. The Art of Metals was translated into several languages and acheived increasing prominence in the seventeenth, eighteenth and nineteenth centuries.

Barba returned to Spain in 1657, where he implemented his discoveries in the silver deposits of Niebla, Huelva.

Barba died in Seville in 1662.