Oxidative heap leaching of base metals

A method of leaching copper from a heap of ore, the method comprising:

• agglomerating ore to form agglomerated ore,
• stacking the agglomerated ore form a heap;
• curing the agglomerated ore in the heap;
• leaching the agglomerated ore in the heap;
• and
• rinsing the agglomerated ore in the heap;
• wherein, during the agglomerating step, the ore is contacted with an acidified solution, nitrate or nitrite, and chloride, to create an oxidative environment prior to the leaching step, wherein:
• a. the ore is selected from a primary copper ore comprising chalcopyrite or secondary copper sulfide minerals;
• b. wherein during the agglomerating and curing steps, the oxidation potential of the solution in contact with the ore is in the range of greater than 800 mV to less than 1250 mV verses SHE (standard hydrogen electrode), thereby increasing the heap temperature as a result of pyrite and copper sulfide mineral oxidation;
• c. wherein during the leaching step, the heap is irrigated with an irrigation solution which is supplemented with nitrate salts or nitrite salts to maintain the concentration of nitrate or nitrite in the range of up to 20 g/L and wherein the addition of nitrate salts or nitrite salts in the irrigation solution maintains oxidation potentials in the range of greater than 800 mV to less than 1250 mV verses SHE to enhance the rate of copper dissolution.