5. Sole ripening

In 1884, inspired by Réaumur's studies, the Frenchman P. Martin succeeded, for the first time, in melting a mixture of cast iron and scrap metal on the hearth of a reverberatory furnace, thus obtaining steel and solving the delicate problem of reusing scrap metal, the quantities of which had been steadily increasing since the introduction of converters. Overall, the Martin process (figure 2 ) is a simple one: the metal charge introduced onto the furnace hearth is heated to melting temperature (approx. 1,600°C). To reach this high temperature level on the hearth, the combustion air and fuel must be brought to a temperature of around 1,000 to 1,200°C. This preheating operation is based on the principle of...