Ann: Revenue Generation Recommences-KBL.AX, page-190

billc3102 answered most of your questions ,
When mining ore that is composed of different valuable minerals , (polymetalic ore ) a compromise occurs as high recoveries of one ore will mean lower recoveries of the other in the flotation cells .
What is floated off as froth in the cells becomes concentrate and sent to a smelter .
ie The gold concentrate (cons) will get a higher recovery of gold, the lead/zinc conc will get a higher recovery of lead at the expense of gold
The above is just my observation and not a metallurgist
71kt*3.7 = 263K grams /31 = 8500 oz in situ , need to then work out what recovery % to use , taillings normally have lower recoveries than the original ore ,
Lets say recovery is 70% then that is 6000 oz approx