ALEXANDRIA, Va., Dec. 23 -- United States Patent no. 12,503,746, issued on Dec. 23, was assigned to BHP CHILE INC. (Santiago, Chile).
"Oxidative heap leaching of base metals" was invented by Clement Chilowa Chibwana (Concepcion, Chile) and Tania Valentina Ibanez Valenzuela (Antofagasta, Chile).
According to the abstract* released by the U.S. Patent & Trademark Office: "A method of leaching copper from a heap of ore which includes an ore agglomeration step, an ore stacking step wherein agglomerated ore is stacked to form a heap, a curing step, a leach step, and a rinse step, wherein, during the ore agglomeration step the ore is contacted with an acidified solution, nitrates or nitrites, and chloride, to create an oxidative environment prio...