Limestone is the raw material for burnt and slaked lime. If the limestone is heated to more than 900 °C, carbon dioxide dissociates and burnt lime (CaO) is formed. This is done in shaft furnaces, rotary kilns or fluidised bed furnaces at a temperature range between 900 and 1,400 °C, depending on the quality requirements. The properties of burnt lime depend on the burning temperature and dwell time in the kiln. High temperatures and long dwell times lead to a low reactivity in burnt lime (dead-burned lime). In contrast, lime produced at lower temperatures is very reactive.
Burnt lime is used in the construction industry, in the iron and steel industry and in waste water treatment, but it is also used for the production of calcium carbide. Moreover, it is very well suited as a desulfurization reagent in the steel industry, but must be prepared appropriately.
Almamet has the necessary know-how to make an effective and reliable desulfurization reagent from burnt lime as well as from unwanted fractions of the converter lime. The desulfurization effect of lime can even be increased further by adding various metallurgically effective additives.