How does one reduce P₂O₅ in phosphogypsum to make it useful for application in the cement industry?

I'm sorry but I don't know how to reduce the P₂O₅ in phosphogypsum. It is inherent in the material and therefore I cannot envisage a means to do that, which would economic for its subsequent use in the cement industry.

I sent you various mails regarding free lime in clinker. Your response was always very positive. Now I am sending you some data of clinker analysis. Please send your comments (data attached to original file - not available here).

Thanks for the extra data. The K₂O contents between the OPC and SRC are very similar, so again that does not seem to explain the high free CaO on OPC production. Do you know the reason why the clinker LSF is 6 per cent lower than the kiln feed when SRC is being produced, and only 1 per cent lower when OPC is being produced? Presumably the coal feed is the same when producing both clinkers? Are you operating with a bypass? Is the dust loading on the electrostatic precipitator the same when producing bioth clinkers? How are you handling the precipitator dust?