Tenor, Tonnage and Grade of an ore

      Ore is a naturally occurring material from where the minerals can be extracted economically. And economic minerals are those minerals which can be used for national economy.
And these are the following factors that the extraction of minerals from the ore is related with:
  1)Tenor:
                Tenor of an ore is defined as the lowest permissible metallic deposit in any particular ore. Or generally it is the total content of minerals deposited in an ore. The amount of minerals deposited in any ore may depend upon local condition, nature of ore and others.
 
2) Tonnage:
                   Tonnage of an ore is defined as the total amount of minerals than can be extracted from any particular ore. Tonnage of an ore depends directly upon the tenor of an ore because more the mineral deposit more the volume that can be extracted. So, tonnage can be calculated on the basis of volume of the ore deposit.
 
    3)   Grade:
               Grade of a mineral in any particular ore can be determined by the proportion of metal in the ore. The value of any precious/economic minerals is determined by its total estimated weight and the grade of the ore. Hence grade of an ore is calculated as gram per unit tonne i.e g/t. On the basis of the grade, ore are classified as:
 
1)   High grade ore: where the metallic content is relatively high.
       
2)   Low grade ore: where the concentration of metal is relatively low.