zinc carbonate zinc carboante good quality zinc carbonate zinc content 57.5% zinc carbonate use in rubber oil drilling Zinc carbonate ... -93 ItemSpecificationsExcellent- classFirst- classConforming- classMain content (in zinc)(dry basis), %≥ 57.55756.5Loss on ignition% 25.0-28.025.0-30 ... with polyethylene bag.5.Photosregards,H.J zinc carbonate basic 57.5%