Investigation of nodule formation in lime kilns using batch kilns

Causes for nodule formation in lime kilns were investigated using rotary batch kilns. The results show that the size of the mud lumps and the sodium content in the mud are important factors in determining the final lime nodule size. Under the test conditions, lumps smaller than 13 mm appear to agglomerate to form larger nodules, while lumps larger than 19 mm do not agglomerate and, therefore, do not form larger nodules. The melting of sodium compounds in lime mud appears to be responsible for particle agglomeration once the sodium content exceeds 5%. Passing air through the bed material in the batch kiln prevented particles from agglomerating and adhering to the kiln wall.