This is my take on the ore that went to the mill. the average high grade ore produced in the world today is less than 6%. high grade ore is between 4-6% so middle grade would be 2-3% Zeff said low grade ore was sent
which i would not expect to be above 1.5%.
Concentration
For more details on Copper ore body formation, see
Ore genesis.
Most copper ores contain only a small percentage of copper metal bound up within valuable
ore minerals, with the remainder of the ore being unwanted rock or
gangue minerals, typically
silicate minerals or oxide minerals for which there is often no value. The average grade of copper ores in the 21st century is below 0.6% copper, with a proportion of economic ore minerals (including copper) being less than 2% of the total volume of the ore rock. A key objective in the metallurgical treatment of any ore is the separation of ore minerals from gangue minerals within the rock.
