Calcination Brings Desired Qualities Rotary Kiln Furnace To Diatomaceous Earth

FLUX CALCINATION OF DIATOMACEOUS EARTH

Flux calcining, in which the material is calcined at higher temperatures in the presence of a fluxing agent (typically soda ash), takes the calcination process a step further, enhancing these effects beyond what can be achieved through straight calcination. Of special importance is that flux calcining produces larger agglomerates and is white in color.¹

Calcination, whether in the presence of a fluxing agent or not, is an adaptable process; process conditions can be manipulated to affect the properties of the end product in certain ways. Depending on the intended application for a given sample of diatomite, other important properties influenced through the calcination process might include:

• Brightness
• Absorptive capaity
• Refractive index
• Inertness
• Chemical stability
• Potential for dust generation
• And more…

THE CALCINATION PROCESS

Upon mining, diatomaceous earth is milled and if necessary, dried in a rotary dryer, at which point it can be calcined. The calcination process is carried out in a rotary kiln (sometimes referred to as a calciner).

Material is fed into the rotary kiln, which is typically of the direct-fired counter-current configuration.