Iron has traditionally been worked in ironworks in Biscay. In 1849, there were over a hundred ironworks in Biscay, and in 1864, only five were operating. The technique evolved into blast furnaces in the mid-19th century.
The first blast furnace in Bizkaia, charcoal, began operating in 1848 for the «Sociedad Anónima Santa Ana de Bolueta», incorporated in 1841.
In 1854, «Ibarra hermanos y Cía» built the factory «Nuestra Señora del Carmen» in Barakaldo, and in it were installed Chenot-type ovens, fed with charcoal, which produced sweet iron without having to resort to blast furnace and refining.
In 1861, the «Sociedad Santa Águeda» was established in Kastrexana, which had, in 1866, three blast furnaces with charcoal.
The first attempt to set up a modern steelwork on the left bank came in 1870 with the company «The Cantabrian Iron Ore Co», which planned to install a large steel plant in the marshes of Sestao. In 1871, the blast furnaces and the railway began to be built to supply them with ore. The last Carlist war paralysed everything in 1872.
The first three factories installed blast furnaces fed with charcoal. They subsequently installed coke batteries and modernised the facilities.
