The patio process was a process used to extract silver from ore. Silver (ˈsɪlvɚ is a Chemical element with the symbol " Ag " (argentum from the Ancient Greek: ἀργήντος - argēntos gen It was developed by Bartolomé Medina in Pachuca, Hidalgo, Mexico in 1557 for the Pachuca-Real del Monte mines. Pachuca, formally Pachuca de Soto ( La Bella Airosa, en The windy beauty) is the capital of the Mexican state of Hidalgo The United Mexican States ( or commonly Mexico (ˈmɛksɪkoʊ () is a federal constitutional Republic in North America. The patio process was the first process to use mercury amalgamation to recover silver from ore. Mercury (ˈmɜrkjʊri also called quicksilver or hydrargyrum, is a Chemical element with the symbol Hg ( Latinized hydrargyrum Other amalgamation processes were later developed, most importantly the pan amalgamation process, and its variant, the Washoe process. The Pan amalgamation process is a method to extract Silver from ore using mercury The Pan amalgamation process is a method to extract Silver from ore using mercury
Silver ores were crushed (typically either in arrastras or stamp mills) to a fine slime which was mixed with salt, water, magistral (essentially an impure form of copper sulfate), and mercury, and spread in a one- to two-foot thick layer in a shallow-walled, open enclosure or patio. Salt is a Dietary mineral composed primarily of Sodium chloride that is essential for Animal life but toxic to most land plants Copper(II sulfate is the Chemical compound with the formula Cu[[Sulfur S]] O 4 Mercury (ˈmɜrkjʊri also called quicksilver or hydrargyrum, is a Chemical element with the symbol Hg ( Latinized hydrargyrum A patio (from the Spanish patio meaning 'back garden' or 'backyard' is an outdoor space generally used for dining or Recreation that often adjoins a Horses were driven around on the patio to further mix the ingredients, and, after weeks of mixing and soaking in the sun, a complex reaction converted the silver to native metal, which formed an amalgam with the mercury and was recovered. 
The patio process solved a crisis in the silver-mining districts of the Spanish colonies in the western hemisphere, where the high-grade silver ore that could be economically smelted (direct-smelting ore) was being rapidly exhausted. By recovering silver from the more common lower-grade silver ore, the patio process and later amalgamation processes allowed silver mining to continue for centuries in the great silver mining districts of Mexico, Peru, and Bolivia. The United Mexican States ( or commonly Mexico (ˈmɛksɪkoʊ () is a federal constitutional Republic in North America. Peru (Perú Piruw Piruw officially the Republic of Peru ( reˈpuβlika del peˈɾu is a country in western South America. The Republic of Bolivia (República de Bolivia) named after Simón Bolívar, is a Landlocked country in central South America. However, the high cost of mercury became a limiting factor in treating marginally economic silver ores.
The amount of salt and copper sulfate varied from one-quarter to ten pounds of one or the other, or both, per ton of ore treated. The decision of how much of each ingredients to add, how much mixing was needed, and when to halt the process depended on the skill of an azoquero (English: quicksilver man). The loss of mercury in amalgamation processes is generally one to two times the weight of silver recovered.