No, there is no precise formula for the relationship between kiln speed and feed rate. This depends on the degree of preparation (calcination) of thefeed at the kiln inlet and the progression of this feed preparation along the kiln length. However, there are "rules of thumb" and guidelines you can use for various kiln process types. What type of kiln are you operating?

I am a Chemical Engineer working in a company in the cement area in South America and the question is: What sort of fluorspar (acid, metallurgic) is used as fluxing agent in clinker process, what percentage of fluorspar and what quantity in the raw mix fed to the kiln. Does it imply savings in heat?

In my experience acid grade fluorspar spar is used as a mineraliser, however there is no reason why other grades should not be used. Again in my experience addition rates have been up to 0.4 per cent to kiln feed, achieving unit fuel consumption savings in excess of 200 kJ/kg clinker.

Can I have the details about "patented TXI Cemstar addition of air cooled slag to cement kilns". Do you have any information of any cement plant using Blast furnace slag as raw material for rawmix. What are the basic requirements and the precaution we must take to use GBFS as a rawmix component. Will it affect productivity of the mill as I heard that slag is very difficult to grind.