Hi,
Does anybody have any practical experience with the volatility of fluoride in the preheater?
We are currently burning 1 - 2tph of Spent Cell Liner (SCL) waste from a local aluminium refinery. This material contains ~10% fluoride.
We have tested our clinker and found that the above usage rates of SCL increase the fluoride level from ~200ppm (no SCL) to ~1000ppm (2t/h SCL)
The literature seems to suggest that this is a modest level of fluoride, with most sources quoting maximum levels of 2000ppm (0.2%) in clinker, with respect to cement performance (particularly setting times) and up to 5000ppm (0.5%) with respect to build-up problems.
Our own mass balance data for fluoride (performed some years ago before the use of SCL) tends to suggest that fluoride is not substantially enriched in either the hotmeal or kiln dust streams.(at least not at levels of ~200ppm in the clinker)
Does anybody have any experience with fluoride-related buildups or other process/operational problems associated with fluoride?
Thanks,
Ted Krapkat (Plant Chemist)
Cement Australia - Gladstone Plant
