Control temperature and chemical compositions in reduction pots.
What does a Control Operator do?
Controls temperature, chemical composition, and level of cryolite baths in reduction pots to smelt aluminum oxide into aluminum: Breaks off sample piece of crust formed on bath surface, and grinds it into powder, using roll crusher. Routes sample to laboratory for analysis. Dips out sample of solution and pours it into containers, using ladle. Drops chemicals into sample and notes resultant color. Adds specified amounts of chemicals and alloys to bath, according to color shade of sample, to maintain solution at specified level and composition. Measures current flow and voltage between electrical connections on pots, using meters, and computes voltage drop between connections. Measures temperature of bath, heat exchangers, and heat-control pipes, using pyrometer, and turns rheostat to regulate temperature. Verifies specified distance between electrodes, using measuring rod. Measures depth of bath, and computes amount of aluminum available for tapping. Records tests made, amount of chemicals and alloys added to bath, and amount of aluminum tapped from pots.