Limestone Calcination in a Rotary Kiln

This calcinations technology has low energy consumption and high output, and after dehydration and decarburization and whitening, the products have stable performance and can be used in such industrial fields as paper making and coating.Commonly known as rotary kiln, it is also called rotary dryer, belonging to construction equipment. Depending on the materials, the rotary kiln falls into three types: clinker rotary kiln, limestone rotary kiln and cement rotary kiln.

An experimental study of the calcination of limestone has been carried out in a highly instrumented pilot-scale rotary kiln. Local gas, solids, and wall temperatures and pct calcination have been measured under a range of operating conditions to determine the influence of limestone type, feed rate, rotational speed, inclination angle, and particle size on calcination and heat flow in the kiln. Thus, it has been found that the local calcination is dependent primarily on the solids temperature and hence on heat transfer. Of the variables studied, the limestone feed rate has the strongest effect on the temperature and calcination fields, whereas inclination angle and rotational speed are relatively less important. The different limestones studied exhibited significant differences in heat-absorption capacity and calcination temperature which may be related to their radiative properties. Increasing particle size over a range of 0.75 to 3.5 mm resulted in an increase in both heat transfer to the bed and calcination.

Working Principle of the Limestone Rotary Kiln

The materials to be burnt get into the stove from the higher end of the cylinder. Due to the slope and slow rotation of the cylinder, the material moves around from top to bottom along the axis to finish its process. At last, the finished materials get into the cooler through the burner hood. The fuel gets into the kiln through the head of the kiln. The waste gas will be discharged from the end of the kiln after exchanging heat with the...