We are facing severe problem of balling ball size is sometimes around 2m dia which chokes the hammer crusher and we are forced to stop the kiln. What are the possible reasons form such big balls, how is a kiln operater responsible for this, how a kiln operator can avoid such balls through process changes, how we can avoid the balls by changing the chemical composition of kiln feed.

We hear of these problems with increasing regularity. At one factory the problem was associated with an increase in the Mn₂O₃ content of the kiln feed associated with one of their additives. There are also instances where an increase in the MgO content of the kiln feed gives rise to balling problems. However, the most likely cause is a difference in the clinkering range of the material in the kiln brought about by variation in the sulphate content. A heavy coating tends to form and the material is then dammed behind this coating and agglomerates into a large clinker ball. You must ensure that there are good combustion conditions in the main burner of the kiln to minimise the recirculating sulphates. The other process response is likely to be an adjustment in either the alighnment or the primary air supply to the main burner of the kiln. Regarding the chemistry then any changes which adjust the liquid content will change the clinkering range in the kiln. Addition of calcium fluoride to the kiln feed is also helpful.

I would like information on the formation of "snowmen" in our kiln cooler. Our kiln produces 2000tpd clinker. The kiln uses 100 per cent solid fuel comprised 80 per cent coal and 20 per cent petcoke.

Snowman formation is caused by some of the flux in the clinker remaining as a liquid after the clinker falls into the cooler. The root cause solution is therefore to achieve more cooling in the kiln itself. There are numerous solutions to the problem of the removing the snowman itself. Blasters are the most commonly used method. Alternatives are acoustíc cleaners or Denko´s "pusher".