Lepidico Making The Grade, page-45

Good source - I was concerned you were going to dredge something up from the 50s or 60s.

Did you read the paragraph after the one you quoted?

"Mineralogical assessment shows that 95% of cassiterite in the plus 20 micron fraction occurs as free grains, which provides confidence that proposed testwork on this fine fraction will improve overall tin recovery. It is estimated that up to 50% of the -30/+7 micron material could be recovered by flotation, boosting overall recovery of tin to 80%..."

80% recovery using conventional processing methods would be an excellent result as hard rock tin ores can be challenging (compare with Achmmach testwork at 78%). 80% is the number used in the Cinovec Scoping Study.