Arsenic Arsenic Arsenic is a chemical element with symbol As and atomic number 33. Arsenic occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. Arsenic is a metalloid. It has various allotropes, but only the gray form, which has a metallic appearance, is important to industry. The primary use of arsenic is in alloys of lead (for example, in car batteries and ammunition). Arsenic is a common n-type dopant in semiconductor electronic devices, and the optoelectronic compound gallium arsenide is the second most commonly used semiconductor after doped silicon. Arsenic and its
Antimony gangue minerals. Antimony can be isolated from the crude antimony sulfide by reduction with scrap iron: The sulfide is converted to an oxide; the product is then roasted, sometimes for the purpose of vaporizing the volatile antimony(III) oxide, which is recovered. This material is often used directly for the main applications, impurities being arsenic and sulfide. Antimony is isolated from the oxide by a carbothermal reduction: The lower-grade ores are reduced in blast furnaces while the higher-grade ores are reduced in reverberatory furnaces. Antimony has consistently been ranked high in European and US risk lists concerning criticality of the element