i think that is just the amount of ore, if grade means what i think it mean in this context, only 2.92% of that ore is good for antimony http://www.firstlibertystrategic.com/wp-content/uploads/FencemakerAntimony_NI43_101_DrillReport_DBain_Final_S.pdf\ http://web.mit.edu/12.000/www/m2016/pdf/antimony.pdf