Group 12 element people in the 17th century. German chemist Andreas Marggraf is usually given credit for discovering pure metallic zinc in a 1746 experiment by heating a mixture of calamine and charcoal in a closed vessel without copper to obtain a metal. Experiments on frogs by the Italian doctor Luigi Galvani in 1780 with brass paved the way for the discovery of electrical batteries, galvanization and cathodic protection. In 1880, Galvani's friend, Alessandro Volta, invented the Voltaic pile. The biological importance of zinc was not discovered until 1940 when carbonic anhydrase, an enzyme that scrubs carbon dioxide from blood, was shown to
Lateritic nickel ore deposits Nickel laterites are generally mined via open cut mining methods. Nickel is extracted from the ore by a variety of process routes. Hydrometallurgical processes include high-pressure acid leach (HPAL) and heap leach, both of which are generally followed by solvent extraction - electrowinning (SX-EW) for recovery of nickel. Another hydrometallurgical routes is the Caron process, which consists of roasting followed by ammonia leaching and precipitation as nickel carbonate. Additionally, ferronickel is produced by the rotary kiln - electric furnace (RKEF) process. High pressure acid leach processing is employed for two types of nickel laterite ores. 1) Ores with a limonitic