Steel

Steel is an alloy consisting mostly of iron, with a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most cost-effective alloying material for iron, but various other alloying elements are used such as manganese, chromium, vanadium, and tungsten.[1] Carbon and other elements act as a hardening agent, preventing dislocations in the iron atom crystal lattice from sliding past one another. Varying the amount of alloying elements and form of their presence in the steel (solute elements, precipitated phase) controls qualities such as the hardness, ductility, and tensile strength of the resulting steel. Steel with increased carbon content can be made harder and stronger than iron, but is also less ductile.

Important ore minerals

Important ore minerals

• Acanthite: Ag₂S for production of silver
• Barite: BaSO₄
• Bauxite Al₂O₃ for production of aluminium
• Beryl: Be₃Al₂(SiO₃)₆
• Bornite: Cu₅FeS₄
• Cassiterite: SnO₂
• Chalcocite: Cu₂S for production of copper
• Chalcopyrite: CuFeS₂
• Chromite: (Fe, Mg)Cr₂O₄ for production of chromium
• Cinnabar: HgS for production of mercury
• Cobaltite: (Co, Fe)AsS
• Columbite-Tantalite or Coltan: (Fe, Mn)(Nb, Ta)₂O₆
• Galena: PbS
• Gold: Au, typically associated with quartz or as placer deposits
• Hematite: Fe₂O₃
• Ilmenite: FeTiO₃
• Magnetite: Fe₃O₄
• Molybdenite: MoS₂
• Pentlandite:(Fe, Ni)₉S₈
• Pyrolusite:MnO₂
• Scheelite: CaWO₄
• Sphalerite: ZnS
• Uraninite (pitchblende): UO₂ for production of metallic uranium
• Wolframite: (Fe, Mn)WO₄