Mining. [Sp. torta: see next.] One of the large flat circular heaps or ‘cakes’ of ore spread upon the floor or patio (PATIO 2) in the Mexican amalgamation process.
1839. Ure, Dict. Arts, 1919. The patio, or amalgamation floor … is capable of containing 24 tortas, or flat circular collections of lama, of about 50 feet diameter, and 7 inches deep.
1881. Raymond, Mining Gloss., Torta, a flat heap of silver ore (slime or pulp) prepared for the patio process.
