Formation of alkali and alkaline earth sulfates and magnesium fluoride when magnesite is roasted in rotary furnaces, and their deposition in the electrostatic precipitators

Abstract

It is found that the caustic dust released to the atmosphere or trapped from the flue gases of a rotary furnace for magnesite roasting contains sulfur trioxide, alkalies, and fluorine, which form simple and complex sulfates of the alkali and alkaline earth metals and magnesium fluoride. The highly disperse caustic dust which is returned to the roasting furnace, and which is formed by dissociation of magnesium carbonate, is an active adsorbent, which simultaneously absorbs sulfur trioxide, alkali vapor, and fluorine, and which effectively removes these components from the outgoing flue gases.